Penerimaan inang dan efisiensi pakan oleh Epilachna vigintioctopunctata pada beberapa tanaman inang

(1)

HOST ACCEPTANCE AND FOOD EFFICIENCY BY

EPILACHNA VIGINTIOCTOPUNCTATA ON SEVERAL HOST

PLANTS

HACHIB MOHAMMAD TUSAR

GRADUATE SCHOOL

BOGOR AGRICULTURAL UNIVERSITY

BOGOR

(2)

(3)

DECLARATION

With due respect I hereby declare that this thesis “Host Acceptance and Food Efficiency by Epilachna vigintioctopunctata on Several Host plants” is my own work under the supervision of an advisory committee. It has not yet been presented in any form in any educational institution. The sources of information which is published or not yet published by other researchers have been mentioned and listed in the reference of this thesis.

Bogor, January 2013

(4)

(5)

ABSTRAK

HACHIB MOHAMMAD TUSAR. Penerimaan Inang dan Efisiensi Pakan oleh Epilachna vigintioctopunctata pada Beberapa Tanaman Inang. Dibimbing oleh ENDANG SRI RATNA dan TEGUH SANTOSO.

Epilachna vigintioctopunctata (Fabricius) (Coleoptera: Coccinellidae) umumnya dikenal sebagai kumbang Hadda. Serangga ini bersifat fitofag dan dapat menjadi hama utama serta menimbulkan kerusakan yang sangat berarti pada tanaman Solanaceae. Kesesuaian hama dan tanaman inang tertentu dapat mempengaruhi aktivitas makan dan kecernaan makanan yang mendukung pertumbuhan dan perkembangan serangga. Hingga saat ini belum ada laporan mengenai penerimaan dan kesesuaian pakan pada beberapa jenis tanaman inang oleh E. vigintioctopunctata di Indonesia. Tujuan penelitian ini adalah menentukan penerimaan inang dan mengukur efisiensi pakan oleh E. vigintioctopunctata pada beberapa jenis tanaman. Larva dan imago E. vigintioctopunctata mengerigiti dan menelan daun pakan Solanum melongena, S. tuberosum, Lycopersicon esculentum, Physalis angulata, Cucumis sativus, dan Cucurbita pepo sebagai tanaman inang. Larva dan imago paling banyak memakan daun S. melongena seluas 6.75 dan 1.771 cm2/serangga/hari, diikuti oleh L. esculentum 4.42 dan 1.35 cm2/serangga/hari. Rata-rata daun L. esculentum yang dimakan oleh larva instar empat awal sebesar 1.5 x 105 µg/serangga/hari lebih tinggi dari S. melongena 1.0 x 105 µg/serangga/hari. Sebaliknya, tingkat pertumbuhan rata-rata dan efisiensi konversi pakan yang dicerna oleh larva berturut-turut sebesar 3723.7 µg/serangga/hari dan 43.17% pada daun S. melongena lebih tinggi dibandingkan L. esculentum sebesar 2984.8 µg/serangga/hari dan 19.94%. Tingkat konsumsi kumbang E. vigintioctopunctata pada S. melongena rendah namun memiliki efisiensi cerna pakan yang tinggi.

(6)

ABSTRACT

HACHIB MOHAMMAD TUSAR. Host Acceptance and Food Efficiency by Epilachna vigintioctopunctata on Several Host Plants. Supervised by ENDANG SRI RATNA and TEGUH SANTOSO.

Epilachna vigintioctopunctata (Fabricius) (Coleoptera: Coccinellidae) is commonly known as hadda beetle. This insect is a phytophagous and causes a serious pest and built a tremendous damage to solanaceaeous crops. The suitability of a certain host plant could affect on feeding activity and digestibility of food that support insect growth and development. Recently, food acceptance and suitability on several varieties of host plants by E. vigintioctopunctata has not been reported in Indonesia. The objective of this research was to investigate the host acceptance and food efficiency by E. vigintioctopunctata on several host plants. Both larvae and adults bite on six species of leaves Solanum melongena, S. tuberosum, Lycopersicon esculentum, Physalis angulata, Cucumis sativus, and Cucurbita pepo. The larvae and adult beetles mostly fed on S. melongena with the areal leaf consumed 6.75 and 1.771 cm2/insect/day, followed by L. esculentum, 4.416 and 1.35 cm2/insect/day. The average rate of consumption on L. esculentum by early 4th instar larvae was 1.5 x 105 µg/insect/day higher than S. melongena was 1.0 x 105 µg/insect/day. On the other hand, the average growth rate and efficiency of conversion of digested food were 3723.7 µg/insect/day and 43.17% higher than in S. melongena than L. esculentum were 2984.8 µg/insect/day and 19.94% respectively. This beetle has low consumption but high efficiency of utilization food on S. melongena.

(7)

SUMMARY

Epilachna beetle (Epilachna vigintioctopunctata Fabr.) (Family Coccinellidae. Order: Coleoptera) is very important pest in Asia that commonly attacks solanaceous plants. Both larvae and adults feed by scrapping the epidermal tissues and built a characteristic skeletonized pattern on remaining leaves. The affected leaves will dry and drop lead to reduce the bearing of the plants. In a high population, this insect may damage up to 80%, even complete defoliation can occur, resulting in total crop failure 10-20% yield loss in aubergine. The suitability of a certain host plant might affect on feeding activity and digestibility of food that support growth and development. The research is conducted to investigate the host acceptance and food efficiency by Epilachna vigintioctopunctata on several host plants.

This study showed that six species of Solanum melongena, Lycopersicon esculentum, Solanum tuberosum, Physalis angulata, Cucumis sativus, Cucurbita pepo were accepted as a fed for E. vigintioctopunctata out from 12 treated leaves of Solanaceous, Cucurbitaeus and Legumineous plants. Between those six types

of food, the highest feeding area caused by larvae and adult was found on S. melongena leaf6.75 and 1.771 cm2/insect/day, respectively. The average rate of

consumption leaf L. esculentum by early 4th instar larvae was 1.5 x 105 µg/insect/day higher than S. melongena is 1.0 x 105 µg/insect/day respectively. On the other hand, all food efficiency parameters above on late 4th instar larvae were not significantly different found in both S. melongena and L. esculentum.

The outcome of this research will supply a basic knowledge of feeding behavior, damaging host plant and a potency of growth and development of insect. The result could support a complementary approach in integrated pest management (IPM) program to reduce the extent of losses caused by E.vigintioctopunctata.

(8)

Copyright© 2013 Bogor Agricultural University

Copyright are protected by law

It is prohibited to cite all or part of this thesis without referring to and mentioning the source. Citation only permitted for the sake of education, research, scientific writing, report writing, critical writing or reviewing scientific problem; Citation

doesn’t inflict the name and honor of Bogor Agricultural University.

(9)

HOST ACCEPTANCE AND FOOD EFFICIENCY BY

EPILACHNA VIGINTIOCTOPUNCTATA ON SEVERAL HOST

PLANTS

HACHIB MOHAMMAD TUSAR

Thesis

as a part of the requirements for acheiving the degree of Master of Science in Entomology at

the Department of Plant Protection

GRADUATE SCHOOL

BOGOR AGRICULTURAL UNIVERSITY

BOGOR

(10)

(11)

Title of Thesis : Host Acceptance and Food Efficiency by Epilachna vigintioctopunctata on Several Host Plants

Name : Hachib Mohammad Tusar

Registration number : A351108061

Approved by

Advisory Committee

Endang Sri Ratna, Ph.D. Teguh Santoso, Ph.D. Chairperson Member

Agreed by

Head of the Program Study Entomolgy Dean of Graduate School

Dr. Pudjianto, M.Si. Dr. Dahrul Syah, M.Sc.Agr.

Date of Examination: 23 January 2013 Date of Completion:

(12)

(13)

ACKNOWLEDGEMENT

My first and foremost earnest gratitude to ALLAH SWT for blessing me and gave me the ability to complete this study. Several people in one or another way were contributed for the success of this work. I would like to convey my sincere and special thanks to my main supervisor Dr. Endang Sri Ratna for her guidance, encouragement, advice and constructive criticisms during the preparation, laboratory analysis and finalizing this thesis. I also thankful to her for allowing me to use her materials for conducting my research; otherwise this work would not be completed in time.

I am also thankful to my second supervisor Dr. Teguh Santoso for his valuable time and comments on this work. I am very much grateful to the Ministry of National Education, Republic of Indonesian for giving me the opportunity to do a Master of Science in Entomology from this prestigious Bogor Agricultural University under the Developing Countries Partnership Scholarship Program (DCPS).

I acknowledge to Dr. Pudjianto, M.Si. coordinator of major Entomology and Djoko Prijono M.Agr.Sc. Lecturer, Research Methodology, IPB for their guidance and encouragement throughout my study period. Special thanks also go to the Yemen), Maroning Useng (Lecturer, Yala Islamic University, Thailand) and my Bangladeshi friends living in Indonesia: Md. Kamruzzaman (University Padjadjaran, Bandung), Md. Shohel Rana (Gadjah Mada University, Yogjakarta).

2. My Bangladeshi teachers Prof. Md. Hamidur Rahman (Dept of Entomology, PSTU), Prof. Dr. Md. Mohsin Hossain Khan (Dept of Entomology, PSTU), Prof. Dr. Habibur Rahman (Dept of Entomology, PSTU), Dr. Mohammad

Atikur Rahman (Associate Prof. Dept of Entomology, PSTU), Dr. Md. Hemayet Jahan (Associate Prof. Dept of Entomology, PSTU),

my friends A.B.M Mahbub Morshed Khan (Asst. Prof. Dept of Agricultural Botany, PSTU), Liton Sen (Lecturer, PSTU), Arifur Rahman Noman (AFS, PSTU), Rahat Mahmood (AFS, PSTU) and Zead Hassan (Upazilla Secondary Education Officer) for their contribution on counseling and moral support during the entire academic period.

Special thanks to my parents, my wife, my brothers, sister and my relatives for their continued prayer.

Bogor, January 2013

(14)

(15)

CURRICULUM VITAE

(16)

(17)

LIST OF TABLES

1 Percentage of feeding on tested host plants 13 2 The effects of two types of food on the rate of consumption, growth

rate and efficiency of utilization of food by early fourth instar larvae

E. vigintioctopunctata 16

3 The effects of two types of food on the rate of consumption, growth rate and efficiency of utilization of food by late fourth instar larvae

E. vigintioctopunctata 16

LIST OF FIGURES

1 Rearing of E. viginctioctopunctata in the Laboratory 9 2 Acceptance test of E. viginctioctopunctata on twelve types of food 9

3 Measurement of feeding area of leaves 10

4 Efficiency test by using larvae E. viginctioctopunctata on S. melongena

and L. esculentum leaves 12

5 Feeding consumption by larvae and adult of E. vigintioctopunctata on

(19)

INTRODUCTION

Background

Epilachna vigintioctopuncata (Fabricius) called hadda beetle is a somber pest of important Solanaceaous crops such as aubergine, potatoes, tomatoes and bitter gourds (Alam 1969; Richards and Filewood 1988). This pest can also attack cucurbitaceous and leguminaceous crops (Imura and Ninomiya 1978). The population of this beetle is distributed over an extensive geographical area such as India, Pakistan, China, Japan, South East Asia, and Oceania (Katakura et al. 1988). This hadda beetle has four generation per year. In general, the peak population is found from July to August (Kalshoven 1981). In Indonesia, the larval population increased rapidly in November and caused seriously damage at the end of December. Both larvae and adults feed on the leaves by scrapping the epidermal tissue to form skeletonized pattern “windows like” that is a typical hadda beetle scrapping (Imura and Ninomiya 1978). Further devastation shows drying and dropping of the leaves leads to harshly distressed growth and yield of the plant (Alam 1969). In a very high population, it evoked complete defoliation resulting in a total crop failure (Rajagopal and Triveldi 1989). The damaging plants could reach up to 80%. Alam (1969) reported that this beetle cause 10-20% yield loss of aubergine.

Nutrients are substances that are necessary for growth, maintaining tissue, reproduction, and supply energy for the organism. Most of the nutrients derived from consumed food. Nutrients required by insects should be in balanced proportion, if insects do not get nutritional balance so the insects growth, molting and egg laying will be failured (Chapman, 1998). Nation (2001) mention that nutrients such as carbohydrates, proteins, fats, sterols, vitamins, nucleic acids, water and minerals are required by insects. Food becomes the cornerstone of efforts to meet the nutrients that will support the growth and development of the insects. The higher efficiency of utilization of food shows the higher quality of the nutrients present in food (Schoonhoven et al. 1998).

According to Kogan (1982), in terms of the suitability of the host plant, the nutritional value of food shows whether or not the food support physiological processes related to growth and development of the larvae. Insect behavior in accepting or rejecting food type can be affected by the chemicals contained in the plant. Primary chemicals are parts of plants that used for growth or development of insects, while secondary chemical has function for rejection (repellent), inhibition of eating (antifeedant), attractants, or a deterrent.

(20)

2

This research supplied an effective complementary approach in integrated

pest management (IPM) to reduce the extent of losses caused by E. vigintioctopunctata. IPM looks for the weak links in the pest’s biology and

behavior (life cycle, food and habitat preferences and sources, how it feeds, mates, reproduces, and disperses). These weaknesses are then exploited to manage the pest by altering or removing one or more of the basic necessities.

Objectives

(21)

3

LITERATURE REVIEW

Biology of Epilachna vigintioctopunctata

Epilachna vigintioctopunctata (Fabricius) has another synonym that is Henosepilachna vigintioctopunctata (Evans 2012). The taxonomy of this species remains confusing throughout history because of its wide variation in external appearance. In Pakistan, this species has been called E. sparsa (Naz et al. 2012). Hadda beetle E. vigintioctopunctata is polyphagous and a serious pest of Solanaceous crops such as aubergine, potato, tomato over a wide range from Japan to South Asia and Australia. In Bangladesh, a group of Solanaceae, Cucurbitaceae and Leguminoceae crops were attacked by this insect (Alam 1969). Moreover, it is as recorded pest of cucurbitaceous crops in India. In Pakistan, E. vigintioctopunctata can be found with varying degree of population densities in all the areas where the host plants are grown (Naz et al. 2012).

Adults are typically ladybird shaped. They are 5-8 mm long, convex dorsally, flattened ventrally and the head is partly hidden beneath the pronotum. Legs and antennae are relatively short. The upper surface is covered with fine, short hairs. Tarsi are composed of four segments. The second segment from the base is strongly lobed underneath, while the third segment is very short and small, and is the same width as the base of the claw-bearing fourth segment (Fabricius 2000). E. vigintioctopunctata has a typical angled of elytral apex. First coxal line is subcomplete. Elytral spots vary between 12 and 28. There are two species one having 12 spots, Epilachna 12-stigma and another having as many as 28 spots, Epilachna 28-punctata (Anonym 2012). Exact diagnosis can be made by examining male genitalia with a well developed basal knife edge and apical thorn on median lobe, siphonal tip tapering on one side. The female genitalia have a deep notch on inner edge. The male genitalia, the median lobe has a basal knife edge beginning at the foot of paramera and a buldge beyond the middle, after which it curves up into an apical hook. Paramera with an apical thorn and covered with hairs shorter than those of median lobe. Siphon gently curved near the base, then straight, ending in a point. The female genital plates has an excavation on the underside with a sharp dark edge toward apex. In the male, the hind margin of the sixth visible sternite is concave; in the female. It has a deep median split. The tarsal claws each have three distinct teeth, the basal tooth is subrectangular (Fabricius 2000).The pronotum presents variable maculation (Naz et al. 2012).

(22)

4

abdomen are rounded, do not reach the hind margin of the segment, and are incomplete externally (Fabricius 2000).

Eggs are yellow, elongate, oval and usually laid on the under surface of a leaf in small batches of 5-40. The eggs are attached on the upper side of the leaf surface by a short stalk at its base. The egg is slightly broader basally than apically gave its length as 1.1 mm and its width as 0.4 mm. Larva have the appearance of the typical ladybird larva. The larval body has elongate and elliptical shaped with moderately long legs and a well-developed head and mandibles. The body is covered with long branched processes bearing spines. There are four larval instars. The final-instar larva is about 6 mm long and 2.8 mm wide across the third abdominal segment. It is generally has pale yellow colour, although the more sclerotized parts and areas around the base of the scoli are brown.

The pupa of E. vigintioctopunctata is white initially, turning yellow later, with brown spots appearing on the dorsal surface. Its size was 4.6 mm long and 3.7 mm wide. The pupal period lasts about 4 days (Fabricius 2000).

E. vigintioctopunctata is found active from April to middle of October and highest population was recorded (8.14 beetles/plant) during middle of September in Terai region, India. Population of this beetle showed significant positive correlation with average temperature, relative humidity and weekly rainfall. Duration of life cycle shortest (26.71 days) in June-July and longest (33.52 days) in September-October. Highest fecundity (272.32 eggs) is recorded during March-April. Life cycle and fecundity is negatively and positively correlated with temperature and relative humidity respectively. High temperature and humidity during July to September decreased the duration of life cycle and increased fecundity leading into rapid multiplication of pest resulting higher population level and there by crop loss during the period (Ghosh et al. 2001).

Hadda beetle feeds actively in the morning and evening hours and feeding declines rapidly in the middle of the day and after midnight. The daily fluctuation in the rate of feeding depends mainly on the temperature which determined the level of metabolism (Tilavov 1981).

Host-Plant interaction

(23)

5

these steps the insect may decide to turn away from the plant before contacting it, or to leave it after contact (Schoonhoven et al. 2005).

Upon contact with the plant an insect obtains additional information on plant quality through tactile (mechanosensory) and contact chemosensory (taste or gustatory) stimuli. Physical features of plant organs or tissues can profoundly influence host-plant selection behaviour. Acceptance of the plant depends upon the nature of the sensory input elicited from appropriate receptors at each relevant stage in this host finding process. The complex patterns created by positive and negative sensory inputs that produce behavioral responses are the result of neural integration which probably occurs within decision-making centers in the higher central nervous system (CNS). Each plant contacted will induce a certain level of excitation, and in that way can be assigned a rank order of preference to an insect, but the level of excitation will be dependent upon factors influencing the plant such as seasonal effects, plant quality and induced plant defenses (Withers 1997). Host finding behavior will change with an insect physiological condition (such as nutritional state, oocyte dynamics, age and stage of development (Barton 1993). The presence of trichomes and wax crystal structures on the plant surface, leaf thickness and toughness, sclerotization, and high silica content may cause avoidance behavior, and such plant traits are assumed to often fulfill a defensive function (Schoonhoven et al. 2005).

Importance of Solanum melongena

Aubergine (Solanum melongena), is an easily cultivated plant belonging to the family Solanaceae. Its fruit is high in nutrition and commonly consumed as a vegetable. The fruit and other parts of the plant are used in traditional medicine. Aubergine fruits can also be pureed, flavoured, and used as a dip or chutney that is popular in Mediterranean and Indian cuisine. In indian cuisine, they are used in curries and even made into soufflés. In traditional chinese medicine, all parts of the plant can be used to stop intestinal bleeding. The fruit of the plant is used as an antidote in cases of mushroom poisoning. In indochina, parts of the plant are used as a purgative. For traditional malay medicine, the ashes of the fruit are used in dry, hot poultices to treat haemorrhoids. To treat ulcers, the root is pounded and applied inside the nostrils (Thulaja 2012). In particular the fruit helps to lower blood cholesterol levels and is suitable as part of a diet to help regulate high blood pressure. It is also used as an antidote to poisonous mushrooms. It is bruised with vinegar and used as a poultice for cracked nipples, abscesses and haemorrhoids. The leaves are narcotic. A soothing and emollient poultice for the treatment of burns, abscesses, cold sores and similar conditions can be made from the leaves. Aubergine leaves are toxic and should only be used externally. The ashes of the peduncle are used in the treatment of intestinal haemorrhages, piles and toothache

(Anonym 2012).

(24)

6 191,525 metric tons with an average yield of 2.56 metric tons per acre. One of the major factors of low yield of aubergine is insect pest such as aubergine shoot and fruit borers, leafhoppers and Hadda beetles that causes serious damage to the crop (Rahman 2009).

Aubergine is a relatively easy to cultivate and high-yielding vegetable with a reasonable nutritional value. It should be possible to breed into aubergine resistance for the more destructive pest and diseases which occur in the tropics. This vegetable is in increasing demand in more affluent countries and are good prospects for export from the tropics and subtropics (CAB 2007).

Importance of Lycopersicon esculentum

Information about the exact date for the first time growing tomatoes is not specified, the tomato was grown in about 500 years before Christ. This plant is native to South America and Central America. During the Spanish colonial period tomato was transferred to other parts of the world i.e. Peru in the sixteenth century and seventeenth-century England and reached to the Netherland. In the early nineteenth century, tomatoes were distributed in the Middle East. Tomato is used as one of the cooking materials. Now a days thousands of (near 7500) tomato varieties are grown throughout the world. Consumption of tomato as a vegetable began since the nineteenth century. According to global statistics 2008, about 130 million tons of tomatoes were produced in the world. China, America, Turkey, India, Italy, Egypt and Iran were the largest producer of tomatoes (Mohammad 2011).

Lycopersicon esculentum is an annual growing crops. It is in flower from Jun to September, and the seeds ripen from August to October. The flowers are hermaphrodite and are pollinated by insects, self. L. esculentum can be used as a savoury vegetable or flavouring in cooked foods, or can be eaten out of hand as a dessert fruit. It is much used in salads and as a flavouring in soups and other cooked foods. A juice made from the fruit is often sold in health food shops. The fruit can also be dried and ground into a powder that can be used as a flavouring and thickening agent in soups, breads, pancakes etc. An edible oil is obtained from the seed. It is suitable for culinary purposes (Anonym 2012).

(25)

7

and the difficulties in urination. A homeopathic remedy is made from the plant. It is used in the treatment of rheumatism and severe headaches (Anonym 2012).

Food conversion efficiency

Food conversion efficiencies may vary considerably within a species. One cause of such variation involves homeostatic (The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes) adjustment of consumption rates and efficiency parameters such that an insect can approach its ideal growth rate even with foods of different quality in various environments. For example, insects that experience reduced ECDs due to increased respiratory costs may be able to compensate by increasing consumption rates or digestion efficiencies (ADs). Not all changes are homeostatic, however. For instance, many insects increase food consumption rates in response to low concentrations of critical nutrients such as protein. Other nonhomeostatic changes in efficiency values may occur in response to plant allelochemicals. For example, compensatory feeding to increase intake of a limiting nutrient may simultaneously increase exposure to plant toxins, which in turn may reduce ECDs. Intraspecific variation in food conversion efficiencies may also be related to insect development (Lindroth 1993).

(26)

8

MATERIALS AND METHODS

Time and Place of Research

All experiments were conducted in the laboratory of Insect Physiology and Toxicology, Bogor Agricultural University from June 2012 to November 2012.

Materials

The materials that were used for this experiment were leaves of Solanum melongena, Solanum tuberosum, Lycopersicon esculentum, Physalis angulata, Cucumis sativus, Cucurbita pepo, Momordica charantia, Vigna angularis,Vigna sesquipedalis, Vicia faba, Sechium edule, Lagenaria leucantha, Plastic cylinder, Larvae and adults of E. vigintioctopunctata, Electronic balance (GR 150, AND Company limited, Japan), Leaf area meter (CI-202, product of CID, INC. USA), etc.

Methods

Preparation of Plants

Twelve host plants S. melongena, S. tuberosum, L. esculentum, P. angulata, C. sativus, C. pepo, M. charantia, V. angularis, V. sesquipedalis, V. faba, S. edule, and L. leucantha were used in this study. The leaves conducted for acceptance and feeding area measurement test were picked up from the farmer organic field surrounding Bogor area, while the leaves conducted for efficiency test was collected from growing plant in the laboratory.

Two plant species used for the efficiency test were aubergine (S. melongena) and tomato (L. esculentum). Seeds were supplied from the market and singly planted in a polythene (10 cm in diameter and 20 cm in depth) with soil media. The plants were maintained with insecticide-free. The leaves used for the experiment were about two months aged when they had approximately 5-10 true leaves.

Preparation of Insects

Beetle was previously identified according to the reference from insect standard collection that is available in the museum of Insect Biosystematic Laboratory and books (Kalshoven 1981; CSIRO 1991). Two sources of beetle E. viginctioctopunctata were carried out in this study. The beetles used for acceptance test were collected from the agricultural fields neighboring Bogor Agricultural University area and the beetles used for feeding area measurement and food efficiency tests were provided from laboratory mass rearing insect.

The maintaining of the insect stock culture was conducted in the laboratory of Insect Physiology and Toxicology, Bogor Agricultural University under temperature between 26-28oC and 85-87% relative humidity.

(27)

9

Figure 1 Rearing of E. viginctioctopunctata in the laboratory

Food Acceptance Test

Early fourth instars larvae and adult beetles were singly placed in a plastic container which contains a sheet leaf with size 6 x 3 cm as a food treatment (Figure 2). These beetles feeding behavior were observed in 5 days for twelve types of plant and food were changed every 24 hrs and damage leaves caused by feeding activity were collected. Each 10 replications were conducted to both stages of beetles. The acceptable food was evaluated and the percent feeding on total treatment was calculated. This experiment was conducted by using no choice method described by Teparkum (2000).

Calculation has been down by using following formula:

Feeding on total replication (%) = total feeded replication x 100/ total replication

(28)

10

Feeding Area Measurement

Six species of plants S. melongena, S. tuberosum, L. esculentum, P. angulata, C. sativus, and C. pepo resulted from a previous experiment were

used for feeding area measurement test. The method of introducing beetles to their food was the same as described previously in food acceptance test. Each 10 replications were conducted to both stages of beetles. Observation has been done for one day. Feeding areas was measured by using leaf area meter machine (CI-202, CID, INC. USA) (Figure 3).

Figure 3 Measurement of feeding area of leaves

Efficiency Test

Two types of larvae were used for carried out this experiment that is early fourth instars with the age of one day after molt and late fourth instars with the age of three days after molt.

Determine of dry weight of leaves and larval proportion. Food S. melongena and L. esculentum that was found as mostly fed from the previous

experiment was cut each of 10 pieces about the size of 6 x 3 cm. Then, the 10 pieces of leaves of each type was weighted initially (wet weight). After that 10 pieces of each type of leaf was wrapped separately into aluminum foil and then put into the oven for 2 hours at 105 °C. After two hours, each envelope containing single piece of leave was weighted (dry weight). If the weight after dry is marked by y and initial weight or wet weight is marked by x, then proportion of dry weight of leaves y/x which is necessary for calculating initial dry weight of leaves to get food consumption rate (CR).

(29)

11

The utilization of food. To determine the utilization of food by the larvae, the following work has been conducted.

A piece of leaf S. melongena and L. esculentum was cut into 6 x 3 cm in size approximately then weighed separately. After that the cut leaf was placed into the petri dish individually. One of fourth instar larva was weighted initially and then placed into a petri dish and then closed. The larva was kept to feed for 24 hrs (Figure 4). This treatment was repeated 10 times for each leaf and each stage of larvae. All treatments were labeled in accordance with the treatment and repetition.

After 24 hrs, the larvae were removed from petri dish. Each larva and the remained leaf were wrapped separately by aluminum foil. Each has been labeled based on treatment and repetition. Both samples of larvae and leaf were allowed to dry within the oven for 2 hrs at 105 °C. All samples were removed from the oven and kept in room temperature and then the sample was weighed individually. In case of undetermined fecal larvae from this experiment, so the weight was assumed zero. The measurements of efficiency parameter were calculated according to the equation below:

RCR = Relative consumption rate (µg leaf / µg larvae/ day)

(30)

12

(31)

13 are solanaceae, E. vigintioctopunctata is a stern pest of solanaceous crops all over the world (Maurice and Kumar 2012). According to Singh and Mukherjee (1987), the larvae of E. vigintioctopunctata developed only on solanaceous hosts. Sugar compounds have been known as feeding stimulants for many insects (Bernays and Simpson 1982). The adults may also feed on members of other plant families, possibly including cucurbits but these are secondary or occasional hosts. The beetle would feed on cucumber (C. sativus) to a limited extent in the laboratory if no other food was provided. It is also possible that some cultivated varieties of

cucurbits have lost their normal plant defences, thus allowing E. vigintioctopunctata to feed on them (Chue 1930). Adult beetle attacked

cucurbitaceous plants when they cannot find solanaceous plant to feed. Secondary compounds such as cucurbitacin contained specifically in

cucurbitaceous plants that act as feeding stimulants for E. vigintioctomaculata, on the contrary, solanine and tomatine contained specifically in potato and tomato did not stimulate the feeding of E. vigintioctomaculata (Abe and Matsuda 2000).

According to Richards and Filewood (1990), the food preference of E. vigintioctopunctata is influenced by odour, taste, and age of host plant and also

by thickness of leaves, proportion of crude fibres, parenchymatous tissue and water content.

Tabel 1 Percentage of feeding on tested host plants

Common name Scientific name Family % feeding

Tomato Lycopersicon esculentum Solanaceae 99

Aubergine Solanum melongena Solanaceae 97

Potato S. tuberosum Solanaceae 95

Cucumber Cucumis sativus Cucurbitaceae 40

Cutleaf ground cherry Physalis angulata Solanaceae 35

Pumpkin Cucurbita pepo Cucurbitaceae 30

Bitter gourd Momordica charantia Cucurbitaceae 0

Red bean Vigna angularis Leguminosae 0

Long bean V. sesquipedalis Leguminosae 0

Broad bean Vicia faba Leguminosae 0

Pipinola Sechium edule Cucurbitaceae 0

(32)

14

E. vigintioctopunctata does not accept M. charantia, V. angularis, V. sesquipedalis, V. faba, S. edule, and L. leucantha. Acceptance or rejection of

any host plant by an insect may be ascribed to the presence of attractants which stimulate feeding and support growth or repellents inhibit feeding (Thorsteinson 1960). Plant odours can attract or repel insects, in either case the volatile plant constituent affects the orientation of the insect with respect to the plant (Dethier et al. 1960). The acceptability of plants to herbivorous insects is influenced by the secondary chemicals. Unpalatability of secondary chemicals is not necessarily associated with detrimental effects, but their presence influence size and duration of feeding (Chapman 1990). Undoubtedly, these compounds play an important role in limiting defoliation and consequently reducing food consumption by insect herbivores (Hinks et al. 1993).

Leaf Areal Damage

From this experiment, it was found that among the four solanaceous and two cucurbitaceous leaves the larvae and adult beetle mostly prefer on S. melongena leaf with the average value of feeding area per day were 6.75 cm2/insect and 1.771cm2 /insect followed by L. esculentum 4.416 cm2/insect and 1.35 cm2/insect.

Larvae and adult beetle showed variation of feeding responses in case of C. sativus and C. pepo. Larvae were fed less amounts of C. sativus and more C. pepo with the average value of 0.01 cm2/insect/day and 2.61 cm2/insect/day but on the opposite way that adults were fed more C. sativus and less amount of C. pepo with average value 0.42 cm2/insect/day and 0.08 cm2/insect/day, respectively (Figure 5).

.

(33)

15

Graphical representation of feeding by larvae and adult of E. vigintioctopunctata also shows that higher damage occurs by larvae rather than

adult on four types of food among the six tested foods. Larvae are voracious and mobile particularly in the last instar (Khan et al. 2000, Kalshoven 1981). According to Dhamdhere et al. (1990), tomato and aubergine are the most suitable

food for E. vigintioctopunctata. Abe and Matsuda (2000, considered that E. vigintioctopunctata are possibly stimulated to feed by some other substances

contained in solanaceous host plants. Methyl linolenate that are present in solanaceous plants and rich in potato leaves plays an important role in the host selection of E. vigintioctomaculata (Endo et al. 2004). Schoonhoven et al. (2005), mentioned that the nutritional value affect on feeding behavior of insect. Photo-period, temperature, and cues related to the physiological condition of the plant involved in the behavioral switch with respect to host-plant selection. Seasonal factors may have changed the chemistry and/or nutritional value of potential host plants to such an extent that the insect switches from one plant species to another. Also, the insect’s innate preferences may have changed. Feeding behaviour may change drastically with the transition from larva to adult, owing to altered nutritional requirements and environmental conditions.

Food Effeciency

The result showed that both averages consumption rate (CR) and relative rate of consumption (RCR) of the early fourth instar larvae were 1.5x105 µg/day and 2.44 µg/µg larvae/day in L. esculentum higher than 1.0x105µg/day and 1.78 µg/µg larvae/day inS.melongena leaves, respectively (P=0.002; t= -3.38, P=0.02; t= -2.25). On the contrary, the growth rate was 3723.75 µg/day in S. melongena higher than 2984.81 µg/day in L. esculentum (P = 0.01; t= 2.39). Both averages relative growth rate (RGR) and efficiency of conversion of digested food (ECD) also higher in S. melongena leaf with the value 0.64 µg/ µg /day and 43.17% compared with L. esculentum leaf 0.48 µg/ µg /day and 19.94% (P= 0.004; t= 3.03, P= 0.005; t= 3.16).

It seem different feeding activity happened in the late intars larvae. The consumption rate (CR) was 7450.23 µg/day relatively higher in S. melongena compared with 5506.07 µg/day in L. esculentum (P= 0.21; t= 0.82). The average growth rate (GR) showed negative values in both S. melongena and L. esculentum leaves were -529.45 µg/day, -649.62 µg/day, respectively (P= 0.39; t= 0.28) (Tabel 2 and 3).

(34)

16

E. vigintioctopunctata is a holometabolous insect which life cycle is in egg, larvae, pupae and adult. Late fourth instar larvae E. vigintioctopunctata is the instar just before pupae, so insect little bit or no feed on this stage and is preparing to become a pupae. According to David (2010), pupae are the resting and non feeding stage of wing insects, included beetle. Young or old leaf may not be influenced feeding behavior in case of late fourth instar larvae because same leaf has been used in case of early and late fourth instar larvae and early fourth instar larvae shows more feeding response.

Insects, like all living organisms, require energy and nutrients for survival, growth and reproductive activity. The nutritional components (e.g. protein, carbohydrates, fats, vitamins, minerals) of ingested food may or may not be digested and absorbed. The proportion of digested food that is actually transformed into net insect biomass is denoted by ECD, the efficiency of conversion of digested food (Lindroth 1993). In short, ECD indicate how efficient the herbivore converts the food into a biomass. Food conversion efficiencies may vary considerably within species. Many insects increase food consumption rates in response to low concentrations of critical nutrients such as protein. Increased Relative Growth rate, % ECD = Efficiency of conversion of digested food.

(35)

17

CONCLUSIONS AND RECOMMENDATION

Larvae and adult beetles Epilachna vigintioctopunctata only feed on four species of Solanaceae and two Cucurbitae host plants. Among these, S. melongena and L. esculentum plant are mostly feeded by both larvae and adults. Three types of food under the group Leguminosae are the unacceptable food by both stages of this beetle. C. sativus and C. pepo are the less favorable food for larvae and adult rather than S. tuberosum and P. angulata. The highest efficiency of utilization food by E. vigintioctopunctata occured in the suitable host S. melongena plant.

(36)

18

REFERENCES

Abe M, Matsuda K. 2000. Feeding of four phytophagous lady beetle species (Coleoptera: Coccinellidae) to cucurbitacins and alkaloids. Appl Entomol Zool. 35: 257-264.

Alam MZ. 1969. Insect pests of vegetables and their control in East Pakistan. Agril Inf Serv Dept Agric, 3, RK Mission Road Dacca. 149.

Ashfaq M, Ahmad A, Ali A. 2000. Physical factor affecting consumption and coefficient of utilization of various food plants by Mythimna separata (Wlk). Pakistan J Biol Sci. 3(3):488-489.

Anonym 2012. Epilachna Beetle, Epilachna vigintioctopunctata Fab. (Coccinellidae: Coleoptera) [Internet] [19 January 2013] Access to: http://www.ikisan.com/Crop%20Specific/Eng/links/tn_brinjalInsectManage

Barton BL., 1993. Physiologically induced changes in resource-orientated behavior. Ann. Rev. Entomol. 38: 1-25.

Bernays EA, Simpson SJ. 1982. Control of food intake. Adv. Insect Physiol. 16: 59–118.

Benchamin KV, Jolly MS. 1984. Studies on ingestion, digestion and conversion efficiency in polyvoltine and bivoltine silkworm breeds (Bombyx mori L.). Proceeding of the 3rd Oriental Entomology Symposium :195- 206.

CAB International. 2007. Crop Protection Compendium. Wallingford (UK): CAB International.

Chapman RF. 1998. The Insect Structure and Function. Cambridge (US). Harvard University Press.

Chapman RF 1990. Food selection. Inside: Chapman RE and John A: Editor. Biology of Grasshoppers. John Wiley and Sons, New York : 39-72.

Chue CC. 1930. Some biological notes on a leaf-feeding coccinellid (Epilachna 28-punctata Fabr.). Lingnan Sci J. 6:301-313.

[CSIRO] Commonwealth Scientific and Industrial Research Organisation. 1991. The Insect of Australia: A Text Book for Students and Research Workers. Second edition volume П. Melbourne (AUS). Melbourne University Press. David AK. 2010. Insects life cycle. [Internet] [2 December 2012]. Access to:

http://www.kendalluk.com/life.html.

Dethier VG, Brown BL, Smith CN. 1960. The designation of chemicals in terms of responses they elicit from insects. J. Econ. Ent. 53:134-136.

(37)

19

Endo N, Makoto ABE, Sekine T, Matsuda K. 2004. Feeding stimulants of Solanaceae-feeding lady beetle, Epilachna vigintioctomaculata (Coleoptera: Coccinellidae) from potato leaves. Appl. Entomol. Zool. 39 (3): 411–416. Evans DH. 2009. Henosepilachna vigintioctopunctata (Fabricius, 1775).

[Internet] [11 October 2012]. Access to: http://lepidoptera.butterflyhouse. com.au/none/ladybird.html.

Fabricius. 2000. Epilachna vigintioctopunctata Arthropod. [Internet] [21 October 2012]. Access to: http://ecoport.org/ep?Arthropod=19265&entityType= AR****&entityDisplayCategory=full.

Farrar RR, Barbour JD, Kennedy GG. 1989. Quantifying food consumption and growth in insects. Ann Entomol Soc Am. 82:593-598.

Ghosh SK, Senapati SK. 2001. Biology and seasonal fluctuation of Henosepilachna vigintioctopunctata Fabr. on Brinjal under terai region of west Bengal. Indian J Agric. 35(3):149–154.

Hinks CF, Hpka D, Olfert O. 1993. Nutrition and the protein economy in grasshoppers and locusts. Comp. Biochem. Physiol. 104(A):133-142.

Imura O, Ninomiya S. 1978. Quantitative measurement of leaf area consumption by Epilachna vigintioctopunctata (Fabricius) (Coleoptera: Coccinellidae) using image processing. Appl Ent Zool. 33(4):491-495.

Kalshoven LGE. 1981. The Pests of Crops in Indonesia. Van der Laan PA, translated from De Plagen Van de Cultuurgewassen in Indonesia. Jakarta (ID). PT IchtiarBaru-Van Hoeve.

Katakura H, Abbas I, Nakamura K, Sasaji H. 1988. Records of epilachnine crop pests (Coleoptera: Coccinellidae) in Sumatera Barat, Sumatera, Indonesia. Kentyu. 56:281-297.

Khan MH, Islam BN, Rahman AKMM, Rahman ML. 2000. Life table and the rate of food consumption of epilachna beetle, Epilachna dodecastigma (Wied) on different host plant species in laboratory condition. Bangladesh J Ent. 10(1-2):63-70.

Kogan M. 1982. Plant resistance in pest management. Inside: Metcalf RL, Lucman WH, editor. Introduction to Insect Pest Management. 2nd. New York (US): John Willey and Sons. hlm 93-134.

Lindroth RL. 1993. Food Conversion Efficiencies of Insect Herbivores. Food Insect Newsletters [Internet] [25 November 2012]. Access to http://www.hollowtop.com/finlhtml/conversion.html.

Maurice N, Kumar A. 2012. Oviposition of Epilachna vigintioctopunctata Fabricius on a wild weed, Coccinia grandis Linnaeus (Cucurbitales: Cucurbitaceae). J Agric Ext Rural Dev. 4(2):41-45.

Mohammad A. 2011. The price for agricultural products-tomato. Aus J Basic Appl Sci. 5(12):2311-2315.

Naz F , Inayatullah M , Rafi MA , Ashfaque M , Ali A. et al. 2012. Henosepilachna vigintioctopunctata (FAB.) (Epilachninae: Coccinellidae); its taxonomy, distribution and host plants in Pakistan. Sarhad J Agric. 28(3):421-427.

Nation JL. 2001. Insect Physiology and Biochemistry. London(UK). CRC Press. Rahman MM. 2009. IPM World Textbook. Minnesota (US). Minnesota University

(38)

20

Rahmathulla VK, Suresh HM. 2011. Seasonal variation in food consumption, assimilation, and conversion efficiency of Indian bivoltine hybrid silkworm, Bombyx mori. J Insect Sci. 12:82.

Rajagopal D, Trivedi TP. 1989. Status biology and management of epilachna beetle, Epilachna vigintioctopunctata Fab. (Coleoptera: Coccinellidae) on potato in India. Trop Pest Manag. 5(4):410-413.

Reynolds SE, Nottingham SF. 1985. Effect of temperature on growth and efficiency of food utilization in fifth instar cater pillar of tobacco hornworm, Manduca sexta. J Insect Physiol. 31: 129-134.

Richard AM, Filewood LW. 1990. Feeding behaviour and food preferences of the pest species comprising the Epilachna vigintioctopunctata Fab. Complex (Coleoptera: Coccinellidae). J Appl Ent. 110(5):501-515.

Scriber JM, Slansky F. 1981. The nutritional ecology ofimmature arthropods. Ann Rev Entomol. 26:183-211.

Schoonhoven LM, Loon JJ, Dicke M. 2005. Insect Plant Biology. New York (US). Oxford University Press.

Singh G, Mukherjee A. 1987. On the oligophagous nature of Henosepilachna dodecastigma (Wiedemann) and Henosepilachna vigintioctopunctata (Fabricius) (Coleoptera: Coccinellidae). Indian J of Entomol. 49:118-126. Teparkum S. 2000. Interaction between insects and apple (Malus x domestica

Borkh.): Insect behavior, genotypic preference, and plant phenolics with emphasis on Japanese beetle (Popillia japonica Newman) [Disertation]. Faculty of the Virginia Polytechnic Institute and State University(UK). Thulaja NR. 2012. Brinjal. Singapore infopedia. [Internet] [30 september 2012].

Access to: http://infopedia.nl.sg/articles/SIP_171_2004-12-15.html.

Thorsteinson AJ (1960). Host selection in phytophagous insects Annu. Rev. Entomol. 5:193-216.

Tilavov TT. 1981. The daily and seasonal feeding rhythm of the adult of the cucumber beetle, Epilachna chrysomelina Fab. Uzbekskei Biol Eskii Zhurnal. 8(5):40-61.

Waldbauer GP. 1968. The consumption and utilization of food by insects. Adv Insect Physiol. 5:229-288.

Withers TM. 1997. Changes in plant attack over time in no-choice tests: an

indicator of specificity. Inside: O Callaghan M. Editor 50th N.Z. Plant

(39)

ABSTRAK

HACHIB MOHAMMAD TUSAR. Penerimaan Inang dan Efisiensi Pakan oleh Epilachna vigintioctopunctata pada Beberapa Tanaman Inang. Dibimbing oleh ENDANG SRI RATNA dan TEGUH SANTOSO.

Epilachna vigintioctopunctata (Fabricius) (Coleoptera: Coccinellidae) umumnya dikenal sebagai kumbang Hadda. Serangga ini bersifat fitofag dan dapat menjadi hama utama serta menimbulkan kerusakan yang sangat berarti pada tanaman Solanaceae. Kesesuaian hama dan tanaman inang tertentu dapat mempengaruhi aktivitas makan dan kecernaan makanan yang mendukung pertumbuhan dan perkembangan serangga. Hingga saat ini belum ada laporan mengenai penerimaan dan kesesuaian pakan pada beberapa jenis tanaman inang oleh E. vigintioctopunctata di Indonesia. Tujuan penelitian ini adalah menentukan penerimaan inang dan mengukur efisiensi pakan oleh E. vigintioctopunctata pada beberapa jenis tanaman. Larva dan imago E. vigintioctopunctata mengerigiti dan menelan daun pakan Solanum melongena, S. tuberosum, Lycopersicon esculentum, Physalis angulata, Cucumis sativus, dan Cucurbita pepo sebagai tanaman inang. Larva dan imago paling banyak memakan daun S. melongena seluas 6.75 dan 1.771 cm2/serangga/hari, diikuti oleh L. esculentum 4.42 dan 1.35 cm2/serangga/hari. Rata-rata daun L. esculentum yang dimakan oleh larva instar empat awal sebesar 1.5 x 105 µg/serangga/hari lebih tinggi dari S. melongena 1.0 x 105 µg/serangga/hari. Sebaliknya, tingkat pertumbuhan rata-rata dan efisiensi konversi pakan yang dicerna oleh larva berturut-turut sebesar 3723.7 µg/serangga/hari dan 43.17% pada daun S. melongena lebih tinggi dibandingkan L. esculentum sebesar 2984.8 µg/serangga/hari dan 19.94%. Tingkat konsumsi kumbang E. vigintioctopunctata pada S. melongena rendah namun memiliki efisiensi cerna pakan yang tinggi.

(40)

ABSTRACT

Epilachna vigintioctopunctata (Fabricius) (Coleoptera: Coccinellidae) is commonly known as hadda beetle. This insect is a phytophagous and causes a serious pest and built a tremendous damage to solanaceaeous crops. The suitability of a certain host plant could affect on feeding activity and digestibility of food that support insect growth and development. Recently, food acceptance and suitability on several varieties of host plants by E. vigintioctopunctata has not been reported in Indonesia. The objective of this research was to investigate the host acceptance and food efficiency by E. vigintioctopunctata on several host plants. Both larvae and adults bite on six species of leaves Solanum melongena, S. tuberosum, Lycopersicon esculentum, Physalis angulata, Cucumis sativus, and Cucurbita pepo. The larvae and adult beetles mostly fed on S. melongena with the areal leaf consumed 6.75 and 1.771 cm2/insect/day, followed by L. esculentum, 4.416 and 1.35 cm2/insect/day. The average rate of consumption on L. esculentum by early 4th instar larvae was 1.5 x 105 µg/insect/day higher than S. melongena was 1.0 x 105 µg/insect/day. On the other hand, the average growth rate and efficiency of conversion of digested food were 3723.7 µg/insect/day and 43.17% higher than in S. melongena than L. esculentum were 2984.8 µg/insect/day and 19.94% respectively. This beetle has low consumption but high efficiency of utilization food on S. melongena.

(41)

SUMMARY

Epilachna beetle (Epilachna vigintioctopunctata Fabr.) (Family Coccinellidae. Order: Coleoptera) is very important pest in Asia that commonly attacks solanaceous plants. Both larvae and adults feed by scrapping the epidermal tissues and built a characteristic skeletonized pattern on remaining leaves. The affected leaves will dry and drop lead to reduce the bearing of the plants. In a high population, this insect may damage up to 80%, even complete defoliation can occur, resulting in total crop failure 10-20% yield loss in aubergine. The suitability of a certain host plant might affect on feeding activity and digestibility of food that support growth and development. The research is conducted to investigate the host acceptance and food efficiency by Epilachna vigintioctopunctata on several host plants.

This study showed that six species of Solanum melongena, Lycopersicon esculentum, Solanum tuberosum, Physalis angulata, Cucumis sativus, Cucurbita pepo were accepted as a fed for E. vigintioctopunctata out from 12 treated leaves of Solanaceous, Cucurbitaeus and Legumineous plants. Between those six types

of food, the highest feeding area caused by larvae and adult was found on S. melongena leaf6.75 and 1.771 cm2/insect/day, respectively. The average rate of

consumption leaf L. esculentum by early 4th instar larvae was 1.5 x 105 µg/insect/day higher than S. melongena is 1.0 x 105 µg/insect/day respectively. On the other hand, all food efficiency parameters above on late 4th instar larvae were not significantly different found in both S. melongena and L. esculentum.

The outcome of this research will supply a basic knowledge of feeding behavior, damaging host plant and a potency of growth and development of insect. The result could support a complementary approach in integrated pest management (IPM) program to reduce the extent of losses caused by E.vigintioctopunctata.

(42)

INTRODUCTION

Background

Epilachna vigintioctopuncata (Fabricius) called hadda beetle is a somber pest of important Solanaceaous crops such as aubergine, potatoes, tomatoes and bitter gourds (Alam 1969; Richards and Filewood 1988). This pest can also attack cucurbitaceous and leguminaceous crops (Imura and Ninomiya 1978). The population of this beetle is distributed over an extensive geographical area such as India, Pakistan, China, Japan, South East Asia, and Oceania (Katakura et al. 1988). This hadda beetle has four generation per year. In general, the peak population is found from July to August (Kalshoven 1981). In Indonesia, the larval population increased rapidly in November and caused seriously damage at the end of December. Both larvae and adults feed on the leaves by scrapping the epidermal tissue to form skeletonized pattern “windows like” that is a typical hadda beetle scrapping (Imura and Ninomiya 1978). Further devastation shows drying and dropping of the leaves leads to harshly distressed growth and yield of the plant (Alam 1969). In a very high population, it evoked complete defoliation resulting in a total crop failure (Rajagopal and Triveldi 1989). The damaging plants could reach up to 80%. Alam (1969) reported that this beetle cause 10-20% yield loss of aubergine.

Nutrients are substances that are necessary for growth, maintaining tissue, reproduction, and supply energy for the organism. Most of the nutrients derived from consumed food. Nutrients required by insects should be in balanced proportion, if insects do not get nutritional balance so the insects growth, molting and egg laying will be failured (Chapman, 1998). Nation (2001) mention that nutrients such as carbohydrates, proteins, fats, sterols, vitamins, nucleic acids, water and minerals are required by insects. Food becomes the cornerstone of efforts to meet the nutrients that will support the growth and development of the insects. The higher efficiency of utilization of food shows the higher quality of the nutrients present in food (Schoonhoven et al. 1998).

According to Kogan (1982), in terms of the suitability of the host plant, the nutritional value of food shows whether or not the food support physiological processes related to growth and development of the larvae. Insect behavior in accepting or rejecting food type can be affected by the chemicals contained in the plant. Primary chemicals are parts of plants that used for growth or development of insects, while secondary chemical has function for rejection (repellent), inhibition of eating (antifeedant), attractants, or a deterrent.

(43)

2

This research supplied an effective complementary approach in integrated

pest management (IPM) to reduce the extent of losses caused by E. vigintioctopunctata. IPM looks for the weak links in the pest’s biology and

behavior (life cycle, food and habitat preferences and sources, how it feeds, mates, reproduces, and disperses). These weaknesses are then exploited to manage the pest by altering or removing one or more of the basic necessities.

Objectives

(44)

3

LITERATURE REVIEW

Biology of Epilachna vigintioctopunctata

Epilachna vigintioctopunctata (Fabricius) has another synonym that is Henosepilachna vigintioctopunctata (Evans 2012). The taxonomy of this species remains confusing throughout history because of its wide variation in external appearance. In Pakistan, this species has been called E. sparsa (Naz et al. 2012). Hadda beetle E. vigintioctopunctata is polyphagous and a serious pest of Solanaceous crops such as aubergine, potato, tomato over a wide range from Japan to South Asia and Australia. In Bangladesh, a group of Solanaceae, Cucurbitaceae and Leguminoceae crops were attacked by this insect (Alam 1969). Moreover, it is as recorded pest of cucurbitaceous crops in India. In Pakistan, E. vigintioctopunctata can be found with varying degree of population densities in all the areas where the host plants are grown (Naz et al. 2012).

Adults are typically ladybird shaped. They are 5-8 mm long, convex dorsally, flattened ventrally and the head is partly hidden beneath the pronotum. Legs and antennae are relatively short. The upper surface is covered with fine, short hairs. Tarsi are composed of four segments. The second segment from the base is strongly lobed underneath, while the third segment is very short and small, and is the same width as the base of the claw-bearing fourth segment (Fabricius 2000). E. vigintioctopunctata has a typical angled of elytral apex. First coxal line is subcomplete. Elytral spots vary between 12 and 28. There are two species one having 12 spots, Epilachna 12-stigma and another having as many as 28 spots, Epilachna 28-punctata (Anonym 2012). Exact diagnosis can be made by examining male genitalia with a well developed basal knife edge and apical thorn on median lobe, siphonal tip tapering on one side. The female genitalia have a deep notch on inner edge. The male genitalia, the median lobe has a basal knife edge beginning at the foot of paramera and a buldge beyond the middle, after which it curves up into an apical hook. Paramera with an apical thorn and covered with hairs shorter than those of median lobe. Siphon gently curved near the base, then straight, ending in a point. The female genital plates has an excavation on the underside with a sharp dark edge toward apex. In the male, the hind margin of the sixth visible sternite is concave; in the female. It has a deep median split. The tarsal claws each have three distinct teeth, the basal tooth is subrectangular (Fabricius 2000).The pronotum presents variable maculation (Naz et al. 2012).

(45)

4

abdomen are rounded, do not reach the hind margin of the segment, and are incomplete externally (Fabricius 2000).

Eggs are yellow, elongate, oval and usually laid on the under surface of a leaf in small batches of 5-40. The eggs are attached on the upper side of the leaf surface by a short stalk at its base. The egg is slightly broader basally than apically gave its length as 1.1 mm and its width as 0.4 mm. Larva have the appearance of the typical ladybird larva. The larval body has elongate and elliptical shaped with moderately long legs and a well-developed head and mandibles. The body is covered with long branched processes bearing spines. There are four larval instars. The final-instar larva is about 6 mm long and 2.8 mm wide across the third abdominal segment. It is generally has pale yellow colour, although the more sclerotized parts and areas around the base of the scoli are brown.

The pupa of E. vigintioctopunctata is white initially, turning yellow later, with brown spots appearing on the dorsal surface. Its size was 4.6 mm long and 3.7 mm wide. The pupal period lasts about 4 days (Fabricius 2000).

E. vigintioctopunctata is found active from April to middle of October and highest population was recorded (8.14 beetles/plant) during middle of September in Terai region, India. Population of this beetle showed significant positive correlation with average temperature, relative humidity and weekly rainfall. Duration of life cycle shortest (26.71 days) in June-July and longest (33.52 days) in September-October. Highest fecundity (272.32 eggs) is recorded during March-April. Life cycle and fecundity is negatively and positively correlated with temperature and relative humidity respectively. High temperature and humidity during July to September decreased the duration of life cycle and increased fecundity leading into rapid multiplication of pest resulting higher population level and there by crop loss during the period (Ghosh et al. 2001).

Hadda beetle feeds actively in the morning and evening hours and feeding declines rapidly in the middle of the day and after midnight. The daily fluctuation in the rate of feeding depends mainly on the temperature which determined the level of metabolism (Tilavov 1981).

Host-Plant interaction

(46)

5

these steps the insect may decide to turn away from the plant before contacting it, or to leave it after contact (Schoonhoven et al. 2005).

Upon contact with the plant an insect obtains additional information on plant quality through tactile (mechanosensory) and contact chemosensory (taste or gustatory) stimuli. Physical features of plant organs or tissues can profoundly influence host-plant selection behaviour. Acceptance of the plant depends upon the nature of the sensory input elicited from appropriate receptors at each relevant stage in this host finding process. The complex patterns created by positive and negative sensory inputs that produce behavioral responses are the result of neural integration which probably occurs within decision-making centers in the higher central nervous system (CNS). Each plant contacted will induce a certain level of excitation, and in that way can be assigned a rank order of preference to an insect, but the level of excitation will be dependent upon factors influencing the plant such as seasonal effects, plant quality and induced plant defenses (Withers 1997). Host finding behavior will change with an insect physiological condition (such as nutritional state, oocyte dynamics, age and stage of development (Barton 1993). The presence of trichomes and wax crystal structures on the plant surface, leaf thickness and toughness, sclerotization, and high silica content may cause avoidance behavior, and such plant traits are assumed to often fulfill a defensive function (Schoonhoven et al. 2005).

Importance of Solanum melongena

Aubergine (Solanum melongena), is an easily cultivated plant belonging to the family Solanaceae. Its fruit is high in nutrition and commonly consumed as a vegetable. The fruit and other parts of the plant are used in traditional medicine. Aubergine fruits can also be pureed, flavoured, and used as a dip or chutney that is popular in Mediterranean and Indian cuisine. In indian cuisine, they are used in curries and even made into soufflés. In traditional chinese medicine, all parts of the plant can be used to stop intestinal bleeding. The fruit of the plant is used as an antidote in cases of mushroom poisoning. In indochina, parts of the plant are used as a purgative. For traditional malay medicine, the ashes of the fruit are used in dry, hot poultices to treat haemorrhoids. To treat ulcers, the root is pounded and applied inside the nostrils (Thulaja 2012). In particular the fruit helps to lower blood cholesterol levels and is suitable as part of a diet to help regulate high blood pressure. It is also used as an antidote to poisonous mushrooms. It is bruised with vinegar and used as a poultice for cracked nipples, abscesses and haemorrhoids. The leaves are narcotic. A soothing and emollient poultice for the treatment of burns, abscesses, cold sores and similar conditions can be made from the leaves. Aubergine leaves are toxic and should only be used externally. The ashes of the peduncle are used in the treatment of intestinal haemorrhages, piles and toothache

(Anonym 2012).