A feasibility study of the control of adults of Heliothis spp. by drifting a cloud of monosized droplets across a cotton field at night

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I,IBR,ARY

A FEASIBILITY STUDY OF TTIE CONTROL OF ADULTS OF HELIOTHIS SPP.

BY DRIFTING A CLOUD OF MONOSIZED DROPLETS ACROSS_trTOTTOÑ_

FIELD AT ^NIGHT

Elizabeth B.A.

B'ie

A

thesis

submitted

in fulfilment of the

requirements

for

^the

degree

of

^l.laster

of Agricuìture, Faculty of Agrìcultural

Science,

University of

Adelaide

May, 1985

8.¿ q-r*L. u{ ¡/

^-

lP

"

'f';'

1't

DECLARATION

This thesis contains

no

material

whìch has been

accepted

for the award of any other degree or di p'l oma and, to the best of my knowl edge and

bel ì

ef,

^contai

ns no

^materi

al

prevì ously publ'ished

or written, or the result of

^{work by}

another

person, except

where

due reference ìs

made.

El ^'i zabeth ^B.

A.

^{Bì e}

May,1985

11'l

I

¿1

i1 .J

I

d

Ï

ACKNo}ILEDGEMENTS

I wish to thank the Australian Plague Locust

Commiss'ion

for giving me the opportunity to undertake the Master of Agriculture course and

especì al

'ly

_Doug'l

as

_Heath

,

^{Phì ì ì 'i}

p

^Pal

mer

and

Catherine Evatt who helped

me

with the

spray

tri

^al s.

My

thanks also go to the staff of Auscott

^Pty

Ltd, Warren, the New South !'lales Department of Agrìculture Research Station at Trang'ie, Dr Vìc

Edge of the New South Wal es Department of Agrì cuì ture' s Bi ol ogì cal and

^Chemi

cal

^Research

Instìtute and Dr Peter

Gregg

of

^{New England}

Univers'ity for their advice and prov'isìon

of f abi I i

ti es

and equ'i pment.

I i

I

I

I

I

1V

CONTENTS

DECLARATION ACKNOI.ILEDGEMENTS SUMI,IARY

INTRODUCTION

CHAPTER

I:

^BIOASSAY

.l

Introduct'ion

.2

^Aims

.3

Methods and materials

.4

^Resul

ts .5 Di scus.si on

CHAPTER

2:

SPRAY TRIALS I ntroduct i on

Methods and materi al s

Resul

ts

Di scussi on

BIBLIOGRAPHY APPENDICES

Page

11

'iii

23

V

I I

1

I I

2.1 2.2 2.3 2.4

3.2 3.3 3.4 3.5

5

5 6 6 0 5

CHAPTER

3':

^{ANALYSIS 0F} THE CHEMICAL REC0VERY AFTER SPRAYING 43 3.

1

Establ ^'i sh'i ng

the

method f

or

detect'i ng f enval

erate

⁴³

us'ing HPLC

Developing

a

standard curve

for fenvalerate

HPLC

analysìs for fenvalerate from

sprayed cobtons Resul

ts

Di scussì on

CHAPTER

4:

^{DISCUSSION 66}

¿5 24 29 32

45 49 50 52

69 72

SUI.,IMARY

The

^poss j _bl

e control of

^adul

t

^{Hel i} oth'i

s

^punctì

gera and

Hel i oth-is

armi

gera

^j

n fl i ght, by drift'ing a cloud of small drop'lets of 'insecticide across the

canopy

of a cotton crop at night, during

^the

time of

^{peak moth}

act'ivity,

^{has been}

ìnvestigated.

Two

i nsecti ci des

,

^feni

troth'i on

^techni

cal and fenval erate, were

init'ia1ly tested for theìr effect'iveness against adult Heliothis

spp.

with a

bìoassay

involving top'icaì applìcation.

Fenvalerate proved

to

be

the

most

effective, with

an LD50

of

0.21

uglg

^body

weìght,

and ^was theref

ore

chosen f

or use

i

n the spray trì a'ls

f ormul

ated as

^Sumi ci d'in ULV

(active ìngredient: fenvalerate

a0

g/l ).

Sìx

spray

trìals

^were

carried out

on consecutive

nights,

^{between 2100}

and 2400

h.

The

trials

were conducted under

condìtions of

^inversion

and

^{'l ì}

ght

wi

nds - typì cal of the I ocati on (northwestern N. S. l,,/. ) and

tìme of year

^(January

to March).

^The

dropìet cloud

was

created by

^a

spì nni

ng

^di

sc

^atomi

zer

^mounted

on bhe back of a four-wheel -dr'ì ve vehì cl e.

Ihe

moth popu'l atì

on

vvas est'imated

by

f I ush'ing them f rom pl

ants

^{a l} ong

transects within the crop

and

by

^pheromone

traps: egg counts were al so made. Anaìysì s of the spray trì al s showed that 'it

_{was poss'ibl e}

to drift an insecticide at lethal concentrations across the crop canopy underinvers'ion and ì ì ght wi nds at nì ght. Moth numbers were

unusuaììy ìow, so the effect of

spray'ing

on the

^moth popu'lation and

egg

lay could not

be determined.