BEETLES OF THE GENUS MYOCHROUS — BLAKE 63 MYOCHROUS CALCARIFERUS, new species

Plate8,Figitbe 1

Between

4

and

5

mm.

in length, elongate oblong, black, with the thorax approximately^aslongaswide,concealing head,

and

elytra

more

than twice as long as thorax; scales

on

thorax

and

elytra

wide and forming

a distinct

brown and

white pattern; punctation of thorax dense; front tibiae with only a faint trace of toothing before the apex, middle

and

probably also the hind tibiae in

male

(males not seen)^,witha ^distinctspurbefore the apex.

Head

concealed

from

above

by overhung

anterior

margin

of pro- thorax, occiput with trace of ridging

on

either side, not entirely covered

by

scales but

showing

the alutaceous surface beneath^; scales broad, curved,

and

not flatly appressed, between antennal sockets finer

and

transversely placed;

labrum and

antennae reddish brown.

Antennal joints oftheusual proportions. Prothorax approximately as long as

wide

with a convex projected anterior

margin;

a faint transversedepressionbehindeyes; sides3-toothed, surface alutaceous with dense

and

not coarse,

round

punctures not entirely concealed bythe

broad brown and

white curvedscales,scales

forming

a pattern.

Elytra

more

than twice as long as thorax, shining bronzy black be- neath thebroad

brown and

whitescales; striate puncturescoarse but not ridged, basalcallositiesnotpronounced,a faint depressionbelow

;

scales

forming

a patternwiththe

humeri and

sides

more

orless white

and

a white spot near apex.

Body

beneath finely alutaceous but moderately shining, breast

and

^first

abdominal

segment not coarsely punctate, with scattered fine white scales; front tibiae with a very obscure tooth before apex

on

the inner side

and

a

more marked

one at apex

on

outer edge; middle tibiae of female with a distinct spur before the apex,probably alsooneof the hindtibiaeof

male

although no

male

examined.

Length

4.3 to 4.8

mm.

^;

width

1.8to2

mm.

Type and

paratypes.

— Type

female in the

Miguel

Lillo Institute,

Tucuman,

Argentina,collected

January

3,1949,

by

Kuschel; onepara- type,

U.S.N.M.

No. 59364; one paratypein the

Museum

of

Compara-

tiveZoology.

Type

locality.

—

Almacea, Trinidad,Bolivia.

Remarks. —

^{Thisspeciesis}very close to

M.

spinipes

from

Venezuela, havingasimilarstructure,particularlyinthe spurs

on

thetibiae. This characteris

found up

to thistimeinthese

two

species only.

The

chief differencebetween the

two

speciesappearstobe intheproportions of the body, in

M.

calcariferus the elytra are over twice as long as the thorax inthe threefemales

examined

althoughthe elytra are scarcely

any

wider than in

M.

spinipes.

There

are also slight differences in thecolor, the Bolivian species being black, the Venezuelan

more

fre- quently brownish,

and

in the punctation on the first

segment

of the abdomen,

which

in theVenezuelan species iscoarser

and

denser.

,64

PROCEEDINGS OF THE NATIONAL MUSEUM

^vol.loi

DISCUSSION OF MYOCHROUS ALBOVILLOSUS JACOBY

Plate S, Figuee 4

Pachnephorus tessellatus Duftschmid, Fauna Austriaca, vol. _3, p. 217, 1825.

Myochrous albovillosus Jacoby, Biologia Centrali-Americana, Coleoptera, vol. 6, pt. 1, p. 176,1882.

Myockrous

dtl)Ovillosus^ described

by Jacoby from

"Mexico," is really a speciesof

Pachnepho7ms

that occurs abouttheMediterranean.

There

are

two

cotypes, oneintheBritish

Museum

(in the

Baly

collec- tion, collected

by

Pilate)

and

theotherinthe

Museum

of

Comparative Zoology

(in the

Bowditch

collection

from Jacoby

's collection). I

compared

a specimen of

Pachnephorus

tessellatus

Duftschmid

with the cotype in the

Museum

of

Comparative

Zoology

and found them

indistinguishable.

The

^short antennae w^ith the greatly thickened distaljoints,thethorax without toothing, the

abdomen

withthe very longfirstsegment,theshallow emarginationat theapexofthemiddle

and

hind tibiae,

and

the broad, bifid scales all place this species in

Pachnephorus

ratherthaninMyochrous.

The

detailed description of the

Museum

of

Comparative

Zoology cotypeisas follows

:

About

3.7

mm.

ⁱⁿ length, oblong oval, shining dark

brown

beneath with the dense, closely appressed, pale

brown and

white scales, the scales short,broad, bifid.

Antennae

barely reaching the base of the prothorax, the five distal joints

much

enlarged,

and

as

wide

as long.

Prothoraxcylindrical, as longas broad, with a small apical

and

basal toothbut

no

signs of lateral toothing, sides arcuate; diskwithout de- pressions except along the basal margin, smoothly covered

by

^broad, palescales,thescalesinthe center alittledarker; punctation beneath apparently rather dense

and

fine. Elytra broader than prothorax, taperingat apex, rather convex,with

prominent

humeri,

and

covered

by

broad scales that

form

a pattern, white along the base

and on

liumeri,

and down

themiddleofeach elytron

two

or

more

white spots,

and

another along the side;

rows

of striate punctures not contingent l)utwell-spaced,

and

thepunctures round.

Body

beneath

more

densely clad with

narrower and

longer scales, particularly along the sides of the

abdomen, down

the

middle

of the

abdomen and on

the

upper

under-

body

less scaly; first

abdominal segment

nearly half the length of

abdomen

; legsless densely scaly, not toothed^; middle

and

hindtibiae with

an

emarginationatapex; anteriortibiaewithouttoothing.

It seems likely that

some

mistake in locality labels

may have

been

made,

as

none

of thespeciesof

Pachnephorus

is

known

tooccurinthe

Western

Hemisphere.

Pachnephorus

tessellatusisreportedⁱⁿJunk's Catalogueas occurringin

middle and

southern Europe, central Asia,

and

Mon":olia.

U.S.GOVERNMENTPRtNTING OFFICE: 1950

U S NATIONAL

MUSEUM

PROCEEDINGS. VOL. ¹⁰¹ PLATE ¹

6. M.platHlonctiur n.

n

^{carinatusJc.c.}

SPECIES OF

MYOCHROUS

8. M.,.en.>nur.

U. S. NATIONAL

MUSEUM

PROCEEDINGS. VOL ^lOI PLATE 2

I. M.SQuamosusLeo- 2. M. severini ^{3. IVl.in}termedⁱus

6.M. floridanus Srliaeff. 7M.HoeIdano^ subsp.texauus

Species of

Myochrous

6 M.tibialisJac.

U S. NATIONAL

MUSEUM

PROCEEDINGS. VOL. 101 PLATE 3

6.M.C0C1103 7.M. bcrbadertois Bloke

SPECIES OF

MYOCHROUS

S.Mfcr..oro(,5ja

U. S. NATIONAL

MUSEUM

PROCEEDINGS. VOL ¹⁰¹ PLATE 4

6.M.bolivlunus 7M chacoccisis

Speciesof

Myochrous

U. S. NATIONAL

MUSEUM

PROCEEDINGS. VOL 101 PLATE5

4. M. leucui-L 5. M.cuicollonoidesLet-

Species of

Myochrous

U, S. NATIONAL

MUSEUM

PROCEEDINGS, VOL. 101 PLATE 6

5 M. LUMiatus Ba 6

M

nionros

SPECIESOF

MYOCHROUS

U. S. NATIONAL

MUSEUM

PROCEEDINGS, VOL. 101 PLATE 7

3 M. jomaicensisBloKe

5 M.br.inneus ^6.M.5olle( Bal4

Species of

Myochrous