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Full text of "Ant larvae of the subfamily Myrmeciinae (Hymenoptera: Formicidae)."

Reprinted from THE PAN-PACIFIC ENTOMOLOGIST 
Vol. 47, October, 1971, No. 4 

pp. 245-256 
Made in United States of America 



Ant Larvae of the Subfamily Myrmeciinae 

(Hymenoptera: Formicidae) 

GEORGE C. WHEELER AND JEANETTE WHEELER 

Desert Research Institute, University of Nevada System, Reno 89507 

Emery (1911) and Wheeler (1922) placed the genus Myrmecia in the 
tribe Myrmeciini of the subfamily Ponerinae. Clark (1951) with Brown 
(1954) concurring raised the tribe to subfamily rank, Myrmeciinae. 

The genus Myrmecia occurs only in Australia and New Caledonia and 
comprises between 65 (Brown and Taylor, 1970) and 96 (Clark, 1951) 
species. The workers range in length from 4 mm to 36 mm. The larger 
species are called bulldog ants because of "the vicious way they attack 
and the tenacity with which their huge jaws hang on to their victim. 
All the workers and females are provided with a large sting with which 
they inflict a severe and painful wound. A burning sensation accom- 
panied by redness and swelling may be felt at the wound some time 
afterwards and may last several days" (Clark 1951: 18). 

The Myrmeciinae are generally regarded as the most archaic of living 
ants. Brown (1954: 22-23) divided them into three tribes of one genus 
each: Prionomyrmecini, Prionomyrmex from the Baltic Amber (Oligo- 
cene) ; Nothomyrmeciini, Nothomyrmecia, one species (only two speci- 
mens known) from Western Australia, which "appears to satisfy nearly 
all conditions demanded of an ancestral stock leading to the Dolicho- 
derinae and Formicinae"; and Myrmeciini, Myrmecia. 

In our previous papers (1952, 1964) we have treated Myrmecia as a 
ponerine. Now we are convinced that it should be in a separate sub- 
family, the Myrmeciinae. In 1952 we described the larvae of two species 
(M. gulosa and M. sanguinea) . In this paper we describe the larvae of 
28 additional species. For all of this new material we are deeply indebted 
to the Rev. Bede B. Lowery, Head Master of St. Ignatius School, Nor- 
wood, South Australia. Rev. Lowery's gift renders Myrmecia the largest 
genus in our collection except Camponotus. Since Camponotus is the 
largest genus of ants (about 600 species) , our 60 species constitute only 
10%; but our 30 species of Myrmecia are either 42% or 31% of the 
genus. 

THE PAN-PACIFIC ENTOMOLOGIST 47: 245-256. October 1971 



246 THE PAN-PACIFIC ENTOMOLOGIST [VOL. 47, NO. 4 

Genus MYRMECIA Fabricius 

Not differentiated into neck and body; elongate and terete; anterior half strongly 
curved ventrally. Integument tough. Body hairs simple or denticulate. Head hairs 
few, simple and slightly curved; about as many sensilla as hairs on head. Clypeus 
granulose. Labrum small and short; posterior surface with spinules usually isolated 
and rather large and with sensilla of various sizes. Mandibles stout and subtrian- 
gular; heavily sclerotized; basal half usually bearing isolated spinules. Maxillary 
spinules usually rather large and isolated. Labium with spinules usually large and 
isolated; with dorsal transverse densely and coarsely spinulose ridge; each palp a 
slightly elevated cluster of sensilla; opening of sericteries wide and salient. Hypo- 
pharynx without spinules. 

The following revised description of M. gulosa is our standard: all other species 
are compared with it. 

MYRMECIA GULOSA Fabricius 

Length 1 about 25 mm. Elongate, terete and slender; diameter greatest at AV 
and VI, diminishing gradually toward strongly ventrally curved anterior end; pos- 
terior half stout; posterior end broadly rounded; lateral longitudinal welt well 
developed. Anus ventral. Leg vestiges moderately large. Segmentation distinct, 
10 differentiated somites. Integument of venters of TI and Til spinulose. Body 
hairs simple, slightly curved, short (0.06-0.2 mm long), uniformly distributed and 
moderately abundant. Head very small, subpyriform in anterior view; cranium 
subovoidal in anterior view, with numerous minute sensilla irregularly scattered 
over surface. Head hairs very few, minute (about 0.03 mm long), simple. Antennae 
mounted on low bulges; small; with 3 sensilla each. Labrum small and short; 
breadth twice the length; strongly bilobed due to wide median incision of ventral 
border; anterior surface of each half with about 12 sensilla and two or three minute 
hairs; posterior surface sparsely spinulose, spinules rather large and usually iso- 
lated; each half of posterior surface with about 12 sensilla of various sizes. Man- 
dibles large; each subtriangular in anterior view; heavily sclerotized apically; 
apical tooth sharp-pointed and slightly curved posteriorly; medial teeth smaller, 
sharp-pointed and directed ventromedially; basal half of anterior surface with 
rather coarse spinules, these usually isolated; apical half with longitudinal striae 
on anterior and posterior surfaces. Maxillae lobose, narrowly round-pointed and 
with apical half spinulose; each palp a frustum with two apical, two subapical 
and one lateral sensilla; each galea a stout cone with two apical sensilla. Labium 
subhemispherical ; anterior surface spinulose, the spinules rather large and isolated ; 
a large densely and coarsely spinulose transverse welt posteriorly; each palp a 
rounded knob with five sensilla; opening of sericteries wide and salient. Hypo- 
pharynx without spinules. (Material studied: 12 larvae from New South Wales.) 

MYRMECIA ARNOLDI Clark 

Length about 25 mm. Body hairs slightly longer (0.09-0.24 mm long). Head 
hairs longer (0.04-0.08 mm long) . Mandibles without spinules on anterior surface. 
Maxillary palps each with four apical and one lateral sensilla. (Material studied: 
one larva from Western Australia.) 



1 All of these larvae are measured from the mouth, through the line of spiracles to the anus. 



OCTOBER 1971] WHEELER & WHEELER ANT LARVAE 247 

MYRMECIA BREVINODA Forel 

Length about 23 mm. Head hairs longer (0.036-0.072 mm long) . Labrum with 
length % the breadth. Maxillary palp with one apical, three lateral and one sub- 
basal sensilla. 

Very Young Larva. Length about 4.8 mm. Shape similar to mature larva. First 
abdominal spiracle about 3 times as large as remainder. Integument with numerous 
denticles 0.11-0.32 mm long, and few minute spinules on venter of each somite. 
Body hairs 0.018-0.11 mm long. Head hairs 0.036-0.072 mm long, with tips simple 
or minutely spinulose. Mandibles with teeth relatively longer and more slender. 
Each maxillary palp a rounded mound; each galea a short stout peg. Each labial 
palp represented by cluster of five sensilla. Opening of sericteries a depressed 
transverse slit. 

Material studied: numerous larvae from New South Wales. 

MYRMECIA CHASEI Forel 

Length about 20 mm. Stouter. Entire integument spinulose or rugulose. Body 
hairs 0.06-0.43 mm long. Head hairs longer (0.06-0.12 mm long) . Mandibles with- 
out spinules on anterior surface. Maxillae entirely spinulose; each palp a round- 
tipped conoid with four apical and one lateral sensilla. (Material studied: 6 larvae 
from Western Australia.) 

MYRMECIA CLARKI Crawley 
(Figs. 1, 2) 

Length about 10 mm. Stouter. Integument of ventral surfaces of anterior somites 
with rather coarse spinules in short arcuate rows and of dorsal surfaces of posterior 
somites with minute spinules in short arcuate rows. Body hairs sparse, 0.03-0.35 
mm long, finely denticulate and feebly flexuous. Head hairs about 0.05 mm long; 
very finely denticulate. Mandibles with teeth all reduced to rounded stumps; 
anterior surface with fewer spinules. Maxillae entirely spinulose. Opening of 
sericteries wide and salient from bottom of a trough. (Material studied: six larvae 
from Western Australia.) 

MYRMECIA COMATA Clark 

Length about 15.5 mm. Venter of thorax with numerous spinules in short arcuate 
rows. Body hairs longer (0.075-0.41 mm long) and of two types: (1) simple; (2) 
with few minute denticles near tip. Cranium more nearly circular; entire head 
less pear-shaped. Head hairs longer (0.054-0.08 mm long). Mandibles with teeth 
larger; each apical tooth more slender and tip more hooked. Galeae longer. (Mate- 
rial studied: six larvae from New South Wales.) 

MYRMECIA DIXONI Clark 

Length about 9.6 mm. Not so slender; posterior end more rounded; entire body 
more curved. Integument of venters of thorax and AI, II, IX and X with spinules 
in short transverse rows. Body hairs less numerous, longer (0.075-0.53 mm long), 
with denticles. Head with occipital outline flatter; widest above antennal level. 
Posterior surface of labrum with spinules fewer, smaller and arranged in short 



248 



THE PAN-PACIFIC ENTOMOLOGIST [VOL. 47, NO. 4 




FIGS. 1 and 2. Myrmecia clarki. FIG. 1. Left mandible in anterior view, X160. 
FIG. 2. Body hair, X267. FIG. 3. M. elegans left mandible in anterior view, X128. 
FIGS. 4-9. M. julvipes. FIG. 4. Larva in side view, X19. FIGS. 5 and 8. Two 
denticulate body hairs, X183. FIGS. 6 and 7. Two views of a hooked hair, X183. 
Fie. 9. Side view of a very young larva, Xl9. 



arcuate rows. Mandiblar teeth longer and more slender. Each maxillary palp with 
three apical, one subapical and one lateral sensilla. Labium with border between 
the palps flatter; each palp a low knob with five sensilla. (Material studied: 
three larvae from New South Wales.) 

MYRMECIA ELEGANS Clark 
(Fig. 3) 

Length about 9.6 mm. Stouter. Integument of ventral surfaces of anterior somites 
and dorsal surfaces of posterior somites with spinules in short transverse rows. 
Body hairs few, short to long (0.06-0.54 mm), finely denticulate, tip highly varied 
(clubbed, spatula te, short-bifid or tapered). Head capsule more nearly circular. 
Head hairs fewer and longer (0.03-0.09 mm long). Mandibles with teeth stouter 
and round-pointed; fewer spinules on anterior surface. Each labial palp a slight 
elevation with five sensilla. (Material studied: three larvae and one semipupa.) 

MYRMECIA FORCEPS Roger 

Immature Larva. Length about 11 mm. Entire integument spinulose, spinules 
larger and more numerous on venters of anterior somites and dorsa of posterior 
somites. Body hairs 0.01-0.32 mm long, very finely denticulate. Head with straight 



OCTOBER 1971] WHEELER & WHEELER ANT LARVAE 249 

sides. Head hairs longer (0.025-0.065 mm long). Mandibles without spinules. 
Each maxillary palp with four apical and one lateral sensilla; galeae digitiform. 
Each labial palp a cluster of four sensilla; opening of sericteries a wide slit in 
trough. (Material studied: eight larvae from South Australia.) 

MYRMECIA FORFICATA Fabricius 

Length about 2 mm. The middorsa of Til and Till each with transverse welt, 
which extends to level of spiracles. Entire integument of most somites with minute 
spinules, isolated or in short transverse rows. Body hairs sparse, slightly longer 
(0.052-0.3 mm long), with numerous minute denticles. Anterior surface of each 
half of labrum with two or three hairs (about 0.018 mm long) and about 20 
sensilla on or near ventral border. Mandibles with teeth wider and longer. Each 
maxillary palp a short peg with four apical and one lateral sensilla. Each labial 
palp a small knob with five sensilla. (Material studied: numerous larvae from 
New South Wales.) 

MYRMECIA FUCOSA Clark 

Length about 9.2 mm. Thorax and AI more curved; remainder of abdomen more 
swollen, with venter flatter and dorsal surface more nearly C-shaped. Integument 
of venters of thorax and AI-IV and dorsa of AI-X with minute spinules in short 
arcuate rows. Body hairs sparser, longer (0.075-0.45 mm long), flexuous and with 
minute denticles. Anterior surface of each half of labrum with two minute hairs 
and about 17 sensilla on or near ventral border. Each maxillary palp with three 
apical and two lateral sensilla. (Material studied: seven larvae from South 
Australia.) 

MYRMECIA FULVIPES Roger 
(Figs. 4-9) 

Length about 11 mm. Abdomen much stouter and shorter, diameter greatest at 
AIV and V, tapering gradually to more narrowly rounded posterior end. Integument 
of venters of anterior somites and AIX and entire integument of AX with minute 
spinules in short transverse rows. Body hair sparser and with numerous denticles. 
Cranium with occipital outline flattened. Antennae larger and near mouth parts. 
Each mandible with apical tooth narrower and medial teeth larger. Each maxillary 
palp with four terminal and one lateral sensilla; galeae digitiform. 

Young Larva. Length about 5 mm. Similar to mature larva except in following 
details. Spiracles of thorax only % diameter of those on abdomen. Body hairs of 
two types: (1) 0.012-0.3 mm, denticulate, on all somites; (2) 0.09-0.18 mm, 
uncinate, with hook and apical portion of shaft minutely denticulate, on AVII-X. 
Antennae smaller. Each maxillary palp a cluster of five sensilla; opening of 
sericteries a transverse slit. 

Very Young Larva. Length about 4 mm. Similar to young larva except in 
following details. Body of nearly uniform diameter. Body hairs (1) 0.09-0.22 mm; 
(2) 0.11-0.22 mm. Head capsule subhexagonal with corners rounded. Head hairs 
0.015-0.06 mm. Labrum with smaller spinules. 

Material studied: numerous larvae from New South Wales and Australian 
Commonwealth Territory. 



250 THE PAN-PACIFIC ENTOMOLOGIST [VOL. 47, NO. 4 

MYRMECIA GRACILIS Roger 

Length about 18 mm. AIX bearing gonopod vestiges. Integument of thorax and 
AI-II bearing minute spinules. Body hairs of two types: (1) 0.038-0.38 mm long, 
with minute denticles near tip, on all somites; (2) 0.032-0.41 mm long, with bifid 
tip and with minute denticles apically. Head hairs 0.024-0.11 mm long, denticulate. 
Mandibles more slender apically. Each maxillary palp a frustum with four apical 
and one subapical sensilla; galeae digitiform. (Material studied: nine larvae from 
South Australia.) 

MYRMECIA GRATIOSA Clark 

Length about 11 mm. Body hairs 0.025-0.35 mm long, very finely denticulate. 
Head hairs 0.01-0.09 mm long, simple. Each maxillary palp a round-tipped peg, 
with four apical and one lateral sensilla. (Material studied: three larvae from 
Western Australia.) 

MYRMECIA HARDERI Forel 

Length about 13 mm. Stouter. Gonopod vestiges on AIX-X. Integument of 
venters of anterior somites and dorsa of posterior somites with spinules in transverse 
rows. Body hairs sparser and longer. Of two types: (1) 0.035-0.53 mm long, 
minutely denticulate, the longer with numerous denticles; (2) about 0.019 mm 
long, a few on abdominal somite X, with denticulate uncus. Head capsule nearly 
circular. Head hairs longer (0.036-0.1 mm long). Anterior surface of each half 
of labrum with two hairs and about 13 sensilla. Mandibles with stouter teeth and 
fewer spinules and striae. Each maxillary palp a frustum with four apical and 
one lateral sensilla; galeae digitiform. 

Very Young Larva. Length about 3 mm. Denticulate body hairs 0.009-0.18 mm 
long; uncinate hairs 0.15-0.23 mm long, few on each AIV-X. Mandibular teeth 
narrower and sharper. Each maxillary palp a low knob with five sensilla. Labium 
feebly bilobed; each palp a cluster of five sensilla; opening of sericteries a depres- 
sion. Hypopharynx with minute spinules in short transverse rows. 

Material studied: 13 larvae from Queensland. 

MYRMECIA LUCIDA Forel 

Semipupa. Length about 13.5 mm. Integument of venters of anterior somites 
and dorsa of posterior somites with few spinules in short rows. Body hairs fewer, 
0.04-0.36 mm long. Each mandible with apical tooth more curved, medial teeth 
stouter and blunter. Each maxillary palp with four apical and one lateral sensilla. 
Labium with much larger spinules basally. (Material studied: one semipupa from 
Western Australia.) 

MYRMECIA MICHAELSENI Forel 

Immature Larva. Length about 10.8 mm. Stouter. Body hairs less numerous, 
length 0.025-0.35 mm. Head more rounded. Head hairs longer (0.027-0.75 mm 
long) . Mandibles with teeth stouter and round-pointed. Maxillae entirely spinu- 
lose; each palp with four apical and one lateral sensilla. (Material studied: one 
larva from Western Australia.) 



OCTOBER 1971] WHEELER & WHEELER ANT LARVAE 251 

MYRMECIA MURINA Clark 

Length about 17.7 mm. Stouter. Entire integument spinulose. Body hairs fewer, 
0.01-0.4 mm long, minutely denticulate. Head hairs 0.013-0.025 mm long, simple. 
Each maxillary palp with four apical and one lateral sensilla; galeae digitiform. 
(Material studied: 17 larvae from Australian Commonwealth Territory.) 

MYRMECIA NIGROCINCTA F. Smith 

Length about 9.7 mm. Gonopod vestiges on AVII-IX. Integument of venters of 
anterior somites and dorsa of posterior somites with minute spinules in transverse 
rows. Cranium subhexagonal in anterior view. Head hairs 0.038-0.075 mm long, 
simple. Anterior surface of mandibles with more striae and fewer spinules. Each 
maxillary palp a short peg with four apical and one lateral sensilla; galeae digiti- 
form. 

Young Larva. Length about 4.7 mm. Similar to mature larva except in following 
details. Body hairs 0.014-0.15 mm long, with denticles. Cranium with occipital 
border concave. Mandibles with longer and more sharply pointed teeth; anterior 
surface with minute spinules, striae feeble. Each maxillary palp a short cone with 
three apical and two lateral sensilla; each galea a frustum. Each labial palp a 
slightly raised cluster of five sensilla; opening of sericteries a slit in depression. 

Material studied: numerous larvae from New South Wales. 

MYRMECIA PICTA F. Smith 

Length about 10.6 mm. Stouter. Gonopod vestiges on AVII-IX. Integument of 
venters of anterior somites and dorsa of posterior somites with minute denticles in 
short transverse rows. Body hairs sparser and longer (0.019-0.41 mm long), each 
with few minute denticles near apex. Head with occipital border flatter. Head 
hairs about % as numerous, 0.018-0.1 mm long, with few minute denticles near 
apex. Mandibles with fewer and weaker striae. Each maxillary palp with four 
apical and one lateral sensilla. Labium with smaller spinules; each palp a slightly 
raised cluster of five sensilla. 

Very Young Larva. Length about 4.9 mm. Similar to mature larva except as 
follows. Body hairs 0.09-0.38 mm long, with numerous minute denticles. Maxillary 
palp a low knob with three apical and two lateral sensilla. Opening of sericteries 
a depressed slit on labium. 

Material studied: 11 larvae from New South Wales. 

MYRMECIA PILIVENTRIS F. Smith 

Young Larva. Length about 8 mm. Integument of venters of anterior somites 
and dorsa of posterior somites with minute spinules in short transverse rows. Body 
hairs sparser and longer. Of two types: (1) 0.045-0.27 mm long, with simple shaft 
and rather numerous minute denticles apically, on all somites; (2) 0.036-0.063 mm 
long, uncinate and with minute denticles, thin in plane of hook and wide perpen- 
dicular to that plane. Occiput flatter. Head hairs longer (0.027-0.72 mm long). 
Mandibles with teeth more acute and closer together. Each maxillary palp a short 
cone with three apical and two lateral sensilla; galeae digitiform. Each labial palp 
a slightly raised cluster of five sensilla. Opening of sericteries a transverse slit 
in slight depression. 



252 THE PAN-PACIFIC ENTOMOLOGIST [VOL. 47, NO. 4 

Very Young Larva. Length about 2 mm. Similar to young larva except as 
follows. Body hairs of two types: (1) 0.018-0.216 mm long, denticulate, on all 
somites; (2) about 0.16 mm long, uncinate, on AVI-X, more numerous posteriorly. 

Material studied: numerous larvae from New South Wales. 

The young and very young larvae are clumped with their posterior 
ends in contact and held together by the uncinate hairs. It is impossible 
to pry them apart with needles. 

MYRMECIA PILIVENTRIS FEMORATA Santschi 

Length about 12 mm. Entire integument spinulose, spinules minute and isolated 
or in short rows. Body hairs 0.025-0.35 mm long, stout, with numerous denticles. 
Head hairs simple, 0.036-0.054 mm long. Each mandible with apical tooth longer 
and more slender and medial teeth larger. Each maxillary palp a slender skewed 
peg, with three apical and two lateral sensilla; galeae digitiform. (Material 
studied: five larvae from Australian Commonwealth Territory.) 

MYRMECIA PILOSULA F. Smith 

Length about 12.5 mm. Slightly stouter and shorter. Entire integument spinulose, 
spinules minute and isolated or in short rows. Body hairs sparser and longer 
(0.025-0.45 mm long) , with minute denticles. Occipital outline flatter. Head hairs 
0.0370.072 mm long, simple or with minute denticles. Mandibles with teeth longer 
and stouter. Each maxillary palp a tall cylinder with four apical and one lateral 
sensilla; galeae digitiform. Labial palp a short peg with five apical sensilla. 

Young Larva. Length about 2.7 mm. Similar to mature larva except in following 
details. Thoracic spiracles Vs diameter of abdominal spiracles. Integument with 
minute spinules, most abundant on AX and venter of thorax, more scattered else- 
where. Body hairs of two types: (1) 0.009-0.18 mm long, denticulate, on all 
somites except AX; (2) 0.054-0.18 mm long, on AIV-X, increasing in number 
posteriorly. Each maxillary palp a frustum; galeae shorter. 

Very Young Larva. Length about 2.4 mm. All spiracles minute. Entire integu- 
ment of posterior somites with minute isolated spinules, venters of anterior somites 
with minute spinules in short transverse rows. Body hairs of two types: (1) 
0.018-0.2 mm long, with minute denticles, on all somites except AX; (2) 0.054-0.18 
mm long, uncinate and denticulate, increasing in number posteriorly. Labrum not 
deeply bilobed; posterior surface with spinules relatively smaller and not so 
numerous. Mandibular spinules minute. Maxillary spinules minute; each palp a 
low knob with five sensilla; each galea a slight elevation with two sensilla. Labial 
spinules shorter, many isolated; each palp a cluster of five sensilla; opening of 
sericteries a short depression. Hypopharynx with minute scattered spinules. 

Material studied: numerous larvae from New South Wales and South Australia. 

MYRMECIA PYRIFORMIS F. Smith 

The name M. sanguined, which we used in 1952 (p. 112) and 1964 
(p. 444), is a synonym of M. pyriformis (Clark, 1951). 

Revision. Entire thoracic integument spinulose; spinules few and minute dor- 
sally becoming more numerous and in transverse rows ventrally. Body hairs fewer 



OCTOBER 1971] WHEELER & WHEELER ANT LARVAE 253 

and shorter (0.037-0.175 mm long). Each maxillary palp taller and with four 
apical and one lateral sensilla; each galea digitiform. Each labial palp with slight 
constriction near base. (Material studied: the thorax and attached heads of three 
larvae from New South Wales.) 

MYRMECIA SIMILLIMA F. Smith 

Length about 35 mm. Gonopod vestiges on AIX. Integument with minute 
spinules in short transverse rows on all surfaces of AX, on dorsa of other posterior 
somites and on venters of anterior somites. Body hairs fewer and longer (0.036-0.5 
mm long) , with minute denticles. Head hairs longer (0.038-0.11 mm long) . Man- 
dibles with teeth longer and closer together. Each maxillary palp a short cone 
with one apical, two subapical and two lateral sensilla; galeae digitiform. Each 
labial palp a short peg with five sensilla. Hypopharynx with few short transverse 
rows of minute spinules. 

Young Larva. Length about 17.6 mm. Similar to mature larva except in follow- 
ing details. Til with transverse welt across the dorsum from spiracle to spiracle. 
Entire integument spinulose, spinules minute but more numerous and larger 
anteriorly and ventrally. Each maxillary palp a frustum with four apical and one 
lateral sensilla. 

Very Young Larva. Length about 8.3 mm. Very similar to young larva except 
in following details. Thoracic spiracles about half diameter of abdominal spiracles. 
Venters of somites with minute spinules in short rows, more prominent anteriorly. 
Body hairs of two types: (1) 0.015-0.45 mm long, with few minute denticles, on 
all somites; (2) about 0.19 mm long, uncinate and flattened, with denticles in 
plane of uncus. Each maxillary palp a frustum with three apical and two lateral 
sensilla. Labium with spinules minute; each palp a slight elevation; opening of 
sericteries a transverse slit in depression. 

Material studied: numerous larvae from New South Wales. 

One of our specimens of M. simillima measures 35 mm in length and 
is the largest ant larva we have seen ; its volume is about 350 mm 3 . We 
do not have a preserved larva of the largest known ant, Dinoponera 
grandis, but as far as we can estimate from a tattered integument, that 
larva has a volume of about 400 mm 3 . 

MYRMECIA SWALEI Crawley 

Immature Larva. Length about 8.8 mm. Stouter. Integument of venters of 
anterior somites and dorsa of posterior somites spinulose. Body hairs less numerous, 
0.05-0.3 mm long, with numerous minute denticles. Cranium more rounded. Head 
hairs 0.013-0.05 mm long, simple. Mandibles with teeth stouter and round-pointed; 
with fewer spinules. Maxillae entirely spinulose; each palp with four apical and 
one lateral sensilla; galeae digitiform. (Material studied: one larva from Western 
Australia.) 

MYRMECIA TEPPERI Emery 

Length about 11.5 mm. Stouter. Integument with spinules in short rows on all 
surfaces of AX and on venters of anterior somites. Body hairs 0.05-0.45 mm long, 



254 THE PAN-PACIFIC ENTOMOLOGIST [VOL. 47, NO. 4 

with fine denticles. Head hairs longer (0.036-0.072 mm long) . Maxillae with most 
of anterior surface of each stipes covered with coarse isolated spinules; each palp 
digitiform, with four apical and one lateral sensilla. 

Very Young Larva, Length about 3.6 mm. Similar to mature larva except as 
follows. Entire integument minutely spinulose, spinules most prominent on AX 
and on venter of TI. Cranium subhexagonal with all corners rounded. Mandibles 
straighter, with teeth long, slender, straight and directed ventrally. Maxillae with 
spinules minute and in short rows on apex; each palp a low knob with four apical 
and one lateral sensilla; each galea a short cone. Each labial palp a slightly raised 
cluster of five sensilla ; opening of sericteries a transverse slit in depression. Hypo- 
pharynx with few minute spinules. 

Material studied: numerous larvae from New South Wales. 

MYRMECIA URENS Lowne 

Length about 7.3 mm. Gonopod vestiges on AIX. Entire integument spinulose, 
spinules minute and mostly isolated but in short rows on AX and on venters of 
anterior somites. Cranium with occipital outline flatter. Mandibles bearing few 
striae, teeth more prominent and closer together. Each maxillary palp a skewed 
peg with one apical, two subapical and two lateral sensilla. 

Young Larva. Length about 3.3 mm. Similar to mature larva except as follows. 
Thoracic spiracles about % diameter of abdominal spiracles. Mandibular teeth 
slender and very acute. 

Material studied: 14 larvae from New South Wales. 

MYRMECIA VARIANS Mayr 

Immature Larva. Length about 9.2 mm. Gonopod vestiges on AIX. Integument 
with spinules on all surfaces of AX and on venters of anterior somites. Body hairs 
less numerous and longer (0.025-0.51 mm long), with short denticles; hairs mostly 
short, but with ring of the longer hairs around middle of each somite. Mandibles 
with notably larger teeth. Each maxillary palp a short cone with four apical and 
one lateral sensilla; galeae digitiform. Each labial palp a slight elevation with 
five sensilla. 

Very Young Larva. Length about 4.3 mm. Similar to mature larva except in 
following details. Body hairs shorter (0.018-0.3 mm long). Mandibles with teeth 
narrow and more acute. 

Material studied: 15 larvae from New South Wales. 

MYRMECIA VINDEX F. Smith 

Length about 21 mm. Integumentary structures of unknown nature and function 
on each ventrolateral surface of each abdominal somite; minute spinules in short 
transverse row on venters of anterior somites. Body hairs fewer, 0.06-0.3 mm long, 
minutely denticulate. Head hairs very few, longer (0.03-0.09 mm long) . Mandibles 
with stouter teeth; spinules fewer and smaller. Maxillae with apex narrower; each 
palp a round-topped peg, with four apical and one lateral sensilla. Labium with 
fewer and smaller spinules. (Material studied: one larva from Western Australia.) 

MYRMECIA WILSONI Clark 

Semipupa. Length about 12 mm. Stouter. Body hairs finely denticulate, of two 
types (with few intergrades) : (1) short (0.035-0.1 mm long), generally dis- 



OCTOBER 1971] WHEELER & WHEELER ANT LARVAE 



255 




FIG. 10. Myrmeciiform body profile. Fie. 11. Myrmeciiform mandible shape. 



tributed; (2) long (0.2-0.3 mm long), a few on each somite. Head hairs longer 
(0.015-0.075 mm long), tip notably slender. Mandibles with teeth much larger 
and round-pointed; fewer spinules. Each maxillary palp with four apical and one 
lateral sensilla; galeae digitiform. Labium with smaller spinules; each palp a 
slight elevation bearing five sensilla. (Material studied: one semipupa from 
Western Australia.) 

DISCUSSION 

In our study of the larvae of the subfamily Myrmicinae (1960) we 
discussed the importance of various characters in taxonomy and de- 
scribed our techniques for generalizing about body profile and mandible 



256 THE PAN-PACIFIC ENTOMOLOGIST [VOL. 47, NO. 4 

shape. We later (1964) applied the same reasoning and techniques to 
the larvae of the Ponerinae, which then included Myrmecia. 

The larva of Myrmecia has a myrmeciiform profile, which was figured 
and described (1964: 458) thus: "Not differentiated into neck and 
body ; elongate and rather slender ; diameter diminishing gradually from 
the fifth abdominal somite to the anterior end; anterior half strongly 
curved." It is refigured here (Fig. 10) . The mandible shape which is 
also termed myrmeciiform is revised to read thus: "Subtriangular in 
anterior view; straight and stout; without a medial blade; with one 
apical tooth and two subapical medial teeth" (Fig. 11). As the term 
myrmeciiform suggests, the profile and mandible shape are both distinc- 
tive for this genus. 

We have selected the myrmeciiform profile as the least specialized 
among known ant larvae, because (1) Myrmecia has generally been 
considered one of the least specialized genera of ants; (2) among the 
larvae of this genus no character shows an extreme deviation from the 
average for all known ant larvae; (3) no character shows adaptation 
to any limited function or habit; (4) among the larvae of Myrmecia 
the majority of characters are only moderately developed in contrast to 
the extremes of the same characters in the family. 

We believe that the larvae of Myrmecia are unspecialized in the 
following characters: body shape; body hairs; head hairs; size, shape 
and position of antennae; size and shape of labrum; mandible shape; 
maxillary palps paxilliform; galeae digitiform; labial palps low rounded 
elevations; opening of sericteries wide and salient; hypopharynx with- 
out spinules; spinules on other mouth parts few, coarse and isolated. 

LITERATURE CITED 

BROWN, W. L. 1954. Remarks on the internal phylogeny and subfamily classifica- 
tion of the family Formicidae. Insectes Soc., 1: 21-31. 

BROWN, W. L., AND R. W. TAYLOR. 1970. Superfamily Formicoidea. Pages 951- 
959 in. "The Insects of Australia." Melbourne Univ. Press, 1029 p. 

CLARK, J. 1951. The Formicidae of Australia. Vol. I. Subfamily Myrmeciinae. 
Commonw. Sci. Ind. Res. Organ. Australia, Melbourne, 230 p. 

EMERY, C. 1911. Hymenoptera: Fam. Formicidae: Subfam. Ponerinae. Fasc. 118 
in Wytsman's "Genera Insectorum." 125 p., 3 pi. 

WHEELER, G. C., AND J. WHEELER. 1952. The ant larvae of the subfamily Poner- 
inae. Amer. Midland Natur., 48: 111-144, 604-672. 
1960. The ant larvae of the subfamily Myrmicinae. Ann. Entomol. Soc. Amer., 

53: 98-110. 

1964. The ant larvae of the subfamily Ponerinae: supplement. Ann. Entomol. 
Soc. Amer., 57: 443-462. 

WHEELER, W. M. 1922. Keys to the genera and subgenera of ants. Amer. Mus. 
Natur. Hist. Bull., 45: 631-710.