THE LARVA OF ACANTHOGNATHUS 
(HYMENOPTERA: FORMICIDAE) 
By George C. Wheeler 1 and Jeanette Wheeler 2 
In 1953 Brown divided the tribe Dacetini into four subtribes: 
Dacetiti, Orectognathi, Epopostrumiti and Strumigeniti. After study- 
ing the larvae of eight dacetine genera ( Daceton , Orectognathus, 
Epopostruma , Mesostruma , Alistruma , Clarkistruma , Strumigenys 
and Smithistruma ) representing all four subtribes, we concluded 
(1954) that the larval similarities and differences confirmed the 
grouping of the adults. But now, alas, our study of the larva of 
Acanthognathus forces us to revise our conclusion. 
Genus Acanthognathus Mayr 
Thorax and first abdominal somite strongly curved ventrally, re- 
mainder of abdomen straight; diameter increasing from head to 
mesothorax, decreasing slightly through metathorax and abdominal 
somite I, then increasing rapidly to abdominal somite V. Posterior 
end broadly rounded. Anus with a small posterior lip. Body hairs 
short to long, moderately numerous. Of three types : ( 1 ) bifid with 
the branches long, on the dorsal surface; (2) nearly straight, with 
the distal half finely denticulate, on the ventral surface and a few 
in a transverse row around the middle of each thorax somite and ab- 
dominal somites IX and X; (3) anchor-tipped, with long flexuous 
shaft, four in a row across the dorsum of each abdominal somite I- 
VIII. Antennae small, each with three sensilla. Head hairs mod- 
erately numerous, moderately long, denticulate. Mandibles long 
and narrow. 
Acanthognathus rudis Brown and Kempf* 
Submature. Length (through spiracles) about 2.6 mm. Thorax 
and first abdominal somite strongly curved ventrally, remainder of 
abdomen straight. Diameter increasing from the head to mesothorax, 
decreasing slightly through metathorax and first abdominal somite, 
then increasing rather rapidly to a maximum at abdominal somite V. 
Research Scientist, Whittell Forest, University of Nevada. 
2 Research Associate, Desert Research Institute. Address of both authors: 
Laboratory of Desert Biology, Desert Research Institute, University of 
Nevada System, Reno, Nevada 89507. 
Manuscript received by the editor May 11, 1969 
*See previous article, this issue. 
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