24 
Psyche 
[March 
THE SUMATRAN “TRILOBITE LARVA” 
By Charles T. Brues 
Biological Laboratories, Harvard University 
The appellation of “Trilobite Larva” has been in use for 
many years to designate the larvae of certain highly aber- 
rant malacoderm beetles. These attain a length of one to 
several inches, with wide, greatly flattened body. The three 
thoracic segments are expanded laterally forming a sort of 
carapace and the abdominal segments bear long, curved 
projections. These gross characters give the larvae an 
almost comical, but nevertheless extraordinarily striking 
resemblance to certain long-extinct trilobites. 
The first reference to these larvae appears to be that of 
Perty made over a century ago, in 1831. His account re- 
lates to a form from Java which Westwood figured in his 
“Modern Classification of Insects” 1 a few years later. With 
his usual taxonomic acumen, Westwood suspected that this 
larva belonged to some species of the family Lycidae. Since 
that time a number of additional species have been discov- 
ered in various parts of the Indomalayan region to which 
they they are apparently restricted. They seem to be best 
represented in Borneo where at least six distinct types have 
been discovered. These have been dealt with at length by 
Mjoberg in 1925 2 who gives an historical and descriptive 
account that need not be repeated here. Mjoberg was suc- 
cessful in rearing one Bornean species to maturity and found 
that the large larvse are females which are destined to un- 
dergo practically no external change on becoming adult. Un- 
fortunately he overlooked a paper by the Dutch naturalist, 
J. C. Koningsberger 3 published more than twenty years pre- 
Wol. 1, p. 254; fig. 27, 1-2 (1839). 
2 The Mystery of the so-called “Trilobite Larvae” definitely Solved. 
Psyche, vol. 32, pp. 119-153, 2 pis. 
3 Een Geheimzinnige Larve. De tropische Natuur, Jaarg. 1, pp. 
17-20 (1912). 
