1947] 
Dilaridce and Berothidce 
157 
The foregoing generic characters are subject to modi- 
fication as larvae of other species become known. In sort- 
ing material, the subapical peg of the penultimate anten- 
nal segment of Nallachius and the sculptured dorsal sur- 
face of the maxilla of Lomamyia have been found particu- 
larly useful characters. The dominance of the maxilla in 
Lomamyia is one of the most fundamental differences be- 
tween the two genera. Withycombe (1925, p. 328) has 
attached considerable significance to the relative domi- 
nance of mandible and maxilla in neuropterous families. 
Tillyard (1916) stated that the mandible of Spermopho- 
rella is dominant, but his figures indicate that the first 
instar larva (figs. 4, 10) is very much like that of 
Lomamyia (figs. 2, 8), and it is possible that he misin- 
terpreted the mouthparts. If that be true, the close 
similarity of Spermophorella and Lomamyia larvae 
strongly suggests the stability of larval family charac- 
ters in the Berothidae, even when represented by genera 
occurring in distant parts of the world. 
Family Relationships 
The larvae of neither the Berothidae nor the Dilaridae, 
as represented by the genera studied, may readily be con- 
fused with those of any other family. The terrestrial 
neuropterous larvae most familiar to entomologists are 
Chrysopidae and Hemerobiidae. The latter are superfi- 
cialy suggestive of Berothidae and Dilaridae, but in each 
case, as in the hemerobiid genus W esmcdius (fig. 9), the 
jaws are strongly incurved, not extending straight for- 
ward. In fact, the berothids and dilarids clearly belong to 
what Withycombe (1925) has termed the straight- jawed 
families of Neuroptera, in contrast to the many families 
whose larvae consistently have strongly incurved jaws. 
First-instar Hemerobiidae have a trumpet-shaped empo- 
dium, but this becomes a broad pad in later instars (fig. 
20). The Chrysopidae is one of the very few families to 
retain a trumpet-shaped empodium in all larval instars 
(fig. 19). The well-illustrated key by Townsend (1935) 
will enable students to recognize the families of most 
Nearctic neuropterous larvae. 
