122 ENTOMOLOGICAL NEWS. [June, 



THE NUMBER OF PROLEGS IN INSECT LARVAE. 



By WM. HAMPTON PATTON, Hartford, Conn. 



Prolegs, normally present in Lepidopterous larvae upon ab- 

 dominal segments 3, 4, 5, 6 and 9 are lacking in many Noctuids 

 upon 3 and 4; e. g. , Erastria and Drasteria. No fully-developed 

 prolegs are found on segments 3 and 4 of Calocainpa previous to 

 the third moult. The Hypenini have no prolegs on segment 3 ; 

 likewise Nola, the young larvae of Leucania and Catocala, and 

 the larvae of Helia americalis Guen. and Anomis texana Riley 

 (although other Helias and Aletia have the usual number). All 

 Geometrids, except Anisopteryx which has prolegs on abdominal 

 segment 5, have no prolegs on segments 3, 4 and 5. 



In Argyromyges and Gracilaria the prolegs are present on 

 segments 3, 4 and 5, but absent on 6. Promiba has no trace of 

 prolegs. Aspidisca is apodous, having the thoracic feet repre- 

 sented by sucker-like discs, the anal prolegs represented by small 

 lobes each with a recurved hook. Antispila and Prodoxus have 

 no trace of either prolegs or legs. Prodoxus cinereus Riley re- 

 semble Aspidisca. In many Notodontians the anal prolegs are 

 converted into a pair of tentacles. 



The existence of three pairs of thoracic feet I have verified in 

 Limacodes, although none of the Cochliopods have prolegs. 

 Prolegs are present in young bag- worms {CEceticus and T^hyrid- 

 opteryx), but are not conspicuous in the full-grown worms, being 

 represented by the hooks only in Thyridopteryx and Eumeta. 



Phyllocnistis and Nepticula have nine pairs of hookless pro- 

 legs. Megalopyge (Lagoa) and Chrysopyga have seven pairs of 

 prolegs. The prolegs on the second and seventh abdominal seg- 

 ments of M. crispata have been found (contrary to Miss Murt- 

 feldt's statement in "Can. Ent.," viii, 202, November, 1896), to 

 be without hooklets, thus differing from the normal larger pro- 

 legs on the third to sixth segments. Micros have the hooklets 

 in an ellipse or circle; in macros they are reduced to an outer row. 



Erioccphala calthella has eight pairs of abdominal legs jointed 

 like the thoracic Trichacis (Proctotrupidae) larva has ventral pro- 

 legs (Fyles "Can. Ent.," June '96). 



Larvae of sawflies may be distinguished from those of Lepid- 

 optera (excepting the first stage of Lithocolletis, which has but 

 one ocellus cf. V. T. Chambers, "Journ. Cin. Soc. ," N. H., 



