1908] GIRAULT — GASTROIDEA CYAXEA 7 



POSTEMBRYONIC StAGES. 



The larvae resemble in general aspect those of Haltica chalyhea Illiger, but are 

 not as robust. They are inclined to be gregarious during early life. Three larval 

 ecdyses and four postembryonic instars occur during development. 



Table II. Average Duration of Postembryonic Instars for a Generation, July, 1907. 



av. daily ef- 

 No. 1st ecdysis. 2nd ecdysis. Entered soil. Emerged. fective tem- 



eggs. Hatched. Instar I. Instar II. Instar III. Pupal instar. Total. perature. 



521. 10 p.m., July 6 7 a.m., July 9 Noon, July 116 p.m., July 13 7 p.m., July 20 



2 dys., 9 hrs. 2 dys., 5 hrs. 2 dys., 6 hrs. 7 dys. 1 hr. 13 dys., 21 lirs. 36.3° F. 



The larvae were given' Hn. abundance of food and confined in the laboratory in 

 an open glass jar filled with clay loam soil. They eat irregular patches of matter 

 from the leaves. Pupation takes place beneath the soil. 



Table III. Av. Width of the Head for Respective Larval Instars. 



Instar: I. II. III. 



Greatest diameter, mm. 0.3735 0.6474 0.9960 



Duration of Life Cycle. 



By combining Table II with Lot No. 1, Table I, the length of the life cycle for a 

 single set of individuals is obtained as follows: 



Table IV. Duration if life cycle for a single generation, July 2-20, 1907 . 



Egg. Larva. Pupa (time in soil). Life cycle 



No. Days. hom's. Days. hours. Days. hours. Days. hours. 



52 4 10 6 20 7 1 18 1 



The Adults. 



Gravid females captured on their foodplant, growing in clay loam of a garden,, 

 on June 28th, July Lst and 7th, were confined in glass jars in the laboratory and sup- 

 plied food daily. Table V siunmarizes. The three females were probably some 

 days old when taken, so that the records probably fall short of the average. It is 



' Lot No. 1, table I. 



