Vol. XXV] ENTOMOLOGICAL NEWS. 



327 



Observations on an Insectivorous Larva (Lepid.). 



The 7th of October, 1911, I went for one day's collecting in the 

 Sacramento Gulch near Fairfax, Marin Co., California. It was very 

 warm in this little gulch, or valley, and was very dry. The only vege- 

 tation was tarweed {Hemizonia Inzulaefolia), which was in full bloom 

 and grew to a height of two feet. But few butterflies were col- 

 lected— 4 Anosia plexippus, 2 Pyrameis carye, 4 Lycaena acmon, 3 Colias, 

 and 4 Junonia (very pale in color) ; i Papilio philenor (very much 

 worn), 2 Chrysophanus hcUoides, g Skippers, a few Coenonympha, 5 

 Vanessa calif ornica (very plentiful) ; 2 Hemihyalea moths (very much 

 worn), and 2 Catocola aholibah (or near) fresh. 



A Noctuid moth (Heliothis dispaceus— determined by Dr. Skinner), 

 was exceedingly plentiful flying about the gulch. Twenty-five were 

 collected but not one of them was perfect, all being worn from flying 

 about through the sticky tarweed, I presume. One caterpillar of the 

 moth was found eating the tarweed. The larva was about one and 

 one-half inches in length, a beautiful little caterpillar of a peculiar 

 shade of green, with few hairs. The larva was placed in a breeding 

 cage with the following larvae: Pontia (Pieris) rapae, Pyrameis 

 carye, Papilio philenor, Hemihyalea edzvardsi (a noctuid), and a few 

 little inoth caterpillars. The larvae lived in perfect harmony for two 

 or three days. WTien one of the Pontia rapae larva pupated, it was* 

 attacked in the first stage of the process by the larva of Heliothis dis- 

 paceus and eaten until not a vestige was left. The next day two 

 Pyrameis carye and another Pontia rapae pupated. The Pontia 

 chrysalid was immediately eaten but the other two pupae were not at- 

 tacked. 



1 attributed the carnivorous appetite of the Heliothis larva to lack 

 of the proper food plant. To test this possibility another experiment 

 was performed. On the 12th of October the same year I went to the 

 same gulch and found another caterpillar of the same species. This 

 time I took a good supply of the food plant (tarweed). The plant was 

 placed in the breeding cage together with seven or eight larvae and 

 the Heliothis larva was then put in. The larva ate the tarweed with 

 relish. Some of the caterpillars turned to pupae at the same time. The 

 only one attacked was the Pontia rapae pupa. The chrysalid was at- 

 tacked in the same way as the two previous ones, the Heliothis larva, 

 beginning at the point of the thorax, then eating its way down the dor- 

 sal part to the end of the abdomen, and from there to the head, tak- 

 ing a path around the edge of the chrysalid and finally eating all the 

 remaining parts of the chrysalid, it taking five hours to complete the 

 repast. 



The next day the carnivorous Heliothis dispaccus larva descended 

 from the top of the cage and entered the ground, forming a cocoon one 



