45 2 Phylum Arthropoda 



the time for transforming has arrived, they rapidly burrow down and 

 form their pupal cells. Some, however, pupate on the surface of the ter- 

 rarium, evidently not liking the conditions below. Slightly moist earth 

 seems to be the most natural substance for the terrarium and an inch 

 or so of depth will suffice. If not too deep, they will often make their 

 cell next to the glass container, where it is favorably placed for observa- 

 tion. 



The adult is chiefly herbivorous. It feeds mostly on the lower forms, 

 such as algae, but does not seem to be restricted to this diet. Decaying 

 vegetation is its favorite food. It feeds also on dead animal tissue 

 (earthworms, insect larvae, etc.). 



The principal egg laying months are May and August, although the 

 egg cases of some species may be found during the entire summer. 



The larvae are carnivorous and cannibalistic, the different genera 

 varying in their greed. The young larvae feed upon small organisms 

 (entomostracans, Tubifex, leeches, etc.) and they capture larger prey 

 as they themselves increase in size. Helophorus was observed feeding 

 on Simocephalus, Cypris, Cyridopsis, Cyclops, and Canthocampus. The 

 full grown larva feeds readily on tadpoles, annelids, fish, and, in fact, 

 almost anything that it can overcome or that is fed to it. 



M. E. D. 



Reference 

 For rearing Hydrophilidae see also p. 453. 



Family silphidae 



J 



SILPHA INAEQUALIS* 



A FEW live specimens of Silpha inaequalis were secured from the car- 

 cass of a cat and placed in wide-mouthed tobacco jars containing 

 several inches of fresh, moist soil, a few dry leaves beneath which they 

 might hide, a shallow vessel of water, and a small piece of beef. The 

 jars were then covered with a tin cover, the center of which had been cut 

 away and a piece of cheesecloth glued over the opening so as to admit 

 plenty of air. 



Freshly killed flies were often thrown into the jar and were eaten by 

 the beetles in preference to the stale meat. They sometimes dug them- 

 selves into the soil but remained on top most of the time, often hiding 

 under the leaves. They were frequently found drinking. Close watch 

 was kept for eggs and the first were found in the soil late in July. These 

 Silphas, without exception, deposited their eggs in the soil. 



♦Abstracted from an article in Ent. News 30:253, 1919, by Milton T. Goe, Portland, 

 Oregon. 



