230 



fppdins habits in the field. On several occasions, however, larvae were 

 taken wliile feeding on snails, which they had evidently killed a short time 

 before being discovered. Numerous larvae were taken into the laboratory 

 where they were placed under as nearly normal conditions as possible for 

 the purpose of determining the nature of their food. On six different occa- 

 sions a slug (AgrioUmax campcstris Binney) was placed with six larvae of 

 PJioturis pcnnsylvanica and in every case it had been eaten before morning. 

 A slug (Af/riolimax agrestris L.) and a snail (Succinea avery Say) were 

 put with six larvae. The snail was eaten during the first night, but the 

 slug was not killed and eaten until the third night. On two different occa- 

 sions two small earthworms (Linnhricus terrcstris L. ) were placed in a jar 

 without earth, which contained eight larvae. One was killed and eaten the 

 second night, and the other on the fifth night. On two occasions a very 

 large specimen of Lnm'bricuH terrcstris was placed with twelve firefly larvae. 

 In each case the earthworm was not eaten, though it remained with the 

 firefly larvae for over a week, and they received no other food during that 

 time. On two occasions a cutworm larva of each of the following species : 

 (Para gratis mcssoria Harris, Paragrotis tcsseUatn Harris, and Peridroma 

 margaritosa Ha worth) were placed in jars with six larvae and in every 

 instance they were eaten the first night. Finally, on four different nights, 

 two second and two third stage squash-bug nymphs (Anasa tristis DeGeer) 

 were placed with six larvae, and in each instance they were eaten before 

 morning. Some of the hard-bodied Arthropods which normally live on the 

 ground, such as sowbugs (Oniscns asellus Paulmier), wireworm larvae 

 {Agriotes mancus Say), ants (Formica sp.) and coleopterous beetles in- 

 cluding the common ground beetles (Ncdria Pallipes Say and Chlaenius 

 pennsylvanicus Say) were placed with these larvae, but they were never 

 eaten. 



These experiments lead one to conclude that the firefly larvae probably 

 eat any soft bodied insect larva, Mollusk or Annelid, that they happen to 

 find in their nocturnal wanderings. Slugs, snails, cutworm-larvae, and 

 small earthworms are probably their chief foods. 



The larvae of many of the fireflies as well as certain other more or less 

 widely separated groups of insects digest their food entirely or partially 

 outside of their bodies. This is accomplished by the digestive juices being 

 exuded through the mouth and hollow mandibles upon the food which is 

 later eaten by the larva in a nearly completely digested condition. Such is 

 true of the larva of Photurus pennsylvanica. When this larva first pierces 

 its prey it immediately injects a substance by means of its mandibular 

 canals into its body, which seems to paralize it. 



As was said before, the larva of Photurus Pennsylvanica lives for nearly 

 two years before transforming to a pupa. During the cold winter months 

 from about November first to March fifteenth it lies concealed underneath 

 stones, logs or something similar. During the warm summer months it 

 wanders about at night in search of food, while during the day it remains 

 concealed. 



About the middle of May of the second year when the larva is approxi- 



