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confined in jars, containing about an inch of dry soil and a little 

 bran. All these stages, except the eggs, were kept in a cement cave, 

 where the temperature more nearly approximated to subterranean 

 conditions, varying from 70° to 80° F. in summer, to 40° F. in March. 

 The results obtained in this way closely coincided with the field 

 observations made throughout the year. 



The freshly laid eggs are white in colour, but when deposited are 

 coated with a sticky solution which causes a thin layer of soil to 

 adhere to them, making them difficult to find in the field. They 

 are laid preferably in the driest soil, and singly, although several may 

 be placed in the same cavity, which is then filled up with soil. The 

 length of the egg stage varies with the season of the year, but is on 

 an average 14 days, eggs being deposited from the middle of July 

 till the middle of October, 8 being the average number deposited by 

 each emale. 



The larva on hatching is creamy white in colour, but after the first 

 moult it changes to black, which colour it retains during the rest 

 of the larval stage. During the summer and autumn the larvae are 

 found from 1 to 6 inches or more below the surface of the ground, 

 burrowing from place to place, and feeding on the roots and seeds 

 of plants, and probably, to some extent, on decaying organic matter. 

 In confinement, they often feed on their cast-ofi skins and on larvae 

 that have died or are in a weakened condition. The average length 

 of the larval stage is 9| to 10| months, and before pupation the larvae 

 enter a semi-pupal stage which lasts from 5 to 10 days, during which 

 they do not feed and are very inactive. 



The average length of the pupal stage is from 17 to 19 days, maxi- 

 mum pupation occurring at the beginning of June. Under both 

 field and experiment conditions adults emerge from the middle of 

 June till the middle of July, the maximum emergence occurring 

 about June 24. E. tricostata may hibernate as an adult as well as 

 in the larval stage, but eggs have never been obtained from these 

 overwintering beetles. Both in the field and in the rearing cages, 

 feeding, mating and oviposition take place generally at night. During 

 the day-time the beetles are found under rocks, boards, logs and manure, 

 where they are rather inactive, but able to run with great rapidity 

 when the cover is removed. In the field, adults have been found 

 feeding on Solidago, Eu])horbia marginata, prairie clover and evening 

 primrose. The length of life of the adults is rather more than a 

 year, females usually living longer than males. 



The members of this genus are not attacked by many predaceous 

 enemies, probably owing to the fact that the adults of most of the 

 species secrete an oily liquid having a strong offensive odour, when 

 disturbed. Skunks however feed on the beetles, and chickens and 

 crows devour them readily. They ha.ve also been found in the stom- 

 achs of the crow, blackbird and red-headed woodpecker. 



Very few parasites have been found attacking any species of Eleodes ; 

 but a Braconid parasite, Perilitus sp. , has been recorded from E. sutur- 

 alis, a Nematode worm from an undetermined adult and a Gregarine, 

 Stylocephalus giganteus, from E. hispilabris, Say, and Eleodes sp. The 

 author has recently found this same Gregarine in the alimentary 

 tract of E. tricostata and E. ojpaca. A species of Sarcophaga has 

 also been reported larvipositing on E. tricostata, E. hisjnlabris, and 



