28'i 



Notes on Life History of Attagenus Plebius Sharp. 



BV J. F. ILLINGWORTII. 



The very destructive habits of this Hawaiian household 

 beetle first came to my attention several months ago, when I 

 opened up two trunks, which had been stored for some time. 

 Everything of animal origin was riddled. Since I am unable 

 to find any notes on the habits or life history of this species, 

 I have made a rather careful study of them. 



DISTEIBUTIOIV. 



So far as I can learn, these beetles have not been found 

 outside of the Hawaiian Islands. Sharp* named the species 

 from specimens secured here, and remarks that they are found 

 in houses in Honolulu. They are probably found on all of 

 our islands, for we have specimens from Maui, and Mr. D. B. 

 Kuhns tells me that they are a pest on the Island of Hawaii. 



LIFE HISTORY. 



After securing newly emerged beetles they were confined 

 in a covered glass dish for thirty-six days before the first eggs 

 and newly-hatched larvae were discovered upon the woolen 

 cloth which had been supplied them together with dried insects 

 for food. It was found that the larval period consists of seven 

 instars, and varies slightly, probably due to the kind of food, 

 etc. The pupal stage lasts from twelve to fourteen days. The 

 periods of tw^o of the individuals are given as typical of those 

 under observation : 



It is interesting to note the rapidity with wliich these in- 

 sects develop under our tropical climat(\ Chittenden found 

 that two years w^ere required for the deve]o]mieut of +he closely- 



* Trans. Royal Dublin Soc. Vol. III. Ser. II. i; 

 Proc. Haw. Ent. Soc. Ill, No. 4, May, 1917. 



p. 147. 



