287 



Notes on Life History of Attagenus Plebius Sharp. 



BY .1. K. ILIAXGWOi; Til. 



The very destructive habits of this Hawaiian household 

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

 opened up two trunks, \vhi(di had beeu stored for souie time. 

 Everything- of animal origin was riddled. Since I am nnalde 

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

 I have uiade a rather careful study of them. 



DTSTRIBUTIOX. 



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

 outside of the Hawaiian Islands. Sharp- named the species 

 from specimens secured here, and reuiarks that they are found 

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

 our islands, for we have specimens from Maui, and ]\[r. D. B. 

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



T.IFE HISTORY. 



After securing newly emerged beetles they were confined 

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

 and newlydiatched larvae were discovered upon the woolen 

 (doth which had been sui)]ilied 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 kiud of food, 

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

 periods of two 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 climate. Chittenden found 

 that two years Avere required for the development of the closely- 



* Trans. Royal Dublin Soc. Vol. III. Ser. II. 188.'>, p. 147. 

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



