484 



THE MONTHLY BULLETIN. 



them almost cosmopolitan distribution. In all probability it is the same 

 with the insect considered in this paper, as it was reported from Europe 

 as early as 1882.^ A popular description only will be attempted in this 

 article, as the life history and habits are not very well known. 



LIFE HISTORY. 



The Egg. Where the egg is deposited is a matter of conjecture. From 

 the character of the ovipositor the egg is supposedly inserted in the tis- 

 sues at the base of the bulb, and the larvfe upon hatching bore their way 



Fig. 112. — Tlie larva of Isoso)nu 

 orchideariDH. (Original.) 



into the center of the bulb and proceed to devour the entire heart. 

 Each infested bud may contain from one to seven larvae. As a con- 

 sequence the young bud assumes a state of increased activity and infes- 

 tation is soon apparent by the abnormal distorted appearance of the 

 new growth (Fig. 111). 



The Larva. The larvae (Fig. 112) are white crescent-shaped insects 

 and are distinctly segmented; head apparent only upon close examina- 

 tion. Length about 6 mm. and width through the widest segment 

 about 1.25 mm. 



Fig. 113. — Pupa of Isosuina 

 dearum. (OriRinal. ) 



orchi- 



The Pupa. The pup^e (Fig. 118) encased in the last larval skin are 

 white when first formed and slowly turn to black. All appendages 

 visible through the entire pupal period. 



=Westwood, Tr. Ent. Soo. Lond. 1S82, page 323. 



