THE TOBACCO BEETLE. 7 



brown. When newly hatched from the eg^ the hirva is very minute, 

 being only about one-fiftieth of an inch in length, and is more active 

 than when more fully grown. 



The fvfa. — The pupa (fig. 4, &) is an inactive or quiescent stage 

 which the insect assumes before transforming to the adult, or beetle. 

 The i^upa period is passed normally within a closed cell composed 

 of small particles of the food substance and refuse cemented to- 

 gether with a secretion of the larva. The pupa is about one-seventh 

 of an inch in length. It is white when first transformed from the 

 larva stage, but before becoming adult it gradually assumes a brown- 

 ish tinge, the eyes becoming reddish or reddish brown. It lies on 

 its back in the pupal cell. Should the cell be broken open and the 



a- 



Fig. 4. — Tobacco beetle : a. Larva ; b, pupa ; c, adult ; d, side view of adult ; c, antenna. 

 a-a. Greatly enlarged ; c, still more enlarged. (Chittenden.) 



pupa removed, transformation is completed in an apparently normal 

 manner, providing the pupa is protected from rapid evaporation. 

 AVhen infested leaf tobacco is handled, many bare pupa3 may be 

 seen which have been dislodged from the fragile cells or cocoons 

 between the leaves of tobacco. 



The adult ^ or heetle. — The beetle (fig. 4, c-e) is the fully devel- 

 oped, or adult, stage of the insect. It is uniformly dull reddish 

 yellow or brownish red. The head is broad and the eyes are small. 

 The head is bent down nearly at right angles with the body, giving 

 the beetle, when viewed from the side, a characteristic humped ap- 

 pearance. The beetles vary greatly in size, the average length being 

 about one-tenth of an inch. The female beetles average somewhat 

 larger than the males. 



DISTRIBUTION AND DISSEMINATION. 



Commerce has served to distribute the tobacco beetle widel}', and 

 probably this insect occurs now in all countries having a temperate, 

 subtropical, or tropical climate. In warm tobacco-growing countries 

 such as Cuba and the Philippines, where the bettles are numerous and 

 breed continuously throughout the year, they are being sent out con- 

 stantly to other countries in shipments of cigars or in leaf tobacco. 

 The nature of their food and their habit of living and breeding con- 



