THE TOBACCO BEETLE. 27 



In the laboratory at Clarksville, Tenn., beetles were kept under 

 observation continuously by Mr. S. E. Crumb during 1910-11. 

 The rearing material was kept in a room heated only during the 

 day during winter. Larva? which constructed pupal cells in No- 

 vember, 1910, became adults May 18, 1911. These beetles deposited 

 eggs about May 31, from which adults were obtained about July 29. 

 These beetles deposited eggs August 13, from which adults were 

 obtained on September 28. Eggs were obtained from these adults 

 October 5. Larvae from this lot of eggs constructed cells in which 

 they passed the winter of 1911-12. This gives for the locality three 

 distinct generations, emerging in the adult stage in May, July, and 

 September. In localities farther south from three to six generations 

 may occur, since under laboratory conditions at normal summer tem- 

 peratures the entire life cycle was found to average 60 days. 



At Richmond, Va., it was determined that three generations may 

 occur under warehouse conditions. On October 14, 1913, eggs were 

 placed in tobacco, and larva? were found in cells in a dormant con- 

 dition during December, which transformed the following spring. 

 Adults collected from the lot May 5, 1914, deposited eggs on May 

 6-7. Adults reared from these eggs were obtained July 22, and 

 eggs were laid about July 25. From these eggs adults were again 

 obtained about October 2. Eggs deposited by beetles from this 

 lot hatched October 18, the larvae becoming dormant during the 

 latter part of November. This shows that for this locality there 

 are three complete life cycles, the adults appearing in May, July, 

 and October, and that from the adults which emerge earliest there 

 is a possibility of a fourth generation reaching the adult stage 

 before winter. 



In the Middle and Northern States, in warehouses and tobacco 

 factories, a sudden appearance of large numbers of adults in spring 

 or early summer is frequently observed. The greater number of 

 larvae which survive the winter complete their transformation and 

 emerge in the adult stage with the advent of warm weather. 



INSECTS LIKELY TO BE MISTAKEN FOR THE TOBACCO BEETLE. 



Belief still prevails in many sections that the tobacco beetle is found 

 on growing tobacco and that it continues to feed upon the tobacco 

 after it has been cured. This impression is due perhaps to its slight 

 resemblance to a smaller and very common insect, the tobacco flea- 

 beetle (Epitrix parvula Fabricius) (fig. 8), which is abundant on 

 growing tobacco in the field and in tobacco plant beds. Contrary to 

 this belief the tobacco beetle {Lasioderma serricorne) does not attack 

 growing tobacco and is not present in tobacco fields. It is not a field 

 insect, but feeds and lives in dried substances, its more common food 

 being cured tobacco. The habit of the tobacco flea-beetle of hopping 

 when disturbed, its occurrence on growing tobacco, its smaller size, 



