BULLETIN 239, IT. S. DEPARTMENT OF AGRICULTURE. 



observation: On one occasion while observing the feeding of the 

 nymphs a ladybeetle {Hippodamia convergens Guer.) was seen to 

 approach the brood, when the adult lace-bug in attendance on the 

 nymphs, with outstretched, slightly raised wings, suddenly darted 

 toward the intruder, driving it from the leaf. 



From the time the nymphs are born until they reach the adult 

 form they pass through five distinct molting periods, and when tem- 

 perature and other conditions are normal the time between molts is 

 quite constant. From Table III it will be observed that two days 

 is the usual period between molts. 



Table III. — Molting stages of nymphs of the eggplant lace-bug, Norfolk, Va., 1914- 



No. 



Date 

 hatched. 



First 

 molt. 



Second 

 molt. 



Third 

 molt. 



Fourth 

 molt. 



Fifth 

 molt. 



Adult. 



1 





July 9 

 ...do 



July 11 



...do 



...do 



July 12 

 July 11 



...do 



...do 



...do 



...do 



July 13 



...do 



...do 



July 15 

 July 13 



...do 



...do 



...do 



...do 



July 15 



...do 



...do 



July 17 



July 15 



...do 



...do 



Dead. 



July 15 



July 17 



...do 



...do 



July 18 

 ...do 



Julv 17 



...do 



...do 

 ...do 





2 







3 





...do 





4 





July 10 

 July 9 

 ...do 





5 



July 7 



Adult. 



6 





7 





...do 





8 





...do.... 





9 





...do 













LIFE CYCLE AND NUMBER OF GENERATIONS. 



Since two days represents the duration of time between molts, the 

 life of the nymph from the egg to the last nymph, under normal 

 conditions, is 10 days. Allowing six days for the egg stage and sev- 

 eral days for time before and after copulation by adults, the life cycle 

 is approximately 20 days. 



In the vicinity of Norfolk, Va., this lace-bug was found breeding 

 as late as November, giving a breeding season of nearly six months. 

 There is a possibility of from seven to eight generations a season. 

 Apparently six generations are spent on eggplant and the remainder 

 on horse nettle. 



Most of the generations in the field overlap, and the following 

 observations made during the summer of 1914 indicate that six 

 generations are spent on eggplant. 



First generation, May 24. 

 Second generation, June 11. 

 Third generation, July 7. 



Fourth generation, July 26. 

 Fifth generation, August 15. 

 Sixth generation, September 4. 



In the region of Norfolk, Va., as stated before, the growing season 

 for eggplant ends about the last of August or the first week in Sep- 

 tember, after which the lace-bug is found on the horse nettle (Sola- 

 rium carolinense) , where it continues to feed. It undoubtedly pro- 

 duces several generations on this plant, for as late as November all 

 stages of the insect, including eggs, were found on it. 



