4 BULLETIN 422^ U. S. DEPAETjV]:ENT OF AGEICULTUKE. ' ' 



Table I. — Mean maximum and minimum temperatures at Baton Rouge, La., during 

 June, July, and August, 1915, when li^e-Mstory studies on eggplant tortoise beetle ivere 

 conducted. w,li l l M. ./.;.: 



Period. 



June . . . 

 July..., 

 August . 



U. S. Weather 

 Bureau, mean 

 teinperatures.i 



Max. 



'F. 

 91.5 

 92.5 

 91.3 



Min. 



'F. 



. 72.3 

 71.9 

 70.0 



Insectary, mean 

 temperatmes. 



Max. 



'F. 

 94.9 

 95.4 

 92.1 



Min. 



"F. 

 73.9 



74.8 

 74.0 



Excess of mean in- 

 sectary tempera- 

 tmes over those 

 of U. S. Weather 

 Bureau. 



Max. 



3.4 

 2.9 



Min. 



1.6 

 2.9 

 4.0 



I Climatological data, Louisiana section, for months of June, July, and August, 1915, by Isaac M. Cline, 

 pp. 46, 54, 62, New Orleans, La., 1915. 



LENGTH OP LARVAL PERIOD. 



The length of the larval period has been found to vary greatly in 

 the insectary. Forty-three larvae that were kept under observation 

 during June and July required from 12 to 20 days to develop, 17 days 

 being the average. No satisfactory reason for this wide difference 

 can be suggested. Larvae that issued on the same day and which 

 were apparently kept uiider similar conditions pupated, in some 

 cases, six days apart. On eggplant grown under cages out of doors 

 the larval period was completed in 12 days during June. 



The larvge are sluggish and occur on both sides of the leaves, in 

 which they eat more or less circular holes. When the larvae are 

 young these holes are small in size, but with the growth of the indi- 

 vidual there is an increase in the quantity of tissue removed. 



LENGTH OF PUPAL STAGE. 



The pupal period occupied from two to seven days in the insectary 

 during June and July, though most of the individuals remained in 

 the pupal stage from four to five days. 



LIFE AND HABITS OF ADULTS. 



The adults, even during the summer, live for a period of several 

 weeks. In the insectary one individual, a female, was kept alive 

 from May 22 to October 9, two months after it had ceased to lay eggs, 

 and others have Hved for two or three months. The winter months 

 are undoubtedly passed in the adult stage. 



The injury done to the leaves of eggplant (fig. 3) by the adults is 

 of the same character as that due to the larvae, the feeding of the 

 beetles producing holes which are somewhat circular in outline. 



NUMBER OF EGGS DEPOSITED BY ONE FEMALE. 



On July 4, beetles that had issued in rearing cages in the insectary, 

 none of which had begun to oviposit, were placed together on egg- 

 plant leaves. The first eggs were noted on Julv 6, when the beetles 



