THE RED SPIDEE ON COTTON. 



57 



There is a larval period of 24 days, requiring 4 instars of 7, 3, 4, 

 and 10 days, respectively, and a pupal period of 6 days, altogether 

 embracing an interval of 30 days from hatching to the issuance of the 

 adult. 



Table XXV. — Feeding capacity of Megilla maculata for red-spider adults, Batesburg, 

 S. C. (Eggs hatched Sept. 11, 1914.) 



1st dav 



Mites. 

 7 



2d day 





3d day 



9 



4th dav 



17 





22 



6th day 



25 





31 



8th day 



4S 



9th day 



63 



10th dav (molted) 



75 



MHes. 



11th day 80 



12th day 100 



13th day 96 



1-lth day (molted) 76 



15th day 83 



16th day 97 



17thday Ill 



ISthday 135 



IQthdav 156 



Mites. 



20th day 218 



21st day 206 



22dday 224 



23d day 12.5 



24th day (pupated). 



T otal consumption ... 2, 01 1 

 Average daily con- 

 sumption 87. 4 



From Table XXV it may be seen that 1 individual in 23 feeding 

 days ate 2,011 adult mites, thus averaging 87.4 mites per day^ There 

 are probably 3 or 4 generations of this coccinellid in a season in the 

 Southeast. 



Fig. 18. — The convergent lady-beetle {Hippodnmia cnnvergens), an enemy of the red spider: a, Adult; h, 

 pupa; c, larva. Much enlarged. (Chittenden.) 



Hippodamia convergens Guerin. — This species (fig. 18) is perhaps 

 the commonest of the ladj^birds in the Southeast. We have seen it 

 on a few occasions busily engaged in consuming the members of mite 

 colonies. We have conducted no special tests with this beetle, either 

 for life history or control efficiency, since we do not consider that it 

 normally spends much of its time in the quest of red spiders. A new- 

 bom larva of this species on one occasion ate 27 adult mites in 24 hours. 

 As compared with Miss Palmer's (1914) life-history records for this 

 species, we obtained 3 days in 2 cases for the egg period and 7 and 

 8 days in 2 cases for the pupal stage, as against 3 days and 4 or 5 days, 

 respectively, for her experiment.^. The fact that the summer adults 

 of the larger lady-beetles live from 2 to 4 months (as established by 

 Miss Palmer, 1914) makes each individual potentially of much greater 

 economic importance. Tliis species deposits about 400 eggs. 



Oocdnella novemnotata Herbst. — Next to th(^ prcMunling species th(> 



