THE EED SPIDER ON COTTON. 37 



INSECTA, THYSANOPTERA. 



Thripidae. 



Scolothri'ps sexmaculatus Perg. — This species of thrips, as pre- 

 viously recorded, was mentioned by Duffey (1891) as being predacious 

 on the red spider at St. Louis. Chittenden (1909) observed this 

 thrips to be predatory on mites on the Kentucky coffee tree at 

 Washington in 1906. Quayle (1913) states that he has repeatedly 

 observed it to feed on the citrus mite, usually attacking the egg and 

 younger spiders, and occasionally eating the adult mites. At Bates- 

 burg this thrips has been under observation during four seasons. It ap- 

 pears to be about the earliest predacious enemy of the red spider, having 

 been seen on March 11, 1914, as the nymph. It becomes common 

 in May and very abundant throughout June, July, August, and Sep- 



FiG. 9. — Anystin agilix, an enemy of the rod spider. Highly magnified. (Ewing.) 



tember, and has been seen as late as December 10. Upon several 

 occasions it has been seen to attack mites in the field. The 6-spotted 

 thrips has been observed feeding upon red spiders at the following 

 localities: Emporia, Va.; Raleigh, Charlotte, and Laurinburg, N. C; 

 Clemson College, Columbia, Leesville, and Batesburg, S. C; and 

 Mount Pleasant, Miss. Yothcrs reports it actively predacious in 

 mite colonies on velvet bean, at Orlando, Fla. 



A few tests were conducted for the purpose of ascertaining the 

 capacity of this thnj)H for the various stages of the red spider, and 

 data (Table VII) were secured from six specimens. These 6 thrips 

 fall nym[)hs) consumed 232 eggs and 5 nymphs and adults in 10 feeding 

 days, whifh giv(!S an average (•()nsnrn[)tion of 23.7 eggs and active 

 individuals per feeding day, OS per <-('iit of which w(;r(; eggs. It is 



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