THE RED SPIDER ON COTTON. 37 
INSECTA, THYSANOPTERA. 
THRIPIDAE. 
Scolothrips sermaculatus 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- 
SASSY, 
Fic. 9.—A nystis agilis, an enemy of the red 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, 5. C.; and 
Mount Pleasant, Miss. Yothers 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 thrips for the various stages of the red spider, and 
data (Table VII) were secured from six specimens. These 6 thrips 
(all nymphs) consumed 232 eggs and 5 nymphs and adults in 10 feeding 
days, which gives an average consumption of 23.7 eggs and active 
individuals per feeding day, 98 per cent of which were eggs. It is 
