THE EED SPIDER OX COTTON. 



15 



Arthiocnodax sp.^ (fig. 10). — During the season of 1912 a species 

 of Ai-tlirocnodax, a fly belonging to the family Itonida? (formerly 

 <QeGidomyiid8e), was first noticed toward the last of June, at which 

 time it Avas not at all common. It increased very rapidly, how- 

 ever, and by the end of July had become quite abundant. It is the 

 larva (grub stage) of this insect which assists the farmer, and the 

 attack seems to be limited entirely to the red-spider eggs. Coming in 

 contact with an Qgg^ the larva instantly thrusts its piercing organ 

 through the shell and begins to feed. Large larva? will devour an 

 egg in from one to two minutes, while the smaller larva' require 

 more time, according to their size. AMien mature, the larva spins 

 a woolly cocoon 1 mm. 

 in length. The adult 

 fly issues after a brief 

 pupal stage, and the 

 full generation requires 

 little time. This insect 

 is probably the most ef- 

 fective enemy of the cot- 

 ton mite, and to its final 

 superabundance is prob- 

 ably largely due the 

 late summer decimation 

 of the red spider. It 

 has been recorded from 

 the following localities: 

 Allendale, Anderson, 

 Batesburg. Brownsville, 

 and St. Matthews, S. C. ; 

 Chase City, Va. ; Macon, 

 Ga.; and Albertville and Boaz, Ala. It evidently has a wide distri- 

 bution. 



Triphleps insidiosus Say (fig. 11). — A small anthocorid bug, 

 Triphleps inskliosus Say, was seen as early as May IG. It is hardier 

 than the Arthrocnodax and appears earlier in the season. Through- 

 out July and August it is extremely common and both in the 

 nymphal and adult stages is second only to the itonid as a red 

 spider enemy. Coming upon a red spider, like a flash the adult 

 thrusts its sharp proboscis through the pest's back and proceeds 

 quietly to siphon out the body contents. The first victim observed 

 was " drained " in about five minutes, but each succeeding meal ■was 

 of shorter duration as the appetite became satisfied. The actions 

 of the nymph (fig. 12) are similar, but the individuals observed 

 were seen only to destroy eggs of the spider. In this operation 



Fig. 11. — Triphleps inskliosus, an important enemy of 

 the red spider : Adult. Much enlarged. (Author's 

 illustration. I 



1 The determination is by Dr. E. P. Felt. 



