16 



THE RED SPIDER ON COTTON. 



the proboscis was not inserted far into the ovum, and two minutes 

 sufficed for draining an egg. 



A species of lace-winged fly {Chrysopa quadri punctata Burm., 

 determined by N. Banks) is abundant at Batesburg throughout most 

 of the summer, and its larva is doubtless very active in reducing the 

 pest. 



Two species of thrips, Euthrlps fusciis Hinds and E. ocehlentaVts 

 Pergande, have been determined this season from cotton. They are 

 commonly found throughout the season about red-spider colonies, 



and may be instrumental in 

 spider destruction. Scolo- 

 t /trips sexmaeulatus Pergande 

 has been recorded as an enemy 

 of the red spider by Pergande 

 and by Duffy. 



Lady-beetle larvae and adults 

 of several species are com- 

 monly seen on infested leaves. 

 These are usually either Coc- 

 ciiiella 9-notata Hbst. or Hip- 

 podamAa convergens Guer., 

 but a small black species, 

 {Scymnus) Stetliorm punctum 

 Lee, is frequentl}' observed. 

 The larger beetles are prob- 

 ably more intent upon cotton 

 aphides^ but the last-mentioned 

 species, although later in ap- 

 pearing and not overnumerous. seems to be more restricted to the 

 the cotton mite than are other species. 



Fig. 12. — Trii>hU:pii hisiiliofitin: Nymph. Greatly 

 enlarged. (Author's illustration.) 



REMEDIAL MEASURES. 



PREVENTION. 



From the abundant experience of the past two years the writer 

 has been forced to the conclusion that the eradication of the red 

 spider must be accomplished through preventive efforts rather than 

 repressive, if it is to be economically effected. The location of the 

 mites through the winter and spring, their preference for the culti- 

 vated violet and the pokeweed, and the manner of dispersion of the 

 pest lead to the presentation of the following cultural expedients. 



Clean culture. — First among preventive measures against the red 

 spider is doubtless that of exterminating the weeds and plants which 

 breed the pest. Pokeweed, Jerusalem-oak weed, Jamestown weed, 

 wild blackberry, and all border weeds and underbrush about fields 

 should be burned or grubbed out during the winter or early spring. 



