44 



BULLETIjST 416^ U. S. DEPAETMENT OF AGEICULTUEE. 



NEUROPTERA. 



Chrysopidae. 



Four species of lacewing flies have been collected during the in-' 

 vestigation at Batesburg. Lacewing flies are frequently seen on 

 cotton leaves associated with common red spiders. Only. one species, 

 Glirysopa rujilabris Banks, is very abundant in South Carolina. 



Gfcryso-pa rujilabris Banks. — This species appears in late spring or 

 early summer, the earliest record being May 6, 1914, on which date 

 eggs and larvae were seen. Together with the thrips, this chrysopid 

 appears to be the earhest red-spider enemy. When an early season 

 prevails, this predator becomes abundant about the middle of June, 

 but, as a rule, this does not take place until July. It is not as hardy as 

 are some of the more coriaceous enemies of the red spider, and seeks 

 winter quarters comparatively early in the season. In fact, the 

 species reaches its optimum development during August, and is rarely 

 seen in any stage later than September 25. This red-spider enemy 

 is recorded from Emporia, Va.; Wilmington, Greensboro, Charlotte, 

 Buies, and Laurinburg, N. C; Spartanburg, St. Matthews, Lees- 

 ville, Batesburg, and numerous points in South Carolina; Savannah, 

 Ga. ; Tallahassee, Fla. ; Girard, Ala. ; and Dallas, Tex. . 



At certain times during the season CJirysojm rujilabris has been 

 seen to exert marked control of the red spider, and its value as an 

 enemy of the cotton red spider can hardly be overestimated. Dur- 

 ing June, 1914, from the 10th to the 22d, lacewing-fly larvae were 

 abundant, crawling in myriads on tree trunks, the ground, the 

 ceilings of porches, and similar positions. At these times man 

 experiences much annoyance from the mandibles of larvae which 

 drop from piazza ceilings. 



Tables XIII, XIV, and XV present data on the life history of 

 Ohrysopa rujilabris. 



Table XIII. — Egg period of Chrysopa rujilabris, Batesburg, S. C. 



Indi- 

 vidual 

 No. 



Egg col- 

 leeted. 



Hatched.i 



Incuba> 



tlon 

 period. 



1 

 2 

 3 



4 

 5 

 6 



June 8 

 July 15 

 Jul> 15 

 Aug. 3 

 Aug. 3 

 Aug. 9 



June 11 



July 18 

 July IS 

 Aug. 8 

 Aug. 8 

 Aug. 13 



Days. 

 3 

 3 

 .3 

 5 

 5 

 4 



Avera 



?e 



4 



3 These 6 rearings are the longest of a large series and probably represent about the normal period for this 

 stage. 



