THE RED SPIDER ON COTTOlsr. 



45 



Table XIV. — Larval period of Chrysopa rufilahris. {Individual No. 1.) 



Hatched, Aug. 3 



Pupated ■. Aug. 22. 



Length of h\rval period 18 days. 



No. 4 of Table XVI was the only larva which was reared through 

 from egg to pupa, and, as will be seen, the entire mite consumption 

 for the individual was also secured. The larval period is 18 days, 

 which is a trifle shorter than Davidson secured from his data based 

 on 2 individuals. No attempt was made to determine the duration 

 of the larval instars, but incidentally the length of the first instar was 

 estabhshed as about 4 days. Table XV presents statistics on the 

 pupal stage of CTirysojM rufi-labris. 



Table XV. — Records of the pupal period of Chrysopa rufilahris, Batesburg, S. C. 



Indi- 

 vidual 

 No. 



Pupated. 



Issued. 



Pupal 

 period. 



Average 

 pupal 

 period. 



Indi- 

 vidual 

 No. 



Pupated. 



Issued. 



Pupal 

 period. 



Average 

 pupal 

 period. 



1 

 2 

 3 

 4 

 5 

 6 

 7 



June 9 



...do 



July 8 

 July 10 

 July 22 

 July 23 

 July 24 



June 17 



-..do 



July 15 

 July 17 

 Aug. 2 

 Aug. 1 

 ...do 



Days. 

 8 

 8 

 7 

 7 

 11 

 9 

 8 



Days. 

 8.6 



8 

 9 

 10 

 11 

 12 

 13 

 14 



July 26 

 Aug. 3 

 Aug. 14 

 Aug. 18 

 Aug. 25 

 Sept. 3 

 Sept. 9 



Aug. 4 

 Aug. 15 

 Aug. 21 

 Aug. 25 

 Sept. 2 

 Sept. 16 



Days. 

 9 

 12 



7 

 7 

 8 

 13 

 7 



Days. 

 8.6 



From these 14 pupal records it is seen that the duration of the 

 transformation period at Batesburg varies from 7 to 13 days, with 

 8.6 days as the weighted average. Thus, exclusive of a possible 

 preoviposition interval, we find that the cycle of the chrysopid from 

 the deposition of the egg to the issuance of the adult is about 30 days, 

 approximating 4 days for the egg stage, 18 days for the larva, and 8.6 

 days for the pupal stage. In the Southeast there are probably four 

 generations of lacewing flies in a season. 



Table XVI. — Rate of destruction of red spiders by the larva of Chrysopa rufilahris. 



Larva 

 No. 



Hatched. 











Red spiders consumed. 









1st 

 day. 



2d 

 day. 



3d 

 day. 



4th 

 day. 



Sth 

 day. 



6th 

 day. 



7th 

 day. 



Sth 

 day. 



9th 

 day. 



10th 

 day. 



11th, 

 day. 



12th 

 day. 



1 



• 

 1914. 

 July 17 



■ 



18 

 31 

 26 

 9 

 24 

 19 

 21 



% 



16 



28 

 37 

 29 

 27 























2 



July 18 



33 

 43 

 14 

 35 

 35 

 20 



34 

 30 

 29 



(>) 

 39 

 18 



48 

 51 

 30 



23 

 40 

 37 



"'84' 

 26 



n 











3 



do 





48 







4 



Aug. 3 



41 



39 



59 



63 



5 



Aug. 8 





6 



July 15 



39 

 33 



17 

 26 



39 

 21 



(2) 

 15 











7 



Julvie. 



"'47' 



(2) 

 62 

 56 







8 



July 19< 



58 

 59 



66 



9 



(U>.^ 















69 



10 



Aug. 22 '' 





















11 



Aug. 18» i 

























12 



Aug. 14' . 

























13 



Aug. 20'' 1 



















































1 Deafl. 



» Lfwt. 



'Entangled. 



< Collected a.s half-grown larva. 



'' Collected as two-thirds-grown larva. 

 Collcoted as mature larva 

 ' (.'oUected as largo larva. 



