25 



of the same class. Just so, the presence of aphids and mealy 

 bugs, which are both largely overproductive, on cotton here, 

 attracts a large number of their natural enemies, many of 

 which were introduced especially to check the ravages of these 

 injurious forms. Among the beneficial species found in the 

 cotton fields may be mentioned the well-known ladybirds or 

 Coccinellid beetles. These differ slightly in their choice of 

 food. Cryptolaemvs montrouzieri and Rliizobius ventralis are 

 known to feed on mealy-bugs ; the following feed on aphids : 

 Coccinella repanda, Platyomus Jividigaster, Scymnns noiescens, 

 Coccinella abdominalis and Scymnus vividus. Orcus chalybeus 

 feeds on the armored scale insects and Cliilocorus circumdaius 

 is a general scale insect feeder. 



The larvae of Syrphid flies also 

 feed on aphids and a familiar one 

 about cotton is the larva of Xan- 

 thogramma grandicornis Macq. *A 

 much similar, though smaller, 

 larva feeding on the cotton aphid 

 is that of the Agromyzid fly, Leu- 

 copis sp. Four predaceous Hemip- 

 tera, Zelus renardU, Hyalopeplus 

 pelluciduS; T r i p h I e p s 

 persequens (probably feeding on 

 thrips) and BlwpaJus liyalinus, 

 have also been found on cotton 

 feeding on aphids. These 

 have actually been taken in the 



7 



I 



iwii 



four Fig. 17 — CryptolcEmus montrouzieri , a 

 predaceous species; 1, larva; 2, 

 adult beetle. Nat. size indicated 

 COttOll field; there are doubtless byline (Copied from Kirk.) 



many more species that feed in a 

 similar way on aphids. 



GENERAL CONSIDERATIONS. 



The present report must be considered as preliminary only. 

 The period of observation has been far too short to speak with 

 much precision about the relative importance of the insects 



