86 



A MANUAL OF DANGEROUS INSECTS. 



COTTON. 



{Gossypium spp. Malvaceae. ^ 



Many species of fiber yielding cotton are cultivated in various parts of the world, 

 and the fiber is a very important article of world commerce. The great impetus given 

 to seed selection in recent years has also caused considerable commerce in the various 

 varieties of seed for planting. Practically the only serious possibility of importing 

 cotton insects is connected with the seed and with lint when not thoroughly cleaned 

 of seed. There is also some danger of injurious insects finding refuge behind the 

 bagging of the bales. Owing to these dangers the Federal Horticultural Board has 

 forbidden the importation of cotton seed except through the Department of Agricul- 

 ture, and has placed restrictions on the importation of foreign baled cotton. 



The cotton plant is one of the most severely attacked cultivated plants, having a 

 very long list of injurious insects. Although the majority 

 of these insects are not liable to introduction, there is 

 always a possibility that they may find entrance into the 

 country in the folds of the bagging of bales or on some 

 food plant. 



A. BETTER KNOWX COTTON INSECTS LIKELY TO BE 

 IMPORTED. 



Eriophyes gossypii Banks. 

 (Cotton Blister Mite. Erioph^-id^e; Acarina., 



Host: Cotton. 



Injury: Injures the foliage, causing death to plants 

 when very numerous. May be distributed on lint or 

 seed. 



Description and biology: A tiny four-legged mite which forms blisters on the leaves 

 of cotton when very young, developing therein. This is a very serious pest. 



Distribution: West Indies. 

 Smith, Longfield. Rept. Agric. Exp. Sta. St. Croix for 1912-13, Copenhagen, 1914, 

 pp. 56-58. 



Dysde^cus spp. 



(Cotton stainers. Pyrrhocoridfe ; Hemiptera.; 



Important species: This genus contains the following species, which are ^'ery injuri- 

 ous to cotton 1 ecause of their ha its of sucking the juices and staining the fi" er: 

 D. andrex Linnaeus, West Indies. D. annuliger Uhler, West Indies. D. cardinalis 

 Gerstilcker, of East Africa. D. cingulatus Fabricius, India, Ceylon, Burma, Malay 

 Peninsula, Australia, and Egypt (see text, fig. 46). D. delauneyi Lethierry, Egypt, 

 India, and the West Indies. D.fasdatus Signoret, Africa. D.fernaldi Ballou, West 

 Indies. D. howardi Ballou, West Indies. D. insularis, Fiji. D. nigrofasdatus Stal, 

 West Africa. D. pacificus, Fiji. D. ruficollis Linnaeus, Brazil, Peru, and Mexico. 

 D. sanguinarius, Cuba. D. sidx Montrousier, New South Wales. D. supcrstitiosus 

 Fabricius, Africa. >j<Z). suturellus H. S., North America, West Indies. 



Hosts: Cotton, okra, eggplant, and various other plants. 



Injury: Serious. 



Description and biology: Adult active sucking i ugs, usually reddish or yellowish in 

 color. The developmental stages are gradual, each nymphal molt showing a Uttle 

 more of the wings. The eggs are small, oval, yellowish, laid in clusters on the ground. 

 The insect in all stages lives by sucking the juices of the cotton plant, especially the 



Fig. 46.— Cotton stainer (Dys- 

 dercus cingulatus): Adult. 

 (Maxwell-Lefroy.) 



