21G 



cotton while still underground, as soon as the cotyledons begin to 

 emerge. Thrips Jiav^is, Schr., was obseived everywhere on cotton, 

 in some cases as early as the 15th May, the hibernating imago having 

 been found on neighbouring lucerne fields in the first half of April. 

 When the cotton seedlings appeared, the insect passed to the cotton 

 fields, where they remained until early in September, when they returned 

 to lucerne. In addition to cotton this insect attacks other plants, 

 such as cucumbers, melons, marrows, etc., in summer. The number of 

 generations is probably considerable. Aphis gossypii was found on 

 marrows, melons and cotton. The practice, common in many parts 

 of Turkestan, of planting marrows and melons amongst the cotton 

 is therefore to be deprecated. Laborator}^ experiments show that 

 these Aphids can Avithstand as low a temperature as from 35° F.- 

 40° F. without injury, and that they do not produce sexual individuals 

 even late in the autumn. Soft soap (about one-third lb. in 3 gallons 

 of water) and common soap (| lb. in the same amount of water) gave 

 satisfactory results, and the cost of applying this remedy does not 

 exceed 7s. 6d. per acre under conditions in Turkestan. In addition 

 to cotton, Tetranydms telarius, L., feeds on various species of 

 Convolvulus, Heradeum (cow-parsnips), Cucurbitaceae and maize ; 

 as maize is frequently cultivated among the cotton plantations, 

 it thus assists the propagation of this mite. In the mountains, 

 T. telarius occurs up to the limit of Juniperus excelsa, on the needles 

 of which it was found in large numbers. The mites Avinter and pass 

 the spring and autumn on weeds, etc., along the boundaries of fields 

 and roads and thus the cotton plants adjoining these spots are the 

 first to be attacked. 



Amongst the minor or casual pests of cotton the following were 

 observed : — Pyrausta nuhilalis, Hb., which occasionally injures cotton 

 in the same way as it does maize ; Plafyedra {Gelechia) vilella, Zell., 

 the larvae of which live on the leaves in their early stages, subsequently 

 boring into the stems ; the early stages of this species are described 

 for the first time : Polia snasa, SchifE. {Mamestra dissimilis, Knoch), 

 not previously recorded on cotton, the caterpillars being also found 

 on lucerne, apples, etc. Single individuals of Chloridea obsoleta, F. 

 {Heliothis armigera, Hb.) were also found on cotton, but they largely 

 attacked other plants, especially tomato and Abutilon avicemme, a 

 common weed in Turkestan. These plants may therefore be used as 

 trap crops. Some of the caterpillars were parasitised by Habrobracon 

 plotnikovi, Kokujev. 



The other pests observed during the year under report were : — 

 Acranycta rumicis, L. var. turanica, Stand., Tortrix [Pandemis) chon- 

 drillana, HS., Acridium aegyptium, L., Crryllus desertus, Pall. var. 

 melas, Charp., the hibernated adults of which may occasionally attack 

 the cotyledons, Gryllotalpa unispino; Sauss., Aci/rthosypJion gossypii 

 gossypii, Mordv., A. vasillievi, Mordv., a species of Tychea not yet 

 identified attacking the roots, Adelphocoris lineolatus, Goeze, Lygus 

 ^yraiensis, Chhrita bipimctata, Agallia sinuat-a, DeJtocephalus sp., and 

 Agrmnyza flaveoh, Fall. 



