COTTON 41$ 



PERFECT STAGE. 



The moth (Plate I, figs. 1-16) has the head, thorax,. 

 and fore wings, bright pea-green, chrome-yellow, or 

 brownish, the latter crossed by three more or less. 

 distinct dark lines, each angled acutely above the middle. 

 The hind wings are semi-transparent white, with 

 pale fuscous margins and apex. The abdomen above is 

 silvery-grey, and the under surface white. The fore- 

 wings frequently have patches of purplish or brown near, 

 the middle. During summer and early autumn the green, 

 forms are in greater numbers, and in the latter part of 

 the year these are comparatively rare, being replaced by 

 the yellow and brownish forms. The patched form seems 

 to occur at the transitory period between the green and 

 yellow forms. This suggests that a seasonal dimorphism 

 exists, which is usually an indication that a protective 

 colouring is necessary for the insect's preservation. In. 

 this case the green insects would be inconspicuous when 

 settled on the green foliage, and the brown and yellow 

 similarly so when upon withered leaves, etc. 



The various forms are described and figured by Mr. 

 Storey, Assistant Entomologist to the Ministry of 

 Agriculture, in vol. iii, part ii, of the Agricultural 

 Journal of Egypt. This illustration is reproduced as. 

 Plate I with this paper. 



The perfect insect measures about 22 mm. in expanse, 

 and the body is about 9 mm. in length. 



It is curious to note that it has been frequently found 

 m desert places far removed from cultivation. Mr. 

 Willcocks mentions that Mr. Graves, of Cairo, found 

 specimens near Moses' Well (opposite Suez) and in Wadi 

 Hof, Helwan, about four miles from cultivation. The 

 species is common in Kharga Oasis in the Western desert, 

 having probably been introduced with cotton or bamiah. 



Habits. With regard to these, Mr. Willcocks says : 

 " During the daytime the moths frequently shelter 

 between the involucre and the boll, and they may often 

 be found at rest on a leaf exposed to the full glare of: 

 the sun. 



