DAMAGE CAUSED BY ANIMALS. 209 



B. SPAN-WORMS (Geometridw). 



102. The Winter Moth or Winter Span-worm, Geometra 

 (Cheimatobia) brumata. 



The male moth has a span of about 1 to 1/2 inches, and its front 

 wings are of a reddish-grey or yellowish-grey colour, with dark 

 wavy lines ; the hind wings are lighter, and with indefinite, 

 indistinct stripes. The female is about 0'32 inches in length, and 

 of a greyish-brown colour with white scales, long feelers and legs, 

 and very reduced, or in reality only rudimentary, wings; it is 

 therefore incapable of flight. 



The 10-footed caterpillar, at first of a grey colour, but changing 

 after the first time of shedding the skin to a yellowish-green, with 

 a pale longitudinal stripe along the back, and a green head, later 

 on assumes a green colour with a dark mark along the back and 

 three light marks along each side ; when full-grown it attains a 

 length of T04 inches. 



The chrysalis is of a light brown colour, and has no protective 

 cocoon. 



The winter moth swarms from October till December, when 

 the males fly about towards the close of the day in search of the 

 females that run up and down the stems of the trees. After 

 impregnation nas taken place, the female deposits her ova on the 

 buds, leaf-scars, and twig-points in the crowns of the trees ; the 

 eggs, which are greenish at first and reddish later on, number 

 about 200 to 300 per individual. 



The tiny caterpillars make their appearance from the ova 

 during the following April and May, damaging many leaf and 

 flowering buds by feeding on them, and then later on devouring 

 the foliage which they twist or roll up somewhat in the manner 

 so characteristic of the insects named " leaf -rollers." About the 

 beginning of June they spin down from the leaves on gossamer 

 threads to the ground, for the purpose of passing the pupal state 

 of rest in a smoothly-formed hole, about two inches below the 

 surface of the ground. 



This insect is, for the most part, injurious to fruit-trees (to 

 Apple, Pear, and Plum trees especially), but it also occurs very 

 frequently on all sorts of broad-leaved species of forest growth, 

 and is especially to be found on Oak, Hornbeam, Lime, and Elm. 



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