WINTER MOTH. 135 



pale brown or reddish yellow ; the hinder wings paler. 

 The wingless females are brown, with two spots on 

 the back of each segment ; the caterpillars may be 

 generally described as brown above, yellow at the 

 side, and greenish yellow beneath. 



Pig. 107. — Winter Moth (Chelmatobia bruviata) : male and wingless 

 females. 



The male "Winter Moths have the fore wings marked 

 with various shades of grey, with paler hinder wings. 

 The females, though not absolutely wingless, are' only 

 furnished with such short wings that they are useless 

 for flying purposes. Their colour is grey, with darker 

 bands, as figured. The caterpillars are so variable in 

 colour, and differ so much after successive moults, 

 that it is hardly possible to give a clear description ; 

 but they may be generally described as at first greyish 

 or greyish green, with dark heads and faint white 

 stripe along the back, and afterwards of a clearer 

 green, this, in the last moult, being of a yellower 

 tint ; there is also a dark line more or less visible 

 down the middle of the back. 



Both of the above-named kinds of caterpillars are 

 "loopers," that is, form an upright loop in walking 

 (see Fig. 106). This is consequent on having, instead 

 of four pairs of sucker-feet below the body, only one 

 pair besides the pair at the end of the tail, so that the 

 caterpillar cannot move continuously forward, but has 

 to bring the sucker-feet on to where the claw-feet are 

 holding firm, and thus progress in a series of upright 

 loops. From this somewhat geometrical figure, like 

 an arch or a pair of compasses, the caterpillars are 



