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Insect Pests. 



black, sometimes with just a speck of black in the middle. There 

 may also be variation in the other parts of the legs. The wings 

 are slightly smoky with pale costa. In the male the antennae are 

 shorter than the body, but in the female they are nearly as long. 



There is apparently much general variation, for Cameron (1) 

 says, "in many specimens the colour is testaceous and may have a 

 yellowish tinge." 



The females appear to lay their eggs during the warmest part 

 of the day. The eggs are placed anywhere on the under surface of 

 the leaves, just as is done by the slugworm. They hatch out in 



about eight days ; a 

 few under observation 

 incubated in five days. 

 The young larvae at 

 once commence to feed 

 on the under epider- 

 mis, eating their way 

 out at the surface. 

 At first the larvae are 

 pale greyish - green 

 with a reddish tinge, 

 sometimes varying to 

 grey, the sides pale 

 green to white, and 

 the last two segments 

 are pale. When older 

 they are green or 

 greyish - green with 

 almost white sides and 

 last two apical seg- 

 ments ; the head is variable, but usually pale, dull, orange-brown, 

 with spots of a lighter orange hue and a very prominent black mark 

 at the back of the head extending forwards. Now and again in 

 mature larva 1 the head is either all deep orange or all dusky black, 

 and even the black mark may be absent. The larvae, when not 

 feeding, remain in a coiled position under the leaves. 



Larval life lasts about three weeks. When mature the larva? fall 

 to the ground and burrow into the earth. An oval cocoon of parch- 

 ment-like material is formed in which it changes to a pale grey 

 pupa. This quiescent stage lasts from nine to twelve days. The 

 whole life-cycle may thus be completed in five weeks. 



The second brood appears about the middle of June, and these 



FIG. 246. C, PLUM LEAF KATF.X BY PLCM LEAF SAWFLY 



(Cladius padi) ; a and b, LARV.E. 



