INSECT AND OTHER PLANT ENEMIES. 



91 



and constitute a very numerous family even in 

 Britain alone. Many of them live upon the 

 leaves or in the stems of Roses, and the more 

 common ones are often destructive. There are 

 several species of Hylotoma, but all are similar 

 in habit to H. Rosce, which may be taken as a 



Fig. 113.— Larva of Rose Sawfly (Hylotoma Rosce). 



type. The fly is J inch long, and yellow, with 

 a black head. The caterpillars are bluish-green, 

 with two lines of yellow spots on the back, and a 

 row of black ones on either side, and a dark 

 head. They appear in May and June, and 

 again in August and September, the fly being 



Fig. 114.— Rose Sawfly (Emphytus cinctus). 



double-brooded, and they eat the leaves from 

 the edges to the midribs in a very short time. 

 The cocoon is formed in the ground. Emphytus 

 cinctus is also common, and feeds in the same way. 

 Cladius pectinicornis is common on Roses. The 

 fly is J inch long, glossy-black, with scattered 

 gray hairs, and pale, smoky wings. The cater- 

 pillars are flattened, tapering each way, and are 

 dark-green, with three rows of warts on each 

 segment, and each wart is furnished with a long 

 brown hair. They lie flat on the under surface 

 of the leaves, and eat holes in them. There are 

 two broods, and the cocoon is formed between 

 dead leaves. Cladius Padi is a smaller fly than 



Remedies. - 



its congener, and its caterpillar feeds upon Roses, 

 Plums, and Pears, making holes in the leaves. 

 Two to four broods are produced in a season, and 

 the cocoons are formed in the ground. Another 

 common species is Blennocampa pusilla — a shining 

 black fly with grayish-brown wings. The cater- 

 pillars are short, fat, and green, 

 with loose folds of skin hanging 

 down on either side; the back is 

 somewhat bristly, and the head 

 brown. They roll the leaves into 

 cylinders open at either end, 

 tying them with threads, and 

 thus form a shelter in which they 

 feed. The perfect fly emerges 

 from cocoons in the ground dur- 

 ing May and June. Lyda inanita 

 rolls the leaves in the same way 

 as the previously -named spe- 

 cies. 



Taking the habits of the above, 

 we have three distinct types to deal with, 

 namely, those which feed exposed on the edges 

 of the leaves and are easily detected, those 

 which lie on the under surface and eat holes in 

 the leaves, and those which roll the leaves and 

 prove more troublesome to destroy. The first 

 two kinds may, however, be destroyed whole- 

 sale by insecticides well sprayed on both surfaces 

 of the leaves. If there are only a few bushes 

 or a small bed, spray the foliage with Paris- 

 green or London-purple (the former being most 

 reliable, because less likely to hurt the foliage) 

 at the rate of 1 tea-spoonful to 2 gallons of 

 water. On a large scale use 1 lb. of Paris-green 

 to 300 gallons of water. An infusion of white 

 hellebore, prepared as for the Garden Pebble 

 Moth, may be used instead. Flowers of sulphur 

 mixed with water and sprayed on the foliage is 

 another remedy sometimes employed. Those 

 which live in rolled packets of leaves would also 

 be destroyed by Paris-green or white hellebore 

 should they eat any of the outer leaves, but 

 some would be sure to escape; therefore hand- 

 picking is more effective, even if a tedious pro- 

 cess. The leaves of valuable Roses should be 

 unrolled or loosened from their ties, and the 

 caterpillars destroyed; but take care that they 

 do not escape by letting themselves down with 

 a thread, the ends of the leaves being left open 

 for that purpose. Boys could accomplish this 

 when shown how to perform it properly. Care- 

 fully collect and burn dead leaves beneath the 

 Roses, so as to destroy the pupa?. When digging 

 the ground, throw the soil from beneath the 

 bushes on the middle of the rows, replacing it 



