DESTRUCTIVE INSECTS. 201 



and the empty skins often remain attached to the leaves in 

 large numbers (Fig. 267 g~). The nymphs run rapidly but do 

 not jump like the adult hoppers. Apparently there is but one 

 full brood annually in New York. All varieties of grapes are 

 attacked, but the thin-leaved sorts suffer the most. 



The adult hoppers are so active that it is difficult to hit 

 them, and insecticides that will kill them damage the vine 

 leaves. We have killed many adults in June by knocking 

 them off and down to the ground with a 5-per-cent. kerosene- 

 water spray and then quickly hitting them on the ground 

 with a 2 5-per-cent. kerosene- water spray. Another practicable 

 method is to catch them on sticky shields. Make a shield by 

 stretching a cloth over a frame and treat it with tar or resin 

 and castor oil (" tanglefoot " ), then in the warm part of the 

 day, when the insects are most active, carry the shield along 

 near the vines and shake the vines. Thousands of them will 

 fly or jump against the shield and be caught. Practise this 

 every day or two until relief is gained. In July the nymphs 

 or young hoppers quickly succumb to a spray of whale-oil 

 soap (one pound in ten gallons of water), but it requires thor- 

 ough and intelligent work to hit them on the under sides of 

 the leaves. 



Currant Borers often work considerable havoc by burrow- 

 ing up and down the stems, usually killing them. There are 

 two species of insects engaged in this nefarious work. One is 

 the caterpillar of a moth allied to the peach-tree borer and 

 known as the Imported Currant Borer (Sesia tipuliformis) ; the 

 other species is the grub of a beetle known as the American 

 Currant Borer (Psenocerus super notatus). The two kinds have 

 similar habits, and remain in the stems over winter. It is 

 thus an easy matter to stop their depredations by cutting out 

 and burning all sickly or hollow stems either in the autumn 

 or early spring. 



The Imported Currant Worm (Pteronus ribesii} must be seri- 

 ously considered when one attempts to grow currants or 

 gooseberries in most parts of the country ; it defoliates mil- 

 lions of these bushes every year. 



The adult insect is a pretty little yellow-bodied saw-fly (Fig. 

 268) which emerges from its cocoon in the soil in the spring 

 when the first few currant leaves have expanded, and at once 



