INSECTS INJURIOUS TO CURRANT AND GOOSEBERRY 487 



into this country about the year 1857, and has since spread over 

 the greater part of the United States and Canada. The eggs are 

 glued to the main-ribs of the leaf as shown in Fig. 350, and not 

 inserted into pockets, as is usually the case with saw-flies. . . . 

 In from four to ten days the egg hatches into a veiy small whitish 

 caterpillar with a white head and ornamented with black spots 

 on each side. This color, however, changes to green as soon as 

 the caterpillars begin to feed, and after their first skin is shed, 

 the head becomes black and many black spots appear on the body. 

 This coloration persists until the last molt when the insect becomes 

 grass-green. The head, however, retains the black spots on 

 each side. The length of the worm is now about three-fourths 

 of an inch. While growing they at first skeletonize the leaves; 

 later they eat the entire leaf, with the exception of the ribs, and at 

 last they devour immense quantities of them, often completely 

 stripping the bushes of their foliage. If this is repeated year after 

 year, the plants produce less and less fruit and eventually die. 

 The larva now descend to the ground, in which they spin a small, 

 oval cocoon of brownish silk, either just below the surface of 

 the ground or among the leaves and rubbish that collect below the 

 plants. Inside these cocoons they change to pupae and later 

 to adults, which are ready to issue as winged saw-flies during the 

 last of June or in July (in Minnesota), sometimes not until the 

 first of August. They now pair and produce a new generation 

 of injurious worms . . ., the adults of which do not, however, 

 issue until the following spring. As the two broods overlap, 

 we can find Iarva3 of all stages during the greater part of the 

 summer." The adult saw-flies are well illustrated in Fig. 350. 

 The female is about one-third inch long, of a light yellowish color 

 marked with blackish as shown in the figure, while the male is 

 smaller and rather darker. 

 Control. See page 488. 



The Native Currant-worm * 



The native currant-worm is not usually so destructive as the 

 European species, but occasionally becomes injurious and is 

 * Gymnonychus appendiculatus Hartig. Family Tenthredinidae. 



