PACKARD.] 



THE EUROPEAN CURRANT SAW-FLY. 



787 



INJURING THE CUERANT. 



The European Currant Saw-Fly, Nematus veniricosus King. (Figs. 67-59). — Devour- 

 ing the leaves from June until August ; a green false caterpillar, changing to a pale 

 honey-brown saw-Uy. 



This destructive insect was imported from Europe into nurseries at 

 Toronto, Canada, and was detected at Rochester, N. Y., during the 

 year 1857. It seems since that time to have spread westward and east- 

 ward, arriving in Eastern Massachusetts about 18C5, as I am informed 

 by Mr. F. G. Sanborn. For eight seasons past it has been very de- 

 structive in gardens in Massachusetts as well as in Illinois and Michi- 

 gan, where it seems destined to spread farther west. 



The parent of this worm is a saw-fly, so named from bearing a saw- 

 like sting, or ovipositor, with which it pierces the leaves or stalks of 

 plants, cutting a gash, in which it deposits an egg, the egg passing out 

 from the ovary through the oviduct, and thence through the blades of 

 the ovipositor into the wound made in the plant. While most of the 

 members of this family cut a gash in the leaf, into which an egg is 

 pushed, a few, as in the present insect, simply place them on the under 

 surface of the leaf, as seen in Fig. 59. (1.) The fly has four wings, and 

 belongs to the same group of insects [Hymenoi)tera) that comprises the 

 bee, wasp, and ichneumon-fly. 



The following account of its habits is taken from the writer's Guide 

 to the Study of Insects: "There are about fifty species of Nematus in 

 this countr^^, of which the most injurious one, the gooseberry saw-fly, 

 has been brought from Europe. Professor Winchell, who has studied 

 this insect in Ann Arbor, Mich., where it has been very destructive, 

 observed the female on the 16th of June, while depositing her cylindri- 

 cal, whitish, and transparent eggs in 

 regular rows along the under side of 

 the veins of the leaves, at the rate 

 of about one in forty-five seconds. 

 The embryo escapes from the egg 

 in four days. It feeds, molts, and 

 burrows into the ground within a 

 period of eight days. It remains 

 thirteen days in the ground, being 

 most of the time in the pupa state, 

 while the fly lives nine days. The 

 first brood of worms appeared May 

 21 ; the second brood, June 25." 

 Fig. 57 shows the eggs deposited 

 along the under side of the midribs 

 of the leaf; 2, the holes bored by 

 the very young larvae ; and, 3, those fig. 57.— Currant-le'af with (l) eggs; 2, 3, 



eaten by the larger worms. holes eaten by the larvae. (After Riley.) 



Fig. 58 {a, enlarged) represents the worm when fully grown. It is 

 then cylindrical, pale green, with a pale-green head, with the segment 

 next behind the head, and the third segment from the end of the body, 

 together with the last or anal segment yellow ; the 16 false or abdom- 

 inal legs are also yellow ; the six thoracic legs are horn-colored. The 

 body is transversely wrinkled, especially on the back, and is slightly 

 hairy. The eyes are black, and the jaws (mandibles) are black, and, 

 on the inner side of the edge reddish... It is about three-quarters of_aa 

 inch in length. 



