REPORT OF THE ENTOMOLOGIST. 201 



spots are seen on the back of the abdomen. However, the casual ob- 

 server who depends on this character alone is liable to be misled, as 

 there is another species of saw-fly — Sarpiphorus maculatus — [the 

 common strawberry saw-fly] closely resembling it, and having similar 

 markings on the back of the abdomen. The most certain method of 

 distinguishing the two species is to note the number of submarginal 

 oells in the fore wings, Monostegia ignota [the new one] having four, 

 and H. maculatus only three. 



" Adult saw-flies of this new strawberry pest were found depositing 

 •eggs from the 1st to the 25th of April, the period of greatest deposition 

 being from the 10th to 20th. Adult females were captured, confined, 

 and eggs obtained that have furnished larvae which have been carried 

 through all the larval stages and their habits studied in connection with 

 observations in the field. The eggs are deposited singly on the under 

 side of the leaf, just beneath the epidermis. In no case were the eggs 

 found deposited in the petiole of the leaf, as is said to be the habit in 

 H. maculatus, but frequently alongside or in the angle between two 

 veins ; seldom more than three or four eggs are found deposited in 

 a single leaflet. 



"When first deposited the eggs (Fig. 15, a) are pure white, taper 

 ing towards both ends, one side slightly concave, the other quite con- 

 vex ; are .475 mm wide by .875 mm long. The point of deposition can 

 hardly be seen at first, but the swelling of the eggs, due to the devel- 

 oping embryo, causes light-colored blisters of 0.6 — .75 by .75 — l mm 

 in size." * * * " When ready to issue the young larvae eat a 

 small hole through the inclosing epidermis and emerge. At first they 

 are slender 22-footed slugs ; bodies white, translucent, much wrinkled ; 

 granular; 2 — 2.3 mm long; upper part of the head cream colored; 

 -claws of the pectoral legs, eyes, labrum, mandibles, brown ; remain- 

 ing mouth parts, whitish brown ; ring around the eyes black. The 

 young worms begin their ravages at once, eating small holes through 

 the leaves. After feeding six or seven days they pass through the 

 first moult, are about one-half larger, the dorsal and lateral surfaces 

 yellowish green, ventral surface pale. At each of the three succeed- 

 ing moults, all of which occur within the next eight or ten days, the 

 color is of a deeper green. The larvae when full grown are between 

 ,55 and .65 inch long. Head and mouth parts, claws, and first joints 

 of the pectoral legs are of a more distinct brown ; body a beautiful 



