tenthredtnid.t:. 228 



mountain-ash. It appears in June and Septcnil)er. The % is 

 shiny black, with the tips of the four anterior femora, and the 

 tibiifi and tarsi, dull white. An egg-parasite, belonging to the 

 genus Encyrtus, renders, according to Peck, a great number 

 of its eggs abortive. 



The Rose-slug, Selandria rosea Harris, is longer than the Pear- 

 slug, the body being scarcely thickened anteriorly, and not 

 covered with slime. It is pale-green and yellowish beneath. 

 It appears in July and August, and does great injury in dis- 



ance about the rose-bushes as soon ^ig- 149- 



as the leaves are expanded, when they may be caught with 

 nets, or the hand on cloudy days. Hand-picking, and the 

 application of a very weak solution of carbolic acid, coal oil, 

 whale oil soap, or quassia, are useful in killing the larvte. 



On the 25th of July a young friend brought me a large num- 

 ber of some remarkable larvae (Fig. 149, natural size) of a 

 saw-fl}-, which I surmised might belong to this genus. It pre- 

 sented the appearance of an animated, white, cottony mass, 

 about an inch long and two-thirds as high. The head of the 

 larva is rounded, pale whitish, and covered with a snow-white 



powdery secretion, with prominent 

 black eyes. The body (Fig. 150, 

 naked larva) is cylindrical, with eight 

 Fig. 150. pairs of abdominal legs, the segments 



transversely wrinkled, pale pea-green, with a powdery secre- 

 tion low down on the sides, but above and on the back, arise 

 long, flattened masses of flocculent matter (exactly resembling 

 that produced by the woolly plant-lice and other Homopterous 

 Hemiptera) forming an irregular dense cottony mass, reaching 

 to a height equal to two- thirds the length of the worm, and con- 

 cealing the head and tail. On the 27th and 28th of July the 

 larvae moulted, leaving the cast skins on the leaf. They were 

 then naked, a little thicker than before, of a pale-green color, 



