HYMENOPTERA. 413 



roots of the grass, and, in such secure places, make their co- 

 coons. The latter are oblong oval cases, of tough grayish 

 silk, and measure nearly three tenths of an inch in length. In 

 due time the insects change to saw-flies, and come out of their 

 cocoons, one end whereof separates, like a lid, to allow of 

 their escape. Although some of them are found to finish 

 then- transformations in August, it is probable that the greater 

 part of them remain unchanged in the ground till the follow- 

 ing spring. 



No means for the destruction of the caterpillars of the fir 

 saw-fly have been tried here, except showering them with 

 soapsuds, and with solutions of whale-oil soap, which has 

 been found effectual. They may also be shaken off or beaten 

 from the trees, early in the morning, when they are torpid and 

 easily fall, and may be collected in sheets, and be burned or 

 given to swine. For other means to check their depredations 

 the reader may consult the articles on the pine and fir saw- 

 flies of Europe, contained in Kollar's " Treatise." 



The following account of a kind of saw-fly which attacks 

 the grape-vine is chiefly extracted from my " Discourse before 

 the Massachusetts Horticultural Society, in 1832," where the 

 insect is named Selandria Vitis. The saw-fly of the vine is 

 of a jet-black color, except the upper side of the thorax, which 

 is red, and the fore legs and under side of the other legs, which 

 are pale yellow or whitish. The wings are semitransparent, 

 of a smoky color, with dark brown veins. The body of the 

 female measures one quarter of an inch in length, that of the 

 male is somewhat shorter. These flies rise from the ground 

 in the spring, not all at one time, but at irregular intervals, 

 and lay their eggs on the lower side of the terminal leaves of 

 the vine. Li the month of July the false caterpillars, hatched 

 from these eggs, may be seen on the leaves, in little swarms, 

 of various ages, some very small, and others fully grown. 

 They feed in company, side by side, beneath the leaves, each 

 •swarm or fraternity consisting of a dozen or more individuals, 

 and they preserve then- ranks with a siu-prising degree of regu- 

 larity. Beginning at the edge they eat the whole of the leaf 

 to the stalk, and then go to another, which in lilve manner they 



