338 MU IIAKDT ON INSfiCTii 



Length, 2^ lines. Two of the pupie attained their final state as flies iiv 

 about 24 days. They are blackish and common looking, not much less than 

 the smallest domestic species. Male — Hlack ; face shining white, with 

 blackish rctlectious, cheeks rather darkest as seen from beneath; sides 

 of the forehead shining white, with a black triangle in which stands a small 

 white point; eye-seam narrow, black; eyes naked, brown; hinder 

 part of the head slaty ; trunk, piceous towards the apex, griseous pubescent; 

 antenna) with the third joint sub-cylindric, its bristle shortly feathered, 

 as well J\s the palpi, black; posterior margin, lower part and sides 

 of the head, edges of the frontal band, base of the antennae, and the rim 

 of the mouih, garnished with long stitf hairs ; thorax black, somewhat slaty, 

 greyish, with darker freckles on the sides, three black, not well defined 

 bands on the back, the scattered hairs black ; scuteilum black; hinder part 

 of the metathorax slaty ; abdomen somewhat conic, narrowish, depressed, 

 ash grey, with the base, a line along the back, and cross bands on the 

 hinder edges of the segments, deep black, the longish pubescence black j 

 beneath grey, the sides alone hairy, two black cylindric processes near 

 the apex, somewhat pubescent; legs black, somewhat slaty; fore thighs 

 fringed with long black bristle-like hairs beneath; intermediate witb 

 fewer and shorter, and two at the tip; hinder rather densely pubescent 

 towards the base, with longer hairs after the middle, and towards the tip; 

 fore shanks with a long and two short bristles near the tip; intermediate 

 with a long and some short ones after the middle, and about four at the 

 tip ; hinder with seven or eight long ones, and about four at the tip, and 

 ciliated with a shorter series; wing-scales brownish white; poisers yellow- 

 ish ; wings glassy, with a greyish tint, darker about the roots ; second 

 cross nerve oblique, rather bent. Female. — Little resembling the male, 

 greyish ; head whitish ; frontal band rather wide, brownish or ferruginous 

 anteriorly, where it sends ofi' two minute lines to embrace the eyelet 

 triangle, which is greyish on the ridge; a shining Avhite spot in the 

 space behind the antenn<e ; body pale ash grey, the surface of the thorax 

 of a deeper tmt than the sides, with a dusky abbreviated dorsal line j 

 abdomen more ovate, with a darker dorsal line of changeable intensity, 

 which goes distinctly on to the fourth segment, and appears composed . 

 of so many isosceles triangles ; third segment at the apex, in certain lights, 

 with a deeper shaded band ; legs slaty or greyish, hinder femora with scat- 

 tered long bristles, but without the thickish pubescence of the male; wings 

 glassy, base of a dirty white; cross nerve oblique, straight. Length, 2.] — 2i 

 lines. 1 observe in gardens a species very nearly related, but differing by 

 having the abdominal processes in the male hirsute, and by the legs, 

 especially the hinder femora, being not so hairy or bristled. The eggs of 

 A. radicumt occur near the base of the foliage ; they are white, rather 

 opaque, elongate-ovate, closely longitudinally striate or sulculate. The 

 grub or maggot on the ground proceeds rather quickly, dragging itself 

 forward by means of its oral hooks, and its roughened ventral rings, and 

 frequently rolls itself from one place to another. By this activity it easily 

 renjoves from one part of the plant to another. Besides living at the base 

 of the turnip leaf, it likewise attacks the bulb, but I have not traced its 

 operations to any extent. It occurs also at the roots, and in the stems of 

 the wild radish {JRaphanus raphanistrum) ; and is particularly noxious to 

 cabbages and greens, frequently causing the crop to fail, by se])arating 

 the cuticle from the tap-root, and by the putrefaction whicli it induces 

 on all sides of its track. 'I'he stems are often stuck full of them, and one 

 of the largest usually occupies the centre of the pith. The plants thus 

 infested may be known at once, by the drooping appearance which they 

 assume in the sunshine. Cabbages may be saved by being pushed on 

 vigorously from the commencement ; for although the main root has failed, 

 bundles of new radicles issue all round, above the wounded parts. Water- 

 ings of liquid guano, of weak gas-water, or of lime water, repeated at 

 intervals, would probably be useful applications in this spliere, as well 

 as top dressings of lime or soot. 



