BRASSICACEOUS PLANTS.— THE BORECOLE. 



113 



the body black; horns seven -jointed; trunk 

 irregularly spotted with palish black ; nervures 

 of wings dark brownish-black; legs black; base 

 of thighs greenish. The female is of a yellowish- 

 green and mealy white, spotted with black ; 

 body large and heavy; legs black; base of thighs 

 green ; horns shorter than in the male; the two 

 first joints are green, while the third is ochreous ; 

 eyes, four in number, two large ones in the head, 

 and two smaller on the collar. 



The Powtia brassicm. — Well known as the large 

 white garden butterfly, fig. 44, vfith black tips 



Fig. 44. 



of the second, green, with small yellow rings on 

 the sides of the body ; and of the third, green, 

 but striped down the back and sides with orange. 



Fig. 46. 



X.AKGE WHITE CABBAGE BUTTERFLY. 



a caterpillar ; b chrysalis ; c butterfly. 



to its wings ; produces the equally well known 

 green caterpUlar, so often found upon the cab- 

 bage tribe in all stages of their growth. The 

 caterpillars may readily be destroyed, and by 

 doing so the increase of following years is 

 greatly diminished, by dusting the plants over, 

 twice a-day, as long as the insects appear, with 

 finely-powdered caustic lime, shaken from a thin 

 canvass bag, or by watering them over head with 

 clarified lime-water. 



And associated with it are Pontia napi, fig. 45, 

 and Pontia rapes, fig. 46, the small white-and- 

 Fig. 45. 



SMALL WHITE CABBAGE BUTTERFLY. 



a caterpillar ; b chrysalis ; c butterfly. 



green veined garden butterfly. The caterpillar 

 of the first is greenish-yellow, with black spots ; 



GREBN-VEINKD CABBAGE BUTTERFLY. 



a caterpUlar ; b clirysalis ; e butterfly. 



When fully grown, they retire to some sheltered 

 dry place, and change into the chrysalis state, 

 ready again in spring to change into their but- 

 terfly state, to lay their eggs, and produce a fresh 

 breed of caterpillars. 



The cabbage powder-wmged moth (Aleyrodes 

 proletella L. — the Aleyrodes elielidonii of Lat- 

 reille) often commits sad havoc amongst the 

 cabbage and broccoli crops in its fly state 

 during the month of November. They begin to 

 make their appearance in May, and live under 

 the leaves where they are hatched, abounding 

 during the months of June, July, and August. 

 They are thus described in " Gardeners' Chro- 

 nicle " for 1851, p. 837 : " The aleyrodes is a 

 minute fly, covered with white powder. The 

 females have been observed about midsummer 

 to remain quite quiet on a leaf for several days 

 when about to lay their eggs ; and when they 

 had left the spot where they had rested, a small 

 circular space covered with white powder was 

 observable, around which were irregularly de- 

 posited from 9 to 14 eggs. These eggs are 

 transparent, but afterwards turning to a yellow- 

 ish tint. They hatch in about 12 days, and the 

 young larvse immediately run a short distance 

 to spread themselves more about the leaf, but 

 in a few hours a scale is formed over them, so 

 that they look like little tortoises or cocci, and 

 exhibit no signs of life. The colour is almost 

 white, with two yellow spots behind. They are 

 not absolutely stationary, but only move very 

 short distances as they increase in size, being 

 furnished with six pectoral legs. The perfect 

 insect is covered with white powder, the head 

 and thorax black, variegated with yellow ; the 

 eyes divided and black ; the antennse nearly as 

 long as the thorax, slender, and five-jointed ; 

 first basal joint stout, second very long, third and 

 fourth shorter, the remainder slender ; the ros- 

 trum bent under the breast in repose; stout, 

 biarticulate, with two very fine bristles passing 

 through ; the thorax sub-globose, the collar 

 short, with three black spots; abdonien short, 

 yellow or rosy ; the apex obtuse and dark ; wings 

 forming a triangle in repose, and more or less 

 deflexed, pure white, mealy ; superior wings 



