32 



through the egg shell, after which it devours the remainder of the egg shell, and then sets 

 to work with an insatiable appetite on the cabbage leaves. 



y\„_ XI. In about a fortnight after hatching, the caterpillar («, fig. 11) has 



acquired its full growth. It is then about an inch and a quarter long, of 

 a pale green colour, finely dotted with black, with a yellowish stripe down 

 the back, and a number of small yellowish spots forming a broken stiipe 

 along each side. When fully fed and about to transform, it leaves its 

 food plant, and taking shelter under the coping of some wall or fence, or 

 other convenient hiding place, there changes toa chrysalis. The chrysalis 

 Q> (h, fig. 11), which is somewhat variable in colour, is usually pale green, 

 sprinkled with very small black dots. The period passed in the chrysalis 

 state varies at different portions of the season. In the summer the chry- 

 salis usually becomes a fiutterfly within a fortnight ; later in the season it 

 remains unchanged until the following spring. There are at least two, 

 perhaps three broods during the year, and the ratio of increase of the in- 

 sect is enormous. 



The caterpillar is dreaded by cooks in every country where it prevails ; it is not con- 

 tent with riddUng tlie outside leaves, but prefers to secrete itself in the heart, so that 

 every cabbage has to be torn apart and carefully e.xamined before being cooked ; and even 

 after it has been disheil up, one needs a watchful eye to avoid an undesirable admixture 

 of animal with vegetable food. 



Remedies. ' 



One method suggested is to search for the eggs at the proper season and destfoy 

 them ; anotlier, tcj employ children with nets to catch the butterflies, and as these latter 

 are rather slow and heavy flyers, this is not a ditficult task ; while a third method re- 

 commended is to lay boards between the rows of cabbages, supporting tliem two or three 

 inches above the ground, with the view of luring the worms to select such places in which 

 to pass the chrysalis stage of their exi.stence, and so secure tlnir destruction. Objections 

 can be readily found to all these methods, but they are tlie uest which man's e.\-perience 

 has yet enabled him to devise. The use of poisons such as Paris Green and Hellebore is 

 not admissible in this case on account of the difficulty of freeing the plant from such .sub- 

 stances before cooking. 



Nature has, however, provided a remedy ; a small parasitic fly (Pleronmhts pupamm) 

 attacks the chrysalis of this species in Europe, and, strange to say, has in some unknown 

 manner also found its way to this country. This is a little four- winged fly about one- 

 eighth of an inch long, with a yellowish body. The female flies about in search of the 

 chrysalids, which she punctures with her ovipositor, inserting a number of eggs in each ; 

 in a short time these hatch into tiny giubs, which consume tiie substance of the chrysalis ; 

 as many as forty or fifty of the.se have been found in a single case. This little friend is 

 now quite common in tlii' State of Xew York, as well as in the eastern parts of Canada. 

 It is probalde that gardeners will suff'er much fiom the depredations of the cater[iiliar for 

 several years, until the parasite reaches us, and has multiplied to a sufficient extent to 

 keep the depredator within moderate bounds. In the meantime it maybe expected to ex- 

 tend its march westward and northward through our own country, and over the fertile 

 plains of the neighbouring States away out to the far west. 



The Pear Tree Slug (Sdandria ccrasi). 



In our Report last year we referred to this insect at some length, and detailed to some 

 extent its ravages in our own neighbourhood. The havoc this disgusting little slug made 

 among the pear trees was terrible, consuming the leaves so thoroughly that the trees 

 looked as if tliey had been scorcheil by (ire — in many instances every leaf ilropped from 

 the trees, leaving them for a time as bare as in midwinter ; fully a thousand trees in tlio 

 young pear orchanl of the writer sufff^red severely. Following on the heels of this de- 

 structive pest We experienced a winter of uriusual severity, wdien, as might be expected, 

 a large number of these trees, thus weakened, perished from the cold. The extreme 

 winter, however, was not an unmitigated evil. The low temperature which killed the en- 



