INSECTS INJURIOUS IN THE FLOWER-GARDEN. 



825 



The body is divided into twelve segments, each 

 having about a dozen black spots or warts, each 

 of them producing a short black hair ; a dark 

 line of green runs down the back. The head 

 is somewhat ochreous. They form beautiful 

 cocoons of network, within which the caterpillar 

 changes in a few days to a pale-green chrysalis, 

 slightly tinged with ochre on the head, wing- 

 sheaths, and tail, and with a double brown 

 streak down the back. About the beginning of 

 May the moths appear. The head, feelers, and 

 horns are white, the thorax cream-coloured, 

 the sides brown, upper wings pale clay-brown, 

 with whitish streaks, and lance-shaped ; a pale 

 streak runs along the inferior margin, the edges 

 waved and brownish, forming a dark line at the 

 base ; a dark streak appears at the centre, as 

 well as a line of black dots along the costal 

 margin ; the posterior margin is dark, freckled 

 with black and light grey, interspersed with 

 specks of ochre ; the wings expand to seven 

 lines ; the under wings, legs, and abdomen are 

 of a slate colour. The wild rocket, in some 

 seasons, abounds with them ; and the fine 

 double flowers of the florist's choicest varieties 

 are often entirely destroyed. The only feasible 

 remedy appears to be crushing the young cater- 

 pillars between the leaves on their being first 

 observed. 



The narcissus fly (Merodon narcissi), fig. 271. 

 — The grubs of this insect are often found in the 

 very centre of the 

 Fig. 271. bulbs of many spe- 



cies of narcissus, 

 which they frequent- 

 ly destroy by eating 

 away their interiors. 

 In November, or at 

 the time of planting, 

 the bulbs should be 

 carefully examined, 

 and if one or two 

 pretty large round- 

 ish holes be found 

 in their outside, it 

 is pretty certain 

 that the maggot of 

 this insect is with- 

 in, where it will re- 

 main feeding on the 

 heart of the bulb 

 during summer and 

 autumn ; the slimy 

 matter discharged 

 from its body dur- 

 ing its long impri- 

 sonment causing the bulb to rot. About the 

 end of November, the maggot is changed 

 into a pupa, at which period it eats its way out 

 of the bulb near its roots, burying itself in the 

 adjacent earth. They remain in this state till 

 the following spring, when the flies issue from 

 them. Upon what part of the plant the eggs 

 are deposited is not very satisfactorily known. 

 In April, the flies hatch, and have much the 

 appearance of small humble-bees, and are like 

 them in colour, being yellow, orange, and black. 

 The only remedy against their multiplying is to 

 remove every bulb that does not send up leaves 



NARCISSUS FLY. 



at the proper season, and to destroy them, for 

 in such are the maggots to be found. If left in 

 the ground, the increase of the insect would be 

 facilitated. 



Tipula oleracea. — The larvse of this very com- 

 mon insect are very injurious to the roots of the 

 ranunculus. The only remedy appears to be to 

 take up the roots carefully as soon as the leaves 

 begin to flag, and remove the larvse from them, 

 returning the roots again to their former place. 



Psylla buxi Geoffroy, Chermes buxi Linn. 

 ■ — This small homopterous insect is frequently 

 found on the common box (Buxus communis). 

 It attacks the leaves, chiefly of the side branches, 

 and by perforating them, causes them to curl 

 up in a rather remarkable manner, resembling 

 little balls, and more or less hollow. The fol- 

 lowing curious discription of this insect is given 

 in the " Gardeners' Chronicle," and although 

 somewhat prolix, gives so clear an insight into 

 its economy that we give it entire. " On 

 opening one of these balls about the beginning 

 of June, a quantity of white powdery grains 

 will be found, amongst which is a variable num- 

 ber of minute flattened green insects of an 

 oblong form, with short slender antenna; and 

 six legs ; in addition to which there are others 

 of a larger size and somewhat broader form, 

 with flat semi-transparent lobes on the sides of 

 the body; these, as well as the smaller ones, 

 often have attached to the extremity of the 

 body a long white filament, like a short bit of 

 thick coarse white thread, particles of which, of 

 various shapes, are also to be observed on the 

 leaves of the box, as well as hanging about the 

 ball of leaves. The smaller insects are the 

 larva3, and the larger ones the active pupse of 

 the psylla ; the flat lobes at the sides of the 

 latter are the cases in which the future wings of 

 the psylla are developed, and the white fila- 

 ments and grains are nothing less than the 

 excrement of the insects. The instrument by 

 which these insects obtain their nourishment, 

 and at the same time cause the alteration in the 

 growth of the leaves, is a short jointed rostrum 

 attached to the under side of the body, so far 

 back as to be close to the fore-legs ; within this 

 rostrum are several delicate threads which the 

 insect has the power of protruding to a great 

 length, and of which the points are thrust into 

 the substance of the leaf, so that it is sometimes 

 difficult for the insect to withdraw them when 

 disturbed. The operation of puncturing the 

 leaf is doubtless attended with the introduction 

 of a certain amount of fluid, which acts as an 

 irritant upon the adjacent vessels, and causes 

 the abnormal growth above described. The 

 precise nature, however, of the action which 

 takes place in this and other analogous cases 

 has yet to be discovered. After remaining a 

 few days in the pupa state, the insect assumes 

 the winged state — the wings which had pre- 

 viously been enclosed in the flattened horizontal 

 lobes being now carried in a slanting direction 

 like the roof of a house ; and the insect, instead 

 of being one of the slowest in its movements, 

 has not only now acquired the power of flying, 

 but leaping with great activity to a considerable 

 distance. The perfect insect measures rather 



