7886 



Insects. 



show that the maggots drop out from between the two cuticles, and undergo their 

 metamorphosis in the ground ; at any rate, I could occasionally discover, by scraping 

 away the soil at the root of the mangolds, here and there a larva; indeed, if the late 

 broods do not remain as pupae under the ground, how are they able to survive the 

 winter, and by what means is the continuation of the species to be carried on ? The 

 larva, at the time of the rupture of the ovum, is about a line long ; it is armed with 

 two strong hook-shaped mandibles; it grows fast, and reaches the size of about the 

 third of an inch in length, feeding upon the green parenchyma of the leaf. 



Anthomyia Bet.e, Curtis. 

 Female. — The ground-colour of thorax light brown, marked with five or 

 six darker longitudinal lines, with four or five bristles similarly disposed; abdomen 

 lather variable in colour, generally light brown or ashy gray, with a distinct or 

 indistinct daiker line down the middle, occasionally with irregular dusky patches, 

 which sometimes become so confluent as to give the abdomen a uniform dusky colour; 

 shape of abdcmen oval, narrow at the extremity; head semi-orbicular; eyes reddish 

 brown, remote, destitute of hairs ; antennae velvet-black, drooping, arista bare ; face 

 satiny while, with black bristles, having a broad bright chestnut band down the centre; 

 ocelli three, situated on a satiny subtriangular spot on the crown ; wings the size of the 

 body, tinged with tawny at the base ; alulae of moderate size; legs black, tawny at the 

 base, long; proboscis dark* with tawny tinge; whole length nearly three lines. 



The female is readily distinguished from the male ; the more general obvious diffe- 

 rences being the shape of the abdomen, which is oval in the female, but linear in the 

 male; the remoteness of the eyes, those of the male being nearly contiguous; and the 

 less bristly character of the female. Two important practical questions will naturally 

 suggest themselves to the agriculturist; 1st. Is this insect likely to abound again in 

 such numbers as to affect the mangold wurzel crops this year? 2ndly. If it does so 

 abound, what remedial measures can the agriculturist adopt? To both these queries 

 it is perhaps impossible to give a satisfactory answer. It has been seen that the 

 injury done to the plants last year is owing, in a great measure, to the large proportion 

 of female flies, a fact which depends on phenomena, of the nature of which we are 

 wholly ignorant. A frost of some weeks duration is generally considered to be the 

 means of destroying many noxious insects, and no doubt this is true to some extent, 

 but it will be remembered that the winter of 1860 was tolerably severe, and yet these 

 Anthomyiae abounded in the following spring. With regard to the second problem, 

 the only possible direct mode of lessening the evil is, as it appears to me, to examine 

 the leaves when the mangolds are young, and when, in consequence, they are most 

 likely to be injured, and to crush between the finger and thumb the little groups of 

 ova, which can readily be" detected by the naked eye, of course this would demand a 

 good deal of valuable time, and perhaps for this very reason, may be deemed altogether 

 impracticable. There can be no doubt that many of our smaller birds are of great use 

 to us in helping to diminish the extent of the injury, and since the first appearance of 

 the larvae of this destructive insect is contemporary with the time when birds are very 

 busy seeking food for their young, perhaps the farmer's best policy is to abstain from 

 an indiscriminate slaughter of the feathered tribes, and to leave with them the chance 

 of being of considerable benefit to him. — Journal of Microscopical Science, January, 

 p. 40. 



