Onion Fly. 243 



and obliquely truncate, with about eight obtuse points, of a con- 

 sistence similar to the rest of the body. Near the extremity of 

 the body are observed two small reddish spots, from which pro- 

 ceed two internal and dark-coloured veins. Bouche gives the 

 length of the insect as a quarter of an inch ; but those which I 

 have reared were nearly half an inch long when full grown. 



When this period is arrived, the larva, by degrees, contracts 

 itself in length, without throwing off the outer skin, and very 

 shortly appears as an oval mass {Jig. 83. ; c, natural size, d , 

 magnified), of a chestnut colour; having its posterior end black- 

 ish, with the extremity red, and with two lai-ge black spots cor- 

 responding with the spots described near the end of the body of 

 the larva. In this state, it is brittle and shining, without very 

 distinct traces of segments; but the head is furnished with two 

 obtuse points ; and the points observed at the other end, in the 

 larva, are also still to be perceived, two of them being rather 

 larger than the rest. Within this puparium the real pupa is to 

 be found, having the limbs laid along the breast. 



The perfect insect {Jig. 83. e, magnified, the cross lines indi- 

 cating the natural size) is of a pale ashy colour; the female 

 (which is here figured) having the abdomen entirely of the 

 same colour as the rest of the body ; but in the male it has an 

 interrupted black line down the middle. The different parts of 

 the body are clothed with long black bristles, arising from black 

 points, which, in the thorax, are nearly regularly disposed in 

 4 lines, and are longer than in the other parts. The mouth, 

 palpi, and antennae are black ; the face shining, and somewhat 

 silvery. There is a broad chestnut line between the eyes, forked 

 behind, leaving the space for the ocelli of the ordinary colour. 

 The nasus is triangularly produced above the mouth ; and the 

 antennal bristle is clothed with very short hairs at the base. 

 Behind the eyes is a transverse row of black hairs. The wings 

 are nearly destitute of colour, but rather buff at the base ; the 

 iridescence pink and green ; and the nervures buff, but darker at 

 the tips of the wings. The legs are black ; and the poisers 

 and winglets of a pale yellow. Expansion of the wings, 5^ lines 

 to 6^ lines (about half an inch). 



According to M. Bouche (to whose capabilities and abilities for 

 observation I am able to bear witness, from having visited his 

 large nursery, and inspected his collections, at Berlin), the female 

 deposits her eggs upon the leaves of the onion, close to the earth ; 

 and she is enabled, doubtless, to introduce them between the outer 

 coats of the bulb by means of her elongated telescope-like oviposi- 

 tor ; so that the larvae, when hatched, readily make their way to 

 the centre of the root, which they soon reduce to a state of decom- 

 position, which seems to be most congenial to their taste. The 

 same author also states that tiie insect may be found in the 



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