Narcissus Fly
(Merodon clavipes). This two-winged Fly is rather troublesome to Continental gardeners, as it feeds in Narcissus bulbs, devouring the inner parts. It is, however, too rare in England to do much harm, or to call for a long notice here. It is nearly 1/2in. long, rather like a hive bee in hairiness and form, but with the end of the body blunt. Its colour varies so much that several of the varieties were named and described as distinct species. The thorax is usually yellowish-brown or whitish in front, black behind; the abdomen pale at the base, brownish-yellow or rust-coloured behind. Sometimes the back is metallic-green. The eyes are hairy, and almost cover the front of the head, meeting in front in the males, but separated by a yellow stripe in the females; and there is a golden-yellow tuft of hair at the base of each antenna. The legs are black, and the last pair have the thighs thick, and each bears a tooth near the tip. The grub is like a rolling-pin in form, wrinkled, greyish-yellow, with a row of backward-directed bristles round each ring. It eats out the centres of the bulbs, and, when full-fed, crawls out, and changes into an oval brown pupa in the soil, near the top of the bulb. Within this present year, Dr. Ritzema Bos has published, in the Archives of the Teylerian Museum, at Haarlem, an exhaustive memoir (of fifty pages, 8vo, with illustrations), upon the Narcissus Fly, under the name Merodon equestris. He mentions that it was introduced with bulbs from the South of Europe into Holland, where, so long as forty years since, it made itself noticeable by injuring Daffodils. It seems quite naturalised in that country, though its numbers are markedly diminished by severe winters. Besides the mechanical injury to the plants, Dr. Bos finds that the larvae excrete an acid, which causes the decay of the tissues around the burrows, and the plants suffer much from the wound being thus extended.
Owing to the mode of life of the larvae, it is very difficult to employ any good remedy for the extermination of these insects, but they would probably yield to the methods employed against the Onion Fly (which see). Of course, sickly plants ought to be removed from among the others without delay. Dr. Bos recommends, as most successful, to keep all bulbs of Narcissus under water for eight days before planting, as this treatment, while not injuring the bulb, will kill the larvae, which, at the usual season of planting out (August), are still near the upper part, and have not done much damage.