Some experiments on the breeding of the mangold fly (Pegomyia hyoscyami, Panz.) and the dock fly (Pegomyia bicolor, Wied.)

Extract

In a previous paper (Ann. Applied Biol. i, 1914, pp. 41–76) in which the author dealt with the life-history of Pegomyia hyoscyami, Panz., it was shown that the foodplants of this species belonged principally to the natural orders Chenopodiaceae and Solanaceae. Various weeds have also been cited in this connection, namely, certain kinds of thistle and the dandelion. Recently E. M. Vassiliev (see Rev. Appl. Ent. iii, Ser. A., 1915, p. 608) has added to the record the following:—Silene (catchfly), Datura stramonium (thorn-apple) and Onopordon acanthium (Scotch thistle). Thus, in addition to the two aforementioned, the orders Caryophyllaceae and Compositae are fairly well represented. As the original paper of the Russian author is not available, it cannot be definitely stated in how far his records are authentic. But as he advises the removal of these weeds from the vicinity of beet plantations, one would naturally infer that he has some reason for assuming that they may be attacked by the mangold fly and presumably provide an ever-present source of infestation to the cultivated crop.