106 



In both these two cases, the galls were of the same year's growth, and 

 inhabited by the gall-making larvae at or shortly before the time that 

 the Moth made its appearance. Thus we see that the very same 

 moth inhabits in the larva state plums that are infested by Curculio, 

 Black-knot that is infested by Curculio, an Elm-gall that is generated 

 and inhabited by Plant-lice, and an Oak-gall that is generated and in- 

 habited by a Gall-fly.* 



In the two latter cases my Plum Moth is clearly a Guest-moth ; 

 but Avhether it confines itself to feeding on the substance of the gall, 

 or whether it also destroys the gall-makers, and whether, if it de- 

 stroys them, it feeds on them, and, in the case of the Plant-louse gall, 

 whether it may not feed partly on the sugary dust secreted from the 

 body of the insect, are all of them points that remain to be investi- 

 gated and^explained. Most authors state that the larvae of this entire 

 Order (Lepidoptera) are almost exclusively vegetable-feeders;! and 

 some have even gone so far as to say, that they feed entirely on vege- 



one tliat Harris had iii view, when he spoke of his nubilipennis. For the 

 mature female, fly jjroduced from Quercus-sculpta has a very distinct dark 

 cloud on the terminal % of its front wing, as Harris describes his gall-fly 

 {Cynips }tubilipenm>s) ; while both the male and the female Gall-fly of the 

 other Oak-gall (Q. singular is) ha^•e no such cloud. Immature specimens, 

 indeed, of tlie female Cynips q. sciilpta, cut out of the gall, do not show this 

 cloud; and it was probably from such that Mr. Bassett drew up his descrip- 

 tion, which says nothing of any such cloud. The male fly of Cynips q. 

 sculpta I have never yet met with. In any case, Harris's description (of his 

 nubilipennis) is so brief and indefinite, that not being sufficient to identify 

 either the gall or the insect satisfactorily, it should be entirely neglected and 

 thrown on one side, and we should adopt IMr. Bassetfs two names. To fol- 

 low any other rule in such cases as these, is simply holding out a premium to 

 slipslop, slovenly describers, who are the curse of Science. — See Osten-Sacken 

 in Proc. Ent. Soc. Phil. IV. pp. 355—6. 



^Similarly, I have bred the small moth Gelechia gallcegenitclla, Clemens, 

 from a Willow-gall made by a Gall-gnat, and likewise from two distinct kinds 

 of Oak-galls made by Gall-flies. Also Batrachedra salicipomonella, Clemens, 

 another small moth, from a Willow-gall made by a G-all-gnat, and from two 

 very distinct Willow-galls made bj'' two distinct species of saw-flies. (See 

 Proc. Ent. Soc. Phil VI. p. 273.) I may add here the hitherto unpublished 

 facts that 1 bred on June iGth from the Oak-gall Quercus inanis 0. S. , 

 which is made by a Gall-fly {Cynips), the Anorthosia punctipennclla of Clem- 

 ens; and three other distinct species of small moths, respectively, from three 

 other distinct Oak-galls, two of which are made by Gall-flies and one by a 

 Gall-gnat (Cecidomyia) . In all these cases, and in many others which I have 

 published, <he motlis aie clearly guests in galls made by other insects. 



•j-Westwood Introd. II. p. 331; Harris Injur. Insects p. 258; &e, &e. 



