Entomological Society. 7687 



remarked on the rarity of Lepidoptcra during the present season, which was probably 

 to he attributed to the cold and wet of the last summer. 



Mr. Waterhouse observed that he never remembered to have seen so few Coleoptera 

 as in the present summer ; and Mr. Smith stated that Hymenoptera had hitherto been 

 extremely scarce ; other members present remarked that their experience confirmed 

 these statements. 



Professor Westwood observed that although mangold wurzel was usually considered 

 almost free from insect attacks, yet the crops this season in many distant counties 

 (Devon, York, Hereford, Oxon, &c.) were attacked by the larvae of a Dipterous insect 

 (fam. Muscidae, and probably allied to Tephrilis), which mine into the leaves, forming 

 large blotches, which soon shrivel up. It was evident, therefore, that the previous 

 season had exerted no influence in checking the production of this obnoxious species, 

 and in like manner the Aphis of the cherry and plum, and the black Aphis of the bean, 

 as well as the gooseberry sawfly, had been most extensively abundant and injurious 

 this season. 



Mr. McLachlan read the following : — 



Remarks on the Supposed Influence of the Food of the Larvae in causing 

 Variation in Lepidoptera. 



" The Natural History of Coleophora olivaceella appears to have some bearing on 

 the question so often asked at our meetings, 'Are not many of the so-called species of 

 Micro-Lepidoptera merely modifications of one or more previously described species 

 produced by the larvae having fed on different plants?' It appears to me that, as has 

 often been said before, this question would never have arisen but for the almost micro- 

 scopic dimensions of the creatures ; and at the same time I would premise that I am 

 decidedly opposed to the creation of species on imaginary diflferences, and that it is 

 possible that some few, now considered distinct, may, when their habits become more 

 known, sink to the rank of varieties ; but that food has any more than the very slightest 

 influence in causing such variation is, I think, very doubtful. Coleophora olivaceella 

 is an insect which, in the perfect state, is very similar to C. solitaiiella, and, moreover, 

 the two larvae feed for at least the greater portion of their existence as such simultane- 

 ously on the same plaut (Stellaria Holosiea) ; but the cases of the larvae and their 

 mode of feeding are so very diff'erent that all who believe in species at all must con- 

 sider them distinct. These difi'erences are not worth pointing out here ; they have 

 already been elaborately detailed by Mr. Stainton in the 'Entomologist's Annual* 

 and ' Intelligencer,' and by M. Fologne in the ' Transactions de la Soeiele Entomo- 

 logique Beige.' Take again Nepticula ulmivora, which is extremely similar to 

 N. marginecolella, and both larvae mine at the same time in elm leaves, sometimes 

 sharing the same leaf, yet the larvae difl'er in colour, and mine in a distinct method, 

 and each larva invariably produces an imago having small though constant distinctive 

 characters, so that no one can believe them identical. 



" Similar instances might be multiplied among the Micro-Lepidoptera almost ad 

 infinitum. Yet it is constantly hinted that two insects, which— in addition to having 

 equal peculiarities with those before mentioned — feed in a different plant, may be only 

 varieties of one caused by the latter circumstance. Now, on the contrary, does it not 

 seem more natural to suppose that, if there were doubt about the matter, this should 

 rather turn the scales, and cause us at once to consider them distinct? In many 

 genera in which the individual species vary the least the larva of each species affects 



