1879.] 45 



the shape of parasites and other insects which prey upon them, and the artificial 

 remedies which may be adopted to arrest their ravages. It is also intended to 

 extend the collection to insects which are either directly or indirectly beneficial to 

 man, and the productions of the more useful species. The collection is exhibited in 

 its present state in the hope that attention may be directed to the subject, and that 

 those who have the opportunity may be induced to observe the habits of insects 

 which injuriously affect their crops and plantations. It is also hoped that farmers, 

 gardeners, timber and grain merchants, &c., will assist in increasing and perfecting 

 the collection which is intended to be permanently placed in the Devon and Exeter 

 Albert Memorial Museum. The arrangement adopted is different from that in the 

 Bethnal Green Museum collection of economic entomology, where each order of 

 insects is grouped separately. In this, each case is devoted to the insects injurious 

 to one plant or groups of allied plants. 



The illustrative vignettes have been executed by Miss G-. Ormerod and the 

 Misses Floud. They are in some instances original drawings from the living object, 

 and in others have been adapted from various sources, especially Curtis's Farm 

 Insects, and the early volumes of the Gardeners' Clu'onicle. The models are the 

 work of Miss E. A. Ormerod. The larvae were prepared by Mr. R. L. Davis of 

 Waltham Cross, and others. The whole collection was arranged by Mr. D'Urban. 

 Specimens of insects that are notably injurious or beneficial, and also small specimens 

 (such as could be sent by post) of portions of the plants or timber injured by them, 

 or of their useful products, will be gratefully received and acknowledged by E. A. 

 Ormeeod, Dunster Lodge, Spring Grove, Isleworth, near London ; or by W. S. M. 

 D'Urban, Curator, Albert Memorial Museum, Exeter. — Exeter : June, 1879. 



On the preservation of Trichopterous insects. --Jiwv'mg the past five years 

 I have had to examine many thousands of European Trichoptera, including the 

 types of nearly all the described species. Much time has been lost, owing to 

 the fact that a vast majority of these specimens were in an unexpanded con- 

 dition. No Trichopterous insects can be properly studied in this condition. They 

 should be prepared precisely as if they were Lepidoptera. It is easy for an 

 Entomologist to expand species caught in his immediate vicinity, or upon short ex- 

 cursions ; but en voyage there is more difficulty, and in the majority of cases the 

 preparation of captures for the purposes of study must be deferred till some future 

 time. With the larger species this is not very difficult, though it does not always 

 result in the production of " cabinet " specimens. With the smaller it is very 

 different. Notwithstanding the greatest care in relaxing, it commonly arises that 

 the wings will not separate from each other, nor from the abdomen. I have recently, 

 therefore, adopted a plan that, to a large extent, gets over the difficulty. Immediately 

 after jo««»2»5r the insect, I S/oic upon it gently from behind, separating the wings 

 from each other and from the abdomen, and allow it to dry in that position. Speci- 

 mens thus treated are usually immediately fit for study, and mostly require no further 

 preparation ; or if it be desired to " set " them, they are in a much better condition 

 for relaxing. This subject is one of the greatest importance, for most of the in- 

 complete and unrecognisable descriptions given by authors, have I'esulted from their 

 having been drawn up from unexpanded materials. 



The plan just explained will apply equally to PsocidcB, small Semerobiidce, &c., 

 and perhaps also to Mlcro-Lepidoptera, PsyllidcB, small Hymenoptera, and a host of 

 minute insects generally. Experience has proved to me that its value cannot be too 

 highly estimated, and I am glad to know it is being adopted by at least one friend 

 to whom I verbally suggested it. — R. McLachlan, Lewisham : June, 1879. 



