HARDWICKE'S SCIENCE-GOSSIP. 



IT 



ON COLLECTING DIPTERA. 

 By E. Brunetti. 



IN recommending all collectors of insects, especially 

 beginners, to take up the study of Diptera, I 

 am aware that I am endeavouring to persuade them 

 to attack one of the least known orders of the whole 

 •class, and it is for this very reason that I so strongly 

 urge on all the necessity of rescuing the Diptera from 

 the chaotic state into which it has gradually fallen, 

 owing first to the small number of entomologists 

 actively working at this order, and secondly, to the 

 want of union between them. 



Union is one of the first and most important rules 

 to be observed in studying an obsolete group. If 

 each worker took up one or two families, or part of a 

 family, according to the number of species comprised, 

 and assiduously confined himself to his special group, 

 the task would be considerably facilitated, more 

 ■especially so if the life histories were also investi- 

 gated. 



It is much to be feared that less is known of this 

 order than any other, I mean, of course respecting 

 ■the British species. All the other orders are at least 

 fairly well known, it being almost unnecessary to 

 remark how much has been done in the Lepidoptera 

 by Messrs. Stainton, Morris, and Newman ; in the 

 Coleoptera by Dr. Sharp, Messrs. Waterhouse and 

 Cox ; in the Hymenoptera by Sir J. Lubbock and 

 Dr. Fitch ; in the Hemiptera by Mrs. Douglas, 

 Scott and Edwards ; in the Neuroptera by. Messrs. 

 McLachlan and Dale, and also in the Orthoptera. 



But when we come to the Diptera we find a most 

 lamentable absence of hard-working entomologists. 

 I believe the number is actually limited to four, 

 Messrs. Newall, Meade, Dale, and Cooke, of whom 

 at least one has restricted his observations almost to 

 a single family. 



Though beginners may do little beyond the mere 

 capture and netting of specimens, they may, in this 

 manner, become of invaluable assistance to those 

 possessing fairly representative collections and more 

 advanced knowledge of the order. 



I will mention an imaginary instance, to illustrate 

 more fully my meaning. 



Suppose the possessor of a good collection of these 

 insects is in correspondence with ten beginners ; 

 suppose also that none of these beginners care any- 

 thing about Diptera, but, to oblige their friend, they 

 ■capture a few flies when on each country excursion. 

 Considering the comparative abundance of individuals 

 •of this order, and the ease with which they may be 

 obtained everywhere on any warm day, it is not 

 unreasonable to assume each to catch ten specimens 

 •during each day's outing, which, on returning home, 

 I suppose them to set (this being a rather important 

 consideration). 



Most collectors manage to obtain at least ten days' 

 insect-hunting during the whole season, so that during 



that time each would obtain one hundred specimens 

 of Diptera in fair condition, which the young 

 entomologist would forward to his friend, who, on 

 receiving an equal number (approximately) from 

 each of his ten correspondents, would find himself 

 possessed of a thousand fresh specimens at the 

 termination of each season. 



This amount of material placed at his disposal 

 would undoubtedly be of very great value, it being 

 not at all improbable that some species new to the 

 British fauna would by these means be added every 

 year. 



I think this imaginary example should be sufficient 

 to show how much beginners may do by combining 

 to assist those more advanced than themselves ; they 

 also would gain by the transactions by having their 

 specimens named, besides the many advantages of a 

 more experienced correspondent. Should a series of 

 one species be sent, it would be advisable to return 

 some of the flies, but the owner of the larger collec- 

 tion should be allowed the unconditional pick of the 

 specimens ; in return, naming all those he does not 

 require, and returning them to the sender. 



And now, in mentioning the return, which I, at 

 least, am willing to make to those who will furnish me 

 with specimens, I am aware of expressing an opinion 

 that will meet with some disfavour from many 

 entomologists. 



I consider it would be a perfectly fair equivalent to 

 pay in money for the specimens forwarded, taking 

 them all round at so much a dozen, limiting, of 

 course, the number of specimens of each species sent. 



It appears to me easy to refute the imputation of 

 degenerating the science to a pecuniary consideration 

 by the following argument. 



Exchange is by all admitted one of the fairest and 

 most generally approved methods of increasing one's 

 collection. 



Now, if in return for, say, one hundred specimens 

 of Diptera forwarded me by a lepidopterist, I offered 

 him two or three dozen moths, he would undoubtedly 

 accept them, and each would probably be satisfied 

 with his bargain. 



Suppose, then, he gave me a list of his desiderata, 

 and, after sending me the Diptera, I bought several of 

 the species he required and forwarded them to him, 

 that also would be a fair transaction, I presume. 



What matters it then, whether he is, or I am, the 

 actual purchaser of the insects ? that is to say, there is 

 no difference between buying the insects myself and 

 then posting them to him, or sending him so much in 

 money to enable him to purchase them himself. 



So far as I am concerned, I shall be most happy to 

 pay a fair value for any consignments of Diptera 

 forwarded to me, should they be of species of which 

 I have not a sufficiently large series. 



I know that there are many collectors who would 

 forward me Diptera without asking for any retur 

 (I could mention several amongst my own corre- 



