5168 Insects. 



and nine females; a friend has also taken a few. Andrena Clarkella, upon which it 

 is parasitic, has also been very plentiful, and may still be found. — Frederick Smith; 

 British Museum, April 21, 1856.— [Id.] 



Uncertain Dates of the Appearance of Insects : Suggestions for keeping a Record 

 of such Dates. — On the 11th of June I saw three specimens of Gonepteryx Rhamni, 

 at Holbroke, near Ipswich. Two of these, male and female, were in fine condition ; 

 the third, a female, was much wasted. In the discussion last year the Rev. J. Greene 

 stated that he did not believe this insect was ever seen in June, and that the advocates 

 of its double-broodedness must see it fine in June to prove their case. Now I am 

 willing to admit that the present is an exceptional season, in consequence of the cold 

 spring, for, as Mr. Doubleday remarked in a private letter, we see spring and summer 

 insects mixed together. The weather, in fact, has exercised a controlling influence in 

 the development and appearance of the Lepidoptera: but still I think the appearance 

 of insects which are known to hybernate, quite fresh, in the middle of summer, gives 

 a somewhat new direction to our inquiries on the subject of hybernation ; it points 

 out clearly, to my mind, that both parties are right, — that part of the autumn brood 

 hybernates, and the rest remain quiescent until the spring of the following year. I 

 saw Libatrix at sugar last night, as fresh as possible, and in considerable number. 

 Surely the eggs laid by these late insects will not produce insects in the autumn, ap- 

 pearing at the same time as those which flew in the warm days of April. It is a fair 

 inference that the latter will produce the hybernating specimens, the former those 

 which pass as pupae through the winter. The influence of weather, confinement and 

 feeding upon the development of insects is a very interesting subject. I do not, how- 

 ever, go the length of ascribing these influences as the invariable cause of the irregu- 

 larity. Nature has defined her laws, and depend upon it they are not broken so easily 

 as we are apt to imagine. Many years ago I used to remark that Anthocharis Car- 

 damines always appeared on or about the 22nd of April : for the last ten years I have 

 seldom seen it before the middle, and this year not till the end, of May. The reason 

 I assign for it is this : the insect and the plant upon which its larvae feed are equally 

 affected by atmospheric influences : the development of each is promoted or protracted 

 by the same cause, and this beautiful provision is evidently designed to prevent the 

 extermination of species. Every collector knows that in most species the first insects 

 he takes are always males : this is evidently designed, though the cause may not be so 

 obvious. It is more difficult, perhaps, to account for the irregularity in the appearance 

 of larvae subjected to precisely the same treatment: thus of two cocoons of Notodonta 

 cucullina, given to me in the spring, and kept, as they themselves had formed their 

 pupae-cases, buried in dried grass, one came out June 5th, the other June 18th. Again, 

 insects appear sometimes in different parts of the country at different periods. Thus 

 Mr. Hodgkinson reports having taken Eurymene Dolobraria, in Westmoreland, on 

 Whit Monday. I never saw it here — a southern locality — before the beginning of June. 

 My brother took in April one of the dark varieties of Harpalyce Silacearia, the H. insu- 

 lata of Haworth. I do not take the light species here till the end of June. For these 

 reasons I think it would be very interesting if collectors would keep a note and publish 

 the first appearance of insects in their particular localities : I will send you a list if you 

 wish it. — C. R. Dree } Stricklands, Stowmarket, June 20, 1856. 



