186 THE entomologist's record. 



eat ash. If so, I should be much obliged. — Hope Alderson, Hilda 

 Vale, Farnboro', Kent. July 2,'^fh, 1890. 



Insect Parasites. — The spider referred to by Mr. Milburn, of 

 Darlington, in the Entom. Record (vol. i., p. 133), is Chagleiiis venii- 

 stissimus. Caradrina cubicularis is frequently infested by it, probably 

 through the moth's habit of resting in hay-stacks, etc. Last June I 

 was unable, through pressure of work, to set immediately a couple of 

 Agrotis ashivorthii. I placed them in a relaxing pot nearly full of 

 damp sand. On the sand was a piece of brown paper to rest the 

 moths upon. In a couple of days I found the moths attacked by a 

 host of similar, but white, spiders. They had eaten through the paper 

 and attacked the moths. I have not got to the end of the puzzle yet. 

 There was apparently, nothing in the pot but beaten sand, which, I 

 ought to say, had been there a couple of years, a few drops of water, 

 and the brown paper. The pot stands in a warm room, and is covered 

 by a layer of damp cloth which fits closely under the tight earthenware 

 lid. — J. Arkle, Chester. 



Killing Lepidoptera. — Notwithstanding the praises lavished upon 

 ammonia, I still prefer the cyanide bottle, the active agent in which, by 

 the way, is not cyanogen, but hydrocyanic, or prussic acid. The great 

 objection urged against the cyanide bottle is that it makes insects so 

 stiff as to render setting difficult. If, however, the insects be left in 

 the bottle for forty-eight hours they will be found quite as supple and 

 easy to set as if killed by ammonia, and will remain so for nearly a 

 week.i The advantages of the cyanide bottle are its much greater 

 handiness and decidedly more rapid action. This last is an important 

 point, as the more rapidly an insect is killed the less chance is there 

 of its knocking itself about in the death-struggle. A great objection to 

 ammonia is the number of species whose colour is damaged by its 

 action, as testified by its advocates. There are a few, such as Agriopis 

 aprilina, Hylophila prasinana and Aielanargia galatea, whose colour is 

 injuriously affected by the cyanide, but they are much less numerous, 

 and in these cases I use chloroform. Mr. Tutt's observation that 

 insects killed by ammonia dry much more quickly than those killed by 

 cyanide puzzles me. It is difficult to see why the mode of killing 

 should influence the rapidity of evaporation of the fluids of the body. — 

 Francis John Buckell, 32, Canonbury Square. 



Killing Libellula depressa. — On May 24th I visited Epping 

 Forest on my first excursion in search of dragonflies, having earlier 

 found the larvse abundant in the many pools. I carried with me a small 

 homoeopathic phial filled with oxalic acid in solution, and a small litho- 

 graphic pen in case. One prick of the pen filled with the solution in 

 the thorax of the depressa was sufficient to kill it, and the specimens 

 were in good condition for setting in the evening. The smaller species 

 I boxed, and killed with a cyanide bottle on reaching home. — R. 

 MarshxMAN Wattson, 14, Narford Road, Upper Clapton, N.E. June 

 28M, 1890. 



^ This is exactly what I say. See Dr. BuckelFs last sentence. 



