120 BRITISH ICHNEUMONS. [Polysphincta. 



cally important notices have been published respecting their develope- 

 ment. Some of these do not specify the insect referred to and must, 

 consequently, be treated generically. In spite of what Ratzcburg says to 

 the contrary, we may I think, assume that it is invariably the spiders them- 

 selves, and not their eggs or their webs, which are attacked by Poly- 

 sphinctae. 



DeGeer relates the history of an ichneumon emerging from a small 

 parasitic white larva, which he had seen sucking the body of a spider, 

 spinning a geometrical web ; the latter died in consequence of its attack 

 and the larva spun for itself an oblong, elongate white cocoon of fine silk 

 in the centre of the spider's web, from which eight days later emerged a 

 small black ichneumon with filiform antennae, yellow legs and two 

 yellowish thoracic lines (Mem. ii. 863 ; pi. xxx, figg. i — 3). 



Dilwynn actualb' witnessed the oviposition — a circumstance rarely 

 recorded : — " 1 have frequently observed a small black species of ichneu- 

 mon successively deposit an G<g^ on the abdomen of two or more spiders 

 on the sandhills near Swansea ; and I doubt whether the spider had in 

 any case arrived at its maturity. On one of these occasions I perfectly 

 recollect having seen a young brood of dark-coloured spiders on Cromlyn 

 burrows, and that when the ichneumon hovered over them they appeared 

 alarmed, and instinctively endeavoured to escape" (Swansea Coleop- 

 tera, 27.) 



Walckenaer took a specimen of a spider, Linyphia montana, Clerck, 

 (which I have captured in Suffolk), sitting on its nest in the Pyrenees and 

 says that it had "une lar\'e blanchatre pareille a une petite chenille le long 

 de son dos. L'abdomen de I'Araignee avait une ligne et quart de longueur 

 et la larve deux tiers de ligne." He gives an inadequate description of 

 the parasite, of which he knew nothing and, indeed, thought might be a 

 chrysalis (Hist. Nat. Ins. apteres. ii, pp. 176 et 233). 



Another unspecified larva of Polysphincta is mentioned by Blackwall 

 (Ann. Nat. Hist. 1843, pp. i cf siqq) on an adult female of his Lcpty- 

 phanies minutus, discovered on 26th October, 1841. It differed in its size 

 from those of P. carhonata described earlier in the same paper ; but, 

 although it destroyed the spider, it failed to attain maturity, after spinning 

 its own cocoon on ist February, 1842. 



Prof. Westwood exhibited " an ichneumon and an Epcira, the larva of 

 the former being an external parasite on the body of the spider" at a 

 Meeting of the Ent. Soc. Lond. on 4th January, 1869. 



Polysphincta (5'fw/'j,Tschek, a central European species, has been bred from 

 Epcira diadcmata, Clerck ; and one of its larvae, about three millimetres 

 in length, was found on July 25th, 1875, on the back of the abdomen of a 

 Thcridion spider about three miles from Dantzig. By the next day it had 

 doubled its size and was shining white with red spots, and the spider was 

 lying dead on the earth. The larva then gradually became whiter in 

 colour till on the 27th it spun a thin, transparant, white and oblong cocoon, 

 wherein it later turned to a yellowish pupa. Fourteen days after the spi- 

 der's death, on August 9th, a male P. boops emerged (Deut. Ent. Zeit. 

 1877, p. 285). Brischke, who made the above observation, bred the male 

 of another Continental species, P. rujipes, Grav., which is not unlikely to 

 occur with us, from Epeira diademata at Konigsberg.* 



*It is interesting to note the, I believe unpublished, fact that Arachnid ektoparasites are also found 

 among the Chalcididac: Rev. O. Pickard-Cambrid^e tells me that he has bred the beautiful little 

 £Kcyrf!(S sj'/fiKS, Dalm., wliicli has been bred iroin a coccid in Prussia, from the somewhat large 

 salticid spider, /lf/!(ro/)s u-t«st/;)n7i(s, Clerck, in Dorsetshire. It certainly passed its whole larval 

 existence attached to the outside of the spider's abdomen, until the moment of the imago's emergence. 



