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AGRIOTYPUS ARMATUS (WALKER), CURTIS: 

 ITS LIFE-HISTORY AND GEOGRAPHICAL DISTRIBUTION. 



BY PROP. FR. KLAPALEK. 



Pig. B. 



Fig. C. 



Fig. D. 



Fig. E. 



Fig. A. 



HISTORICAL SKETCH.* 



This most interesting species of Ichneumonidce was first found by Walker on 

 the Clyde, near Lanark, and was described and delineated by Curtis in his " British 

 Entomology," No. 389, in the year 1832. In the Entom. Mag., 1835, vol. iii, p. 412, 

 we learn from a short notice by Walker, that he observed the female of Agriotypus 

 descending beneath the surface of the water, and remaining there for ten minutes ; 

 he asks whether it does not deposit its eggs in the aquatic larvae of some Neuropterous 

 insect ? At this stage remained the knowledge of the habits of Agriotypus until 

 the year 1857,t when von Siebold reared the insect from cases of Trichostoma 

 picicorne, Pict. He described, in a short paper (L T eber Agriotypus armatus in 

 Trichostoma picicorne, in Amtl. Bericht. d. Versamml. d. Naturforscher in Carlsruhe, 

 1858, p. 211), the cases which enclosed the parasite, and which were furnished with 

 a long band-like appendage at their head end. The cases were sent to him by Dr. 

 Kriechbaumer from Munich, and von Siebold himself found at the same locality 

 many cases with larvae and nymphs of Aspatherium picicorne, some of which in- 

 cluded the parasite. The females of Agriotypus were found creeping on the stones 

 in the water, and the males flying above the water. 



In the following year (1858) E. Holmgren, not knowing the original description 

 by Curtis, described the insect as Crotopus ahnormis (Ofvers. k. Yet. Acad. For- 

 handl., 1858, t. xv, p. 354). He gave some remarks as to its systematic position 

 and a detailed description, but knew nothing of its development. His dimensions 

 (If — 2'") are smaller than those given by Curtis. There can be little doubt as to 

 the identity, but the habitat is peculiar. He says : — " Habitat in graminosis ad 

 littora lacuum per Sueciam meridionalem rarius ; scilicet in Scania (Munch af 



* I am much obliged for many data respecting the more recent literature to Mr. McLachlan 

 and Mr. Bridgman. 



t Compare Westwood, Introd., vol. ii, p. 142 (1840). 



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