Notes upon some aquatic Hymenoptera 



(Anagrus Brocheri SCHULZ 

 Prestwichia aquatica LUBB., Agriotypus armatus WALK.) 



by Kai L. Henriksen 



Assistant at Zool. Muséum of Copenhagen. 



In 1918, the author gave an account of ail then known aquatic 

 Hymenoptera of Europe (1), in which was collectée! facts gathe- 

 red from littérature as well as a considérable number of hat- 

 chings ci différent forms, not hitherto mentioned in littérature. 



Only in few instances I had so much material myself that I 

 could folio w the developmental stages of a species, but in 

 Anagrus, Prestwichia and Agriotypus I fortunately had enough 

 for that purpose, and I thank Mr J. A. LESTAGE for kindly pro- 

 posing me to publish the results respecting thèse forms in this 

 periodical. 



I. Anagrus Brocheri ScHULZ. 



It is a well known fact that two species of Anagrus are bound 

 to freshwater, viz. suhjuscus FoRSTER, and Brocheri ScHULZ. 



Anagrus subfuscus FôRST. was reared by HEYMONS (2) from 

 ,, Calopteryx virgo " — eggs inserted in the underside-tissue or 

 Nymphœa- and Nuphar-leaves ; RUSCHKA and THIENEMANN (3) 

 reared it from ^4gnom'ne-eggs in leaves of Stratiotes and Nuphar; 

 RlMSKY-KoRSAKOW (4) records it from Agrion- and Lesfes-eggs 

 in the underside of Nymphœa- and NupharAeaves and in Calla- 

 stalks. The eggs placed in the underside-tissue of Nymphaea- 

 cean leaves originate, as reiterated Danish rearings (by Dr. 



(1) Entomol. MeddeL, XII, 1918, pp. 137-251. 



(2) Deutsche Entom. Zeit., 1908, p. 141. 



(3) Zeit. wiss. InsektenbioL, IX, 1913, d. 82. 



(4) Revue Russe d'Entom., XVI, 1917, pp. 22-225. 



