297 



RlMSKY-K0RSAK0V(M.). Kl* SionOrJM BOAHblXT. HataAHMKOBl*. [On 

 the Biology of parasitic aquatic Hymenoptera.] — « HtypHaJlli 

 ripMKnaAHOM 3HTOIIonoriH.» [Journal of Applied Entomology], 

 Kiev, vol. 1, no. 1, 1917, pp. 1-7. 



Parasitic Hymenoptera living in water possess some practical 

 importance as being enemies of certain voracious aquatic insects that 

 prey on fish fry. In addition to some Braconids and Chalcids, they 

 include a number of minute species of the family Mymaridae, 

 parasitic; in the eggs of different insects. The author's observations 

 on these were carried out in parts of Russia and Finland and also 

 in South Germany. 



The most common species found in most ponds, ditches, etc., is 

 Prestu'ichia aqnaiica, Lubb. This insect winters in the larval wStage 

 in the eggs of various Dytiscid beetles, deposited in the stems of water 

 plants. In the north the adults emerge m May ; they are able to 

 swim by means of their legs and also to jump with the aid of their 

 wings, but do not fly. In dry tubes they die in a few hours, while in 

 moist air they are able to live several days. In May they oviposit 

 in the eggs of larger beetles, such as Dytiscus and Cybister, 50 or more 

 eggs being laid in each egg of the host. The larvae hatch in 2-4 days, 

 the larval stage lasting 8-15 days and the pupal stage 12-15 days. 

 The adults remain for one or two days inside the egg during which 

 time pairing occurs. The adult life outside the eggs continues for 

 10-15 days. The second generation appears at the end of June or 

 beginning of July. This generation oviposits again in the eggs of 

 other Dytiscids, the eggs available at that time being those of Acilius, 

 Agabus and other smaller species ; from 8-15 larvae of the parasite 

 breed in each of these. A third generation appears in July and a 

 partial fourth one in August. 



The females are dimorphic, some of them having rudimentary 

 wings like the males. As a rule the females emerging from one egg 

 are all of one form, especially in those bred from the smaller eggs. 

 From the larger eggs both forms emerge, which is due to the fact that 

 several females oviposit in them. Another species parasitising the 

 eggs of Dytiscus, is Anaphes cinctus, Hal. {Polynema nafans, Lubb.). 

 It is less common than Prestwichia and little is known about it. A 

 third species, Anagrus subfuscus, Forst., parasitises the eggs of dragon- 

 flies of the genera Agrion, Lestes and Calopteryx. Only one parasite 

 occurs in each egg. This species is less adapted to life in water and 

 is very active, jumping, and even flying, in the air. Several other 

 species, not yet identified, were also observed and reared. 



Tarnani (Prof. I. K.). OpraHHsai^ifl HaSniOAeHiM HaA"b WMSHbio 

 MaMCKaro wyna npn nocTOAHHoii KoMMCciM no/itcHOMyonbiTHOMy 

 A'b/iy. [The Organisation of Observations on the Biology of Melo- 

 lontjia by the Permanent Commission on Forest Experimental 

 Work.]— «}KypHam» flpuKJiaAHOM 3HTOMonoriM.» [Journal of 

 Applied Entomology], Kiev, vol. 1, no. 1, 1917, pp. 8-21. 



The author was deputed in 1911 by the Forestry Department to 

 investigate the infestation of tlie forests of the governments of Tambov, 

 Vladimir, and Samara by larvae of Melolontha. These were found 



