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little slinrter than tlie latter. Tlie author points out that these 

 flies, at least in his experience, never lay their e<><>s directly 

 upon the material on which the larvae are to breed, but near it. 

 In his opinion this cannot be regarded as accidental, but is done 

 purposely, in order to prevent the tiny eg'gs from being damaged or 

 destroyed by other flies or insects, if laid on the same material. 

 Near St. Petersburg the eggs of H. dentipes hatch 36 hours after 

 oviposition. 



The larvae are described in all their stages. They are more 

 or less long-lived, their development depending on the tempera- 

 ture, as well as on the quality and quantity of the food. In 

 certain experiments the larvae lived long enough to allow of their 

 devouring two and even three consecutive broods of larvae of 

 M. domestica. When mature they pass into the earth, where 

 they remain for some time before pupating; those which buried 

 on 23rd July emerged only on the 11th August. In the latitude 

 of the Government of St. Petersburg this fly can hardly produce 

 more than two to three generations in a year. It is assumed by 

 vspecialists that this fly is found everywhere in Europe. 



The author further describes his observations on the insect 

 fauna of the Southern part of the Government of Stavropol 

 (North Caucasus), made from July to August, 1911. He visited 

 there a number of newly founded farms which in his opinion, 

 as regards their fly fauna, greatly resemble oceanic islands 

 which are gradually inhabited by immigrant species, the 

 farms being situated in a dry waterless steppe. There was a 

 total absence of Calllpliora and Lucilia caesar, the place of the 

 latter being taken by L. sericata, w^iicli, however, contrary to 

 experience in Holland and in England, is of no importance to 

 sheep; likewise Alvsca corvicina, Pyrellia cadaverina, Myosjnla 

 meditahunda, Mydaea vrhana, Polyetes albolineata, and many 

 other species of flies that are quite common on dung in other 

 places, were not to be found. Hydrotaea dentipes was also 

 absent, whilst Musca ovipara and Pla^vemyla {Mvsca) vitripennis 

 occurred seldom and then only singly. Besides the great heat, 

 which makes the breeding of these flies almost impossible, owing 

 to the dung drying too quickly, the fierce competition of numbers 

 of dung-beetles would be against them. 



The author found Mxiscina stahulans on these farms, but very 

 seldom. Baits of rotten meat or of rotten melons attracted a 

 remarkable collection of flies, the most numerous hein^ Sarcoj)hagn 

 latifrons and some species of viviparous flies, such as Sarcophaga 

 melcmura, S. cruenta, WoTilfalirtia rnagnifica (which is very 

 annoying and dangerous to sheep in these parts, some 25 per 

 cent, and even more being yearly infested by its larvae), W. 

 halassogloi, Lucilia sericata, Phorinia regina, and two species of 

 Tachinids — CnephaUa hucepliala and Tachina larvannn. The 

 author points out that of these vivaparous flies two species of 

 Sarcophaga attack and parasitise a grasshopper, Calojdcnu^ 

 italicvs, which in that year was widely distributed in this district; 

 while WohJfdhrtia J)(d(usogloi in the larval stage is parasitic on 

 the eggs of a large species of locust. The presence of the 

 Tachinids was explained by the appearance in that year of great 



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