116 THE ENTOMOLOGIiST. 



been bred from other hosts, but that its occurrence as a parasite 

 of one of the Sesiidse is new. This Tachinid probably attacks 

 another species of lepidopterous larva in June or July, the re- 

 sulting brood reaching the pupal stage in the autumn, and 

 remaining as pupse until the following spring. The life-histories 

 of the Tachinidfe are, however, scarcely known ; the number of 

 broods in a season, the various hosts infected by a particular 

 species, and the proportion of caterpillars they destroy is still a 

 very uncertain question. The fact of many Tachinidse being 

 parasitic on certain Lepidoptera, and thus helping to keep some 

 of the ravages of the latter under control, compensates in a great 

 measure for the pernicious habits of other members of the 

 Muscidae ; so that really some of the creatures many persons 

 often condemn as an unmitigated nuisance are, in various ways, 

 of the greatest service to man, and their bionomics of great 

 economic importance. 



I wish to express my thanks to Mr. C. J. Wainwright for help 

 received in connection with one or two of the species mentioned 



ODONATA IN GEEMANY.--I. 

 By E. E. Speyer, F.E.S. 



Last year (1907) I had the opportunity of making some 

 observations on Odonata in Germany. I spent the summer 

 from April till the end of September at Marburg-on-the-Lahu, a 

 University town lying just north of Frankfurt-on-the-Maine. In 

 April I had found two or three stagnant ponds, which seemed 

 suitable for Odonata collecting, and of course there was also the 

 river Lahn. 



On the outskirts of the town there is a large pond, lying 

 parallel with the river, and separated from it by a bank only. 

 At one end of it is a reed-bed, and all along it, on the opposite 

 side to the river, runs a high bank covered with grass and small 

 bushes. 



At the other end of the town, near the Southern Eailway 

 Station, is another large sheet of water some distance from the 

 river. This pond is surrounded by high and steep banks, 

 covered with trees and bushes on one side of the water, and with 

 high grass on the other. The water is ornamented with yellow 

 water-lilies and high reeds, the whole forming an ideal spot for 

 insect life. 



In the immediate neighbourhood there is no other stagnant 

 water, with the exception of two small ponds in a brickyard on 

 the road to Giessen. 



