194 SUxMMARY OF CURRENT RESEARCHES RELATING TO 



Notes on Common Flies.— G. S. Graha^i-Smith {Parasitologij, 

 1919, 11, 347-84, 2 pis., 23 figs., 2 charts). The curve indicatmg the 

 number of flies caught in a trap baited with excrement corresponds with 

 the curve for maximum temperature recorded bj a thermometer exposed 

 in the sun. Flies spend a very large proportion of their time in cleaning 

 themselves and usually follow a definite routine. Empusa disease occurs 

 in a good many species. Certain Gamasid mites destroy both fly eggs 

 and young larvae. Certain species of beetles destroy large numbers of 

 fly puparia. Numerous parasites were obtained from naturally infected 

 fly puparia, especially species of Chalcidida^ and Braconid^. The 

 Chalcid Melittohia acasta frequently parasitizes puparia already infected 

 with the Braconid Alysia manducator. The males, which are blind, 

 unable to fly and relatively few in number, reach maturity before the 

 females in the same puparia, and the stronger specimens destroy the 

 weaker. The males never leave the puparia in which they hatch, but 

 mate with the females before the latter escape from the puparia. 

 Fertilized females lay large numbers of eggs from which a few males 

 and numerous females develop. Virgin females only lay a few eggs, 

 from which males develop. If fertilized subsequently, numerous eggs 

 are deposited which develop into both males and females. These 

 parasites oviposit in puparia, not in larvae. The Brachonid Alysia 

 manducator attacks large larvae ; some of the imagines emerge in spring 

 and others in autumn, one from each puparium. Virgin females lay 

 numerous eggs which develop into males. J. A. T. 



Mosquitoes.— F. W. Edwards {Puhlications British Museum, Kat. 

 Hist., 1916, Economic Series, 4, 1-19, 6 figs.). An admirably clear and 

 terse account of the general characters and life-history of mosquitoes, 

 which are grouped for practical purposes as domestic, stream and pool, 

 sylvan, and swamp mosquitoes. The distinctive features of the Anopheles 

 mosquitoes are discussed, and the relations of mosquitoes to malaria, 

 yellow fever and elephantiasis are briefly dealt with. Practical measures 

 are also discussed. J. A. T. 



Anopheles crucians. — C. W. Metz (Beports U.S. Public Health 

 Service, 1918, 495, 215G-69). This species occurs along with A. 

 punctipennis and A. quadrimacidatus in the gulf coast region of the 

 United States. It is a swamp mosquito ; it seemed to live on non- 

 living vegetable debris ; it was breeding prolifically at the beginning of 

 April and continued breeding until late summer at least ; it will become 

 distributed over an area within approximately 7,000 feet of the source. 



J. A. T. 



Sense-Organs in Antennae and Palps of Diptera.— K. M. Smith 

 {Proc. Zool. Soc, 1919, 31-G9, 4 ])ls., 43 figs.). An interesting compara- 

 tive study, very abundantly and clearly illustrated, of " sense-pits " and 

 similar structures. Each component element consists of a large, modified, 

 hypodermal cell, above which is a very thin-walled chitinous process, 

 rising from the thicker chitin of the general surface, and of a nerve- 

 iibre which runs close up to the base of, if not actually into, the 



