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466 



Ball (E. D.). How to Control the Grasshoppers. — Utah Agric. Coll. 

 Expt. S(a., Logan, Bull. no. 138, February 1915, pp. 79-116, 

 6 plates. [Received 28th May 1915.] 



The migratory grasshopper, Camnula -pellucida, occurs in the U.S.A. 

 throughout the mountain region of the West and extends across the 

 continent to the north. Serious outbreaks have been reported from 

 Idaho, Wyoming, Montana and Utah. The young hatch in May or 

 the beginning of June ; migration takes place in late June and July 

 and oviposition begins in August. Migration is almost always in a 

 south-east or southerly direction and reaches a maximum speed on 

 warm, sunny days. Water will stop migrations entirely. The 

 breeding grounds selected are dry and dusty, usually strongly alkaline. 

 The eggs are laid in the ground in masses of from 19 to 23 ; each female 

 lays about 40 eggs. The greatest damage in Utah is to pasture land 

 and grain crops. In addition to the generally known control methods, 

 such as destruction of eggs by ploughing, trenching and spraying, a 

 special " balloon " catcher has been devised. This consists of a bag 

 fitted to a frame which is drawn over the field. The eggs are 

 destroyed to a large extent by a parasitic fly and by a predaceous 

 species of Calosoma. The non-migratory forms, Melanoplus jemur- 

 rubruni, M. ailantis and M. vittatus attack lucerne crops and young 

 orchards. A trap, similar in principle to the " balloon " catcher, has 

 given good results in capturing these species. It consists of a curved 

 sheet of tin, about 2i feet high, below which is fixed a box about 16 

 feet long by 2 square feet in section. The apparatus is drawn over 

 the field and the grasshoppers, jumping against the tin surface, shde 

 down into the box below. Young orchards can be adequately pro- 

 tected by the use of poisoned bran mash. The eggs are attacked by 

 the same enemies as those of C. pellucida. The larvae and adults are 

 controlled by the larvae of the hair snake, by red mites, and by a 

 fungus disease caused by Empusa grylli. Anabrus simplex seriously 

 menaces crops in the spring. When the swarms reach low lands, they 

 can be checked by the same methods as are apphed to grasshoppers. 



Thompson (W. R.). Sur un Diptere Parasite de la larve d'un Mycetho- 

 philide. [On a Dipterous parasite of the larvae of a Mycetophilid.] 

 —G. R. Soc. Biol, Paris, Ixxviii, no. 5, 19th March 1915, 

 pp. 87-89, 1 fig. 



Parasitism of Diptera by Diptera seems to be rare. Roubaud, in 1906, 

 described the Tachinid, Bucentes (SipJiotia) cristata, F., as parasitising 

 the larvae of Tipida 7naxima, and according to Bezzi and Stein, Admontia 

 arnica is also a parasite of a Tipulid. The author records a Dipterous 

 parasite of the larvae of a Mycetophilid of the genus Sciara, the con- 

 ditions differing from those of the cases cited, in that, instead of 

 attaching itself to the tracheal system of the host, this larva inhabits 

 the general body cavity and is therefore dependant for oxygen on such 

 as is dissolved in the plasma. The larva is believed to be either a 

 Dexiid, or more probably a Tachinid. 



