74 Miscellaneous. 



Measurements (No. 1S066, female). — Leugth 30*5 millim, ; 

 reatest width 38 ; width between postorbital spines 19. 



The male is unknown. 



This species can be distinguished from other Thelphusidse by its 

 produced round-lobed front, narrow orbits, and numerous spines. — 

 Froc. Nat. Miis. vol. svii. no. UbO, pp. 25-27. (Communicated by 

 the Author.) 



The Bipterous Parasites (Sarcophagidte) of Locusts. — Apteny and 

 Parasitic Sterilization. By M. J. Kijnckel D'HEiiCtiLAis, 



Among Diptera the countless species comprised in the family 

 Muscidaj furnish their contingent of enemies of the Locust, some of 

 which attack their victims in the perfect stage, while others prey 

 upon the eggs which are deposited in the ground ; not content with 

 playing a beneficent role in contribating to a large degree to arrest 

 the multiplication of the Acridians, they present biological pecu- 

 liarities and possess physiological attributes which are worthy of 

 being recorded. 



AVe shall devote our attention in the first instance to the Muscidie 

 which i)rey upon Acridians. 



At the time of the great invasion of Xorthern Africa by migratory 

 locusts in. 1S66 it was found at different points in Algeria (military 

 subdivisions Aumale and Medeah) that Muscid larvae were present 

 in a certain number of these insects*. In 1889 the considerable 

 invasion of Stauronottis maroccanus gave an opportunity of making 

 fresh observations in the Department of Constantino, in civil as well 

 as in military territory ; I myself found around Constantine, which 

 was besieged by the Acridians, that a quantity of Stauronotus, as 

 well as of other species, svere affected ; but it was not until the 

 year 1890, at Teniet-el-Haad (Department of Algiers), that I was 

 able to carry out methodical investigations. Just as in the previous 

 year, I observed everywhere where the bands of locusts, escaping 

 from destruction, had acquired their wings, that numbers of 

 individuals crawled along among the herbage without having been 

 able to follow their companions, the flights of which traversed the 

 air. I had some sacks full of them collected : a few days afterwards 

 some hundreds of larva3 were crawling at the bottom of these sacks. 

 If the return of 1889 1 showed that 65 per cent, of the locusts 

 lagging behind were infected with parasites, that which I made in 

 189U gives the number thus affected as 75 per cent., and a post- 

 mortem examination revealed the fact that each Stuuronottis con- 

 tained one, two, or three Muscid larva?. 



These larvte hid themselves immediately in earth which was 

 supplied to them in order to undergo the transformation into the 



* Letter of the General of Division commanding the province of 

 Aloiers (General de Wiinpffen) to the Marshal the Governor of Algeria 

 (M'iirsbal MacMahon), 2oth July and 0th August, 1800: registered 

 DOS. 2541 and 1^770. 



t Return drawn up at my initiative by the exertions of M. L. Tardieu, 

 administrator of the mixed commune of ll'hiras (Department of Con- 

 stantine). Observations of M. Chartrousse, deputy-administrator. 



