19^2.] Gl 



swarrua for some years at least, Lut this is not sure, as previous swarms Lave 

 not been critically examined. I saw the rooms on May 26th, 1921, but there 

 was then no trace of flies or Clialcidids, alive or dead, exposed or concealed ; 

 but this must be attributed partly to thorough cleaning up of dead and torpid 

 insects. The rooms face gardens and park-land. 



J'evei/, Switzerland. Dr. Charles Ferriere, of the Museum at Berne, wrote 

 (March 12th, 1919) that he bad seen in October 1916 thousands of Chalcidids 

 in a house near Vevey, in rooms facing South, and had determined them as 

 Stenninaltis imtscarum, but not with entire certaintj'. 



The occurrence of the Stenomcdus in company with hibernating flies 

 is discussed by Major T. K. Gaskell and Dr. Waterston, " Scottish 

 Naturalist," 1916, pp. 139-14'2. The places iVom which the latter had 

 seen samples are Largo, Fifeshire (in company with the Limnopliora 

 and several other flies) ; Swindon, Gloucestershire (in company with 

 Limnopliora and Follenia rudis) ; and Hever, Kent (on windows in 

 Mr. Meade- Waldo's house, xii.1915). 



University Museum of Zoology, Cambiidge. 

 Fehruary Qth, 1922. 



NOTES ON THE BIONOMICS OF AN APHIDOPHAGOUS FLY OF THE 

 GENUS LEUCOPIS IN THE ANGLO-EGYPTIAN SUDAN, 



BY E. COTTAM, 



Entomological Laboratory Assistant, 



Wellcome Tropical Research Laboratories, Khartoum. 



Dm-ing November 191-1 the larva of a small silverj'-grey fly 

 belonging to the genus Leuco])is w^as noticed feeding on the dura aphis 

 {ApJiis soiyhi Theob.), and the following year, fi-om February to April, 

 an opportunity presented itself of studying its habits in the vicinity of 

 Khartoum. A croj) of dura {Sorghum vulgare Pers.) growing at the 

 Mogren — the junction of the Blue and White Niles — was heavily in- 

 fested with A. sorghi, and in company with the larvae of the syrphid 

 {Sgrjjhus oeggjjfius Wd.) and the coccinellids {Cocci nella vicina Muls. 

 and C. luideciinpunctata Linn.) were large numbers of the larva of the 

 Leucopis species preying upon the aphis. The combined efforts of 

 these predacious larvae had a marked effect in keeping the aphis in 

 check. A Leucopis species was further noted, in February of that 

 year, as being the onl}^ predacious insect attacking the cotton aphis 

 {A. gossypii Glover) infesting cotton on Tuti Island near Khartoum 

 North. 



Throughout the entire period from February to April, when the 

 dura crop was cut, all stages of the fly were present on the dura leaves. 



