HABITS, ETC., OF HYLEMYIA GRISEA, FALL. 13 



THE HABITS AND LIFE-HISTORY OF HYLEMYIA 

 GRISEA, FALL., AN ANTHOMYIID FLY NEW 

 TO THE SCOTTISH FAUNA. 



By (Miss) L. H. HuiE, F.E.S. 



The following notes on Hyleuiyia grisea are the outcome 

 of observations made during visits to Argyllshire. Hyleiiiyia 

 grisea has not before been recorded from Scotland, and till 

 now there has been no definite information ^ as to its life- 

 history or the feeding l>abits of its larvae. The only 

 statement has been the general one by Zetterstedt that 

 the larvae live parasitically on the larvae of Hymenoptera 

 Aculeata. 



The wild bee Andrena analis, Panz., nests in banks of 

 sandy earth, and in many parts of our West Highlands is 

 very abundant. Although a solitary bee, it is gregarious, 

 and the burrows are often so numerous and close together 

 that it is difficult to decide in making an excavation, whether 

 an exposed set of brood chambers is the work of one bee, or 

 of more than one. The task of investigating an individual 

 burrow from orifice to brood cells is obviously difficult 

 because of the tendency of the sand to fall in and obliterate 

 the tunnel. The plan adopted by me was to insert a small 

 pencil to about half an inch, and carefully scrape away the 

 sand until the pencil was again entirely exposed ; then 

 re-insert it and repeat the scraping, sometimes also moisten- 

 ing the excavation with water. Working in this patient way 

 I made out that the burrows usually slope inwards and 

 downwards ; a few are nearly vertical. When the burrow 

 has reached a point about i i or 2 inches below the soil, that 

 is, a point that might be 3 inches from the entrance of 

 a sloping burrow, the brood chambers may be found. These 

 chambers are just large enough to hold the pupa comfortably ; 



^ The adult fly has been described in Dipteia Sca7idinavta {\.o\t\, iv., 

 p. 1422) by Zetterstedt ; and in Dipterologia Italica: (vol. iv., p. 181) by 

 Rondani. All that Schiner says is that the larvae are found in nests of 

 Hymenoptera. 



