NEMESTRINIDAE BOMBYLIIDAE 485 



sometimes with excessively long proboscis; antennae short, with a 

 Mmple third joint, and a jointed, slender, terminal ctppendcujc ; the 

 tibiae hare no sjvtrs, the empodium is pulvillus-like. The wing- 

 ncrvuration is I'crhaps the most complex found in Diptera, there 

 being numerous cells at the tip, cdmost after the fashion of 

 Xeii.roptera. "With this family we commence the aerial forms 

 composing the Tromoptera of Osten Sacken. Nemestrinidae is a 

 small family of about 100 species, but widely distributed. 

 Megistorhynchus longirostris is about two-thirds of an inch long, 

 but has a proboscis at least four times as long as itself In 

 South Africa it may be seen endeavouring to extract, with this 

 proboscis, the honey from the flower of a Gladiolus that has a 

 perianth just as long as its own rostrum ; as it attempts to do this 

 when it is hovering on the wing, and as the proboscis is, unlike 

 that of the Bombylii, fixed, the Insect can only succeed by con- 

 trolling its movements with perfect accuracy ; hence it has great 

 difficulty in attaining its purpose, especially when there is much 

 wind, when it frequently strikes the earth instead of the flower. 

 M. Westermann thinks ^ the life of the Insect and the appearance 

 and duration of the flower of the Gladiolus are very closely con- 

 nected. The life-history of Hirmoneura obscura has recently been 

 studied in Austria by Handlirsch and Brauer." The larva is par- 

 asitic on the larva of a Lamellicorn beetle {Rhizotrogus solstitialis) ; 

 it is metapneustic, and the head is highly modified for predaceous 

 purposes. The young larva apparently differs to a considerable 

 extent from the matured form. The most curious fact is that the 

 parent fly does not oviposit near the Lamellicorn-larva, but places 

 her eggs in the burrows of some wood-boring Insect in logs ; the 

 larvae when hatched come to the surface of the log, hold them- 

 selves up on their hinder extremity and are carried away by the 

 wind ; in what manner they come into contact with the Lamellicorn 

 larva, which feeds in turf, is unknown. The pupa is remarkable 

 on account of the prominent, almost stalked stigmata, and of two 

 pointed divergent processes at the extremity of the body. This 

 life-history is of much interest, as it foreshadows to some extent 

 the complex parasitic life-histories of Bombyliidae. The Nemes- 

 trinidae are not represented in the British fauna. 



Fam. 20. Bombyliidae. — Body frequently fringed with down, 



' Ann. Soc. ent. France, ii. 1833, p. 492. 

 2 Wien. ent. Zeit. ii. 1883, pp. 11 and 24, p]. i. 



