122 Orthorrhapha brachycera. 



of piants. Imhoff (Isis, 1834, 536) found the pupa in a situation which 

 pointed towards their living on Andrena humilis. Mac Leay (Ann. 

 Nat, Hist. II, 1838, 12) declares that some tropical Bombyliids live on 

 bees. Morelet (Bull. Soc. Ent. d. Fr. 1854, XXIV) bred a Bomhylius 

 from the nest of Halictus succinctus. Leon Dufour (Ann. Soc. Ent. 

 de Fr. VI, 1858, 505, pi. 13, flg. 3) found pupa skins of B. major 

 sticking out of the ground, together with newly hatched imagos, at 

 piaces much frequented by Andrenids. Westwood (Trans. Ent. Soc. 

 Lond. 1876, 498) found B. medius flying in association with species 

 of Andrena^ and found pupa-skins protruding from the ground. 

 Schmidt-Goebel (Stett. Ent. Zeit. 1876, 393) bred a Bomhylius from 

 Colletes fodiens. Algernon Ghapman (1. c.) bred B. major from cells 

 of Andrena lahialis. Finally Nielsen (1. c.) bred B. minor from cells 

 of Colletes daviesana as mentioned above^ The hibernation seems 

 to be different in the different species; Algernon Ghapman (1. c.) found 

 larvæ of B. major in the winter; thus these probably hibernate. 

 Nielsen (1. c.) on the contrary found the newly hatched larvæ of B. 

 minor in the Colletes cells in April, and they developed to imagines 

 in the same summer, in this latter case the egg or the young larva 

 must hibernate, the larva not getting into the Colletes cell before the 

 spring, as Nielsen expressly states, having examined many Colletes 

 cells in the winter without tinding eggs or larvæ. 



The species of Bomhylius are rather characteristic flies, by their 

 dense fur being somewhat similar to humble-bees. They occur on 

 sandy piaces at the outskirts of woods and similar localities; they fly 

 very well and are able to stay hovering in the air; they frequent 

 flowers and while sucking they generally only touch the flower with 

 the legs, without sitting, but using the wMngs which are in constant 

 vibration as already observed by Zeller (Isis 1840, 14); the same 

 author states that they rest on straws and flowers in the night; on 

 being disturbed they move the wings but are unable to fly. While 

 flying they produce a somewhat loud sound. 



Of the genus about 100 species are known from the palæarctic 

 region, the majority being southern forms; 2 species have hitherto 

 been found in Denmark. 



Tahle of Species. 

 1. Wings with a sharply bounded blackish tinge on the anterior 

 part ; occiput with long hairs at the posterior eye-margin ; costa 

 without spinulous hairs at the base 1. major. 



^ Nielsen mentions that the Bomhylius larva was also found on the larva of 

 Epeolus productus, which is parasitic on the Colletes in that it eats the pollen 

 stored up by this. It also happened that the Bombylius larva devoured two 

 Colletes larvæ or even, besides the Colletes larva, a larva of its own. 



