168 BIBIOXIDjE. 



Anterior cross-vein about the centre of the wing, of moderate 

 length ; 4th longitudinal vein always forked, at a little beyond 

 the anterior cross-vein and at its junction with the posterior 

 cross-vein ; the 5th vein forked, the 6th nearly straight, not 

 reaching the wing-margin, the 7th absent ; posterior cross-vein 

 always distinctly beyond the anterior cross- vein. Alulae well 

 developed ; tegulse rudimentary. 



Range. World-wide. 



Life-history. The larva of Bibio lives in various substances, in 

 the earth, in decaying animal and vegetable matter, in the roots 

 of grass and corn, the stems of plants, and similar situations. 

 It is dirty white or brownish in colour, cylindrical, with a brownish 

 head which has three pairs of large bristly hairs and some smaller 

 ones. The body is twelve-segmented, the first narrow, with two 

 rows of fleshy tubercles, the remainder large, each with a single 

 row of six tubercles; the 12th 'segment a little smaller, with two 

 black dots on its dorsal surface. There are some tubercles around 

 the base of the anal segment, and there are also two lateral 

 tubercles on each segment and two rows of four in each on the 

 ventral surface. The larva possesses twenty spiracles. 



Pupation, so far as European species go, takes place in June, 

 the pupa being dark brown, with a shrivelled appearance, one- 

 third of an inch long and very broad ; the anal segment very 

 small, with two divergent spines on the dorsal surface; the wing- 

 cases small, closely surrounding the legs, the thoracic part much 

 elevated. 



The life-histories of several European species have been des- 

 cribed, that of Bibio marci, L., by Heeger (Sitzb. k. Acad. Wiss. 

 ix, p. 263). B. hortulanus,Ij., is known to breed in garden-earth, 

 and B. johannis, L., in cow-dung. 



Bibio is essentially a spring genus, some species appearing, 

 however, in the autumn. The males love the sunshine, and 

 perform aerial dances beneath the boughs of trees ; the females are 

 more often found in woods or more shaded spots. The sexes are 

 frequently taken in copula, and often differ very considerably in 

 coloration. I have myself taken B. rnarci and B. hortulanus in 

 that way in England, and several paired couples of B. obscuripennis 

 at Darjiling. 



Table of Species. 



L Thorax partly or wholly reddish yellow or 

 brownish yellow (at "least the dorsuni 

 wholly red in all the species except dis- 



calis, in which it is black) 2. 



Thorax wholly black 3. [p. 169. 



2. Dorsum of thorax yellowish hortulanoides, Brun., $ , 



Dorsum of thorax black discalis, Brun., p. 174. 



-3. Abdomen wholly reddish yellow abdominalis, Brun., 



Abdomen wholly black . '. 4. [p. 172. 



