Bibio hortulanus (Linnaeus, 1758)

Skartveit, John, 2010, The larvae of European Bibioninae (Diptera, Bibionidae), Journal of Natural History 36 (4), pp. 449-485 : 462

Bibio hortulanus (Linnaeus, 1758) (®gures 26±32)

Brownish yellow, dull. Body processes long and slender.

Body length 15.9 mm (n = 1, larva collected in October, not full grown). Only possible to measure in one larva.

Head. Head capsule widths of four larvae 1.07, 1.22, 1.53 and 1.60 mm., the two smaller probably represent sixth and the two larger seventh instar. Labrum (®gure 26) with three pairs on strong, blunt sensillae on fore margin, one pair of short, pointed sensillae on transverse carina. Mandible (®gure 27) with ®ve teeth. Maxilla (®gure 28): comb strongly curved with six or seven indistinct teeth, mesal teeth large and rounded. Prementum (®gure 28) with prominent anterior corners, wide mesal process and 10 sensillae. Stemmata present in the specimens at hand. Antenna rather large with numerous small, conical sensillae.

Body. Processes long and slender. Outer processes of dorsal process row much longer than the four inner processes. Post-spiracular process as long as ®ve to six spiracle diameters, situated two spiracle diameters posterior to spiracle. Ninth abdominal segment rather short. Cuticle: prothorax (®gure 29) scales in the anterior part of segment slightly irregularly transverse-ova l scales apparently without spines, 20±40 m m wide by 20 ±27 m m long, between processes with larger oval scales carrying four to seven spines. Metathorax (®gure 30) and ®rst abdominal segment with larger scales 30±50 m m wide by 20±30 m m long, carrying one to ®ve spines and smaller, irregular, unarmed scales, 10 ±20 m m wide, between them. Fourth abdominal segment (®gure 31) with larger scales 30±50 m m wide mostly with a single spine, but some with up to three spines, and irregular unarmed scales between them. Ninth abdominal segment (®gure 32) with indistinct, transverse, unarmed scales.

Distribution. North and possibly also East Africa, Middle East, Europe north to the extreme south of Sweden.

Ecology. Common on cultivated land, may occasionally damage crops severely.

Material. England: Hants., Battey , 9 October 1908, Lady M. S. Jenkyns leg., 4 larvae ( BMNH). The larvae were collected from a lawn in which they were very abundant .