Pipiza. 77 



has five visible segments, three hidden and a small ninth segment 

 vvith two small lamellæ. Legs as in Pipizella, hind femora generally 

 more or loss thickened or clavate; hind metatarsi likewise more or 

 less thickened. Wings relatively a little longer than in Fipizella; 

 medial cross-vein before the middle of the discai cell; the upper 

 marginal cross-vein starting about rectangularly below, then bent out- 

 wards parallel vvith the margin with a round or more angularly cm-ve, 

 the shape of the curve varying even in the same species, and some- 

 times the curve is rather weak; the upper angle acute; vena spuria 

 not strong. Alula well developed, tongue-like. Plumula with slightly 

 branched hairs. Alar squamulæ with longish, simple hairs, thoracic 

 squamulæ with long, furcate hairs. 



The larvæ of Pipiza are recorded to be aphidiphagous; Schiner 

 notes that Giraud has found hibernating pupæ on Quercus aceris, and 

 from North America the larva of P. femoralis is recorded feeding on 

 Schizoneura lanigera and Phylloxera vastatrix. 



The species of Pipiza are easily known by the yellow spots on 

 abdomen, and in want of these on the whole shape and the some- 

 what hanging abdomen. They occur on iields, in fens and woods in 

 low herbage, on grass and flowers; most species are specially numer- 

 ous in spring, but may also be seen later in the year. — The species 

 are very difficult to distinguish and the present stage of our know- 

 ledge of the limits of the species is not good. 



About 12 species are known from the palæarctic region; below 

 I have endeavoured to recognize 8 from Denmark. 



Tåhle of Species. 



1. Anterior tarsi all yellow; pubescence of the body all 



pale 1. luteitarsis. 



— Anterior tarsi not quite yellow; pubescence not quite 



pale 2. 



2. Abdomen normally with four yellow spots; epistoma 

 rather low, antennæ inserted a little below the middle 



of the head 2. quadrimaculata. 



— Abdomen with two spots or unspotted ; epistoma higher, 

 antennæ not below the middle of the head 3. 



3. Abdomen normally with spots; epistoma in the male 

 black-haired (except in signata) ; wings clear or clouded, 



but not with a specially strong blotch 4. 



— Abdomen normally unspotted; epistoma in the male 

 white-haired ; hind femora rather thickened; wings 

 strongly blotched ; somewhat dullish species 7. 



4. Epistoma in the male black-haired; wings clear or 

 with a brownish cloud, in the latter case the abdominal 

 spots in the female generally large 5. 



