348 Syiphidae. 



Also this species varies much, especially with regard to the ab- 

 dominal markings; the described form should answer to the true 

 menthastri; the next variety has the first abdominal band entire but 

 is otherwise similar; the abdominal bands reach the margin or are 

 isolated; the legs pale or more or less dark at the base; epistoma 

 with a slight or without middle stripe (var. dubia Zett.). Then comes 

 a form with the abdominal bands all interrupted, the spots quite 

 isolated or more or less reaching the side margin; the epistoma with 

 a generally distinct, black middle stripe and the mouth edge and 

 jowls black; coxæ and trochanters, and also base of femora black or 

 blackish (var. pida Meig.). A quite similar form has the legs all yel- 

 low, the tarsi paler; only a slight epistomal stripe and the jowls paler 

 (var. philanthus Meig.). Finally a form occurs with scutellum quite or 

 almost quite yellow-haired, and also sometimes the vertex more or 

 less yellow-haired; the abdominal bands are entire and broad or very 

 broad; they may reach the margin or be more or less isolated; the 

 fifth segment yellow with small spots, and the black middle line often 

 interrupted; the legs are pale or somewhat dark or blackish at base^ 

 the tarsi rather pale, and the front tibiæ generally much yellow-haired 

 (var. taeniata Meig.). 



Female. Vertex broad, black and shining, from it a broad, black 

 stripe goes down to the antennæ; the hairs black, but paler above 

 the antennæ. Abdomen with four yellow, somewhat narrow bands, 

 shelved off at the sides but generally reaching the margin; the first 

 band narrowly interrupted, second and third entire, sometimes more 

 or less emarginate behind, and rarely the third band interrupted; the 

 fourth band is interrupted and the spots are produced a little for- 

 wards and backwards at the inner end, and thus somewhat hammer- 

 like; the side margins of abdomen are very narrowly yellow; the sixth 

 segment is yellow with a black middle spot at the base and two 

 lateral spots near the hind margin, the spots often connected, and 

 sometimes the side spots reaching the front margin; seventh segment 

 orange, more or les black on the middle; the hairs on abdomen short, 

 all black, also at the margin except at the basal corners. Legs all 

 yellow, only the tarsi more or less darkened; hind femora as in the 

 male with no bare space at the base. 



The female varies mainly in the same way as the male, i. e. with 

 regard to the abdominal markings, but as the legs are always yel- 

 low the varr. 'philanthus and picta cannot be discerned from each 

 other. 



Length 6,5 — 9 mm. 



The varieties may be distinguished in the following way: 



