THE CANADIAN ENTOMOLOGIST 203 



Description. 



Alate viviparous female (spring form). 



Head black. Thorax shiny black. Abdomen dull reddish of 

 various shades at the base, sometimes yellowish red, with four 

 black lateral spots and a black area on the posterior region, with 

 3-4 lateral tubercles before the cornicles. Antenna? black, not 

 quite as long or nearly as long as the body; first segment longer 

 than the 2nd; the 3rd with many sensoria over its whole length 

 (47-60); the 4th scarcely longer than the 5th, with many sensoria 

 over its whole length (27-35) ; the 5th with 3-0 sensoria on the basal 

 ^ and the usual sub-apical one; the. 6th a little longer than the 

 3rd; the last three segments imbricated. Cornicles black, cylin- 

 drical, moderately long, imbricated. Cauda small, dusky. On 

 the 7th and 8th abdominal segments are two pairs of dorsal tu- 

 bercles. Legs with yellowish-brown trochanters; bases of femora 

 and tibiae pale, apices of the same dark. Wings with brownish 

 veins and paler insertions; venation often very variable. . 



Length — 2 to 2.5 mm.; wing expanse, 7-8 mm. Sanderson 

 says "abdomen yellowish-red," and figures it with only four 

 pairs of dark lateral spots. All European specimens have a large 

 dark abdominal area, as in the return migrant. 



Alate viviparous female (return migrant). 



Head and thorax black. Abdomen reddish, with a large 

 dark dorsal area of various extent, often extending from close to 

 the thorax up to the cornicles,* at others time quite small; black 

 transverse bars caudad of the cornicles, and three large black 

 lateral spots before the cornicles and traces, more or less distinct, 

 of one caudad of them. Antennae black and similar to the spring 

 form. Legs and cornicles the same as the spring form. No trace 

 of the four tubercles on segments 7 and 8 of the abdomen, according 

 to Sanderson; but I have found them in all British specimens 

 I have examined. Rostrum reaches to the second pair of legs. 

 Cauda dark, small. 



Apterous viviparous female. 



Colour varying from slaty-grey to bluish black, plum colour, 

 brown, brick-dust red, pink, rosy and almost black. The young 



*Now and then almost black specimens occur. 



