AFRICAN APHIDIDAE — PART III. 285 



10. Aphis pruniella, sp. nov. (fig. 10). 



Alate viviparous female .— Antennae shorter than body ; basal segment wider and 

 longer than second ; third longer than fourth, but not quite so long as the sixth, 

 with 4-5 round sensoria scattered over the whole length ; fourth and fifth about 

 equal in length, the latter with a normal subapical sensorium ; sixth with basal 

 area about half the length of the flagellum ; all the segments imbricated. Head 

 flat in front ; eyes large ; stemmata marked. Proboscis reaching to third coxae, 

 acuminate ; apical segment longer than the penultimate ; pale at base, dark at apex. 

 A prominent papilla on each side of pronotum and one between the meso- and 

 meta-thoracic legs ; there are also other smaller lateral abdominal papillae. Cornicles 

 dark, moderately long, cylindrical or slightly swollen towards the base ; markedly 

 imbricated, the imbrications long ; sides serrated. Cauda not nearly as long as the 

 cornicles ; dark ; spinose, with three pairs of long lateral hairs, the apical pair curved 

 inwards. Anal plate dark ; spinose, with some long hairs. Legs with apices of tibiae 

 and all the tarsi dark ; tibiae with a few short hairs. Wings much longer than the 

 body ; the costa, stigma and veins yellowish brown ; membrane slightly tinged. 

 Length, 1*5 to 1'9 mm. 



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Fig. 10. Aphis pruniella, sp. n., alate $ : A, head and antenna ; 



B, cornicle ; C.cauda. 



Apterous viviparous female. — Antennae shorter than body ; basal segment larger 

 than second ; third a little longer than fourth, not quite so long as the sixth ; fourth 

 and fifth equal in length, the latter with the normal sub-apical sensorium ; sixth with 

 basal area half as long as the flagellum ; all the segments from the third imbricated ; 

 the third and fourth paler than the remainder. Head with small lateral prominences ; 

 eyes large. Proboscis reaching past second coxae, acuminate ; apical segment 

 longer than penultimate. Prominent lateral pronotal papillae ; a large papilla 

 between meso- and meta-thoracic legs. Skin markedly reticulate. Cornicles fairly 

 large ; black ; somewhat'expanding towards the base ; markedly imbricated ; sides 

 serrated. Cauda dark ; very spinose ; not so long as the cornicles ; with three 

 pairs of lateral hairs, curved apically. Anal plate dark, spinose, with a few long hairs. 

 Legs with apices of tibiae and all the tarsi dark. Length, 1*5-1 '9 mm. 



British East Africa : Nairobi (T. J. Anderson). 



Food-plant. — Plum. 



Described from a number of alatae and apterae preserved in spirit. It appears 

 to be a darkish species, with paler (apparently deep greenish) abdomen, and with 

 dark antennae, cornicles, cauda and anal plate, and black thorax in the alatae. The 

 sensoria on the antennae in the alate female separate it from any species I have yet 

 seen on Prunus. The common Aphis pruni, Linn., has many sensoria on segment 

 three and a good many on four and the cornicles are green, not black. 



