AFRICAN APHIDIDAE — PART II. 145 



Egypt : Salka, xi. 12 (F. C. Willcocks), 



Food-plant. Willow {Salix sp.). 



This large Lachnus agrees in all the essential characters with L. viminalis, which 

 I have found in abundance in Britain and in parts of France, and I have no doubt 

 whatever that it is the same species. It has been recorded from France, Norway, 

 Italy and Belgium, and probably occurs all over Europe. Sulzer (1761) undoubtedly 

 refers to this species, and Curtis (1800) described and figured this insect as an Aphis 

 on willows. 



This large species can at once be told by the curious horn-like process on the dorsum 

 of the abdomen. Numerous interesting papers and notes have been written on it, 

 the chief of which have been mentioned here. It undoubtedly has considerable 

 economic importance in osier cultivation on account of the damage it now and then 

 does, and its occurrence in vast colonies at certain times has given rise in the past 

 to speculation as to its possible value as a sugar and dye producer ; needless to say, 

 it is of no commercial value. 



Genus Protolachnus, nov. 

 Head large ; eyes very prominent ; the two stemmata of the alate female raised 

 up and in front of the eyes ; antennae thin, shorter than the body. Proboscis long, 

 blunt, the last two segments short and equal. Body narrow and rather long. 

 Cornicles circular, nearly flat. Legs long, especially the hind pair, femora and tibiae 

 hairy, especially the hind tibiae ; both tarsal segments long ; coxae of the hind legs 

 very large, especially in the alate female. Head with very long hairs, also the body, 

 the hairs arising from prominent tubercles. Wings narrow, the first vein not arising 

 from the subcostal and only once forked, very indistinct. 



Fig. 33. Anterior wing of Frotolachnus tuherculostemmata^ sp. n. 



The chief characters of this genus are the tuberculate stemmata in the alate female, 

 blunt proboscis, greatly enlarged hind coxae and the wing venation. 



Protolachnus tuberculostemmata, sp. nov. (figs. 33, 34). 



Alate viviparous female. — Body very flat, green ; thoracic lobes dark ; antennae, 

 ends of tibiae and tarsi brown. Head large, brownish ochreous, with four large 

 slightly capitate hairs in front and two rows of four on the vertex, arising from 

 tubercles ; eyes large, projecting, black ; stemmata in front of the eyes, pale, placed 

 on a dark projecting area, having a tuberculate appearance. Antennae of six 

 segments, shorter than the body, thin ; first and second of the same colour as the 

 head ; third pale at base, the rest dusky ; basal segment shghtly wider than the 

 second and of about the same length ; the third the longest ; the fourth half the 

 length of the third and shorter than the fifth, both with a subapical sensorium, that 

 on the fifth oval ; sixth shorter than the fifth, with short blunt nail and two sensoria, 



