1918. | BASHAMBAR Das: The Aphididae of Lahore. 225 
leaves. On this plant (Ageratum conyroides) they remain throughout the rains and 
may be collected even up to August. ; 
The case is the same in the hills where they are present up to August on several 
species of Prunus, particularly P. padus. 
It is on record for the European form that alate males and oviparous females are 
produced in November. The latter after mating deposit eggs which remain dormant 
throughout the winter and hatch again in the spring. Such a course is probably 
taken by this Aphid in the hills in India but not in the plains. I have never observed 
it on any species of Prunus or Ageratum after September. It is very likely that the 
males and females are produced before the end of summer and these lay eggs which 
hatch again in March, but nothing can be definitely said until further investigation. 
The alternate host Ageratum might possibly send back the “ return migrants ’’ 
to peaches, which may give birth to males and females in autumn, but in the absence 
of definite data nothing can be concluded. There is scope here for further work that 
would amply repay the labour involved as the insect is of very great economic 
importance. Any methods of controi would entirely depend upon a fuller knowledge 
of its life-history. 
Early application, before the leaves are fully out, of some good spray of kerosine 
emulsion or tobacco decoction is what seems to be practised in America for such 
pests. 
Systematic.—So far the insect has been referred to in current literature as ‘‘ Aphis 
pruni,’’ but it seems anomalous to group this species along with A. rumicis or 
A. gossypw, etc., in the same genus. Several important characters, among others the 
peculiar form of the cauda and the anal end as well as the absence of lateral tubercles 
on the seventh abdominal segment, differentiate this species from the true genus 
Aphis. Mr. van der Goot, in his proposed revision of the subfamily Aphidinae, in- 
cludes this species along with a few more in his new genus Brachycaudus. I am in 
entire agreement with him on this point and have accordingly adopted his name. 
According to him we should further consider A. helichrysi (Kalt.) as a synonym of this 
species, and as the former was employed at an earlier date the name Brach. helich- 
ryst should have priority. 
Since writing the above, I have secured males and true females of this Aphid in 
December on peaches, along with the males of Myzus persicae. So the life-history 
here is practically the same as in the West. ‘The males are very similar to the alate 
females except that the antennae have sensoria on all the joints and the anal end is 
provided with the genital armature. 
Hyalopterus pruni (Fabr.). 
(Mealy Aphis of Peach and Reed). 
Synonym.--H. arundinis (Fabr.). 
Hosts.—Arundo donax (Vern. Nara). 
Phragmites kirkı. 
Prunus persicae (Peach). 
