1918.| BASHAMBAR Das: The Aphididae of Lahore. 197 
Life-history.—In its essential details the life-history of this so-called ‘‘ Green bug ” 
does not materially differ from those of other Aphids. It has been more or less 
thoroughly worked out in America, and its course in India appears to be very nearly 
the same. The details, however, have not as yet been worked out in India, and I am 
not aware if the Agricultural Department of India have taken any notice of this pest. 
So far there is no mention of its occurrence in any of their Bulletins or Memoirs issued 
from the Research Institute at Pusa. 
Natural enemies —In normal years it is kept in check by the various predaceous 
insects and their larvae, and is also extensively parasitised by Lysephlebus sp. The 
Fungus Entomophthora aphidi was observed killing numbers of them in wheat fields 
along the Ravi in March. 
Possible source of danger .—As it has been shown by its past history in Europe and 
America that its outbreak in any: year might become extremely serious, it would be 
worth while to look upon it as a possible dangerous insect. In the words of Prof. 
Sanborn of America, ‘‘ Whenever the natural conditions permit this aphis to flourish, 
it can devastate all the wheat and oats that may be planted on its latitude of infesta- 
tion. The financial losses are almost inconceivable’’ (Bull. U.S. Dept. Agric., no. 60, 
1906). mae 
Toxoptera cyperi (van der Goot). 
Host.—Cyperus rotundus. 
eres" MotHa or “° Dila’ 
Distinguishing features.—Twice a year, in September and November, and March 
and April, this Aphid is often seen abundantly, on the lower surface of the common 
Cyperus (‘“ Motha”’ or “ Dila”’ grass) sitting in rows one behind the other. 
In colour it is dark green, almost black with variegated or mottled abdomen ; jet 
black, long antennae ani cornicles, with a brownish intercornicular band ; the deeply 
marked veins of the wing and the cubitus which is forked only once are characteristic. 
Almost all the species of the genus Toxoptera are of a destructive nature. Cyperus 
would often be found quite weakened and ultimately killed by the incessant drain 
caused by individuals of this species. 
Hunter, in his ‘‘ Studies of Parasitism,’’ has demonstrated that Toxoptera 
graminum (Rond.), though much smaller in size than the common grain louse Macro- 
siphum granarum, inflicts much severer injury on wheat than the larger Aphid. 
Nineteen Tox. graminum adults would kill a healthy plant of wheat in about eleven 
days, while twenty Mac. granarum adults, after the same number of days, would 
do a similar plant comparatively little harm (Hunter, Kansas Umiv. Bull., vol. IX, 
no. 2, 1909). 
Injury to plant.—We have found here the case with Tox. cyperi to be more or 
less similar. Two adult apterous viviparous females were placed on a healthy vigor- 
ous Cyperus. The plants and Aphids were protected under a lamp chimney in the 
usual way, in November. It was observed that after twenty days the plants turned 
yellow and died. Of the insects most of the young changed into pupae and later 
developed into alate females. 
