164 Memoirs of the Indian Museum. — [Vor. VI, 
(I) The cornicles are unusually small and stout; reticulation extends over 
more than two-thirds of its distal surface, while in other species it 
occupies only a small apical portion. 
(2) The cauda is very large and thick, irregularly deal with a rounded 
tip, not sabre-like and pointed. 
(3) The cauda is longer than the cornicles, while in typical species it is con- 
siderably smaller. 
It would perhaps be appropriate to separate it into a different genus or subgenus. 
A Macrosiphontella has been described from chrysanthemums by Del Guercio 
recently in the Italian Journal “ Redia,” with which at present I am unacquainted. 
It may be this species.! 
Macrosiphum solidaginis, Fabr.’ 
Hosts.—Sonchus oleracea, Sonchus arvensis, Sonchus sp. 
Biology.— This insect is of no economic interest as it infests only the wild species 
of Sonchus. The earliest date of its appearance in Lahore is the first week of 
January ; it soon thickly covers over the stalks of inflorescence and later attacks the 
leaves. About this time it is usually destroyed wholesale by the Fungus Entomop- 
thora sp.; from January onwards up to May it is found on its host only occasionally. 
A few observations were conducted on some colonies kept in the laboratory, 
relative to the effect upon them of the diurnal heat. As the maximum temperature 
for each day began rising and reached about 95° F. in third week of March all the 
insects deserted the plant. After two weeks or so there was a shower of rain and 
during two cloudy days that followed several apterous females were seen on the same 
plant. In the middle of April when the maximum reached 104° F. again not a single 
insect was to be observed above-ground; early in the last week, however, another 
slight rainfall with threatening weather brought out the Aphid on the same plants. 
They seemed to come up after every slight rainfall. 
These observations were not carried forward into the season, neither was the 
further life-history followed as to what time the sexuales, etc. are produced. 
The three species of Sonchus are the only hosts known at present in Lahore, 
though in Java many other species of Compositae are said to be its food-plant. 
Systematic.—The ‘‘ Eastern Sonchus Aphid’’ is quite different from the insect 
familiarly known by the same name in the West, 7.e. Macrosiphum sonchi, Linn. 
1 en sanborni, Gill. very Gene clone to the genus Macrosiphoniella, Del Guercio, 
which genus seems to differ principally from Macrosiphum, Pass. in having the cornicles shorter than the 
cauda. This same chrysanthemum-aphid has been described by Mr. Theobald as Macrosiphoniella bed- 
Jordi, Theob. (Bull. Ent. Research, vol. IV, 1914, p. 318), a name later on corrected by this author to 
Macr. chrysanthemi, Del. Guercio (Bull. Ent. Res., V, 1915, p. 112), which again must fall as a synonym 
to Macr. sanborni, Gill., the latter name being of an earlier date (1908). P. v. d. G.]. 
? [Literature on Macr. solidaginis, Fabr. :— 
a. Kaltenbach, Die Pflanzenläuse, 1843, p. 32. 
b. Koch, Die Pflanzenläuse, 1857, p. 197. 
e. v.d. Goot, Beitr. z. Kenntniss der holländischen Blattläuse, 1915, p. 90. P. v. d. G.]. 
