204 Memoirs of the Indian Museum. [Vorr vas 
The size is very variable; ill-fed specimens from Indigo or C ajanus may be half 
the size of others fed on the juicy creepers of Dolichos. 
The species may be noticed sparingly practically all the year round. Numerous 
Leguminous plants serve as its host ; the names of the plants with dates are given in 
the host-index at the end of the paper. Those most common are the species of 
Cajanus, Indigofera, Dolichos, Dalbergia, Medicago, Vicia, Sesbania, Cassia, etc. 
The adult apterous females have the curious habit of falling from the twig or leaf 
at the slightest alarm. Nothing is known about the life-history or whether the sexes 
are ever formed or not. 
Systematic.—The original description by Koch (loc. cit. p 94) is not very clear; 
neither does his plate (fig. 126) give a satisfactory picture of the apterous insect; it 
rather shows two rows of dorso-lateral black spots alternating with white ones, and 
two or three dark bands on the hind body-segments. Koch evidently did not notice 
any large polished black blotch on the dorsum, as he was always particular to illus- 
trate such a character, and has done so in several other instances. 
There may therefore be some justification for the suspicion in the minds of 
certain writers that Koch probably was only redescribing A. rumicis, L., from a 
Leguminous plant, under a new name. A. rumicis, L. does infest such plants in 
Europe, but not to my knowlege in India. It is possible, therefore, that A. medicagims 
(Koch) may turn out to be a synonym of A. rwmicis (Linn.). But in America all the 
aphidologists have taken A. medicaginis (Koch) to represent the species described 
above, which is clearly distinct from A. rumicis. 
If, in reality, Koch’s name is proved to be a synonym, then this Aphid ne 
without a name) will have to be renamed, and A. papilionacearum as proposed by 
van der Goot is very appropriate indeed. 
Aphis nerii (Boyer de Fonscolombe). 
Synonym.—Myzus nerii (Boyer). 
Literature :— 
(I) Fonscolombe, Ann. Soc. Ent. Fr., X, p. 157. 
(2) Essig, Pom. Coll. Jour. Ent., III, 3, p. 530. 
(3) Lefroy, Ind. Ins. Life, p. 748. 
Distinguishing marks.—This species is known in the country as “ Ak ka tela,’’ 
and can be recognised very readily by the deep rich yellow colour of its body, on 
which stand out conspicuously the beautiful large black cornicles. It is often seen 
clustering along the veins of leaves of Calotropis gigantea (Vern. Ak). The branches 
and lower leaves get smeared with the sweet oily-looking excreta which attracts 
numerous ants, flies and wasps. In bad attacks the plants look very sickly, and the 
leaves are smutted with a sooty fungus, Capnodıum. 
As the species has been fairly well described in the first two references above, no 
further account of it is given here. The Punjab insect is apparently exactly the 
same as the European and the American forms, only it never infests Nerium odorum, 
from which host it takes its specific name. This plant, though abundant, is practi- 
cally immune from Aphid attack of any kind, 
