Systematic Course. 21 
species that affects the particular crop which they are intended 
to shelter, Information upon the subject of thejtrees attacked by 
the various species is still very imperfect in India, The School 
Museum possesses some specimens of lac, and: any insects that can 
be procured should also be examined, 
Aphide.—These minute insects do an enormous amount of damage to 
vegetation and are likely to prove extremely destructive in Indian 
forests, though little has as yet been recorded upon the subject. Apple 
trees in the Nilgiris and the Himalayas suffer very seriously from the 
attack of the species Schizoneura lanigera, Hausm., while tea, coffee, 
cinchona, mustard, spruce and bamboos in various parts of India 
have been reported as attacked by other species. The irritation set 
up byAphidz in feeding on the juices of plants often results in the 
formation of galls. This feature is specially remarkable in the case 
of the form (Chermes abietis Linn.) which attacks the twigs of the 
spruce fir (Ades Smithiana) in the North-Western Himalayas, pro- 
ducing a gall which may readily be mistaken for a fir cone, also in 
that of Schzzoneura lanigera, Hausm., which produces a knotty 
growth upon the twigs and roots of apple trees. In Hurope one of 
the best known species is Phyllowera vastatrix which has done an 
enormous amount of damage to vineyards. It has not yet been 
recorded from India, but is likely to occur in Kashmir. 
The life history among Aphidw is extremely complicated. The 
following are the main features of what usually goes on in the case 
of species inhabiting a temperate climate, and the same will probably 
prove to obtain in a more or less modified degree in India.—A_ single 
so-ealled “ winter egg” is laid in the autumn by each female on the 
bark of the food plant. This hatches in the spring, producing a wingless 
female, which gives birth, without the intervention of a male, to other 
females, which may be either winged pr wingless. These again repro- 
duce themselves in a similar manner, and the process goes on through 
an indefinite number of generations until the weather begins to grow 
cold. Males and females are then produced. These copulate and the 
female produces, either directly or through the intervention of a 
further generation, the single winter egg, which, as we have seen, 
hatches in the following spring. 
Most Aphidaw have a pair of elongated dorsal tubercles on one of 
the posterior segments of the abdomen, These are the ducts of simple 
glands which secrete the honey dew that is greedily sought after by 
ants, The resultis that many species of Aphide are attended and pro- 
tected by ants. The rose bushes in the Dehra school compound 
usually afford a plentiful supply of Aphide with their attendant ants 
for the students to examine. 
