34 
Elementary Manual of Zoology. 
species do much damage in India by defoliating agricultural plants. 
In Europe and America they occasion some loss also by defoliating 
forest trees, and a species of the genus MMelasoma has recently been 
reported as attacking willow trees in the North-West Himalayas. 
Generally speaking, however, the family has not been noticed as 
specially destructive in this connection ia India. The larve are 
usually active little creatures, sometimes covered with spines on which 
they carry their cast-off skins as a kind of shelter, The pupze may be 
formed either on the leaves or in the ground, Several generations 
are sometimes gone through in the rainy season. Spraying the 
insects with washes made of the arsenical poison known as London 
purple will always destroy them, but this treatment is only likely to 
be practicable in exceptional cases in India. 
The School Museum contains specimens in various stages of 
development for examination by the students. 
Coccinellide (Lady-bird beetles).—These trimerous beetles have often 
a good deal of superficial resemblance to Chrysomelide, but ean be 
at once distinguished by the structure of their tarsi. They are small 
in size and usually more or less hemispherical in shape, Both in the 
larval and the beetle stage they feed upon Aphidw and Coccide, and 
are most useful in keeping these destructive insects in check. Mauy 
species of Coccide have particular lady-birds which specially feed 
upon them, This fact has been taken advantage of with the best 
result by the United States Entomological Department, who have 
successfully colonised Coccinellide beetles in several parts of the 
world amongst destructive scale insects attaeked by them. 
In Dehra there is a common species by name Epilachna vigints- 
octopunctuta, Fabr., which, contrary to the usual habits of the 
Coccinellids, feeds upon the leaves of plants. This case however must 
be looked upon as altogether exceptional. 
The School Museum contains numerous species of the group for 
examination. 
V,—Hymenoptera, 
These insects pass through a well-marked pupal stage. They have 
the mouth parts formed for biting or licking. The wings, when present, 
are four in number and membranous, with comparatively few nervules. 
On comparing the mouth parts of the bee with those of the cock- 
roach we find that there is no very essential difference in the labium and 
the mandibles; the maxillex are much produced to aid the tongue, 
whicb is composed of an elongation of the central portion of the labium, 
the labial palps being elongated and modified to assist. If time allows, 
each student should pick out, mount, and sketch the mouth parts of a 
