COCCINELLIDiE. 
305 
Hibernation or periods of scarcity are universally passed in the imago 
stage, the beetles living for long periods without food and awaiting 
the proper conditions for egg-laying. 
The imago is protected by the exud¬ 
ation of oil, in some cases, an acrid 
yellow fluid being excreted at pores 
on the margin of the prothorax or at 
the joints of the legs. With the excep¬ 
tion of Epilachnides , nearly all are 
predaceous upon scale insects, mealy¬ 
bugs, aphides and similar small forms 
of life. Many species are known though 
no complete list of Indian forms is 
available. The most important of the 
plains forms are described below ; this 
by no means exhausts the common 
species, and much has yet to be learnt 
of the species which prey upon the less evident forms of pests. Each 
species appears to have a well defined series of prey, which it exceeds 
only when it must, and we know little of what preys upon the rarer 
species of Aphides and Coccides. 
A great deal has been written about the value of introducing lady¬ 
bird beetles to destroy scale insects and the like ; hundreds of trials 
have been made, a regular exchange of Coccinellids was established and, 
as a result, there was one real case in which good resulted. Unfor¬ 
tunately, the idea has been taken up by the Press at different times and 
still crops up. Ladybirds, like parasites, do their best where nature 
puts them, but cannot be moved about the world to eat indiscriminately. 
The species of this country play an essential part in maintaining an 
equable balance of life, and we have a large number of useful species 
which would repay more careful study. Coccinellids are divided into 
two series those with simple or bifid mandibles which feed on insects, 
and those with many toothed mandibles which feed upon plant tissues. 
All of the species mentioned are confined in the first series, excepting 
Epilachna. Crotch revised the family in 1874 and since then Gorham 
has described numerous species (Ann. Soc. Ent. Beige, 1892, 1894, 
1895, 1903) as has also Weise (Ann. Soc. Ent. Beige, 1892, 1895 and 
ii l 20 
Fig. 185.— Chilocorus nigritus 
LARVA X 8. 
