REMARKS ON INJURIOUS AND BENEFICIAL INSECTS 17 



Many of the Chrysomelidae beetles feed upon leaves, such as the Podoniia 

 beetle (p. 258) which defoliates the Spondias mangiferae and Ficus elastica ; 

 and an Aphis so reduces the vitality of the needle-bearing twigs of the blue 

 pine that the needles fall either wholly or in part. These are but a few 

 instances of the serious defoliation to which trees are subject by insect pests. 



{g) Damage done to the Inflorescence.— It is probable that the in- 

 florescence suffers very seriously from the attacks of insects. I have 

 as yet but a few actually observed examples. The commonest form 

 of attack is for the eggs to be deposited in or on the inflorescence, and 

 for the resulting grubs to mature in and gradually destroy the developing 

 fruit or seed. 



The blister beetle {Mylabris, p. 247) actually feeds upon and destroys 

 the flowers of the Artocarpus and many shrubs such as the Hibiscus, etc. 



The caterpillars of the moth Boarmia selenaria devour the inflores- 

 cence of the sal-tree in the forests of the United Provinces Terai and 

 Siwalik areas. 



(h) Damage done to the Fruits and Seeds. — A great deal of investigation 

 work remains to be carried out in the study of the damage done by insects 

 to the fruits, and seeds of forest trees in India. Sal seed in Assam is 

 infested by the caterpillars of several species of small moths [Conogethes, 

 Laspeyresia, and Cacoecia), and also by a small scolytid beetle {Coccotrypes, 

 p. 543). In the United Provinces and Siwaliks the caterpillars of other 

 species of moths (the pyralid Dichrocosis Icptalis and Microlepidoptera) are 

 responsible for the failure of what may promise to be a good seed year. 



The cones of the chief conifers of the North-West Himalayan forests, 

 the deodar, silver fir, spruce, and blue pine, are infested by one or both of 

 the caterpillars of the moths Phycita ahietella and Euzophera cedrella. 



The Quercus incana seed is infested by a small weevil, Calandra, p. 446. 

 Small bruchid beetles, species of Caryoborus, are responsible for damage to 

 the seed of Banhinia, Tamarindns, Cassia, whilst the small caterpillars of 

 the moths Trachylepidea friicticasiclla and Cryptophlebia carpophaga infest the 

 seeds in the long pods of Cassia fistula and C. occidentalis. 



The acorns of the oak Q. semicarpifolia are destroyed by the grubs of the 

 hymenopterous fly Callirhytis seniicarpifoliae. 



(0 Damage done to the Timber. — Every forester is aware that once the 

 tree is dead the timber is liable to a more or less rapid decay, the rapidity 

 depending to some extent on climatic and surrounding influences. In India 

 a variety of insects play a very important part in assisting this falling off in 

 quality of the timber. The attacks of others lower the market value of the 

 timber owing to the presence of galleries and holes on theouter sapwoodor in 

 the heart-wood, as in the case of the sandalwood longicorn beetle (cf. pi. iii and 

 p. 380). The number of timber-boring insects is very large, some of the chief 

 pests being found in the families Bostrychidae, Elateridae, Cerambycidae, 

 Curculionidae, Scolytidae, Platypodidae, Termitidae, Siricidae, Cossidae, etc. 



9003 B 



