4 INDIAN FOREST INSECTS 



As a first case, a tree may have a wide distribution, and its particular 

 pest may accompany it throughout. This is true of the tun-tree {Cedrela 

 toona) twig-borer, Hypsipyla robusta, which appears to be as widely dis- 

 tributed as the tree itself. I have personall}' taken the insect from twigs and 

 branches at Changa Manga in the Punjab, in the United Provinces, Central 

 Provinces, Bengal, and at Maymyo in Upper Burma. Similarly the two 

 well-known defoliators of teak, the caterpillars of the moths Hyhlcea pitera 

 and Pyrmista machaeralis, appear to be found wherever the tree exists as a 

 forest in India, i.e. in Bombay, Central Provinces, Madras, and Burma. 



Or a pest may infest a variety of trees occupying very different climates, 

 and have itself a wide distribution. Amongst the family Bostrychidae 

 instances are common. Both Sinoxylon crassum and S. anale infest several 

 species of trees, tunnelling into and riddling their timber. These beetles 

 occur as a serious pest in the Changa Manga plantations, where they infest 

 sissu {Dalbersi^ia sissoo) and Acacia viodesta. I have also taken one or other 

 or both of the insects in sal, Terininalia tomentosa, Acacia catechu, Ano- 

 gcissus, Pterocarpns, Albizzia, Prosopis, etc., in the forests of the United 

 Provinces, Bombay, Sind, the Central Provinces, Assam, and Burma. 

 Again, the genus Dinodenis includes two species, Dinodcrns pilifrons and 

 D. niinutus, one or other or both of which are to be found infesting 

 bamboos throughout the length and breadth of India. 



Caryoborus gonagra again (one of the Bruchidae) infests the seeds of a 

 variety of trees, and appears to be equally at home in Bombay, the Central 

 Provinces, and Madras. The common noctuid caterpillar Ingiira subapicalis 

 defoliates the sal in Ganjam, and also in the United Provinces Terai and 

 Oudh forests in the monsoon months. 



On the other hand, to come to our other case, there is an assemblage 

 of moths belonging to the families Lasiocampidae and Noctuidae which 

 defoliate the sal-tree in the Central Provinces and Chota Nagpur (species 

 of Trabala, Ingura, etc.). In the sal forests of the United Provinces Terai 

 the Central Provinces species are replaced by others {Suana, Boannia) ; 

 whilst again in Assam an entirely different set of defoliating cater- 

 pillars are met with on the sal, several species of Lyuiantria, DasycJiira, 

 Leucoma, etc. 



To quote one more instance amongst plains insects, a genus of bark 

 beetles, Sphaerotrypes, which infests the sal-tree, has this local distribution. 

 S. siwalikensis is found infesting the sal of the Siwaliks and United Provinces 

 Terai. A second species, S. globulus, is found in the Central Provinces 

 on the same tree ; whilst a third species, S. assaniensis, infests the sal in 

 Assam. A fourth species attacks the Anogeissus latifolia in Coimbatore in 

 Madras. It is unnecessary here to dwell on further instances of the anoma- 

 lies in the distribution of some of our forest species in the plains, as they will 

 be alluded to at length later on. 



Turning now to the insects of the Himalayan forests, investigation has 

 shown that the assemblage of insect pests present in the Western Himalaya 



