102 FAMILY HISTERIDAE 



forest pests. As a whole the family are found either beneath the bark or 

 wood of the stems, roots, or branches of trees, in decaying animal or 

 vegetable matter, or in fungi "puff-balls." They are not for the most part 

 diurnal insects, and therefore during the daytime they must be searched for 

 in their homes. Some species are to be found under stones, logs, and other 

 debris in the forest during the daytime. Here, however, we are more 

 particularly concerned with the members of the family who live in and 

 breed in the trees. Of their habits something has already been learnt, but 

 much remains to be done in the study of their exceedingly interesting life 

 histories. That some of the species whose habits have already been 

 investigated are of the first importance in the forest, the life histories of the 

 two species of Niponius, to mention but one genus, will show; and yet the 

 first of these, xV. andrewesi, of the plains forests, was described as a new 

 species in 1893, the other, N. canalicollis, of the Himalayan coniferous areas, 

 in 1901. In a previous chapter I have already dealt with the importance of 

 these predaceous enemies of the bark- and wood-boring beetles. 



Mr. G. Lewis, F.L.S., has suggested * that the striae on the elytra 

 might be of use as guiding lines in the case of species such as Niponius, 

 assisting them to follow wood-boring Platypi down their tunnels. My 

 ten years' investigation work in various parts of India would seem to 

 show that the genera Niponius, Platysoma, Cylistosoma, and Paromalus seek 

 out the sub-cortical Scolytidae, such as Scolytus, Toniicus, Polygraphus, 

 Sphacrotrypes, etc., obtaining access to the tree through the entrance bore- 

 holes of the beetles, and crawling down these to reach the partially or fully 

 formed egg-galleries in the bast layer. In the case of some genera, e.g. 

 Niponius, the eggs are laid in these latter galleries. 



Niponius. 



This genus was founded on some Japanese species. The three Indian 

 species known were described in 1893 (2) and igoi. 



Niponius andrewesi, Lewis. 



References. — Lewis, Ent. Mag. xxix, p. 183 (1893) ; Ann. Xat. Hist, xiv, p. 151, pi. 6, f. 3, 3rt (1904) 



Habitat. — United Provinces, Central Provinces, Assam, Madras. Also 

 reported from Bombay Presidency. 



Habits. — This insect {vide fig. 317) is predaceous upon all the species of 

 Sphacrotrypes bark-borer of the sal-tree in India. The beetle is of cylindrical 

 shape, of about the same diameter as the Sphacrotrypes, and enters their 

 tunnels and oviposits in the egg-gallery of the bark-borer, two or three large, 

 spherical, pale-whitish, translucent eggs being deposited. The grubs feed 

 on the bark-borer grubs. 



* Ann. Mag. Nat. Hist. June 1892 ; Eni. Monthly Mag. 2nd ser. 183 (1893). 



