1885.] Forest Trees in South Africa. 19 



in time to come. And that the effect of the tar in keeping away the 

 insects has been most beneficial I can testify, having carefully 

 observed it since the beginning of last year. 



I will ask yon therefore to bear in mind that those insects that live, 

 or whose larvae live in decomposed standing timber, are no less 

 pernicious indirectly than those who live in the tree itself, because, 

 first, they are much more numerous, and secondly, that they occasion 

 a rapid disintegration of the fibre, enable the water to percolate, and 

 cause often that black stain called *' dry rot " in Knysna, so noticeable 

 among other timber, in the Outeniqua Yellow-wood — Fodocarpus 

 elongatus. 



FAMILY NITIDULARIAE. 



The larvae and imago of some species live in rotten wood, also in 

 fallen timber, in damp places. Some species are very numerous in 

 the chinks and crevices of the oak-tree '' Quercus pedmiculata.''^ We 

 have only 28 species described, but I expect that this number will be 

 more than doubled. They are all small. 



FAMILY CUCUJIDAE. 



The form of these insects which is extremely depressed, points at 

 once to their mode of existence. They are generally found under the 

 bark of trees, and so are the larvae. It is not quite certain that they 

 live on wood, some Entomologists think that they prey on insects, but 

 I am inclined to believe that they are xylophagous. I only know 

 thiee species, 1 Sectarthrum from the Transvaal and the banks of the 

 Zambezi, and two Parandridae, one the " Catagenus carinatus,^' found 

 in the silver-tree " Leucodendron argenteum,''^ and another from the 

 Transvaal. All those three species seem to be rare. 



LUCANIDAE. 



The larvae of that family live in decomposed timber, in the rotten 

 trunks aad forks of standing trees. We have only seven species. 

 The genus Colophon with two representatives is strictly South African. 

 It is rather singular that there should be so very few representatives 

 here of this wood-loving family, and we have an instance of the 

 natural barrier caused by the absence of forests in the western side, 

 to the mingling of one fauna with another. The West Coast of 

 Africa possesses many species of the genus Chdognathus, allied to 

 the English well-known Stag-beetle, but the only representative here 

 of this genus C. natalensis, whose appearance is very peculiar, is 

 found in the extreme eastern parts of the Colony, Natal and the 

 Transvaal. The afiinity of forms in that region lies with the eastern 

 coast of Africa, and no Cladognathus has been found there until 

 now. This is a singular case of isolation. 



SCARABAEIDAE. 



Of this considerable family, the tribe '' Melolonthidae " feeding 

 only on leaves when in the imago state, is the only one known to be 

 seriously injurious to trees, for it has been ascertained that the growth 

 of the concentric rings in those trees, the foliage of which is devoured 

 by the cock-chafer, Melolontha vulgaris, was greatly impaired. We 

 have no true Meloloutha, but a closely allied tribe, the Macrophylidae 

 includes the Leontochaeta alopex, an hirsute beetle of good size, 



