INTRODUCTiON. 1 1 



occurivd at intervals, enabling the insects to turn ruuiid. In 

 the brancli-tunnels eggs, 20 or more in nuinbci', were laid 

 at regular intervals of about one-eighth of an inch in a s\m'iil 

 line round the wall, each in a slight depression, and the chamber 

 was afterwards packed with wood dust. Each grub, on 

 hatching, bored straight into the wood, the mother- beetle 

 remaining in the main burrow. It is jirobable that the mother 

 usually dies near the entrance to the workings and so bars 

 the way to any insects seeking to prey upon her brood. 



It has been stated by Katzeburg (Die Forstinsekten, 

 vol. i, 1837, p. 106), that the male and female of a Dorcus (the 

 European D. paralleloplpcdu.s L.) work in association, but 

 this has never been confirmed. It is very likely tliat such 

 collaboration will be found to occur in Lucanid genera, such 

 as Figulus and Nigidins, in which, as in the Passalid^, the 

 two sexes are aUke and there is no extravagant enlargement 

 of the mandibles of the male. It is significant that the 

 genus Hiyiodendron , which contains only three known species, 

 is quite unlike all other LuCANiDiE in having the mandibles 

 of the male very small and the head and thorax provided 

 with horns similar to those of dung-beetles, Copris, etc., in 

 which nidification by the male and female working in co- 

 operation is well known. The thoracic horns in Sinodendron, 

 as in many Coprin^, have become specially modified to adapt 

 them to the purpose of removing excavated material and 

 debris from the burrow. 



The LrcANin.^ have been charged with the destruction of 

 living trees, but without adequate reason. In his ' Report 

 on Insects destructive to Forests,' Thompson stated " The 

 Stag-beetles are both numerous and connnon in individuals 

 and are, of the whole order of wood-beetles, the most destruc- 

 tive to Uving trees." According to E. P. Stebbing (' Indian 

 Forest Insects ') this statement was the result of confusion 

 with another beetle {Lophostermis) belonging to the family 

 Cerambycid^ ; of the Lucamd^ Stebbing reports, on the 

 contrary, " The tree selected (by the egg-laying female beetle) 

 is invariably a dead one in which the wood has already 

 undergone considerable decay. In no cases have I ever found 

 the grubs or beetles in sound timber, nor have I been able 

 to find any corroboration of the statement made by Thompson 

 that these beetles and their grubs destroy oak timber." 



Stebbing records, concerning Lucanus lunifer (Indian 

 Forest Insects, p. 71), that fully developed larvie, pupa? and 

 mature beetles were all found in rotten oak stumps during 

 July, and that the beetles are on the wing in June, July and 

 September. The i)upal stage lasts a month or six weeks at 

 most, but the beetle spends some time resting before emergence. 

 The female beetle lavs her eggs in crevices of the l)ark or creeps 



