.-ljt»r// 3, 1920.] Agricultural Gazette of N.S.W. 273 



The Powder-post Beetle and its Parasite. 



W. W. FROGGATT, F.L.S., Government Entomologist. 



The members of the family Cioidce, to which the powder-post beetle 

 {L'jctiis hninneus) belongs, are all small insects with short antennse, the 

 terminal joints of which thicken to a club. They have short feet com- 

 possd of four joints, middle and hind pair of legs with coxiae small and 

 oval, i nd flexible abdominal segments. The larvae are small, semi- 

 transparent, slightly hairy grubs. The eggs are deposited in the sapwood 

 of dead timber, or in fungi growing upon decaying timber. The typical 

 genus Cis contains over a hundred species of tiny oval beetles breeding 

 in fungi, and one of these, Cis holeti, is found all over Europe. Out of 

 forty-two species of this family described from Hawaii, according to 

 Perkins, twenty-nine belong to this genus, and are chiefly collected in the 

 large fungi growing externally on trees or on dead bark, under which there 

 are usually many small fungus growths. 



The family is poorly represented in Australia. In Gemminger and 

 Deharold's great " Catalogue of the Coleoptera," published in 1869, no 

 species is recorded from Australia, and in Masters' " Catalogue of the 

 Described Coleoptera of Australia " only one — our common powder-post 

 beetle — is listed. 



The members of the genus Lyctus differ considerably in general form from 

 the fungus-infesting species, being elongate, flattened on the dorsal surface,, 

 with the thorax larger and squarer, and the divisions between the abdomen, 

 thorax and head well defined. The adult beetles vary in colour from black 

 to reddish-brown, most of them being about -y% of an inch long. 



Timber Infested at an Early Stage. 

 The female probably deposits her eggs in the outer surface or sapwood 

 when the tree has been cut down and the bark is drying. This may happen 

 in the forest if the logs remain there for any length of time, or when exposed 

 in the mill yard. There is no question that the eggs or young larvae are in 

 the sapwood when the timber is sawn up and used for building purposes, 

 though usually there is no evidence of their presence until about twelve 

 nwnths after the house has been erected. Then the householder notices 

 little dabs of wood dust on the floor. If the boards along the skirting or 

 wainscote are infested, these heaps will be very noticeable, and the little 

 pinholes from which the wood-dust has fallen will be well defined. Sometimes 

 this will end in a year, and there will be no further damage, the adult beetles 

 emerging through the pinhole and dying outside. At other times generation 

 after generation of active grubs are hatched out of eggs, evidently deposited 

 bv the adult females before thev emerge from the infested timber or furniture, 



