34 ON THE LIFE-HISTORIES OF AUSTRALIAN COLEOPTERA, 



them, depositing an egg under each ; eggn oval, horn-colonred, and 

 showing a regular network structure under a lens. If the beetle, 

 which also feeds on the decaying bark, can find a dying broken 

 branch, it dispenses with the girdling process and lays its eggs at 

 once. 



The beetles are plentiful, but from their uniform grey colour, 

 and their habit of closely clinging to the twigs, they easily escape 

 detection. They are dull brown, but so thickly covered with 

 short grey hairs that it is only old rubbed specimens that show 

 the ground colour; on either side of the elytra just below the 

 shoulder is a well-defined crescent-shaped mark, by which this 

 species is easily identified. 



PlESARTHRIUS MARGINELLUS, HopO, PrOC, Zool. Soc. 1840, p. 35. 



Larva dirty white, segments long and slender, with short 

 ferruginous legs, and rounded at apex ; mouth parts with an 

 irregular band ferruginous above, jaws black, rouuded at forehead, 

 above flattened and shining ; a furrow running down the centre 

 of segments from behind the forehead to anal segment, each 

 segment broadly divided from the preceding by a narrow band 

 formed by the constricted apex of the segment, anal segment 

 rounded at tip, covered with a few scattered hairs. 



The larva feeds upon the stems of Acacia longifolia, in its earlier 

 stages eating the centre out of the smaller twigs, it comes down- 

 ward, gnawing all the wood off just under the bark on the top of 

 the main limb, which then falls off; the larva now gnaws straight 

 down the centre of the stem, tilling up the opening at the top 

 with wood debris. Hundreds of branches and young saplings are 

 cut off every year at Rose Bay, the beetle coming out in the 

 middle of December. I have also bred it from a branch of Acacia 

 decurrenfi, received from Mr. J. H. Maiden. Mr. French informs 

 me that it is a common beetle in Victoria on this Acacia. 



I have never taken it at large, though I have bred a large 

 number from infested twigs. The beautiful feathered antennae of 

 the male, with the dull reddish-brown longitudinal stripes on the 



