41 6 NOTES ON NEW AND RARE LOCAL BEETLES. 



IV. — Epuraea angustula, Er., and Acrulia inflata, GylL, 

 Coleopterous Parasites on species of the Stephensian 

 gemis Trypodendron. 



By Richard S. Bagnall. 



(Sept. 7, 1906). 



Many theories, interesting, probable and otherwise, are now 

 and then put forward to explain the great rarity of certain 

 insects ; some insects are rare according to the rarity of the 

 food upon which they subsist, others because of the peculiarity 

 of the conditions, or series of conditions, necessary for their 

 existence, but we feel sure that the majority of so-called 

 "very rare" insects (at any rate so far as beetles are con- 

 cerned) are only of such rarity because their true habits and 

 haunts are unknown to us, and to bear out this view many 

 interesting instances could be quoted. This is the case with 

 Epurcza angustula, Er., and Acrulia inflata, Gyllenhal. The 

 writer regards both species as in some measure parasitical 

 upon certain species of wood-boring beetles of the genus 

 Trypode?idron, Steph., and is almost certain that on the 

 publication of these meagre and very incomplete notes both 

 species will be found in various parts of the country, and 

 many more interesting facts relating to their life history will 

 be brought to light, and in these hopes alone is the writer's 

 excuse for hastening publication at the expense of complete- 

 ness. Owing to the tediousness and difficulty of working 

 Trypodendron burrows, however, we do not think that the 

 species will ever come to be regarded as " common." 



It may be advisable first of all to give a brief outline of the 

 wood-borers upon which our little friends prey. The species 

 of this genus \_Trypodendron, Steph. {Xyloterus, Er.) Brit. Col., 

 v., 444-446, pi. clxxx., fig. I, and pi. clxxix., fig. 13], which 

 are almost confined to the northern hemisphere, are small 

 cylindrical insects with the head and thorax usually dark, and 

 the elytra testaceous with or without longitudinal dark bands, 

 and almost glabrous except towards the apex. The perfect 

 beetles bore galleries into the solid wood perpendicularly to 



