84 OUR HOUSEHOLD INSECTS 



obvious that in many cases these household specimens 

 may not really be British at all, but, if the timber be 

 foreign, may have been imported with it. 



The female of Sirex gigas has a black head and 

 thorax, and a long cylindrical yellow abdomen, with a 

 broad black band, like a mourning band, across the 

 middle. Behind the eyes, which are not situated on 

 the bend of the head, as they are in wasps, are also 

 two yellow patches, which are so conspicuous and shin- 

 ing that they might very probably at first sight be 

 mistake^ for the eyes themselves. The antennae and 

 legs are long and yellow, and the former are proportion- 

 ately much longer than in the wasps, since they consist 

 usually of about twice as many joints. The four large 

 membranous wings are shining and transparent, though 

 strongly tinged with yellow, and are without the minute 

 hairs that cover those of wasps. When the wings are 

 fully spread, the insect may measure as much as two 

 inches across, but specimens are often found much 

 smaller than this. Like all wood-feeding insects, they 

 vary greatly in size. The abdomen is attached to the 

 thorax by the whole of its base, instead of the slender 

 peduncle that constitutes the familiar and proverbial 

 wasp's waist. 



But the most interesting part of the insect is the 

 ovipositor, which consists of three parts, two yellow 

 side-sheaths, which are toothed outwardly towards the 

 extremity, and a black central borer, which is notched 

 at the end, and is therefore able to act something 

 like a gimlet. This instrument runs up underneath 

 the abdomen, and has its origin more than half-way 

 up the latter; it also projects beyond the abdomen 

 to about the same extent, and measures almost an inch 

 in total length. In addition to this, the last segment 



