THE TENTHREDINHXE OF GUERNSEY. 119 



bee-like insect. The larva, in addition to its general re- 

 semblance to that of the Lepidoptera, forms a hard, brown, 

 oval cocoon. These cocoons being attached to the twigs of 

 whitethorn, are conspicuous in the winter months when the 

 leaves have fallen from the bushes, and are sometimes 

 mistaken for those of the Egger Moth. 



The galls formed on the leaves of the willow by Nematis 

 gallicola are of a red colour and are very pretty objects, many 

 leaves having a double row of them placed in regular order. 

 They have been extremely abundant this season, Mr. Hocart 

 having brought me large branches, every leaf of which was 

 completely covered with these galls. 



One of the most interesting of our saw-flies is Abia 

 nigricomis, its body being of a rich metallic silken hue. I 

 have taken several specimens here although it is somewhat 

 rare in England. 



The Cephidcz, or Stem Saw-flies, and the Siricidce,OY Tailed 

 Wasps, are closely allied to the Tent fir cdinidce. I have, there- 

 fore, included them in the following list. The Cephidce are 

 represented on our list by an injurious species, Cephus pygmcBus^ 

 which is very destructive to corn crops in Europe. The 

 larvae feed within the stem of the corn, thus weakening it, so 

 that when ripe, under the influence of a strong wind, it breaks 

 in two and causes the ear to fall to the ground. 



The SiricidcB are, like the Tenthredinidce, also vegetable 

 feeders. They are not a very extensive family in England, 

 and I know of only two species that have occurred in Guern- 

 sey. The females are provided with a long ovipositor 

 projecting from the extremity of the body, and looking very 

 much like a strong sting. This ovipositor is a remarkable 

 structure. With it the insect is able to bore into the solid 

 wood of trees to a considerable depth and there deposit her 

 eggs. When these develop the larvre feed upon the wood, 

 making long burrows in the trunk in the course of the two 

 years they pass in the larval state. 



I have taken two specimens of Sirex gigas in Guernsey ; 

 it is a formidable looking insect, although quite harmless. It 

 is somewhat rare in England, but abundant on the Continent, 

 especially in the neighbourhood of fir forests. 



Sirex juvencus is a smaller insect of a dark steel-blue 

 colour. 



Although the following list of species is the result of 

 considerable research, I consider it far from complete. I have 

 specimens of several obscure species still unnamed, and I have 

 no doubt many more will be found. 



