184 INSECTS. 



The Chalcididae number upwards of 1190 species, and 

 are of great value in keeping under the numbers of 

 injurious insects. The " Death-watch," which feeds on 

 the woodwork of houses, is among their victims. 



The fifth and last family of the Spiculifera is Procto- 

 trupidae, or the Proctotrupes family. These, like Chalci- 

 didse, are very small insects, with few or no veins in 

 their wings. They differ in form from Chalcis, which is 

 the most squat of the parasitic families, being of more 

 slender proportions. They may also be distinguished 

 from these by their antennae, which are less decidedly 

 angulated, and by the absence of a hollow in the fore- 

 head, which in Chalcis receives the antennae. In colour 

 they are less conspicuous, being chiefly black and 

 brown, and although in some species the thighs are 

 slightly thickened, they never present the remarkable 

 appearance of the legs in some of the Chalcididae. 



If the small size of the Chalcididae was shown by their 

 being hatched within an aphis, or a butterfly's egg, it may 

 give some idea of the minuteness of the Proctotrupidae 

 to mention that the little caterpillar which mines the 

 roseleaf is said by Mr. Westwood (from Dr. Gees) to be 

 infested by one species. Many individuals have also 

 been reared from one butterfly's egg, and they have been 

 found in the larvae of a minute insect, which feeds within 

 the envelope of a grain of wheat. 



There are about four hundred British species in this 

 family. 



Division II. TUBULIFERA. Tube Bearers or Ruby 

 Tails (see PI. VI. 6). The Chrysis, or "ruby tail," is 

 a beautiful insect which can hardly have failed to attract 

 the attention of the reader. The fretted surface of the 

 head and thorax is a deep but brilliant green or blue, the 



