2988 



THE JOINTED ANIMALS 



as Me so stenus gladiator, on account of its long needle-like ovipositor. It flies in 

 June, and may be found in the vicinity of old crumbling walls, where bees of vari- 

 ous kinds make their nests in the holes and crevices. In the same illustration is 

 figured Ephialtes manifestator, representing the subfamily Pimplariince . In some 

 members of this group the ovipositor issues from a ventral cleft in the abdomen, 

 and in others from the tip itself; the instrument being sometimes three times the 

 length of the entire body. All the species of the genus are much alike in general 

 appearance, the smaller kinds being parasitic on small larvae, and the larger on those 

 of superior size. They may be seen flying about in woods in summer, in search of 

 the wood-boring larvae in whose bodies they lay their eggs. With intelligent agil- 

 ity the female hurries over the trunk, but by what sense she ultimately detects the 

 presence of a larva within, and directs the ovipositor straight down to the spot, it 



is impossible to say; sight can be of 

 no assistance, nor, one would judge, 

 can touch. Can the antennas be 

 used, as the dividing rod is supposed 

 to be used in the search for water, 

 when common sense methods have 

 failed? Possibly, however, the sense 

 of smell assists, and thus the seem- 

 ingly miraculous becomes once more 

 a commonplace. The females ap- 

 parently follow the borings of the 

 larvae, for it would be next to im- 

 possible for them to penetrate the 

 hard fibres of the timber in which 

 their victims burrow. One of the 

 commonest members of the family, 

 and one of the largest English forms, is Pimpla instigator, which preys upon many 

 species of larvae, especially those so destructive both in gardens and the forests. 

 The perfect insect may be seen on tree trunks, in woods and hedgerows, searching 

 for larvae, with its wings raised, ready for instant action. The illustration repre- 

 sents this species attacking the larvae of the satin moth. 



Pimpla instigator, female to the left, stinging the larva of the 

 satin moth. To the right is the moth, beneath it the pupa, 

 from which emerges the adult, while the male of the par- 

 asite is seen below. 



Family 



The members of this family are very similar in general appearance to those of 

 the last, though the differences in the number and form of the cells inclosed by the 

 wing nervures forms an easy distinction. In habits the Braconida are similar to 

 the Ichneumonidce, attacking as a rule the larvae of I^epidoptera, although they are 

 found as well in those of other insects. Upward of a thousand parasitic grubs of 

 the genus Microgaster have been taken from a single caterpillar. It must be re- 

 membered that the grubs are not in reality gnawing at the vitals, but are nourished 

 by the fluids circulating through the system. As an example of the family, we may 



