Classification of Insects : Hymenoptera, Diptera. 179 



702. The AlucitxB, or feather-winged moths, is a small tribe of 

 not much importance from the injuries done. 



(6.) Hymenopteea (Saw-Flies, Ants, Wasps, Bees, etc). 



703. These are insects with jaws, four veined wings in most species, 

 the hinder pair being the smallest, and a piercer or sting at the end 

 of the abdomen. Transformation complete. Larvse mostly maggot 

 or slug-like ; of some, caterpillar-like. Pupse with the legs and 

 wings unconfined. 



704. In the adult state, these chiefly live upon honey, the pollen of 

 flowers, and the juices of fruits. As slugs or false caterpillars they 

 sometimes injure plants. Some are wood-borers and wood-eaters, 

 the pines and firs suflering most. Others cause galls and excres- 

 cences upon leaves and twigs, those upon the oak furnishing the nut- 

 galls of commerce. On the whole, the injury they do is far more 

 than counterbalanced by their benefits, especially in the ichneumon 

 flies, which destroy enormous numbers of noxious insects, by 

 puncturing their eggs or their larvse, and depositing their own eggs 

 within them. 



705. Others lay their eggs in the provisioned nests of other 

 insects, whose young are starved by the food being first eaten by 

 the earlier-hatched intruders. The larvse in which the ichneumon 

 fly has laid its eggs do not at once die. They may even complete 

 this stage, and form a cocoon, from which, in due time, an ichneumon 

 flv will emerge in place of the original insect. 



706. The wood- wasps, sand-wasps, etc., are predaceous, and feed 

 upon other insects. Our honey-bee and the bumble-bee belong to 

 this order, and serve a most useful purpose, by conveying the pullen 

 from one blossom to another, and thus fertilizing them. 



(7.) DiPTEEA. (Musquitoes, Gnats, Flies, etc). 

 706J. These are insects with a horny or fleshy proboscis, two 

 wings only, and two knobbed threads, . called balancers or poisers, 

 behind the wings. Transformation complete. Their maggots have 

 no feet. These are generally not injurious to trees. The Cecidomy- 

 diadce includes the midges, or gall-gnats, whose effects are often seen 

 on the leaves of trees, but generally not so as to materially injure 

 their growth. The wheat-fly, Hessian-fly, and fruit-flies belong to 

 this order. 



