356 UTILITARIAN ZOOLOGY 



{At ha Ha spinarum), Apple Saw- Fly {Hoilocampa teshidinea). 

 Gooseberry and Currant Saw- Fly {Nematus ribesii), Cherry and 

 Pear Saw- Fly {Et'iocampa limaciiia), Plum Saw- Fly {Hoplocampa 

 fulvicornis), and Pine Saw-Fly {Lophyrns piiii, fig. 1254). 



Other net-winged insects may at times be injurious, e.g. Wasps 

 sometimes damage large quantities of fruits, while Ants make raids 

 on provisions (especially those containing sugar), and Carpenter- 

 Bees {Xylocopd) destroy woodwork. 



Injurious Net-winged Insects {N europterd). — The Biting- Lice 

 {Mallophagd) live as ectoparasites on birds or mammals, and feed 

 on their feathers or hairs, at the same time causing much irritation. 

 Domestic fowls are pestered by no less than five species of these 

 insects, one {Mcnopon pallidum) being particularly common. The 



P'i'-' 125-i- — I'inc Saw-Fly [Lophvrns pini^,. On the branch to the left arc two lan'rc. a cocoon, and an adult male; 

 on the right is an adult female, enlarged actual size indicated by the line!. 



Biting Dog-Louse [Tricliodectcs latus) not only torments its host, 

 but also harbours a stage in the life-history of a tape-worm which 

 lives when adult in the dog's intestine. 



In some of the hotter countries of the world Termites or 

 "White Ants" are very harmful to furniture and woodwork, on 

 account of their habit of excavating and feeding upon wood (see 

 p. 120). An interesting example is giving by Sharp (in The 

 Cainbridge Natural History), who says: — "A Termite {Termes 

 tenuis) was introduced — in what manner is not certainly known 

 — to the island of St. Helena, and committed such extensive 

 ravages there that Jamestown, the capital, was practically de- 

 stroyed, and new buildings had to be erected ". 



Injurio7is Straight-zuinged Insects {Orthoptcra). — Locusts have 

 been one of the scourges of mankind from the earliest times, 

 owing to their enormous fertility and the wholesale manner in 

 which they devour all sorts of vegetation (see vol. i, p. 382, and 

 vol. iii, p. 379). The species which migrate from place to place 

 in vast swarms are those which do most mischief The follow- 

 ing quotation from Sharp (in The Cambridge Natural History) 



