ZOOLOGY. 63 



become a serious plague. The absence of trees in many districts of Ire- 

 land entails scarcity of many insect-eating birds, and a consequent alarming- 

 increase in the numbers of insects. On the other hand, the numerous sea- 

 birds in the maritime counties often do great service to the farmer by 

 devouring grubs as they follow the plough. 



Among the insects affecting fruit trees, the most prevalent are the 

 " American Blight " on the Apple, and the grubs of the Savvflies {Nciiiatus 

 ribesii and Enocampoides Innacina) of the Gooseberry and Pear respec- 

 tively. The extension of Fir-plantations in Ireland has been followed by a 

 spread of the characteristic pme-insects. The great pine Sawfiy iSircx 

 gigas) is now established throughout Ireland, but the accompanying beetles 

 —the weevil Hylobhis abietis, and the bark-borers Hylurgus pimperda 

 and various species of Hylastes — are more destructive. Among insects whicli 

 injure other forest trees, the bark beetle of the Ash {Hylcsinns fraxini), 

 and the caterpillar of the " Hornet-clearwing " Moth {Trochilium crabrom- 

 f or mis) which burrow in the wood of Willow and Poplars may be mentioned 

 as especially noteworthy. The " Lusitanian " weevil Mesites Tardyi is often 

 common enough to injure seriously the timber of Beech and Holly. 



In a grazing country like Ireland, the maggots of the Warble-fly {Hypo- 

 derma bovis) feeding beneath the skin of cattle, often cause great suffering 

 to the beasts and loss to their owners. The alHed Bot-fly of the Horse 

 Gastrophilns equi), whose maggots feed in the lining of the stomach, is 

 also too common. The Sheep Bot-fly (Oestrus ovis) occurs in Ireland, but 

 far more injurious to flocks is the Sheep Flesh-fly {Lucilia sericatd) whose 

 maggots live parasitically on the skin and even in the flesh of neglected 

 sheep. The usual parasitic Lice and Mites of the domestic animals are 

 prevalent in Ireland, and the voracious grass Tick {Ixodes r'edtivius) is 

 especally abundant m the western counties. 



Although insect ravages to crops and stock may be less serious in Ire- 

 land than in countries with a richer fauna, the subject has received less 

 attention than it deserves from Irish agriculturists. The most effective 

 means for destroying injurious insects are found to vary with different 

 localities, and careful observations and experiments as to the special needs 

 of Ireland in this respect would probably lead to valuable results. That 

 very important branch of Economic Zoology — Fisheries — is fully dealt with 

 in another section of this work. It is certain that the study of the animal 

 life of Ireland and its surrounding seas has a most direct bearing on the 

 welfare and prosperity of its people. 



