Fereday. — On the Injuries to Vegetation hy Insects. 289 



Art. XXXIII. — On the dArect Injuries to Vegetation in New Zealand hy 

 various Insects^ especially with reference to Larvoi of Moths and Beetles 

 feeding upon the Field Crops; and the Expediency of introducing 

 Insectivorous Birds as a Remedy. By R. W. Fereday, C.M.E.S.L. 



{Read before the Philosophical Institute of Canterbury, 12th December, 1872.] 



The little time and attention that I have been able to afford to its inve.stiga- 

 tion prechides my treating exhaustively a subject so comprehensive as that of 

 Injuries caused by Insects, and Benefits derived from Insectivorous Animals; 

 but, should the memVjers of the Society be sufficiently interested, 1 hope, on 

 some future occasion, to enlarge upon the subject in a series of papers. 



It has been observed by the authors of a valuable work on entomology, 

 that if it were not for certain counter-checks restraining them within due 

 limits, insects would drive mankind, and all the larger animals, from the face 

 of the earth. — That " the common good of this terraqueous globe requires 

 that all things endowed with vegetable, or animal life, should bear certain 

 proportions to each other, and if any individual species exceeds that pro- 

 portion it becomes noxious, and interferes with the general welfare." And 

 they ask, " How is it that the Great Being of beings preserves the system, 

 which he has created, from permanent injury in consequence of the too great 

 redundancy of any individual species, but by employing one creature to prey 

 upon another, and so overruling and directing the instincts of all that they 

 may operate most where they are most wanted." 



So long as this balance remains undisturbed, so long will harmony prevail; 

 and whenever we suffer excessive injuries from insects, or other animals, the 

 cause may generally, if not invariably, be traced either directly or indirectly 

 to the agency of man alone. Man, in his blindness, is ever breaking, or 

 throwing out of gear, some wheel of the great cosmical machine, and disorder 

 necessarily follows. 



In illustration of this, I would point to the great increase of caterpillars, 

 and other larvae, in the neighbourhood of Christchurch during the last four or 

 five years — an increase attributable in all probability to the following simple 

 causes : — 



In the early days of the Canterbury settlement, quails, larks, and other 

 birds that fed upon insects and their larvae, abounded on the plains ; but the 

 quails have been exterminated, the larks have become comparatively scarce, 

 and the other birds have almost disappeared. So long as the plains remained 

 open and uncultivated, extensive grass-fires sweeping over the land consumed 

 an enormous amount of insect life, and took the place of that counter-check 

 which was being removed by the decrease of the birds ; but within the last 



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