208 Transactions. — Zoology. 



In the early days of the colony, when the species flourished 

 on the plains, vast swarms of caterpillars infested the open 

 grassy country, living in the dense tussock {Pea). In a few 

 years after the annual burning of the sheep-runs commenced, 

 the caterpillars disappeared from the plains and attacked the 

 cereal crops, working great destruction among them. Some 

 years after the introduction of the house -sparrow, which 

 increased at an unprecedented rate, the caterpillars were soon 

 reduced in numbers, and are now no more trouble to the agri- 

 culturist. They were the larva of the yellow underwing 

 moth, still to be obtained feeding on the introduced Cape 

 broom. 



The moth (Botys polygonalis) is double-brooded, the first 

 brood appearing in August and September, the second in 

 January and February. The larva is abundant every year, 

 often to such an extent as to cause the complete defoliation of 

 the food-plant. The species would unquestionably increase, 

 and probably again become troublesome to farmers, but for 

 the presence of the house-sparrow, which hunts vigorously in 

 the hedges for the larvae, and keeps them in check. As the 

 plant is not indigenous, the moth has apparently acquired a 

 special taste in selecting it as the food of the larva, the 

 colours of both assimilate closely, wdiich affords some protec- 

 tion to the species. 



On good land, where the tussock-grass is thick and allowed 

 to remain unburned for a number of years, the ground is soon 

 covered with a considerable thickness of dead grass. In this, 

 many species of Coleoptera and the chrysalis of moths can, at 

 all seasons, be found. Such were precisely the natural con- 

 ditions of the plains in the days of the quail, excepting that 

 they were on a superior scale, and the food-supply at all 

 times more abundant. K fire sweeping over a large area 

 of such country* would effectually annihilate all insect 

 life in its course, and leave the country black and bare. 

 Frequently the fires raged for several days and nights 



* Some authors, writing on the nioa age, maintain that fires were 

 kindled for the purpose of driving the huge birds on to the sea-shore to 

 enable the hunters to capture them more easily. Supposing such a 

 theory to be tenable, it may be asked, " Why did not the quail become 

 extinct with the moas?" In answer, it may be said tliat, if ever fire 

 was used as an agent to destroy the moa, its ravages would be confined to 

 small limits, and its progress intercepted by the rivers of the plains. I, 

 however, am not a believer in the fire-theory put forth to account for the 

 extinction of the Dinornis. To my mind, the thick grass would be a great 

 protection to the hunters, and would be used by them as an ambush 

 when tracking or surrounding the moas. If the quail existed in New 

 Zealand along with the moas, the burning of portions of the grassy plains 

 occasionally would scarcely affect the economy of the species. It is the 

 annual and wholesale burning of the lands, and the clearing and cultiva- 

 tion that followed, which completed the work of extermination. 



