270 Insect Pests. 



feed very ravenously ; fifty having been observed to strip a moderate- 

 sized gooseberry bush in three days. 



The earliest date that the larviB were observed in 1901 to reach 

 their full-fed stage was the 3rd of June, when many under observa- 

 tion commenced to pupate. At the same time 

 there were on the bushes quite small larvie, not 

 one-third grown. These were also of the first 

 brood, but from eggs laid later than the fully 

 mature ones. It appears that the same generation 

 cocooxoKCdosKiiKiuiv of pupiL' uiay hatch out over a period of four 

 ^•^^"""•- weeks. 



The larva? when ready, fall to tlie ground and tlien bury them- 

 selves just under the earth, where they spin a brown or dull 

 yellow case of parchment-like silk, mixed with saliva. This cocoon 

 becomes covered on the outside with little grains of earth. The 

 variety of the colour of the cocoon is very marked, some are very 

 deep coffee-brown, others pale brown and yet others almost yellow. 

 All the larvae do not enter the soil to pupate, for it is by no means 

 unusual to find the cocoons spun against and under a leaf or twig 

 lying on the ground. The majority, however, pupate in the soil in 

 earth-covered cocoons. The pupa is yellowish-green, often very 

 pale, with orange on the thorax and on the apex of the abdomen. 

 The pupal stage lasts during the summer from ten days to nearly 

 three weeks. Miss Ormerod (2) says three weeks. 



The winter is always passed in the larval stage inside the cocoon 

 beneath the earth, the larvte pupating in the eaily spring. 



Number of Beoods of N. Eibesii. 



Cameron (5) says two broods exist. This statement seems to 

 have been repeatedly copied. From observations made during the 

 last twenty years I find that there are nearly always more than two 

 broods ; and as many as four have been observed. During the year 

 1903 three broods had appeared by July. The first brood appears 

 from April to the end of May ; hence we find larva? of all sizes on 

 the bushes during the late spring. The first hatched larvae pupate 

 from the middle to the end of May, these hatch out in ]\Iay and 

 early in June. The larva? of the second brood have been observed 

 to mature by the 20th of June, and from these a third l^rood have been 

 hatched in July. In 1887 I obtained a fourth generation from 

 these flies, which grew rapidly and went to earth on the 2nd of 

 August. 



