INSTITUTE, PUSA, FOR 1917-18 99 



found that it is possible to rear this insect on sugarcane 

 stems also. 



(4) An unidentified Longicorn (Plate XV, fig. 2) was 

 found boring and killing orange shoots in Sylhet. The 

 grubs bore into the new shoots which appear in spring and 

 cause them to wither. 



(5) Eurytomine wasp in Sesbania pods. A small Eury- 

 tomine Chalcidid was observed to infest Sesbania pods at 

 Pusa in September, 1917, and was kept under observation 

 throughout the year. The eggs are laid in the green pods, 

 the larvae feeding on the seeds, almost all of which are 

 destroyed. Pods infected when young do not develop any 

 seed but shrivel up; in older pods the seeds are rendered 

 useless, their contents being consumed. At the end of the 

 season the damage in a small experimental plot amounted 

 to about 90 per cent. Various remedial measures, such as 

 deterrent spraying, were tried, but picking off the dry pods 

 at frequent intervals gave the best results. 



Investigations into the life-histories and habits of pests 

 and other insects were continued. Brief accounts of the 

 observations on the pests of sugarcane, rice and other main 

 crops are given above under those crops. The more 

 important points noted with regard to some of the other 

 insects under rearing during the year are noted below : — * 



(6) Amsacta moorei sara. Hibernating pupae were 

 received from Dohad in May, 1917. In the Insectary at 

 Pusa moths emerged from these up to 24th June, 1917. 

 Eggs were obtained and a cycle observed; this took a full 

 year, the pupal period extending from July, 1917, to June, 

 1918. This Gujarat form seems to be biologically distinct 

 from the typical South Indian form moorei, but I have 

 been unable to detect any morphological differences. 



(7) Eugnamptus marginatus (Plate XVI, fig. 1). The 

 salient points in the life-history were given in last year's 

 Report. A point determined by subsequent observation is 

 that the grubs sometimes remain underground in a resting 

 condition for more than a year. 



