Mr, M. M. Lal. 
Mr. Fletcher. 
Mr. M. M. Lal. 
Mr. Fletcher. 
Mr. M. M. Lal. 
Mr. Fletcher. 
Mr. M. M. Lal. 
Mr. Fietcher. 
Mr. M. M. Lal. 
Mr. Fletcher. 
106 PROCEEDINGS OF THE SECOND ENTOMOLOGICAL MEETING 
You cannot always be sure of that because the District Agricultural 
Staff is not trained to do this. But we take care that several of the 
primary plots do contain the parasites ; we examine the affected bolls. 
and see that the parasites are present. We have to take our chance 
as to whether the parasites are present in the boxes sent out from the 
secondary plots. 
Have you any data regarding the percentage of bollworm attack 
before and after the use of these parasite boxes ? 
Last year it was taken before the boxes were placed in the fields 
and we obtained the percentage in some cases. It was fairly high and 
showed a tendency to go higher, from 15 per cent. to 20 per cent. and 
from 20 per cent. to 25 per cent., and figures like that. That was before 
we used the parasite boxes. After the parasite boxes were used, the 
percentage of attack remained constant for some time and then slowly 
began to decrease. Of course, it was impossible to get exact figures. 
How did you obtain the figures you have given ? 
One can easily take the percentages from plots in which the para- 
sites have been liberated and compare them with those of areas in which 
the parasites have not been introduced. 
How many boxes did you use ? 
About 2,000 boxes were used altogether. Each District Assistant 
was given 100 boxes which he used five or six times over. Actually 
about 400 boxes were in use at one time. 
You really thmk that the parasite-boxes did good work ? 
The conclusion we have arrived at is that by the use of the parasite - 
boxes the attack of bollworm is generally lessened. Where the para- 
site-boxes are not used, the attack is always bad. 
1 think that a great deal more investigation is required before we 
can say much definite about the real value of these parasites. Our. 
experience at Pusa, in breeding these parasites under the most favour- 
able conditions, in special plots which are kept full of Harias, is that 
the percentage of parasitization is extremely low, less than 10 per cent. 
in the case of cotton and only about 12 per cent., rising to 21 per cent. 
at the most favourable time of the year, in the case of bollworms 
feeding in Hibiscus abelmoschus. If the percentage of parasitization 1s 
so low it is difficult to see how so great an effect on the boliworm attack 
on cotton can follow the liberation of the parasites. The conditions 
may, of course, be different in the Punjab but, as I just said, we want 
to know a great ceal more about this matter. 
Another point is the identity of the parasites concerned. When this 
work was first taken up it was supposed that there was only one species 
of Rhogas, R. lefroyi, parasitic on Farias in India. A closer examination. 
