546 I'ROCJLEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



and so larvae would be less likely to leave the bolls to pupate, because 

 as a matter of fact I rather think the soil under the wheat was moister 

 than it should have been on account of seepage from a near-by canal 

 through which water was run fairly frequently to irrigate other crops. 

 Unfortunately this point was overlooked at the time when the pits were 

 dug, the land then being uncropped. 



" I should have expected the smallest number of live larvae from 

 bolls buried in Plot I under bershn as, owing to the large amount of water 

 necessary for the growth of this crop, the ground is always moist, not 

 to say wet, even at 5 cm. depth during the winter and spring. However, 

 whether the effect of these conditions was to cause the larvae to leave 

 the bolls in greater numbers in order to pupate or whether they died 

 in larger numbers owing to the damp surroundings rendering them less 

 resistant to diseases, I do not know — the old trouble of the fate of the 

 " missing " larvae again. I am in favour of the first explanation. It 

 is curious however that the fewest pupae and empty pupa cases were 

 found in the pits under bershn and most in the wheat-pit bolls^the 

 reverse of what I should have anticipated. But I do not attach much 

 importance to the figures for pupation ; to begin with, it is probably 

 only a small minority of larvae which pupate in the soil, and also the 

 moister the soil is the more difficult it is to see pupae and especially empty 

 pupa cases when digging into the soil — it would have been better had 

 the soil been sifted. 



" The small number of larvae in the bolls buried at 15 cm. and 20 

 cm. depth I also account for by the much moister conditions causing 

 the larvaj to leave these bolls more readily than those under the drier 

 surroundings prevaiUng in the 5 cm. and 10 cm. pits: 



" Please make any use of this letter you like — if you think anything 

 in it is of sufficient interest. You will not mind, I am sure, my saying 

 that I must reserve the right to also pubhsh the figures in the Society's 

 publications, should my Chief wish to do" so. 



" I much regret that I am unable to give you more information on 

 the points you mentioned in your letter, but I have been working on 

 insects feeding on the graminaceous crops during the past two years 

 and have had little time to give to the Pmk Bollworm. 



" As you know no doubt, we have Chilo simplex here and I think 

 Egypt is saved from very serious loss from this insect (which I think 

 may be from 6-8 brooded) by a iuinute egg parasite. I will send you 

 specimens of the latter and perhaps you would be so kind as to 

 compare it with your Chilo egg parasite and see if it is the same." 



