BITING AND NOXIOUS INSECTS OTHEK THAN MOSQUITOES 41 



was saved. It is probable the mere vigorous washing was the eifective agent in clearing off 

 the aphides. Petroleum itself is said to have no effect on them. 



I have found, and sent to Mr. Theobald, certain other aphides which were present ^^'^ Aphide 

 on the bamboo in the south, and on diseased melon plants forwarded from Kamlin by 

 Major Dickinson who takes a keen interest in these matters. Both, I believe, are new 

 species. Some communications from Major Dickinson regarding his observations on the 

 Aphis sorghi are here recorded. 



" I have noticed that the honey is almost invariably found on the upper side of the leaf 

 ami the insect on the under side. In the few cases where the insect is found actually in the 

 honey on the upper side, it can always be accounted for by its having dropped off a leaf 

 immediately above. Is it known yet what becomes of the fly from December to the time 

 of its appearance, viz : — in September or early in October ? As far as I can observe with 

 the naked eye the first appearance of the pest is a faint covering of honey on the leaf of the 

 plant. I have never seen any insect engaged in depositing tliis honey, nor have I been able 

 to detect any insects in the honey itself, except as already mentioned, when they have 

 apparently fallen from another leaf above. If the insect is hatched in the honey it seems 

 that it must crawl round to the other side of the leaf while still too small to be seen with 

 the naked <'ye. I have also fouud crowds of the fly in its crawling stage on a leaf that 

 seemed to be perfectly dry. A great deal of this honey drips off the plants on to the ground. 

 Is it possible that the insect may be bred in the ground from this honey and spread among 

 the plants the following season ? The head of dura which I have sent you is the kind 

 knowTi as Wwl Fuhil. It and two other kinds, Aiiiinn and Fiki MuMchi are said by the 

 natives to be particularly liable to the attacks of the Asal fly and they certainly seem 

 to be in a worse plight than some other kinds, such as Fetanta ; though I have not come 

 across any kind yet on irrigated land that is not affected more or less. I think that this fly 

 is in danger of becoming a very serious pest. If it cannot be hatched out before the end 

 of September the ravages might perhaps be lessened by making the natives sow their crops 

 earlier than they do now." Again and later, " I am anxious to hear whether you discover 

 any trace of the Asal fly itself ini the infected cotton from Berber. I planted dura at wide 

 intervals among the cotton on the Government farm here, and some of the cotton plants 

 which are close to the dura stalks have the honey on their leaves, but I cannot find on any 

 of them any trace of the fly itself. I do not think that the fly attacks the cotton plant, but 

 if planted with dura a certain amount of the honey falls from the dura on to the cotton plant, 

 and this perhaps may injure the plant by stopping up the pores of the leaves. I will be able 

 to see whether it does or not later on. It does not seem that the plan of wide planting does 

 anything towards mitigating the injury done by this pest. The dura planted among the 

 cotton on the farm was sown ;dong each ridge at intervals of 10 feet, and the ridges 

 themselves are rather more than a yard apart. Yet this dura is as badly affected by the 

 Asal fly as the closely-planteil dura on the native sakias, and I have had to root up quite 

 half of it." 



About the same time as the above were written a report reached nie from the Eahad 

 stating that the kinds of dura known there as Fctarita and Mngml were infected. Xajjud 

 was apparently immune. 



The only dura plants recognizable from these native names are Anilriijioijini cennnnn 

 [Fcfiiritd) which yields a white grain, and Xnjjud or NaijoiH, which is the black and red 

 variety. As it has been impossible to undertake much field work or to study the Aphis 



