160 



first larvae of A . ypsilon are noticed. The parasites cannot be reared 

 through the heat of summer under ordinary conditions. From obser- 

 vations of parasitic cocoons it has been found that at about 80° F 

 (which is the mean maximum temperature for two weeks preceding 

 emergence from the cocoon) the functional activity of the parasite 

 pupa is greatest, and the length of the pupal stage under such con- 

 ditions is five days. If the temperature rises, the larva within becomes 

 dormant, and if it falls lower, the pupal period gradually lengthens, 

 until at 53° F. it is as long as 58 days. This relation between tem- 

 perature and length of the pupal stage is shown in a graph. It has 

 not been possible to determine the lower temperature limit for the 

 functional activity of the parasite. Above 85° F., emergence of 

 parasites from the cocoons stops, but the functional activity of the 

 pupae may be revived, even after two months, by reducing the 

 temperature below 80° F. So far as temperature is concerned, there- 

 fore, it is possible, by regulating this, to obtain emergence of adults 

 at any desired time. The parasite pupae can be forced to become 

 dormant by exposing them to a temperature much below 53° F., but 

 as it is not economical to maintain it for several months, it has been 

 found necessary to handle the problem by modifying the humidity, 

 which is more easy to control than temperature. An experiment on 

 these lines is in progress. At a constant relative humidity of 5° a 

 cocoon becomes dormant and is still alive after two months in this 

 condition ; whether successful emergence in the adult stage can be 

 obtained under favourable conditions of humidity remains to be seen. 

 If this can be accomplished, it will be possible to use a very much 

 cheaper and more effective remedy for A. ypsilon than in the past. 



Ramachandra Rao (Y.). A Preliminary List of the Insect Pests of 

 Mesopotamia. — Rept. Proc. 4th Ent. Meeting, Pusa, February 

 1921, Calcutta, 1921, pp. 164-173. 



A number of insect pests noticed during a year's observations are 

 recorded ; these cannot be taken as by any means an exhaustive list, 

 and it has been impossible to identify many of them. They are listed 

 under the crops attacked. 



The most prominent element of agriculture in Mesopotamia is the 

 cultivation of the date palm, and the most serious pest of the date 

 crop is the moth producing the " hashaf " condition in the fruit 

 [R.A.E., A, vii, 189], which has now been identified as the Cosmop- 

 terygid, Batrachedra amydraula, Meyr. Other date pests, besides 

 those previously listed [R. A.E., A, ix, 91] include a Longicorn, which 

 oviposits under the leaf bases or in cracks in the stem, into which 

 the larvae bore, rendering the tree liable to break during high winds ; 

 this has been wrongly identified as a species of Rhynchophorus, which 

 does not occur in Iraq. A Fulgorid, which has two generations in 

 a year, feeds in large numbers on the fronds, and a Coccid, Phoenico- 

 coccus marlatti, is found between the leaf bases and the trunk. 



On wheat and barley, a fly, suspected of being the Hessian fly 

 [Mayetiola destructor'], is recorded. Mr. T. Bainbrigge Fletcher, in 

 discussing this paper, remarked that it is very important to know 

 whether this identification is correct. 



In view of the possibilities of cultivation of cotton and other crops 

 in Mesopotamia, it is of great importance that every effort should 

 be made to prevent the introduction of such pests as the pink 

 bollworm [Platyedra gossypiella], certain Citrus pests, and the 

 Mediterranean fruit-fly [Ceratitis capitata]. 



