80 Indian MuscMin Notes. [ \q\^ JJJ^ 



Bengal, little damaofe, however, hns been reported, and the insects seem 

 to have been too few to cause any anxiety. 



It will be remenmbered that the only important points in the life 

 Notes on the life history of bistory of the insect on which any serious 

 the insects. doubts were indicated in the previous report, 



were upon the subject of the number of g'eneration in the year and the 

 relationship borne by the young- locusts which hatch out in the spring- 

 to those which hatch out in the autumn. An attempt lias since been 

 made to settle these points by rearing the insect upon a considerable 

 scale in large cages v^hich were specially constructed for the purpose 

 in the Indian Museum. The cages were placed under somewhat differ- 

 ent conditions of sunlight and moisture, but in each case the insects, 

 though reared from the egg to the imago stage without difficulty, died 

 off before any ovipositing took place. 



Considerable quantities of eggs were received from Rawalpindi and 

 Peshawar in the spring of 1891. The first sets dried up without hatcli- 

 ing, in spite of the attempts that were made to keep them moist by 

 watering the earth in which they were placed ('). Eggs received in the 

 end of March, however,>hatched out freely, though a large proportion are 

 believed to have been destroyed by the parasitic flies that also emerged 

 in large numbers{^). These young locusts were reared through all their 

 stages without difficulty, though there was considerably greater mortal- 

 ity amongst them than had been the case with the ones that were reared 

 in the Museum the previous year, and this in spite of the fact tliat the 

 rearing cages were larger than before, and. were kept, some in the 

 Museum and others in the open air, with a view to testing the conditions 

 most favourable to the development of the insect. The young locusts 

 acquired wings by the middle of May, but died off so rapidly that there 

 Avas hardly any of thern left by the end of the month. It was not possible, 

 therefore, to make any observations as to the time at which they would 

 lay their eggs. 



On the 19th June 1S91, Captain C. G. Pai'sons wrote from Kohat, 

 that up to a few days previously locusts had been obtainable in the 

 western portion of the district in every phase of development from eofgs 

 to fully-winged insects. He concluded that the process of egg-hatching 

 had continued from the beginning o[ April until the beginning of June 

 in tracts of country where the difference in elevation caused only a slight 

 change of climate. "We have seen that the locusts that were hatched 



{}) This would seem to indicate that hrealdng up the land to expose the eggs to the air 

 would be useful, provided it were done soon after the eggs were laid. Later on ploughing 

 up the land becomes nlniost useless as the eggs hatch out whether exposed to the 

 air or not. 



(2) Noticed more fully in No. I of this volume, pnges 34 and 35. 



