28 REPOET OF SEARCH FOR ENEMIES OF CITRUS WHITE FLY. 



ii second set of potted nursery trees (PI. VII, fig. 2). The trees were 

 carefidly examined before being introduced into the house in order to 

 destroy any of the pests that could be seen. This was not difficult 

 of accompfishment, as the pests pupated in the trees. Inspection 

 was continued every few days so that the plants were soon free of the 

 pests and in due tmie tlie development of young growth followed. 



Notes on the Life History of Aleyrodes citri in Northern 



India. 



The following notes on the life history of Aleyrodes citri on citrus 

 were made at Lahore during 1911 and might be said to be typical 

 of this insect m the great plams of northern India. Observations 

 made at different times of the year in other parts of India would 

 tend toward the probability that the development recorded in the 

 northern part would also be more or less applicable to central India. 



On May 1-4, 1911, the earliest dates of observation, the white 

 ^y was in tlie egg and larval stages. Calcidating on the basi^ of 

 the conclusions of Morrill and Back m their white-fly investigations 

 in Florida that during the spring the duration of the egg stage 

 averages somewhat less than two weeks, it would appear from the 

 stages of development existing at Lahore on May 1 that the first 

 brood of adult fUes had emerged during the earlier part of April. 

 This conclusion was somewhat corroborated by information from a 

 native entomologist who stated that he had seen adidt Aleyi'odes in 

 great numbers during the first part of Apiil about the citrus liedge 

 which the WTiter had found well mfested and which he had selected 

 as a basis for operations in collecting. Circumstances prevented a 

 close observation of white-fly development between the middle of 

 May and Jime 1 1 , but an examination on the latter date showed the 

 insects to be in the pupal stage. By June 24 the pupae were almost 

 fully matm^ed and in a lew individuals the purple eyes of the adults 

 had commenced to be prominent. On June 25 a sinaU number of 

 adults emerged and this emergence continued during the following 

 two or three days. Emergence had stopped and practically all 

 adults disappeared by June 29. From this tune throughout July 

 and up to August 20, a penod of about eight weeks, the insects appeared 

 to remain perfectly dormant. The last 10 days of August were a 

 period of great activity. Excretions of honeydew appearing on the 

 pupse between August 20 and 25 marked the first evidence of activity 

 follo^^^ng tlieii' dormancy during the hot, dry summer. From August 

 26 to 30 the pupae rapidly thickened and the purple eyes and whitish 

 \\dngs of the adults became evident through the thin pupal cover- 

 ing. The first adults commenced to emerge on August 31, and within 

 a \yeek or ten days the fhght was as its height. By September 13 

 itically the entire brood had emerged. On September 20 very 



