1903.] 219 



CONTRIBUTIONS TO THE LIFE-HISTORY OF 



OELECHIA {liECUUVAIlIA) NANELLA, Mb., FROM AN ECONOMIC 



POINT OF VIEW. 



BY J. T. lIOUaUTON. 



Ill the suuimcr ot" 1002 I was asked to examiue the fruit trees in 

 the gardens at Osbertoii Hall, Worksop, the seat of the E,t. Hon. F. J. 

 S. Foljauibe, with a view to suggesting a remedy for the devasta- 

 tions of a minute insect which in previous years had practically 

 destroyed the crops of apricots. The results of my observations 

 appear to have proved of so much interest that I venture to give them 

 for the benefit of entomologists generally. 



The first indication of the presence of the insects was given 

 during the first week in A.ugust, when the larvae were noticed mining 

 in the leaves of apricots ; throughout August and September they 

 continued to feed in the leaves ; on October 10th I found that many 

 were leaving the mines, and were forming silken hibernacula, some 

 ill the crevices of the wall, others in the pieces of cloth used to 

 fasten the trees to the wall, while others again had formed them in 

 the axils of the buds. On October 'J5th I opened some of the silken 

 cases and found the larva inside still unchanged. 



On February 15th one larva in captivity emerged from its hi- 

 bernaculum and began to attack the tip of the bud, boring towards 

 the base ; by the 18th it was quite inside, and I found it feeding 

 between the leaves and the bud scales. Under natural conditions I 

 observed the first larva crawling on the twigs on February 27th, 1903. 



On again examining the trees on March 5th, I found that all the 

 larvae were on the move, some boring into the bud at the base, and 

 others attacking it at the apex. On this date I also found some of 

 the same larvae on the buds of a cherry tree. 



No further change was noticed until March 31st, when on again 

 examining the trees I found many of the leaf buds of the apricot 

 bound to the side of the twig with silk, and on examining the bloa- 

 aoms of some of the peach trees I found many of them were ruined 

 by the larva having eaten out the entire contents of the bud. Some 

 of the buds were lined with silk, and on May 2Sth I found the first 

 pupa inside the bud. This appears to be the favourite position for 

 pupation, but I have also found the pupa enclosed in a white web 

 in the shreds of cloth used in fastening the tree to the wall. On 

 emergence the pupa case does not protrude, and it is therefore 

 difficult to see from which of the buds the moth has emerged. 



