Ll. Lloyd 67 



the stems of the plants. It is no uncommon thing to find three or four 

 fruits on a truss thus destroyed by a single larva in a night. One grower 

 had three tons of fruit destroyed by this means out of a total crop of 

 40 tons in the season. Another, who grows an acre of tomatoes, esti- 

 mates that the pest cost him £150 in the present year, in spite of the 

 fact that he partially controlled it by spraying. In a recent year the 

 damage in the Lea Valley alone was estimated at £30,000, but when 

 the cost of picking off the larvae by hand is added to this it is certainly 

 an underestimate. In some cases the whole staff of a nursery have had 

 to be occupied on this work, to the neglect of other duties, in order to 

 bring the pest within bounds. 



The Experimental Committee of the Lea Valley Tomato Growers 

 Association therefore approached the Director of the Rothamsted Ex- 

 perimental Station with a view to the provision of an Entomologist to 

 investigate the habits of the moth and to indicate means of control. 

 Experiments were carried out in a large trade nursery, and laboratory 

 work was done at the Cheshunt Experimental and Research Station. 

 The thanks of the entomologist are due to the President of the Associa- 

 tion, Mr H. 0. Larsen, J. P., for his unfailing assistance in the conduct 

 of the experiments in his nursery, given often at considerable incon- 

 venience; to Mr A. Bacot of the Lister Institute of Preventive Medicine, 

 who has helped greatly with his wide knowledge of the habits of the 

 British Lepidoptera; also to Dr A. D. Imms, Chief Entomologist of the 

 Rothamsted Experimental Station, who has been frequently consulted. 



This report embodies the work done from the middle of April to 

 the end of September. 



2. CHARACTERS, LIFE HISTORY, AND HABITS. 



The species is common and generally distributed throughout the 

 British Isles to the Shetlands, the greater part of Europe, and also occurs 

 in Asia Minor (Meyrick). The moth normally flies in June and July, 

 with sometimes a partial second brood in the autumn. The larvae feed 

 on a wide variety of low plants, and on certain shrubs and trees. In 

 the neighbourhood of the nurseries they have been observed out of doors 

 on Polygonum, Chenopodium, Rumex and Brassica, and on one occasion 

 on tomato. The eggs were found on nine occasions on Chenopodium, 

 but were not observed on any other plants. 



5—2 



