VII. Preliminary Reports of Experiments witli 

 the Potato Flea Beetle. 



Althoiigli more than one species of flea beetle is known to attack 

 the potato, the one that is best known on Long Island among potato^ ' 

 growers, and has come to be called the potato flea beetle, is the com- 

 mon little black species, Crepidodera cucumeris. 



This little insect has come to be a serious pest to potato growers 

 in the locality above mentioned. During dry seasons they are 

 usually very abundant, not infrequently coming in such numbers as 

 to seriously cripple the potato vines before the tubers reach matu- 

 rity. Although feeding upon a great variety of plants, this insect 

 is pre-eminently a potato and tomato pest on Long Island. 



Last year the beetles were abundant in the vicinity of Jamaica 

 until the middle of June. From that time on they became less 

 numerous for several weeks, although the year before they had been 

 very abundant throughout the season. 



The beetles injure the plants by eating small holes in the leaves,, 

 which finally causes the leaves to wither and die. They feed from 

 both the upper and under surfaces, hence in applying insecticides 

 for them care should be taken to cover both surfaces. 



Early in the season a field of potatoes at Bay Side, Long Island, 

 was engaged for the purpose of conducting a series of experiments 

 with remedies for the flea beetle. It was the original intention to 

 continue these experiments throughout the season. The work was 

 only just begun, however, when the beetles became so scarce that 

 the effects of the treatment were not apparent. 



The field was divided into eight plots and treated as follows. 

 There was not time to make more than one application of the insecti- 

 cides before wet weather commenced and the beetles became 

 comparatively scarce : 



Plot I, containing five rows,* was sprayed with Paris green 



* Each row was about teu rods long. 



