256 Forty-fifth Report on the State Museum. 



may be hatched on the following day, or some may not have been 

 reached on the first day, so that the vaporization should be fre- 

 quently carried on, until the insects have entirely disappeared, and 

 after that it should be repeated every week in order to prevent a 

 fresh invasion. 



The tobacco juice of the proper strength is purchasable at the 

 tobacco factories in France for about fifteen cents (of our money) 

 a quart. Its expense, at this rate, would be but about twenty-five 

 cents a week for a grapery of about fifty feet by sixteen and ten. 



A strong infusion of tobacco leaves, made by boiling, would 

 be a substitute for the above. It might be prepared in quantity 

 and evaporated to 1 the proper degree, for convenience of keeping 

 and for ready use. 



Although the so-called thrips — it might properly be designated 

 the " grapevine leaf chopper " — is more abundant within the shelter 

 of graperies than elsewhere, still in favorable seasons and in certain 

 localities, it is a great pest in vineyards, where it is less amenable 

 to remedial measures. Early in the season, while yet in its 

 larval stage, benefit has been derived from showering the lower 

 surface of the leaves with an infusion of tobacco or soapsuds, or 

 of both combined. A still more effectual application should be 

 spraying with an emulsion of kerosene oil and common soap, made 

 after the formulas given for its preparation. 



Another method has been used for destroying this insect, with 

 good results, it is stated. A long strip of building-paper is 

 smeared with coal-tar on one side, and stretched between the rows, 

 when, with a brush, the insects are driven up from the vines against 

 the sticky surface, to which they adhere. Two men and a boy can 

 go over a vineyard in this manner in a short time, and a few repeti- 

 tions will nearly exterminate them. 



The Rose-leaf "Thrips." 

 This little pest, which is almost always present with us during 

 the summer months, to mar, if it does not destroy, the leafage of 

 our rose-bushes, is a near relative of the insect which we have 

 been discussing. It is the Tettigonia r<>s<t of tihe Harris 1 reports,* — ■ 

 a small, yellow -bodied leaf-hopper, with while and transparent 



* Now, Empoarosa (Harrlfe). 



