60 



doors to see what the result would be. The screens from a doorway 

 (T b} r 5^ feet) were left open from 10 in the morning to 3 in the after- 

 noon, after which between a pint and a quart of flies of the size of the 

 common costalis were procured from the windows upon the inside 

 of the building. All but about a dozen of these were females, which, 

 as was proved by dissection, had not yet laid their eggs. I believe 

 that a trap might be manufactured that would attract Tabanids in the 

 same way that the}^ are attracted to the building to question. 



It is worth mentioning that a few females of atratus were taken with 

 the above, so it is probable that if this species had been as numerous 

 as the others just as striking results could have been obtained with 

 regard to it. 



THE NEW DISTILLATE SPRAY IN CALIFORNIA. 



By C. L. Marlatt. 



On account of the small margin of profit in the growth of citrus 

 fruits fumigation is now often considered too expensive, and a good 

 deal of spraying is done in California with oil washes. The use of 

 distillate emulsion, prepared substantially after the formula of kero- 

 sene emulsion, described in detail in other publications of this Office, 

 has been very generally discontinued, and in its place a mechanical 

 mixture of the distillate and water is employed. The California oil 

 lends itself to emulsifying with water far more readily than do the 

 lighter oils of the East. The process consists in putting the oil and 

 water together in the spray tank, which has a capacity 7 of about 200 

 gallons. The oil being added to the proportionate amount to give the 

 strength desired, is kept thoroughly emulsified with the water by 

 means of a rotating agitator in the tank operated by the gasoline 

 engine. A ver} r homogeneous and fairly stable milky fluid is secured, 

 which does not separate for hours, and enables the mixture to be 

 sprayed with perfect confidence as to uniformity of strength. Two or 

 four lines of hose are commonly employed, and a pump provided with 

 an air chamber to equalize the pressure. 



There has been considerable complaint of spotting of fruit from the 

 use of this mixture. It is now determined, however, that a 2 per 

 cent strength does not hurt the foliage or fruit, but, unfortunately, is 

 not alwa} T s thoroughl} 7 effective against the scale. The lemon tree 

 will stand a stronger mixture than the orange. Mr. F. Kahles, the 

 manager of the Crocker-Sperry ranch, near Santa Barbara, employs a 

 2i per cent strength for the orange and a 3 per cent strength for the 

 lemon. Mr. S. A. Pease, the horticultural commissioner of San Ber- 

 nardino County, uses 2 per cent strength on the lemon and 3 per cent 

 strength on the orange, without injury to leaf or fruit. Mr. Pease has 

 also used a 5 per cent mixture against the black scale on apricot after 



