REPORT OF THE ENTOMOLOGIST. 489 



orange-growers by two species (the leery a in question and the Cali- 

 fornia Red Scale), introduced from Australia, we know of no way in 

 whi(di the Department could more advantageously expend a thousand 

 dollars than by sending an expert to Australia to study the parasites 

 of the species there and secure the safe transport of the same to the 

 Pacific coast; and the fact that the Commissioner of Agriculture 

 is prevented from doing so by restrictions imposed on the Division 

 of Entomology is a sad commentary on the narrow Congressional 

 policy which seeks to limit and control administrative action in de- 

 tails which can neither be properly understood nor anticipated by 

 committees. 



Preventive Action. — The value of clean culture and fertilizing 

 where necesary to induce vigorous growth, but more particularly of 

 wise pruning, so as to let in the sun and rain to the heart of the tree, 

 lias been set forth in the special report of the Division on the Insects 

 affecting the Orange, by Mr, Hubbard, and apply equally to California 

 as to Florida. We have also been particularly impressed with the 

 value of wind-breaks of coniferous trees not affected by the Coc- 

 cidse that infest the Orange, both as shelter to the trees and as screens 

 to prevent the spread of the Icerya from infested trees outside the 

 grove. 



Spraying with Insecticides. — The orange-growers of the Pacific 

 have suft'ered greatly from the advice and recommendations of biased 

 or interested persons, who were prejudiced in favor of their own par- 

 ticular remedies, and were for a long time unwilling to profit by the 

 results of thorough and careful experiments which we have for some 

 years conducted in the East, and which are in the main embodied in 

 Mr. Hubbard's report. A pretty thorough personal survey of the 

 field has convinced us that while the resin soaps experimented with 

 by Mr. Koebele are a valuable addition to our insecticides for the 

 orange Coccidse, yet in the main our experience in Florida is repeated 

 in California, and all the more satisfactory washes have kerosene as 

 their effective base. There has been, and is, however, a very great 

 waste in applying it, and where from 10 to 50 or more gallons have 

 been used on a single tree, from 2 to 4 would suffice. 



We cannot urge too strongly the fact that in the case of this Icerya, 

 as most other orange-feeding Coccidse, it is practically impossible, 

 with the most careful and thorough spraying, to reach every one of 

 the myriad individuals on a good-sized tree. Some few, protected 

 by leaf-curl, bark-scale, or other shelter, will escape, and with their 

 fecund progeny soon spread over the. tree again if left unmolested. 

 Hence two or three sprayings at intervals of not more than a month 

 are far preferable to any single treatment, however thorough; and 

 this is particularly true of the Icerya, which occurs on so many other 

 plants, and which in badly infested groves is crawling over the ground 

 between trees. It is now the custom to use the time of a team and 

 2 men for fifteen to twenty minutes or more, and 10 gallons and 

 upward of liquid on a single medium-sized tree. In this way the tree 

 is soaked until the fluid rains to the ground and is lost in great 

 quantities, some growers using sheet-iron drip-plates around the 

 base of the tree to save and re-use the otherwise wasted material. 

 This is all wrong so far as the oil emulsion is concerned, as the oil, 

 rising to the surface, falls from the leaves and wastes more propor- 

 tionally than the water. 



_ The essence of successful spraying of the kerosene emulsion con- 

 sists in forcing it as a mist from the heart of the tree first and then 



