REPORT OF THE ENTOMOLOGIST. 



373 



(3.) Solution: 1 pound (12 ounces) potash to 1 gallon water. Mites 

 nearly all killed. A single living adult seen. Molting mites and eggs 

 not all killed. Leaves devitalized, but not charred. 



(4.) Solution: 8 ounces potash to 1 gallon. Adult mites nearly all 

 killed. One half-grown mite seen crawling about among crystals of 

 potash. Molting mites and eggs not killed. 



(5.) Solution: ounces potash to 1 gallon. Adult mites killed. Sev- 

 eral recently molted mites seen crawling on second day. Molting mites 

 not killed. Eggs uninjured. 



(6\) Solution: 4 ounces potash to 1 gallon. Many adult mites killed; 

 some alive. Numerous young mites alive on second day. Molting 

 mites and eggs uninjured. 



(7.) Solution: 3 ounces potash to one gallon. Same results as Xo. G. 



Solutions of 1 pound to the gallon have been used upon orange trees, 

 and although all the leaves and portions of the bark were destroyed, 

 they recovered rapidly from the effects of the application. Such heroic 

 treatment for insect pests is, however, unnecessary and unadvisable. 



Pyrcthrum. — Applied in fine powder, this insecticide visibly affected 

 the adult mites and caused them to erect themselves frequently upon 

 their anal prolegs. The free mites left the leaves in a few hours, but it 

 is doubtful if many of them were killed. The molting mites and eggs 

 remained uninjured. Continued exposure to contact with the strong 

 powder disables and finally kills the mites, but they are not as violently 

 affected as many of the higher insects, and recover from slight appli- 

 cations. 



Lime. — Not the slightest effect was obtained with applications of 

 lime, as the following experiiwents will show: 



(1.) Freshly air-slaked stone-lime dusted thickly over infested leaves. 

 Mites continued feeding and propagating under the coating of lime- 

 powder, and did not abandon the leaves during eight days in which 

 they were kept under observation. 



(2.) Slaked lime: 1 pint measure suspended in 1 quart water, and 

 allowed to partly settle. Leaves dipped iu the turbid liquid. No in- 

 jurious effect upon the mites or their eggs. Adult mites were rendered 

 restless by fine particles of lime adhering to them, and all left the leaves 

 within two days, but were not killed. 



(3.) Same solution as Xo. 2, clarified by standing several days. Leaves 

 dipped in the clear lime-water. Xo effect whatever during eight days' 

 observation. 



Ashes. — Finely-sifted hard wood ashes dusted upon the leaves pro- 

 duced no effect whatever upon the mites, and did not seem to discom- 

 mode them in the least. 



The above experiments were made in December during continued 

 cold weather, which retarded the development of the mites and inter- 

 fered somewhat with observations as to hatching of the eggs under 

 treatment. 



CAUTION. 



There is danger in applying penetrating liquids to orange trees during 

 the winter. First, because any shock to a dormant tree is apt to start 

 the buds and induce new growth, at a time when there is danger of frost. 

 Secondly, a succession of cold nights and*cloudy days, such as frequently 

 occurs in severe winters, following immediately after an application, will 

 increase to an injurious extent its effect upon the plant, by preventing 

 evaporation of the liquids used and allowing them to remain too long 

 in contact with the leaves and bark. Serious loss is liable to follow a 

 di&rcgard of this warning. 



