82 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



Mr. T. J. Headlee: No. We tried it last year with apples. 

 Professor George A. Dean: The next paper is by P. J. Parrott. 



CONTROL OF SUCKING INSECTS BY DUSTING 



By P. J. Parrott, Geneva, N. Y. 



Among the problems of pest control that confront the orchardist 

 and general farmer, those bearing on dusting continue to attract at- 

 tention. In a previous report the writer presented an outline of the 

 scope and nature of his activities with respect to dusting, and announced 

 some preliminary results relative to the effectiveness of materials in 

 powdered form in controlling certain injurious insects. The present 

 paper summarizes the results of experiments in continuation of previous 

 work, considering especially the susceptibility of apple red bugs and 

 various species of aphids. 



The Apple Red Bugs 



In the experiments with the bright red bug (Lygidea me-ndax Reuter) 

 and the dark red bug {Heierocordylus malinus Reuter), dusting mixtures 

 containing 0.25, 0.50, 1.0, and 2.0 per cent nicotine, respectively, were 

 toxic to the insects. The preparations with the highest amounts of 

 nicotine gave, on an average, more uniform results and displayed 

 higher killing power than those containing the smaller ratios. Mixtures 

 with 0.25 per cent nicotine are probably too weak to obtain satis- 

 factory control. Dusts containing 0.5 or more per cent nicotine should 

 bemused in rather liberal amounts and applied with care to destroy the 

 majority of the insects and to avoid high dosage cost. Prevailing 

 conceptions of dosage requirements for typical bearing orchards tend 

 to underestimate the quantity of material necessary to accomplish 

 effective results. 



Efficient dusting mixtures against red bugs require a larger nicotine 

 content than spraying mixtures, which makes the dosage cost for 

 dusting higher than that for spraying. Dusting requires less time than 

 spraying, resulting in appreciable economies in time and labor. At 

 prevailing prices for materials dusting is more expensive than spraying. 

 Considering the needs of average growers and cost of labor and materials, 

 the apple red bugs can be more effectually and economically controlled 

 by spraying than by dusting. In large commercial orchards dusting 

 could doubtless be used to great advantage in a supplementary ca- 

 pacity to the usual spraying operations. 



