340 journal[of economic entomology [Vol. 14 



Either casemate or sea moss, as spreaders, were added to the vary- 

 ing dilutions of nicotine sulphate, in the second series of tests. Case- 

 inate, as referred to here, was in all cases powdered casein 1 part and 

 h3'drated lime 3 parts thoroughly mixed. The preparation of the sea 

 moss spreader has been described previously. Caseinate was employed 

 at the rate of 1 pound, and sea moss at the rate of 2 pounds, to 50 gal- 

 lons of water. Inasmuch as there was no appreciable difference in the 

 merits of these respective spreaders, the results are reported as one. 

 The addition of a spreader influenced the effectiveness of the nicotine 

 sulphate, especially in the case of the greater dilution. In the tests 

 of this series, 44.4, 75.4 and 84.5 per cent of the sprayed eggs did not 

 hatch.whereas, an average of 87 per cent of all check eggs were hatch- 

 ing, and in the case of the 1-500 dilution tests, only 4.7 per cent of the 

 check eggs failed to hatch. This increased killing power due to the 

 addition of a spreader is shown by the higher percentages of efficiency, 

 29.8, 61.4 and 79.7, as compared with the results in the first series of 

 tests, in which nicotine sulphate was used alone. 



Nicotine-arsenical combinations (nicotine sulphate at the same va- 

 rying dilutions and powdered lead arsenate always at the rate of 1 

 pound to 50 gallons of water), with the addition of a spreader (employ- 

 ed as discussed in the preceding paragraph), constituted the third series 

 of tests. Briefly, the combination of nicotine sulphate with an arsen- 

 ical, in the hope of killing the young larvae immediately after hatching, 

 ■did not give satisfactory results. The highest per cent of unhatched 

 eggs in this series was 71.9 in the case of a 1-800 nicotine -lead arsenate- 

 sea moss mixture, and in these tests, as high as 17.8 per cent of the 

 check eggs failed to hatch. The highest percentage of efficiency, 54.1, 

 was, therefore, considerably lower than that recorded in either the 

 first or the second series of tests. Failure, here, is due probably to the 

 ■commonly observed larval habit of rejecting the first few mouthfuls of 

 food material, when entering twigs or fruit. 



Extensive studies of the seasonal life history of the peach moth were 

 conducted in connection with this experimental control work to deter 

 mine the varying abundance of eggs present on the foliage during the 

 egg-laying periods of the successive broods. The records of the depos- 

 ition of 12678 eggs, in 1920, show that the dates for the heaviest de- 

 posits of eggs on the foliage in northern Virginia, as given in the pre- 

 vious report, are correct within seasonal variations. The dates of 

 heaviest deposition, May 10 to 28 and June 27 to July 9. for the first 

 and second broods, respectively, are quite distinct. The last two broods 

 overlap to such a degree, however, that eggs are present on the foliage 



