104 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



SPRAYING EXPERIMENTS FOR THE DESTRUCTION OF THE EGG MASSES. 



EXPERIMENTS AT ESPANOLA, N. MEX. 



The work at Espanola, N. Mex., was conducted in the apple 

 orchard of Mr. Henry L. Pollard. The orchard consisted of 14-year- 

 old trees in fair condition. For the spraying a barrel outfit was used 

 and the pressure maintained ranged from about 75 to 100 pounds. 

 The number of trees in each of the plats is shown as follows : Plat I, 

 21; Plat II, 22; Plat III, 14; Plat IV, 22; Plat V, 22; Plat VI, 6. 

 The days upon which the sprays were applied were clear and quite 

 cool. The results of the experiments are shown in the following 

 table: 



Table IV. — Spraying experiments for destruction of egg masses of the fruit-tree leaf-roller, 

 Espanola, N. Mex., 19 J 1-12. 



Plat 

 No. 



Treatment. 



Num- 

 ber of 

 count 

 trees. 



Total 

 num- 

 ber of 



egg 

 masses 



ob- 

 served. 



Number 



of egg 



masses 



hatched. 



Number 

 of 3gg 



masses 



un- 

 hatched. 



Percentage of egg 

 masses- 



Hatched. 



Un- 



hatched. 



I 



II 



III 

 IV 



V 



VI 

 VII 



Commercial lime-sulphur solution 

 at 1 gallon to 8 gallons water 



6 



6 

 6 



6 



6 



6 

 6 



265 



277 

 310 



285 



252 



272 

 250 



263 



276 

 21 



285 



251 



16 

 250 



2 



1 



289 







1 



256 

 



99.24 



99.63 

 6.77 



100. 00 



99.60 



5.88 

 100. 00 



0.76 



.37 

 93.23 







.40 



94.12 

 



Commercial lime-sulphur solution 

 at 1 gallon to 10 gallons water on 

 December 14, 1911 



Miscible oil at 1 gallon to 15 gallons 

 water on Decern Der 14, 1911 



Commercial lime-sulphur solution 

 at 1 gallon to 9 gallons water on 

 Februrary 17, 1912 



Commercial lime-sulphur solution 

 at 1 gallon to 7 gallons water on 

 Februrary 17, 1912 



Miscible oil at 1 gallon to 12 gal- 

 lons water on February 17, 1912. 





As will be noted, the trees sprayed with miscible oil showed good 

 results from the spraying. The spraying of Plat III with the oil at 

 the rate of 1 gallon to 15 gallons of water prevented 93.23 per cent of 

 the eggs from hatching, and Plat VI, upon which the oil was used at 

 the rate of 1 gallon to 12 gallons of water, showed a benefit of 94.12 

 per cent in favor of the spraying as compared with the checks. It 

 should also be noted that all egg masses on the unsprayed trees 

 hatched. The commercial lime-sulphur solutions gave little or no 

 beneficial results for the treatment. On Plat IV practically all the 

 eggs hatched, and on Plats I, II, and V there was only a benefit 

 of 0.76, 0.37, and 0.40 per cent, respectively, from the treatment as 

 compared with the check trees, upon which all the eggs hatched. 



