we evaluated five different fornuilations of hot 

 pepper additive, whose active ingredient (cap- 

 saicin) is known to deter rodent feeding. 



4) To reduce damage caused by birds, we evalu- 

 ated black spheres versus red spheres. 



5) To inhibit growth of fungi on the surface and 

 in the body of the spheres, we incorporated 

 1.0% sorbic acid mto the ingredients of each 

 sphere body as a preservative. 



In an attempt to extend the residual activity of 

 sucrose as the necessary feeding stimulant on pes- 

 ticide-treated wooden spheres, each sphere was fit- 

 ted with a 1.25-inch plastic dish containing 15 

 grams of molten sucrose, which cooled and hard- 

 ened after pouring. In concept, as these spheres 

 are exposed to rainfall, the sphere surface is re- 

 treated with a dilute sucrose solution from the res- 

 ervoir atop the sphere. If there was a constant 

 release of sugar to the sphere surface under condi- 

 tions of rainfall, then ideally each sphere would 

 have enough sucrose to replenish the active supply 

 through several inches of rainfall. 



In addition to structural modifications of pes- 

 ticide-treated spheres, we increased the level of 

 imidacloprid (Merit formulation, 75 WP) from 

 1.5% to 2.0% active ingredient to extend late-sea- 

 son effectiveness of the spheres (see following ar- 



ticle), l-'or all pesticidc-treated spheres, the toxi- 

 cant (iniKiacloprid) was applied to the spheres at 

 2.0% a.i. in Glidden Latex Gloss Enamel paint. 

 In 1998, we evaluated odor-baited sticky spheres, 

 modified wooden pesticide-treated spheres, and im- 

 proved biodegradable pesticide-treated spheres in 

 32 commercial orchard blocks. Blocks used in 1998 

 were the same blocks used in 1997; spheres were 

 emplaced in eight commercial orchards, each con- 

 taining four blocks of 49 trees. Each block receiv- 

 ing spheres was surrounded by 26 spheres of the 

 same type at a 5-meter interval, and each sphere 

 was baited with a vial of butyl hexanoate. 



Results 



In laboratory tests under conditions of artifi- 

 cial rainfall, the following body composition 

 proved the most durable for biodegradable spheres: 

 16% wheat flour, 16% pre-gelatinized corn flour, 

 5% corn starch, 20% powdered sugar, 13% granu- 

 lated sugar, 7% corn syrup, 8% glycerol, and 9% 

 water. Spheres of this composition were found to 

 harden very quickly and were much more resis- 

 tant to premature breakdown than the body style 

 used in 1997. 



Of materials tested to deter rodent feeding, the 

 best product was African cayenne pepper powder, 



Table 1. Control of apple maggot flies by odor-baited sticky-coated wooden spheres, wooden 

 pesticide-treated spheres (PTS), biodegradable pesticide-treated spheres, or three applications 

 of azinphosmethyl in 32 blocks of medium-size apple trees in eight commercial orchards in 

 1998. 



* Values here represent injury during five sampling periods (every 2 weeks from mid-July 

 tiirough harvest), during which 100 fruit per block were sampled on each sampling date. 



Fruit Notes, Volume 63 (Number 4), Fall, 1998 



