-17- 



to A. fallacis are not recommended for use after bloom, and those 

 witH~"moderate toxicities of 401 or greater are not recommended 

 for use after the first cover spray. Although most Aj_ fallacis 

 are still in the ground cover at the time of the first cover spray, 

 even small amounts of highly toxic materials falling on the ground 

 cover can severely injure them. 



Results with principal orchard pesticides tested at three 

 different concentrations are given in Table 2. Five of the 

 m.aterials (Imidan, Guthion, Cyprex, Captan, and Benlate) were of 

 low toxicity to A^ fallacis even at double the recommended field 

 concentration. Zolone 3EC was highly toxic even at half the recom- 

 mended field rate, while Glyodin 30% was moderately toxic at double 

 the recommended field rate. 



TABLE 2. TOXICITY OF PRINCIPAL ORCHARD PESTICIDES AT THREE 

 DIFFERENT RATES (ONE-HALF, ONE, AND TWO TIMES THE 

 RECOMMENDED RATE) TO Ambly s eius fallacis (BISHOP 

 STRAIN) . 



MORTALITY (?6) 



1/2 TWICE 



RECOMMENDED RECOMMENDED RECOMMENDED 

 PESTICIDE RATE RATE* RATE 



Imidan (phosmet) 50WP 2 10 15 



Guthion (azinphosmethyl) 5 0WP 4 10 12 



Zolone (phosalone) 3EC 94 100 100 



Benlate (benomyl) 50WP 7 15 14 



Cyprex (dodine) 65WP 5 12 15 



Captan 50WP 4 9 18 



Glyodin 30IEC 5 21 48 



* See Table 1. 



Influence of Pesticides on Reproductive Capability of A. fallacis 



To test the influence of pesticide residues on the reproduc- 

 tive capability of A_^ fallacis , adult females were placed on 

 detached living bean leaves which had been previously dipped into 

 a solution of pesticide at the recommended orchard rate and allowed 

 to dry for 3 hours. We daily offered the predators two- spotted 

 mites as food and counted their eggs over the succeeding 2-week 

 period. (The two-spotted mites caused only slight damage to the 

 leaves.) Each treatment, (including water-dipped check leaves) 

 was replicated 14 times. 



The results are given in Table 3. Five of the pesticides 

 tested (Imidan, Guthion, Cyprex, Captan, and Glyodin) had little 

 or no apparent effect on A^ fallacis reproductive ability. However, 

 the presence of Benlate residues totally destroyed the ability of 



