Can Apple Maggot Fly Control Benefit 

 from Sprays of Provado Aimed at 

 Killing Leafminers and Leafhoppers? 



Xing Ping Hu, Andrew Kaknes, and Ronald Prokopy 

 Department of Entomology, University of Massachusetts 



The insecticide Provado (containing imidacloprid 

 as the active ingredient) was synthesized by Japanese 

 Chemists in 1985. In 1995, it was labeled for use on 

 apple in the United States. One of its greatest perceived 

 advantages is its high toxicity to several major apple 

 pests but comparative lack of toxicity to beneficial 

 predators and parasitoids. Indeed, Provado has proven 

 very effective against leafminers, leafhoppers, and 

 aphids in apple orchards of Massachusetts and other 

 states [Fruit Notes 60(4)]. Provado may be used ef- 

 fectively when applied against either first-generation 

 leafminers and leafhoppers at petal fall in May, or 

 against second-generation leafminers and leafhoppers 

 in late June. Application in late June conceivably also 



could provide control of early-invading populations of 

 apple maggot flies. One reason for believing this might 

 be so stems from recent tests of Provado applied, to- 

 gether with latex paint, on red spheres aimed at killing 

 alighting apple maggot flies. Results of these tests 

 showed high toxicity of Provado against the flies even 

 at very low doses [Fruit Notes 62 (4)] . Here, we evalu- 

 ated effects of Provado against apple maggot flies when 

 applied to the foliage and fruit of apple trees. 



Materials & Methods 



Provado was provided by Bayer Corporation (Kan- 

 sas City, MO). Flies used in bioassays were obtained 



>. 



o 

 E 



u. 



40 

 35 

 30 

 25 

 20 

 15 

 10 



5 i 

 



— •— Flies caged immediately following spray 

 -•— Flies caged 24 hours after spray 

 -•— Flies caged on insprayed leaves 



1 



I 



4 



6 



2 3 4 5 



Days of exposure to sprayed foliage and fruit 



Figure 1 . Mortality of apple maggot flies caged on apple trees sprayed with Provado (0.03% a.i.). 



Fruit Notes, Volume 63 (Number 2), Spring, 1998 



