Influence of Insecticide on the Ability of 

 Traps to Capture Plum Curcullos 



Jaime Pinero, Sara Hoffmann, Everardo Bigurra, and Ronald Prokopy 

 Department of Entomology, University of Massachusetts 



Several factors may influence the effectiveness of 

 different types of traps for capturing and monitoring 

 plum curculios (PCs). We have determined, for 

 example, that temperature is an important factor 

 influencmg the ability of both Plexiglas panels (traps 

 capturing flying PCs) and pyramid traps (traps 

 capturing crawling PCs) to monitor extent and timing 

 of PC immigration when traps are deployed at the edges 

 of an orchard, in close proximity to woods. We found 

 that panel traps are more effective than pyramid traps 

 on warm days and, conversely, that pyramid traps 

 outperform panel traps on cool days. 



For both branch-mimicking cylinder traps (which 

 are positioned vertically on apple tree branches) and 

 Circle traps (which are wrapped around orchard tree 

 trunks), weather may have a lesser effect because the 

 purpose of such traps is either to capture PCs already 

 present within tree canopies (cylinder traps), or to 

 intercept adults crawling up tree trunks into canopies 

 (Circle traps). However, as indicated in the 2002 Winter 

 issue of Fruit Notes, odor-baited cylinder traps have 

 yet to demonstrate value for predicting extent of PC 

 injury to fruit when deployed in commercial orchards. 

 Similarly, odor-baited Circle traps, although able to 

 capture numerous PCs under unsprayed orchard 

 conditions, have not proven to be effective as a tool 

 for predicting, in commercial orchards, the timing of 

 PC injury to fruit based on extent of PC captures. 



The principal aim of this study was to determine 

 the influence of insecticide presence (via orchard spray 

 application) on surfaces of cylinder, pyramid, and 

 Circle traps on trap performance. 



Materials & Methods 



Field studies. Studies were performed from May 

 16 to June 28 (2001) at the UMASS Cold Spring 

 Orchard Research & Education Center, and from May 

 22 to June 6 (2002) at Atkin's Farm. Both orchards are 



located in Belchertown, MA. The UMASS orchard 

 block consisted of Delicious/M.7 and Cortland/M.7. 

 The Atkins' block consisted of Idared/M.7. 



2001 Field study. In 2001, we evaluated two trap 

 types: (1) a black cylinder trap (3 inches diameter x 12 

 inches tall) and (2) a reduced version of a pyramid trap 

 (6.5 inches at base x 12 inches tall). Cylinders were 

 made from PVC pipe. Pyramids were made from 

 plywood. Both trap types were painted black using flat 

 black latex paint. 



On May 16, just after petal fall, 14 traps of each 

 type were deployed on branches of perimeter-row trees. 

 Only one trap was used per tree. For every tree bearing 

 a trap (central tree), there were two trees without traps 

 (adjacent trees), one on either side (Figure 1). A few 

 hours before an insecticide application was made (using 

 a tractor-driven mist blower delivering 150 gallons of 

 water per acre), seven traps of each type were covered 

 with plastic bags. Traps were uncovered the morning 

 after spray application. These traps will be referred as 

 "unsprayed" traps. The remaining 14 traps, along with 

 all tree canopies, received an application of Imidan® 

 (70% WSB) at 3/4 pound per 100 gallons water. These 

 traps will be referred as "sprayed" traps. This procedure 

 (trap covering and uncovering) was repeated three 

 times, once in association with each insecticide 

 application against PC: May 16, May 25, and June 14. 



Each trap was baited with one 1-ml white, low- 

 density polyethylene vial containing 1 ml of 

 benzaldehyde (release rate: ~2.5 mg per day) and one 

 dispenser releasing PC pheromone ( 1 mg of grandisoic 

 acid per day). Both baits were placed inside the trap 

 tops that capped cylinder traps. Benzaldehyde and 

 pheromone dispensers were replaced once (on June 11). 



All traps were inspected twice per week (11 

 inspections in total) to determine PC captures. At every 

 inspection, 20 fruit were sampled for PC injury in each 

 trap-bearing tree and each of two adjacent trees (Figure 

 1). For presentation of results, we arranged data on 



Fruit Notes, Volume 67, Fall, 2002 



