Table 1. Numbers of overwintering plum curculio adults captured on unbaited pyramid traps at tree-trunk, inter-tree, or orchard-border positions and percent of fruit showing ovipositional injury by plum curculio across sampling dates before, between, or after insecticide spray applications against plum curculio in blocks of small, medium-size, or large apple trees and across eight commercial orchards studied in Massachusetts in 1997.




Tree size




Sampling dates

No. orchard blocks

Sampling dates per block
Adults captured per sampling date
Injured fruit per sampling date (%)
Trunk traps
Inter-tree traps
Border traps

Small

Before first spray
16
1.1
0.22
0.22
0.22
0.00

 

Between first and second spray
16
2.5
0.00
0.05
0.05
0.35

 

Between second and third spray
6
2.7
0.00
0.00
0.00
0.36

 

After final spray
16
4.4
0.00
0.00
0.00
0.45

Medium

Before first spray
16
1.1
0.00
0.11
0.11
0.00

 

Between first and second spray
16
2.5
0.05
0.00
0.05
0.33

 

Between second and third spray
6
2.7
0.00
0.00
0.00
0.36

 

After final spray
16
4.4
0.00
0.00
0.00
0.42

Large

Before first spray
16
1.1
0.22
0.00
0.11
0.00

 

Between first and second spray
16
2.5
0.10
0.00
0.05
0.31

 

Between second and third spray
6
2.7
0.00
0.00
0.00
0.48

 

After final spray
16
4.4
0.03
0.00
0.00
0.90