Phytoseiids in Washington commercial apple orchards: biodiversity and factors affecting
abundance
Experimental and Applied Acarology
Rebecca A. Schmidt-Jeffris, Elizabeth H. Beers, and David W. Crowder
Washington State University, Tree Fruit Research & Extension Center, 1100 N. Western Ave.,
Wenatchee, WA 98801
Email: rebecca.schmidt@wsu.edu
Online Resource 2: Full and selected models
(1) Variables included in the full models for both presence/absence (analyzed using logistic
regression) and abundance (analyzed using general linear models) of Galendromus
occidentalis and Amblydromella caudiglans. For each analyses we used stepwise regression
with information criteria to select a best-fit model (shown below)
Variable name
Cumulative degree days
Latitude
Elevation
Orchard cultivar
Block age
Canopy density
Irrigation type
Dust problems
Row middle weediness ranking
Herbicide strip weediness ranking
Mite problem ranking
Two-spotted spider mite problem ranking
European red mite problem ranking
Use of bifenazate
Use of fenproximate
Use of novaluron
Use of lime sulfur
Use of napthelene acetic acid
Use of carbaryl
Overall pesticide intensity
Dominant land cover within 50 meters
Variable type (continuous or categorical)
Continuous
Continuous
Continuous
Categorical
Continuous
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
Categorical
(2) The following show the corrected Akaike’s information criteria (AICc) and Bayesian
information criteria (BIC) for the full models for the presence/absence (analyzed using
logistic regression) and abundance (analyzed using general linear models) of Galendromus
occidentalis and Amblydromella caudiglans.These models provided a significantly worse fit
to the observed data than the best-fit models (shown below in sections 3-6)
Galendromus occidentalist presence/absence full model (all variables listed above included)
AICc: 749.50
BIC: 559.87
Ambyldromella caudiglans presence/absence full model (all variables listed above included)
AICc: 621.69
BIC: 441.48
Galendromus occidentalist abundance full model (all variables listed above included)
AICc: 1950
BIC: 250.46
Ambyldromella caudiglans abundance full model (all variables listed above included)
AICc: 1950
BIC: 250.46
(3) Galendromus occidentalis presence/absence final model (i.e., “best-fit model)
Variables included: Overall pesticide intensity
AICc: 85.33 (1864.67 lower than full model)
BIC: 96.20 (154.26 lower than full model)
(4) Amblydromella caudiglans presence/absence final model
Variables included: Orchard cultivar, herbicide strip weediness
AICc: 105.29 (1844.71 lower than full model)
BIC: 120.19 (130.27 lower than full model)
(5) Galendromus occidentalis abundance final model
Variables included: Use of bifenazate, overall pesticide intensity
AICc: 535.43 (214.07 lower than full model)
BIC: 551.17 (8.70 lower than full model)
(6) Amblydromella caudiglans abundance final model
Variables included: Use of bifenazate, orchard cultivar, herbicide strip weediness
AICc: 382.83 (238.86 lower than full model)
BIC: 403.33 (38.15 lower than full model)