Field evaluation of systemic imidacloprid for the management of avocado thrips and avocado lace bug in California avocado groves

BACKGROUND: The efficacy of systemic applications of imidacloprid for the management of avocado thrips and avocado lace bug was determined in field trials. Following insecticide treatment by chemigation, leaves of appropriate age for each insect were sampled over a 6 month period and used for bioass...

Full description

Saved in:
Bibliographic Details
Published in:Pest management science 2010-10, Vol.66 (10), p.1129-1136
Main Authors: Byrne, Frank J, Humeres, Eduardo C, Urena, Anthony A, Hoddle, Mark S, Morse, Joseph G
Format: Article
Language:English
Subjects:
Animals
avocado lace bug
avocado thrips
avocados
Bioassays
Biological and medical sciences
California
chemigation
Control
Fruits
Fundamental and applied biological sciences. Psychology
imidacloprid
Imidazoles - metabolism
Imidazoles - pharmacology
Insect control
Insect Control - methods
insect pests
Insecta - drug effects
Insecta - physiology
insecticide residues
Insecticides
Insecticides - metabolism
Insecticides - pharmacology
Leaves
lethal concentration 50
mortality
Neonicotinoids
Nitro Compounds - metabolism
Nitro Compounds - pharmacology
Persea - drug effects
Persea - metabolism
Persea - parasitology
Persea americana
Pest control
Phytopathology. Animal pests. Plant and forest protection
Plant Leaves - drug effects
Plant Leaves - metabolism
Plant Leaves - parasitology
plant pests
Protozoa. Invertebrates
Pseudacysta perseae
Scirtothrips perseae
species differences
systemic insecticide
systemic insecticides
toxicity
uptake mechanisms
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:BACKGROUND: The efficacy of systemic applications of imidacloprid for the management of avocado thrips and avocado lace bug was determined in field trials. Following insecticide treatment by chemigation, leaves of appropriate age for each insect were sampled over a 6 month period and used for bioassays. Imidacloprid residues were measured by ELISA in leaves used for bioassays to determine concentrations of insecticide that were toxic to both pests.RESULTS: The uptake of imidacloprid into treated trees was extremely slow, peaking in the current year's leaf flush at only 8 ng cm⁻² leaf tissue after 15 weeks. Avocado thrips mortality in bioassays with young flush leaves, the preferred feeding substrate for this insect, was minimal, indicating that imidacloprid concentrations were below threshold levels needed for effective control. Residues present in older leaves, which are preferred by the avocado lace bug, were higher than in young flush leaves, and provided good control of this pest. Probit analysis of bioassay data showed that the avocado lace bug (LC₅₀ = 6.1 ng imidacloprid cm⁻² leaf tissue) was more susceptible to imidacloprid than the avocado thrips (LC₅₀ = 73 ng imidacloprid cm⁻² leaf tissue).CONCLUSIONS: In spite of the slow uptake of imidacloprid into avocado trees, the levels of imidacloprid would be sufficient to control avocado lace bug infestations. In contrast, the slow uptake would be problematic for avocado thrips control because inadequate levels of insecticide accumulate in new flush foliage and would allow avocado thrips populations to build to levels that would subsequently damage developing avocado fruit. Copyright
ISSN:1526-498X
1526-4998
1526-4998
DOI:10.1002/ps.1991