Insecticidal Control of Asian Citrus Psyllid and Citrus Leafminer on Hamlin Oranges, 2003

Dissipation Rates and Effectiveness of Malathion, Imidacloprid, And Dimethoate at Controlling Asian Citrus Psyllids under Field Conditions

“…MAL showed better ACP population reductions (100%) and no ACP increases, which may be due to a lower rate constant and more persistence observed in the field, as well as no ACP remaining after treatment to continue reproducing (Tables , S11–S15). These results agree with other field studies of ACP response to insecticides that showed higher insecticide efficacy when fewer ACP were reported before and after treatment. ,, Although these observed efficacies are less than 100%, they were better than the 30% reduction observed in our control (Tables S9, S10, Figure S7) and some other field studies with different crops or method parameters. ,, For instance, DIM’s efficacy was 12 (adults) and 20 (nymphs) percent higher than afidopyropen, another insecticide applied under similar field and ACP population conditions . This suggests DIM (a systemic organophosphate insecticide) controlled ACP better than afidopyropen (a semisystemic pyropene insecticide).…”

“…This suggests DIM (a systemic organophosphate insecticide) controlled ACP better than afidopyropen (a semisystemic pyropene insecticide). Furthermore, our ACP observations after IMI treatment showed better initial ACP decreases (mean per tree: ranging 70.5 to 100%) by 24 HAT (Table ) than another study of IMI applied to Hamlin oranges, which reported varied results of insignificant increases (means ranging 105–112%) and decreases (mean 8%) by 96 HAT and a lower seasonal mean mortality (43 to 65%) . However, it is unclear how IMI was applied (foliar spray or soil drenching) and they did not observe significant ACP decreases until after a second IMI treatment, 10 days after the first treatment.…”

“…The degradation kinetics and efficacy of insecticides against pests have been investigated in lab studies and under controlled greenhouse conditions previously. ,− Previous studies have reported that insecticides (e.g., malathion, imidacloprid, and dimethoate) are effective at killing ACP ,,− and revealed a broad range of half-lives ranging from 5.9 min to 1250 days under various conditions and sample mediums (e.g., solvent, water, soil, crops) (Table S1). − ,,− The most common, first-order degradation pathways of these insecticides include hydrolysis and photolysis, which could occur in the aqueous tank mixture or in the plant material in the field. ,, Insecticide dissipation in the field includes degradation as well as other loss processes like volatilization and wash-off .…”

Quantification of insecticide spatial distribution within individual citrus trees and efficacy through Asian citrus psyllid reductions under different application methods

“…Previous studies investigating ACP response to insecticides in the laboratory and field conclude that insecticides are effective at killing psyllids 11, 29–34 . The few studies assessing both insecticide application efficacy with ACP inspections either lacked the variety of application methods commonly used in high management groves or an effective ACP inspection method 11, 29–31 .…”

“…Previous studies investigating ACP response to insecticides in the laboratory and field conclude that insecticides are effective at killing psyllids. 11,[29][30][31][32][33][34] The few studies assessing both insecticide application efficacy with ACP inspections either lacked the variety of application methods commonly used in high management groves or an effective ACP inspection method. 11,[29][30][31] To date, no studies have thoroughly examined insecticide efficacy by quantifying insecticide concentrations and spatial distribution, extensively sampling entire citrus trees while simultaneously quantifying ACP population response, from multiple insecticide spray methods in a high-management commercial field.…”