The psyllid Bactericera cockerelli (Sulc) (Hemiptera: Psyllidae) is the vector of a bacterial pathogen causing zebra chip (ZC) disease in potato, Solanum tuberosum L. (Solanaceae). Recently, ZC has become important to potato growers and the potato chipping industry in the southwestern United States, Mexico, Central America, and New Zealand. In the current study, we evaluated the knockdown effect of 12 insecticides against adult B. cockerelli, and we examined the effects of treating potato leaves: top side only, bottom side only, or both sides. Within 48 h of exposure, abamectin showed the highest and most consistent rate of adult B. cockerelli mortality and a dosage response to three dosages within labeled field rates. Choice tests conducted in petri dishes, involving untreated potato leaves and leaves treated with abamectin, revealed that abamectin did not affect host preference of adult B. cockerelli. A residual test under field conditions revealed that, although highly effective immediately after application, abamectin-effect was nonsignificantly different from control treatments 24 and 48 h after field application. Higher adult B. cockerelli mortality was recorded from potato plants treated with ground application compared with aerial 48 h after application. Our results indicated that abamectin has a high knockdown effect on adult B. cockerelli and that it can be used effectively in insecticide rotation programs against adult B. cockerelli and ZC control in potatoes.

Uniform and controlled applications of insecticides constitute a fundamental aspect of applied research on performance of insecticides. We describe and evaluate a spraying device made from an artist airbrush and a soda bottle, the "bottle sprayer," which can be used to apply insecticide formulations both under laboratory and field conditions. Using the bottle sprayer in conjunction with quantitative behavioral analysis, it was shown that (1) miticides can significantly affect movement patterns and (2) it is possible to quantify mite repellency to miticides. The combination of controlled sprays to portions of trial arenas and quantification of behavioral responses by individual spider mites may be used to address a wide range of applied questions related to spider mite ecology. We used the bottle sprayer to apply water on water-sensitive cards and used simple image analysis techniques to correlate average reflectance per pixels (quadratic reflectance in blue color band) with water dose applied. Consequently, we were able to propose a method to quantify dose applied based on average color on water-sensitive cards. The spray card analysis based on data generated with the bottle sprayer was used to interpret spray card data obtained from spray applications in a commercial potato, Solanum tuberosum L., field and to discuss the possibility of developing quality control procedures for insecticide applications in field crops.

Female wheat midges, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), were provided with wheat spikes, Triticum aestivum L. (Poaceae), for oviposition while being exposed to air that had passed over wheat spikes of contrasting genotype or growth stage. Spikes of postanthesis ‘Roblin’ and preanthesis ‘Key 10’ are known to deter oviposition. Volatiles emitted by these spikes suppressed oviposition on preanthesis ‘Roblin', which is preferred for oviposition. Volatiles emitted by spikes of preanthesis ‘Roblin’ did not increase oviposition on preanthesis ‘Key 10'. Reduced oviposition on a resistant genotype and on a deterrent growth stage of wheat is consistent with production of deterrent volatiles rather than a lack of stimulatory volatiles.

Some spring wheat lines are known to be antixenotic to ovipositing orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae). The genetic basis of antixenosis, expressed in the plant as oviposition deterrence to S. mosellana, was explored using a population of 92 doubled‐haploid wheat lines from a cross between a susceptible parent and a deterrent parent which also had antibiosis resistance. Wheat midge egg densities on wheat spikes were obtained from a standardized laboratory cage test and from the field in 2006 and 2007. Compared to the susceptible parent, egg densities on 55–88% of the lines were reduced by more than half in the laboratory and both years in the field. Twenty‐five of the 92 lines were consistently at least as deterrent as the deterrent parent in all three environments. Frequency distribution of egg densities compared to the parents indicated that deterrence was conferred by more than one gene, with complementary interaction among genes. Heritability of deterrence was estimated at 67%, showing that environment had a substantial effect on the phenotypic expression of the trait. Consistently deterrent lines had a larger proportion of eggs laid on the rachis compared to the other lines in all environments, suggesting that the presence of deterrence affects where on the spikelet the females lay their eggs. There was no evidence for linkage between deterrence genes and the antibiosis gene, Sm1. Oviposition deterrence is a promising means for suppressing wheat midge oviposition in commercial wheat crops; however, the multigenic nature of oviposition deterrence in wheat to S. mosellana and the influence of environment on its expression will provide challenges for incorporating this trait into wheat breeding programs.

Many food products are subjected to quality control analyses for detection of surface residue/contaminants, and there is a trend of requiring more and more documentation and reporting by farmers regarding their use of pesticides. Recent outbreaks of food borne illnesses have been a major contributor to this trend. With a growing need for food safety measures and -smart applications‖ of insecticides, it is important to develop methods for rapid and accurate assessments of surface residues on food and feed items. As a model system, we investigated detection of a miticide applied to maize leaves and its miticidal bioactivity over time, and we compared two types of reflectance data: fourier transformed infrared (FTIR) data and hyperspectral imaging (HI) data. The miticide (bifenazate) was applied at a commercial field rate to maize leaves in the field, with or without application of a surfactant, and with or without application of a simulated -rain event‖. In addition, we collected FTIR and HI from untreated control leaves (total of five treatments). Maize leaf data were collected at seven time intervals from 0 to 48 hours after application. FTIR data were analyzed using conventional analysis of variance of miticide-specific vibration peaks. Two unique FTIR vibration peaks were associated with miticide application (1,700 cm −1 and 763 cm −1 ). The integrated intensities of these two OPEN ACCESSRemote Sensing 2010, 2 909 peaks, miticide application, surfactant, rain event, time between miticide application, and rain event were used as explanatory variables in a linear multi-regression fit to spider mite mortality. The same linear multi-regression approach was applied to variogram parameters derived from HI data in five selected spectral bands (664, 683, 706, 740, and 747 nm). For each spectral band, we conducted a spatial structure analysis, and the three standard variogram parameters (-sill‖, -range‖, and -nugget‖) were examined as possible -indicators‖ of miticide bioactivity. We demonstrated that both FTIR peaks and standard variogram parameters could be used to accurately predict spider mite mortality, but linear multi-regression fits based on standard variogram parameters had the highest accuracy and were successfully validated with independent data. Based on experimental manipulation of HI data, the use of spatial structure analysis in classification of HI data was discussed.