An 18-day, 3 °C cold treatment effectively kills Ceratitis capitata (Diptera: Tephritidae) in kiwifruit (Actinidia spp.).

A series of experiments were carried out to develop a phytosanitary disinfestation protocol to kill Ceratitis capitata (Weidemann) (Mediterranean fruit fly, Diptera: Tephritidae) in 'Hayward' kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang and A.R. Ferguson) and 'Zesy002' kiwifruit (Actinidia chinensis Planch.). Experiments on 4 immature life stages (eggs and 3 larval instars) with treatment durations of between 5 and 18 days showed that third instars were the most tolerant to temperatures around 3 °C, with the lethal time to 99.9968% (probit 9) mortality (LT99.9968) estimated to be 17.3 days (95% confidence interval (CI) 16.4-18.2). Larvae reared and treated in 'Zesy002' were significantly more susceptible to cold treatment than those reared in 'Hayward'. A large-scale trial testing a disinfestation protocol of 3 ±â€…0.5 °C for 18 days treated over 500,000 third-instar C. capitata with no survivors. These results demonstrate that a cold treatment of 3.5 °C or below for 18 days induces C. capitata mortality in kiwifruit at a rate that exceeds 99.9968% with a degree of confidence greater than 99%.

An Integrated Biosecurity Risk Assessment Model (IBRAM) For Evaluating the Risk of Import Pathways for the Establishment of Invasive Species.

An important aspect of analyzing the risk of unwanted organisms establishing in an area is understanding the pathways by which they arrive. Evaluating the risks of these pathways requires use of data from multiple sources, which frequently are uncertain. To address the needs of agencies responsible for biosecurity operations, we present an Integrated Biosecurity Risk Assessment Model (IBRAM) for evaluating the risk of establishment and dispersal of invasive species along trade pathways. The IBRAM framework consists of multiple linked models which describe pest entry into the country, escape along trade pathways, initial dispersal into the environment, habitat suitability, probabilities of establishment and spread, and the consequences of these invasions. Bayesian networks (BN) are used extensively to model these processes. The model includes dynamic BN components and geographic data, resulting in distributions of output parameters over spatial and temporal axes. IBRAM is supported by a web-based tool that allows users to run the model on real-world pest examples and investigate the impact of alternative risk management scenarios, to explore the effect of various interventions and resource allocations. Two case studies are provided as examples of how IBRAM may be used: Queensland fruit fly (Bactrocera tryoni) (Diptera: Tephritidae) and brown marmorated stink bug (Halyomorpha halys) (Hemiptera: Pentatomidae) are unwanted organisms with the potential to invade Aotearoa New Zealand, and IBRAM has been influential in evaluating the efficacy of pathway management to mitigate the risk of their establishment in the country.

Optimizing metabolic stress disinfection and disinfestation components to control Pseudococcus longispinus.

Metabolic stress disinfection and disinfestation (MSDD) has been demonstrated to effectively control longtailed mealybug, Pseudococcus longispinus (Targioni Tozzetti). Standard components previously used for testing MSDD system included a 30-min physical phase of short cycles pressure changes followed by a 60-min chemical phase using ethanol vapor at 10 kPa. This study investigated the effect of varying the following MSDD components on mealybug mortality: duration of the physical and chemical phases, ethanol concentration, and extent of vacuum during the chemical phase. Mealybug mortality responses were analyzed, and the components were optimized using binary logistical regression to achieve 99% mortality of three life stages of the longtailed mealybug (adults, second- and third-instar nymphs and crawlers). Data indicated that the optimal components to achieve 99% mortality of all life stages were a 30-min physical phase and a 45-min chemical phase with 275 mg/liter ethanol at 30 kPa. Optimized components were obtained using binary logistical regression models. These optimized components yielded a 15-min reduction in total treatment time and a 20-kPa decrease in pressure during the chemical phase. Achievement of optimal insecticidal efficacy required all four MSDD components. Nevertheless, optimization and validation achieved 17 and 22% reductions in duration of treatment time and extent of vacuum, respectively.

Mass trapping of Prays nephelomima (Lepidoptera: Yponomeutidae) in citrus orchards: optimizing trap design and density.

The moth Prays nephelomima (Meirick) (Lepidoptera: Yponomeutidae) is a significant pest of citrus (Citrus spp.), and the recent identification of the female sex pheromone has enabled new direct control tactics to be considered. Six trap designs were compared for suitability in mass trapping, and Pherocon III delta traps were chosen to further evaluate mass trapping. A mass trapping field trial was carried out at five lemon, Citrus limon L., orchards to determine the effect of trap density on catch and rind spot damage on fruit. One plot (0.33-1.0 ha) of each of the five trap density treatments (3, 10, 30, 100, and 300 traps/ha) were operated at each orchard over 12 wk. Catch per trap was reduced as trap density increased and a mean of 12,000 and 16,000 males per ha were killed at the trap densities of 100 and 300 traps per ha, respectively. Increased trap density reduced the percentage of flowers infested with P. nephelomima larvae and reduced the number of moths emerging from flowers. The incidence of rindspot damage on fruit decreased from 45 to 16% as the density of traps increased from 3 to 100 traps per ha. Incidence (percentage of fruit with rindspot) and severity (number of rindspots per fruit) was similar at 100 and 300 traps per ha, indicating that the optimal trap density for reducing rindspot damage is likely to be between 30 and 100 traps per ha. Prospects for converting mass trapping to a lure and kill system are discussed.

Major sex pheromone components of the Australian gum leaf skeletonizer Uraba lugens: (10E,12Z)-hexadecadien-1-yl acetate and (10E,12Z)-hexadecadien-1-ol.

Two sex pheromone components of the gum leaf skeletonizer, Uraba lugens (Lepidoptera: Nolidae), recently established in New Zealand, were identified. Gas chromatography (GC) electroantennographic detection analyses of female pheromone gland extracts gave three compounds that consistently elicited antennal responses. Chemical analyses, using GC and GC-mass spectrometry, in conjunction with 4-methyl-1,2,4-triazoline-3,5-dione and dimethyldisulfide derivatizations, identified these compounds as (10E,12Z)-hexadecadien-1-yl acetate (E10,Z12-16:Ac), (10E,12Z)-hexadecadien-1-ol (E10,Z12-16:OH), and (Z)-11-hexadecen-1-yl acetate (Z11-16:Ac). A trapping trial in Queensland, Australia, in 2002, indicated that a blend of the two major components E10,Z12-16:Ac and E10,Z12-16:OH could attract gum leaf skeletonizer males. In the same trial, E10,Z12-16:Ac alone trapped large numbers of an unidentified nolid, Nola spp. Further trials in Auckland, New Zealand established that these two components were sufficient and necessary for trap catch of males; adding minor gland components, (10E,12E)-hexadecadien-1-yl acetate (E10,E12-16:Ac), Z11-16:Ac, or octadecan-1-ol (18:OH), to the two-component lure did not result in increased trap catches. Behavioral observations and gland analyses of the Auckland population revealed that female moths begin calling soon after emergence, with peak calling and pheromone production occurring 7 hr into the scotophase. Analysis of gland extract at two-hourly intervals during the first activity period showed that the ratio of E10,Z12-16:Ac to E10,Z12-16:OH (mean of 86: 14, respectively) and pheromone titer were fairly constant. No qualitative or quantitative differences in pheromone components were detected between gland extracts from Tasmanian univoltine and Auckland bivoltine populations of U. lugens.