Pierces Disease Control Program

Arvin, CA, United States

Pierces Disease Control Program

Arvin, CA, United States
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Wang X.-G.,University of California at Berkeley | Levy K.,University of California at Berkeley | Son Y.,Pierces Disease Control Program | Johnson M.W.,University of California at Riverside | Daane K.M.,University of California at Berkeley
Biological Control | Year: 2012

Long-term separation of a host from its native parasitoids may result in divergent thermal adaptation between host and parasitoid. The olive fruit fly, Bactrocera oleae (Rossi), most likely originated from Sub-Saharan Africa, but has since had a long invasion history in cultivated olives that spans geographical barriers and continents. This study compared three major thermal performance profiles (development, survival, and reproduction) across a wide range of temperatures (10-34°C) among a Californian population of the olive fruit fly and two African parasitoids, Psyttalia lounsburyi (Silvestri) and Psyttalia humilis (Silvestri), believed to have co-adapted with the fruit fly in its native range. Temperature ranges for the development and survival were 10-30°C for the fly, 10-28°C for P. lounsburyi, and 14-32°C for P. humilis. There was no difference in any thermal performance measured between two P. humilis populations (Kenya and Namibia) tested. The most suitable temperature ranges for reproduction were 22-30°C for the fly, 18-32°C for P. humilis, and 18-26 °C for P. lounsburyi. The results showed slight differences in the thermal profiles among olive fruit fly and both parasitoids species, with P. humilis being more heat tolerant whereas P. lounsburyi was less heat tolerant than the fruit fly. The results are discussed with respect to thermal co-adaptation and classical biological control of the olive fruit fly. © 2011 Elsevier Inc.


Son Y.,University of California at Riverside | Groves R.L.,San Joaquin Valley Agricultural science Center | Groves R.L.,University of Wisconsin - Madison | Daane K.M.,University of California at Berkeley | And 3 more authors.
Environmental Entomology | Year: 2010

The glassy-winged sharpshooter, Homalodisca vitripennis (Germar), vectors the bacterium Xylella fastidiosa that induces Pierce's disease of grape. This study determined the effect of temperature on the feeding activity of H. vitripennis adults and the resulting production of excreta. The Logan type I model described a nonlinear pattern that showed excreta production increased up to an optimal temperature (33.1°C), followed by an abrupt decline near an estimated upper threshold (36.4°C). A temperature threshold for feeding, at or below which adults cease feeding, was estimated to be 10°C using a linear regression model based on the percentage of adults producing excreta over a range of constant temperatures. A simulated winter-temperature experiment using fluctuating thermal cycles confirmed that a time period above the temperature threshold for feeding was a critical factor in determining adult survival. Using data from the simulated temperature study, a predictive model was constructed by quantifying the relationship between cumulative mortality and cooling degree-hours. In field validation experiments, the model accurately predicted the temporal pattern of overwintering mortality of H. vitripennis adults held under winter temperatures simulating conditions in Bakersfield and Riverside, California, in 2006-2007. Model prediction using winter temperature data from a Riverside weather station indicated that H. vitripennis adults would experience an average of 92% overwintering mortality before reproduction in the spring, but levels of mortality varied depending on winter temperatures. The potential for temperature-based indices to predict temporal and spatial dynamics of H. vitripennis overwintering is discussed. © 2010 Entomological Society of America.


Son Y.,Pierces Disease Control Program | Nadel H.,University of California at Riverside | Nadel H.,Animal and Plant Health Inspection Service | Baek S.,University of California at Riverside | And 2 more authors.
Biological Control | Year: 2012

The effects of temperature on the development (egg-adult emergence) of Gonatocerus morgani Triapitsyn, a newly-described parasitoid of Homalodisca vitripennis (Germar), were determined at 14.8, 18.7, 23.5, 26.9, 28.7, 30.4, 32.8, and 33.8°C in the laboratory. Survival rate (percent adult emergence from parasitized host eggs) varied significantly among the experimental temperatures, with the highest (59%) and lowest (0%) occurring at 30.4 and 33.8°C, respectively. The survival rates (%) were fitted with a polynomial model to describe a temperature-dependent pattern. Developmental rates (1/d) across seven temperatures were fitted with the nonlinear Briere model, which estimated the lower threshold to be 8.06°C, the optimal temperature to be 29.22°C, and the upper threshold to be 33.49°C. A linear model fitted to developmental rates at 14.8-28.7°C indicated that 189.75. degree-days above the lower threshold of 9.71°C were required to complete development. A simulation model of G. morgani adult emergence was constructed to predict daily counts over the entire range of constant temperatures by incorporating the survival rate model, the Briere model, and the Weibull model. In outdoor validation, a degree-day model for predicting adult emergence showed ≤2. d differences between prediction and observation. Based on the observed temperature requirement, the insect could complete thirteen to sixteen generations per year in southern California, depending on weather and location. © 2011.


Bruening G.,University of California at Davis | Kirkpatrick B.C.,University of California at Davis | Esser T.,Pierces Disease Control Program | Webster R.K.,University of California at Davis
California Agriculture | Year: 2014

An outbreak of Pierce's disease of grapevine in the Temecula Valley in the late 1990s was one in a decades-long series of sporadic appearances of this infection in California. However, the new outbreak was qualitatively different because of the rapidity with which it spread in the vineyard and its appearance almost simultaneously at distant locations. The causative agent of Pierce's disease is the bacterium Xylella fastidiosa, and the distinct characteristics of the Temecula Valley outbreak were traced to the establishment of a new insect vector in California, the glassy-winged sharpshooter. Intensive and collaborative efforts among government agencies, industry and research institutions over 15 years have successfully contained the disease, and given scientists time to discover promising long-term potential solutions through genetic resistance. © 2014, University of California, Oakland. All rights reserved.


Daane K.M.,University of California at Berkeley | Wang X.,University of California at Berkeley | Duerr S.S.,University of California at Berkeley | Kuhn E.J.,University of California at Berkeley | And 2 more authors.
Environmental Entomology | Year: 2013

Habrobracon gelechiae Ashmead (Hymenoptera: Braconidae) was studied as a parasitoid of the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae) in California pistachio (Pistacia vera L.) orchards. Ovipositional behavior, adult longevity and fecundity, and the effects of temperature on developmental time and survival were determined. Habrobracon gelechiae develops as a gregarious, ectoparasitic idiobiont on late-instar C. rosaceana larvae. At 25°C, adult female wasps survived longer when provided honey and water (35.4 ± 4.9 d) or honey, water, and host larvae (34.4 ± 2.4 d) than when provided water (8.9 ± 1.1 d) or no food (5.9 ± 0.8 d). Over the adult lifespan, females parasitized 20.6 ± 2.1 hosts and deposited 228.8 ± 24.6 eggs. The intrinsic rate of increase was 0.24, the mean generation time was 18.15 d, and the double time 2.88 d. At constant temperatures, H. gelechiae successfully developed (egg to adult) from 15 to 35°C. The developmental rate was fit to a nonlinear model, providing estimates of the parasitoid's lower (10.5°C), upper (36.0°C), and optimal (33.3°C) development temperatures. Based on a linear model, 155 degree days were estimated for egg to adult eclosion. Temperature-dependent nonlinear model of survival showed similar shape with the model of development rate. The wasp developed under two diurnal temperature regimes, with 31.0 ± 13.3% survival at low (4-15°C) and 63.0 ± 11.4% survival at high (15-35°C) temperature regimes. The results are discussed with respect to H. gelechiae potential as a parasitoid of C. rosaceana in California's San Joaquin Valley. © 2013 Entomological Society of America.


Ahn J.J.,West Virginia University | Ahn J.J.,Research Institute of Climate Change and Agriculture | Son Y.,Pierces Disease Control Program | He Y.,West Virginia University | And 2 more authors.
PLoS ONE | Year: 2016

Temperature plays an important role in the growth and development of arthropods, and thus the current trend of climate change will alter their biology and species distribution. We used Chaetodactylus krombeini (Acari: Chaetodactylidae), a cleptoparasitic mite associated with Osmia bees (Hymenoptera: Megachilidae), as a model organism to investigate how temperature affects the development and voltinism of C. krombeini in the eastern United States. The effects of temperature on the stage-specific development of C. krombeini were determined at seven constant temperatures (16.1, 20.2, 24.1, 27.5, 30.0, 32.4 and 37.8°C). Parameters for stage-specific development, such as threshold temperatures and thermal constant, were determined by using empirical models. Results of this study showed that C. krombeini eggs developed successfully to adult at all temperatures tested except 37.8°C. The nonlinear and linear empirical models were applied to describe quantitatively the relationship between temperature and development of each C. krombeini stage. The nonlinear Lactin model estimated optimal temperatures as 31.4, 32.9, 32.6 and 32.5°C for egg, larva, nymph, and egg to adult, respectively. In the linear model, the lower threshold temperatures were estimated to be 9.9, 14.7, 13.0 and 12.4°C for egg, larva, nymph, and egg to adult, respectively. The thermal constant for each stage completion were 61.5, 28.1, 64.8 and 171.1 degree days for egg, larva, nymph, and egg to adult, respectively. Under the future climate scenarios, the number of generations (i.e., voltinism) would increase more likely by 1.5 to 2.0 times by the year of 2100 according to simulation. The findings herein firstly provided comprehensive data on thermal development of C. krombeini and implications for the management of C. krombeini populations under global warming were discussed. ∗Scientific Article No. 3278 of the West Virginia Agricultural and Forestry Experiment Station, Morgantown, West Virginia. © 2016 Ahn et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Baek S.,West Virginia University | Son Y.,Pierces Disease Control Program | Park Y.-L.,West Virginia University
Journal of Pest Science | Year: 2014

The spined soldier bug, Podisus maculiventris (Say), is a generalist predator that can control >75 insect pests in various agroecosystems. Despite valuable results from the previous studies, thermal development and survival of P. maculiventris over a wide range of temperatures had not been elucidated completely. This study was conducted to investigate the stage-specific development and survival of P. maculiventris at eight constant temperatures (13.2, 18.4, 21.7, 23.7, 27.2, 32.7, 35.2, and 40.6 °C) covering the entire thermal range for P. maculiventris development. Completion of egg development was observed at 13.2-32.7 °C, whereas nymphs successfully developed into adults at 18.4-32.7 °C. Survival model using log-normal equations showed bell-shape patterns for all stages, and temperatures resulting in highest survival of P. maculiventris were 19.9, 24.3, and 24.5 °C for egg, nymph, and egg to adult, respectively. Developmental rates at the eight temperatures were fitted with a nonlinear Briere model, which estimated optimal temperatures for development as 31.2, 30.6, and 30.6 °C for egg, nymph, and egg to adult, respectively. Operative thermal ranges (i.e., in-between the lower and upper developmental thresholds) were estimated to be 8.9-35.2, 12.8-35.2, and 12.7-35.2 °C for egg, nymph, and egg to adult, respectively. In a linear model, the lower thresholds were 10.9, 13.1, and 13.0 °C for egg, nymph, and egg to adult, respectively. Findings herein provide comprehensive data and explanations on optimal temperature and thermal requirement for P. maculiventris, which can be used to optimize environmental condition in mass rearing and predicting phenology of P. maculiventris in the field. © 2013 Springer-Verlag Berlin Heidelberg.

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