A5052712913- Phytoplasmas and Hemiptera pathogens
- Insect-Plant Interactions and Control
- Cocoa and Sweet Potato Agronomy
- Plant and animal studies
- Insect symbiosis and bacterial influences
- Plant Virus Research Studies
- Hymenoptera taxonomy and phylogeny
- Insect behavior and control techniques
- Plant Pathogenic Bacteria Studies
- Insect and Arachnid Ecology and Behavior
- Fluid Dynamics and Heat Transfer
- Plant Parasitism and Resistance
- Plant Surface Properties and Treatments
- Insect Pheromone Research and Control
- Animal Behavior and Reproduction
- Plant and Fungal Interactions Research
- Research on scale insects
- Forest Insect Ecology and Management
- Animal Vocal Communication and Behavior
- Hemiptera Insect Studies
- Insect Pest Control Strategies
- Insect Resistance and Genetics
- Evolution and Genetic Dynamics
- Cephalopods and Marine Biology
- Botanical Research and Applications
Agricultural Research Service
2009-2024
San Joaquin Valley Agricultural Sciences Center
2014-2023
United States Department of Agriculture
2012-2023
University of California, Riverside
2005-2009
University of California, Berkeley
2005-2007
Utah State University
2005
Discovery of Xylella fastidiosa from olive trees with "Olive quick decline syndrome" in October 2013 on the west coast Salento Peninsula prompted an immediate search for insect vectors bacterium. The dominant xylem-fluid feeding hemipteran collected orchards during a 3-mo survey was meadow spittlebug, Philaenus spumarius (L.) (Hemiptera: Aphrophoridae). Adult P. spumarius, November ground vegetation X. fastidiosa-infected orchards, were 67% (40 out 60) positive by polymerase chain reaction...
EFSA was asked to update the 2015 risk assessment on
Olive (Olea europaea) trees exhibiting leaf scorch or branch dieback symptoms in California were surveyed for the xylem-limited, fastidious bacterium Xylella fastidiosa. Only approximately 17% of diseased tested positive X. fastidiosa by polymerase chain reaction, and disease could not be attributed to infection olive greenhouse pathogenicity assays. Six strains isolated from Southern California. Molecular assays identified recovered as belonging subsp. multiplex. Pathogenicity testing on...
Abstract Studies designed to measure dispersal capacity of Diaphorina citri Kuwayama (Hemiptera: Liviidae) are needed provide the epidemiological knowledge necessary improve management citrus huanglongbing. In this study, a mark–release–recapture technique was used investigate whether 1) host or non‐host plants D. can act as barriers for dispersing insects and 2) presence absence young leaves influence movement towards plants. The experimental field consisted four circular adjacent areas...
A study on seasonal abundance of Auchenorrhyncha species and their infectivity by Xylella fastidiosa in the Apulia region Italy was conducted to identify ideal periods for monitoring adoption potential control measures against insect vectors. Adult populations were monitored monthly over a 2-yr period from five olive groves. total 15 captured, identified, tested presence X. polymerase chain reaction (PCR). For three species, Philaenus spumarius L., Neophilaenus campestris (Fallèn), Euscelis...
Abstract Food consumption and waste elimination are vital functions for living systems. Although how feeding impacts animal form function has been studied more than a century since Darwin, its obligate partner, excretion, controls constrains behavior, size, energetics remains largely unexplored. Here we study millimeter-scale sharpshooter insects ( Cicadellidae ) that feed exclusively on plant’s xylem sap, nutrient-deficit source (95% water). To eliminate their high-volume excreta, these...
ABSTRACT The glassy-winged sharpshooter, Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), is a xylem fluid-ingesting leafhopper that transmits Xylella fastidiosa Wells et al., plant-infecting bacterium causes several plant diseases in the Americas. Although role of water stress on population density and dispersal ofH. has been studied, nothing known about effects transmission X. by H. vitripennis. A laboratory study was conducted to determine influence sharpshooter stylet probing...
Abstract BACKGROUND The glassy‐winged sharpshooter (GWSS), Homalodisca vitripennis , is an important pest of grapevines due to its ability transmit Xylella fastidiosa the causal agent Pierce's disease. GWSS mating communication based on vibrational signals; therefore, disruption could be alternative insecticides for suppression population. Our objectives were identify spectral features female signal that elicit male signaling, design disruptive signals able alter perception and acceptance a...
Abstract Animal communication is a complex behavior that influenced by abiotic and biotic factors of the environment. Glassy‐winged sharpshooters ( GWSS ), H omalodisca vitripennis G ermar) emiptera: C icadellidae), primarily use vibrational signaling for courtship communication. Because major pest, transmitting plant pathogenic bacterium X ylella fastidiosa Wells et al., interruption possible avenue control. Playback white noise, pre‐recorded female signals, artificial noise (continuously...
Glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) is an important vector of the bacterium Xylella fastidiosa, causal agent Pierce's disease grapevine. Area-wide insecticide applications have suppressed GWSS populations for ∼ 25 years, but reduced levels susceptibility been reported. Therefore, alternative methods control are needed. Objectives this study were to evaluate efficacy playback vibrational mating communication signals disrupting in a...
Journal Article Plant Water Stress Effects on the Net Dispersal Rate of Insect Vector Homalodisca vitripennis (Hemiptera: Cicadellidae) and Movement Its Egg Parasitoid, Gonatocerus ashmeadi (Hymenoptera: Mymaridae) Get access Rodrigo Krugner, Krugner 2 1United States Department Agriculture (USDA) - Agricultural Research Service (ARS), San Joaquin Valley Sciences Center, Parlier, CA 93648. 2Corresponding author, e-mail: rodrigo.krugner@ars.usda.gov. Search for other works by this author on:...
"Large bug" damage to pistachio nuts varies by season, as well among insect species and development stages, with larger bugs typically causing more than smaller bugs. We investigated three large bug (leaffooted bug, redshouldered stink flat green bug) at different stages throughout the using field surveys cage studies. Before fruit set occurs in June, most damaged are dropped from cluster without reducing load. The midseason period (June July) is critical because remain cluster. After shell...
A 2-yr study was conducted in a citrus orchard (Citrus sinensis L. Osbeck cultivar Valencia) to determine the influence of plant water stress on population dynamics glassy-winged sharpshooter, Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% crop evapotranspiration rate (ET(c)) and continuous deficit-irrigation regimens 80 60% ET(c). Microclimate conditions monitored temperature humidity tree canopy, leaf surface temperature, potential, fruit quality...
Honeydew from phloem-feeding insects and fruit fly insecticidal baits may serve as adult food resources for some insect species. In California (USA) olive orchards, the black scale [Saissetia oleae (Olivier) (Hemiptera: Coccidae)] is a common honeydew producer, spinosad-based bait (GF-120) used to control [Bactrocera (Rossi) (Diptera: Tephritidae)]. We investigated effects of GF-120, resources, on foraging behaviour survival two parasitoids in agroecosystem: Scutellista caerulea...
Controlling navel orangeworm, a key pistachio pest, is problematic because the moth overwinters in “mummy” nuts. After harvest, there may be more than 30,000 nuts (mummies) left behind per acre. To provide better information for winter sanitation decisions, we investigated number of available mummies and their levels orangeworm infestation from through early summer California orchards. Navel mortality was highest late December mid-February, also higher on ground trees. Mortality when were...
Abstract Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) is an invasive vector of Xylella fastidiosa, the causal agent Pierce's disease grapevines (Vitis vinifera L.). Transmission efficiency X. fastidiosa to by H. originating from two geographically separated populations in California (Riverside and Bakersfield) based on gender age was evaluated. To evaluate transmission efficiencies among groups, insects were given a 96-h acquisition access period infected caged groups five...