Observations of First Occurrence and Severity of Potato Leafhopper, \u3ci\u3eEmpoasca Fabae\u3c/i\u3e (Harris), (Homoptera: Cicadellidae) in the North Central and Eastern United States.

This paper presents available data on the first occurrence dates and the damage severity of the potato leafhopper in the north central and north eastern United States collected during the past 47 years (1951-1997). The data were collected from a variety of sources including: potato leafhopper literature review; published reports; pest alerts; pest surveys; and delphi surveys. First occurrence and severity data show that the arrival time of potato leafhopper and subsequent damage severity varies substantially from year to year. A correlation analysis between date of first occurrence and severity of damage for Michigan, Minnesota, Wisconsin, the north central region and the northeastern region indicated no significant relationship between first arrival dates and damage severity. The lack of a relationship between the time of arrival of the migrant leafhopper and severity indicate that other factors, including frequency and magnitude of arrivals, weather conditions during the growing season and crop management contribute to the eventual severity of damage caused to crops by this migratory pest. The analysis of potato leafhopper severity data showed significant differences between years. There were no significant differences in severity among states within the north central region, indicating that potato leafhopper severity is a regional phenomenon

Optimizing pesticide spray coverage using a novel web and smartphone tool, SnapCard

International audienceThe overuse of pesticides leads to contamination of water and food. Therefore, there is a need for tools and strategies to optimize pesticide application. Here we present SnapCard, a user-friendly and freely available decision support tool for farmers and agricultural consultants, available at snapcard.agric.wa.gov.au. SnapCard allows to predict, measure, and archive pesticide spray coverage quantified from water-sensitive spray cards. Variables include spray settings such as nozzle orifice size, sprayer speed, water carrier rate and adjuvant, and weather variables such as barometric pressure, relative humidity, temperature, and wind speed at ground level. We use separate regression models for four nozzles types. Our results showed that there are strong and positive correlations between water carrier rate and spray coverage for all four nozzle types. Moreover, sprayer speed is highly negatively correlated with obtained spray coverage. In addition, there is no consistent effect of either nozzle type or use of a particular adjuvant, across water carrier intervals. We conclude that varying combinations of spray settings and weather conditions caused marked ranges of spray coverages among the four nozzle types, thus highlighting the importance of selecting the right nozzle orifice size and type. We demonstrate that realistic scenarios of environmental conditions and spray settings can lead to predictions of very low spray coverage with at least one of the four nozzle types. We discuss how the novel and freely available smartphone app, SnapCard, can be used to optimize spray coverage, reduce spray drift, and minimize the risk of resistance development in target pest populations

Pest control and resistance management through release of insects carrying a male-selecting transgene

Development and evaluation of new insect pest management tools is critical for overcoming over-reliance upon, and growing resistance to, synthetic, biological and plant-expressed insecticides. For transgenic crops expressing insecticidal proteins from the bacterium Bacillus thuringiensis (‘Bt crops’) emergence of resistance is slowed by maintaining a proportion of the crop as non-Bt varieties, which produce pest insects unselected for resistance. While this strategy has been largely successful, multiple cases of Bt resistance have now been reported. One new approach to pest management is the use of genetically engineered insects to suppress populations of their own species. Models suggest that released insects carrying male-selecting (MS) transgenes would be effective agents of direct, species-specific pest management by preventing survival of female progeny, and simultaneously provide an alternative insecticide resistance management strategy by introgression of susceptibility alleles into target populations. We developed a MS strain of the diamondback moth, Plutella xylostella, a serious global pest of crucifers. MS-strain larvae are reared as normal with dietary tetracycline, but, when reared without tetracycline or on host plants, only males will survive to adulthood. We used this strain in glasshouse-cages to study the effect of MS male P. xylostella releases on target pest population size and spread of Bt resistance in these populations

Observations of First Occurrence and Severity of Potato Leafhopper, \u3ci\u3eEmpoasca Fabae\u3c/i\u3e (Harris), (Homoptera: Cicadellidae) in the North Central and Eastern United States.

This paper presents available data on the first occurrence dates and the damage severity of the potato leafhopper in the north central and north eastern United States collected during the past 47 years (1951-1997). The data were collected from a variety of sources including: potato leafhopper literature review; published reports; pest alerts; pest surveys; and delphi surveys. First occurrence and severity data show that the arrival time of potato leafhopper and subsequent damage severity varies substantially from year to year. A correlation analysis between date of first occurrence and severity of damage for Michigan, Minnesota, Wisconsin, the north central region and the northeastern region indicated no significant relationship between first arrival dates and damage severity. The lack of a relationship between the time of arrival of the migrant leafhopper and severity indicate that other factors, including frequency and magnitude of arrivals, weather conditions during the growing season and crop management contribute to the eventual severity of damage caused to crops by this migratory pest. The analysis of potato leafhopper severity data showed significant differences between years. There were no significant differences in severity among states within the north central region, indicating that potato leafhopper severity is a regional phenomenon