Developmental Rate and Longevity of \u3ci\u3eIllinoia Pepperi\u3c/i\u3e (Homoptera: Aphididae) on Excised Blueberry Leaf Disks

The aphid Illinoia pepperi is the vector of blueberry shoestring virus, a serious disease of cultivated high bush blueberry. We present a laboratory study of the developmental rate of I. pepperi on excised blueberry leaf discs at different temperatures from 5 to 29°C. Growth rates were lowest at the upper temperature treatments (26 and 29°) and at 10°C. Growth rate and duration in degree-days for each life stage are presented as well as an overall regression equation for development. The lower developmental threshold was calculated at 3.4°C. The results are being used in a phenological management system and an epidemiological model for predicting spread of blueberry shoestring virus

Comparison of Leafhopper Species Complexes in the Ground Cover of Sprayed and Unsprayed Peach Orchards in Michigan (Homoptera: Cicadellldae)

Two Michigan peach orchards were sampled for leafhoppers using a fixed-area ground sampling device attached to a D-vac®. Absolute abundance estimates indicated that routine tree insecticide applications greatly depressed leafhopper populations. This, and the fact that no resident, known vectors of the X-disease pathogen were detected, suggests that increasing insecticide applications to check the spread of the disease through vector control would be ineffective

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

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