Effects of southern highbush blueberry cultivar and treatment threshold on flower thrips populations

Effect of Cultural Practices on Neopamera bilobata in Relation to Fruit Injury and Marketable Yields in Organic Strawberries

Simple Summary

The strawberry seed bug is a native insect that has recently been causing injury to strawberries in Florida. This study examined the effects of two common cultural practices on the strawberry seed bug: cover cropping and runner removal. Cover cropping is used only in organic strawberry production while runner removal is common to both production systems. The effects of cultivar were also examined. Lastly, small bags were tied around strawberry fruits and different numbers of nymphal and adult seed bugs were released into the bags to examine the effects of their feeding on strawberry fruits. The use of cover crops did not impact seed bug populations. The results for runner removal were inconsistent but it was clear that removing runners does not increase seed bug populations or their injury to fruit. The cultivar “Florida Brilliance” received less injury likely because its seeds are recessed in the flesh of the fruit, making them more difficult for seed bugs to access. Both adults and nymphs caused injury to ripe fruit. Adults did not feed on unripe fruit, so injury to unripe fruit is likely caused by nymphal feeding.

Abstract

The strawberry seed bug, Neopamera bilobata (Say), is an emerging pest of organic and conventional strawberries in Florida. There is limited information on this Rhyparochromidae species. Thus, the type of injury caused is not clearly documented and management recommendations are lacking. In this study, we evaluated the effect of strawberry cultivars, cover crops, and the presence of runners on N. bilobata populations and yield. We also investigated the effect of select cultivars and the presence of runners on N. bilobata injury levels. In addition, we used fruit bagging experiments to investigate the effects of N. bilobata population and life stage (nymph vs. adult) on strawberry fruits. There was no effect of cover crop or cultivar on N. bilobata populations. In the 2017–2018 season, strawberry plots with runners contained higher N. bilobata populations compared with plots without runners, and adult infestation was significantly higher than nymphal infestation. In the 2018–2019 season, the trend was reversed with higher numbers of N. bilobata collected in plots with runners removed. In the 2019–2020 season, there was no significant difference in N. bilobata populations in plots with and without runners. In both 2018–2019 and 2019–2020, nymphal infestation was higher than adult infestation. Less injury was recorded in “Florida Brilliance” compared with the other cultivars tested. In the 2019–2020 season, less injury was recorded from plots without runners while the difference was not significant in 2017–2018 or 2018–2019. Releasing five and ten adult N. bilobata on ripe (red) fruit produced a similar level of injury while no injury to unripe (green) fruit was observed. Both adults and nymphs cause injury to ripe fruit. These findings can help contribute to the development of an integrated pest management program for strawberry N. bilobata.

Blueberry IPM: Past Successes and Future Challenges

Blueberry is a crop native to North America with expanding production and consumption worldwide. In the historical regions of production, integrated pest management (IPM) programs have been developed and provided effective control of key insect pests. These have integrated monitoring programs with physical, cultural, biological, behavioral, and chemical controls to meet the intense demands of consumers and modern food systems. Globalization of the blueberry industry has resulted in new pest-crop associations and the introduction of invasive pests into existing and new blueberry-growing areas. Invasive pests-in particular spotted wing drosophila-have been highly disruptive to traditional IPM programs, resulting in increased use of insecticides and the potential to disrupt beneficial insects. Moreover, regulatory agencies have reduced the number of broad-spectrum insecticides available to growers while facilitating registration and adoption of reduced-risk insecticides that have a narrower spectrum of activity. Despite these new tools, increasing international trade has constrained insecticide use because of maximum residue limits, which are often not standardized across countries. Great potential remains for biological, behavioral, cultural, and physical methods to contribute to blueberry IPM, and with more regions investing in blueberry research, we expect regionally relevant IPM programs to develop in the new production regions.