Temporal and spatial factors influencing Systena frontalis (Coleoptera: Chrysomelidae) behavior in Virginia nurseries

Abstract

Ornamental plant production in eastern Virginia nurseries have been greatly impacted by Systena frontalis (F.), also known as the red-headed flea beetle. With the advent of S. frontalis as a prevalent pest in the past 2 decades, baseline phenology and behavior are currently understudied within Virginia nurseries. This pest is costly to control due to insecticide expenses and loss of saleable plants. In 2021 and 2022, populations of this insect were monitored at 2 commercial nurseries in eastern Virginia in order to better understand their temporal and spatial population dynamics. Patterns that emerged indicated S. frontalis could have up to 3 generations in eastern Virginia, with peaks of adult abundance in June, late July, and late August to early September. Phenylethyl alcohol was tested as an adult attractant lure, but it was found to be ineffective under nursery conditions. Diel monitoring demonstrated these adults were most active from 1100 to 1500 h. Severity of defoliation at the leaf level increased linearly with increased density of adults, where 5 individuals defoliated up to 4% of any Hydrangea paniculata cv. ‘Limelight’ leaf in 1 wk under greenhouse conditions. Timing of scouting and insecticide sprays according to the adult activity peaks of the day and across the season may allow reduction in overall insecticide usage.

Feeding potential of adult Systena frontalis (Coleoptera: Chrysomelidae) on leaves of Hydrangea paniculata (Cornales: Hydrangeaceae)

“…Systena frontalis (F.) (Coleoptera: Chrysomelidae), commonly referred to as the red-headed flea beetle, is a defoliating pest of ornamentals in nurseries ( Lane and Del Pozo-Valdivia 2021 , 2023 ) as well as other crop systems such as soybeans ( NDSU 2022 ) and cranberries ( Jaffe et al 2021 ). The presence of this pest is distributed across the eastern United States, including Virginia ( Joseph et al 2021 ).…”

“…After eclosion, larvae will feed on root hairs. Pupae will remain inside the pots, and then adults will emerge from the potting media ( Lane and Del Pozo-Valdivia 2021 , 2023 , Lane 2022 ). Adult feeding results in leaves with shot holes and skeletonization that are unsightly and ornamentals that are unsaleable ( Lane and Del Pozo-Valdivia 2021 , 2023 ).…”

“…Pupae will remain inside the pots, and then adults will emerge from the potting media ( Lane and Del Pozo-Valdivia 2021 , 2023 , Lane 2022 ). Adult feeding results in leaves with shot holes and skeletonization that are unsightly and ornamentals that are unsaleable ( Lane and Del Pozo-Valdivia 2021 , 2023 ). As a polyphagous insect, they feed on a wide variety of economically important nursery crops ( Joseph et al 2021 ).…”