VTechWorks staff will be away for the winter holidays starting Tuesday, December 24, 2024, through Wednesday, January 1, 2025, and will not be replying to requests during this time. Thank you for your patience, and happy holidays!

Browsing by Author "Knowles, B. K."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Interactions among biological control agents on water hyacinth: impacts of herbivory on the oviposition and development of Megamelus scutellaris
    Goode, A. B. C.; Knowles, B. K.; Tipping, P. W.; Foley, J. R.; Gettys, L. A. (2020-11-01)
    Multiple biological control agents have been developed and released to increase control and reduce treatment costs ofPontederia (Eichhornia) crassipesin Florida. Although two species of weevil (Neochetina eichhorniaeandNeochetina bruchi) and the planthopper (Megamelus scutellaris) utiliseP. crassipesfor feeding and reproduction, little is known about their interactions including any negative interactions that might reduce their individual or overall effectiveness in suppressing the plant.Megamelus scutellariswas provided with the choice of weevil-damaged or undamaged plants and allowed to oviposit. Plants were then monitored individually for nymph emergence to determine the plant preference for adults. There were no differences in F(1)emergence numbers among the treatments indicating that in this specific situation the potential for negative interactions betweenNeochetinaspp. andM. scutellarisis minimal. Additional studies are required to quantify the potential for other types of interactions among these biological control agents.
  • Thumbnail Image
    Megamelus scutellaris (Berg) (Hemiptera: Delphacidae) biology and population dynamics in the highly variable landscape of southern Florida
    Goode, A. B. C.; Tipping, P. W.; Minteer, C. R.; Pokorny, E. N.; Knowles, B. K.; Foley, Jeremiah R.; Valmonte, R. J. (2021-09)
    Changes to the historical flow and nutrient levels of freshwater bodies in Florida have made control of waterhyacinth difficult. Biological control agents were introduced to augment herbicidal control of this plant. The newest insect agent, Megamelus scutellaris, was released in 2010, has established, and has been documented dispersing more than 6 kms away from release locations, across aquatic and terrestrial habitats. These insects were able to successfully disperse away from herbicide treated areas and across terrestrial habitats to reach new mats of waterhyacinth. Macropterous individuals were the first M. scutellaris documented at three non-release sites, indicating that the established wild populations are producing flighted individuals and are dispersing actively. Established populations appear to have reached an equilibrium density of 10.74 +/- 19.74 M. scutellaris/ m2 and this does not fluctuate with additional releases.