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Air potato, Dioscorea bulbifera L. (Dioscoreaceae), is an invasive vine that climbs into vegetation outcompeting native species and altering ecosystems in the southeastern USA. The biological control agent, Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae), has been released in Florida since 2011 and in other states including Georgia (2015), Louisiana (2016), Texas (2017), Mississippi (2018), and Alabama (2018) to manage air potato. Despite the wide distribution of the weed and mass rearing efforts, there are no studies documenting the establishment of L. cheni outside of Florida. The objectives of this study were to document the beetle release efforts by several agencies and determine the establishment and impact of L. cheni across the southeastern USA. Using community science reports and field surveys, we documented the distribution of air potato and L. cheni. Results demonstrated that the distribution of air potato extends to temperate regions from South Carolina and Georgia to subtropical regions of Louisiana, Texas, and Florida. Surveys showed that the beetle is present across all states with releases, and numbers fluctuated between 6 and 37 beetles counted per 30-surveyor-minutes. Most sites sampled had moderate to high beetle damage (scales of 3–4 out of 5), and air potato cover was low to moderate (2–3 out of 5). However, air potato was still abundant in some areas, which suggests the need for additional beetle releases and/or the use of other tactics to achieve management goals. [ABSTRACT FROM AUTHOR]

Optimal foraging theory attempts to explain the foraging patterns observed in animals, including their choice of particular food items and foraging locations. We describe three experiments designed to test hypotheses about food choice and foraging habitat preference using bird feeders. These experiments can be used alone or in combination and can also provide a foundation for students to develop extensions incorporating the basic methodology. We see these experiments as most applicable in secondary and postsecondary education, but they could be adapted for a variety of educational environments and for students with a variety of backgrounds.

Results demonstrate that filamentous cells of Escherichia coli exhibit movements and chemotaxis response similar to the normal-sized non-filamentous cells. Data indicate that the chemoreceptors are localized at both ends of the pole and intervals along the filamentous cell.

Biological control is a sustainable method of weed management because agents can establish persistent and self-dispersing populations on a landscape scale. Strategic releases are often conducted to accelerate the widespread dispersal and establishment of agents. Drones (unmanned aerial systems, UAS) could facilitate these releases, particularly in remote areas that are difficult or dangerous for humans to access. Lygodium microphyllum (Lygodiaceae), Old World climbing fern, is a damaging weed that outcompetes native plants in many habitat types in Florida. This weed often occurs in remote conservation areas accessible only by helicopter, airboat, or swamp buggy. Although the biological control agent Neomusotima conspurcatalis (Lepidoptera: Crambidae) is established and dispersing in Florida, populations are patchy and additional releases are needed, particularly in conservation areas where human access is limited. We conducted the first releases of N. conspurcatalis using a drone to test agent survival and larval transfer to field populations of L. microphyllum. In the survival experiment, 85% of individuals were recovered from the flight, flight with impact, and control treatments with no treatment differences. In the larval transfer experiment, significantly more larvae and pupae were recovered four days post-release from the drone releases than hand releases. Drone releases of N. conspurcatalis could improve the establishment and potential impact of this agent on a landscape scale. In general, drone releases in L. microphyllum and other biological control systems could help to mitigate limits of agent dispersal. [ABSTRACT FROM AUTHOR]

The successful establishment or failure of a new population is often attributed to propagule pressure, the combination of the number of independent introduction events, and the number of individuals released at each event. The design of optimal release strategies for biological control agents benefits from an understanding of the impact of propagule pressure on the species being released. The dispersal rate of individuals from nascent population foci can also affect establishment success. We assessed the minimum threshold for establishment and measured dispersal of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent for Dioscorea bulbifera (Dioscoreales), air potato. Replicated releases of 10, 50, and 100 adults of L. cheni were conducted on the east and west coasts of south Florida. Dispersal was measured from 19 of these sites plus 19 additional release locations in south and central Florida. Lilioceris cheni established populations from all three release sizes with no apparent influence of site location. Releases of 10, 50, and 100 adults resulted in 50%, 67%, and 85% establishment, respectively. Beetles dispersed an average of 1.41 ± 0.515 km/yr. Dispersal distance was significantly affected by the time since release but not the number of individuals released. Our results suggest that future releases of 100 individuals could be spaced several kilometres apart on the landscape to facilitate rapid colonisation of D. bulbifera infestations. [ABSTRACT FROM AUTHOR]

Integrating classical biological control with other management techniques such as herbicide, fire, mechanical control, grazing, or plant competition, can be the most effective way to manage invasive weeds in natural areas and rangelands. Biological control agents can be protected from potential negative impacts of these weed control methods through untreated refugia or by applying the treatment at a time when the agent is not vulnerable. A literature review of experiments that integrated biological control with other management strategies from 1987 to 2017 yielded 39 terrestrial and 16 aquatic studies. The tactics most frequently integrated with biological control were herbicide applications and plant competition. Despite numerous examples of successful programs and calls for more widespread integration of biological control with other weed management strategies, there was no increase in the number of studies reported annually over time. Additional studies investigating the ecological and economic benefits of integrated weed management are needed. [ABSTRACT FROM AUTHOR]