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Abstract: Tropical soda apple (TSA), Solanum viarum Dunal (Solanaceae), has invaded many pastures and natural areas in Florida. The biological control agent Gratiana boliviana Spaeth (Coleoptera:Chrysomelidae) is providing adequate control of TSA stands in South and Central Florida. However, poor or no establishment of this agent has occurred in northern Florida. The goal of this study was to examine the mortality factors that influence the population dynamics of G. boliviana in Florida. Horizontal life tables were constructed by following cohorts of individuals in the laboratory and inside closed and open cages at field sites in Central and North Florida. Fertility life table parameters were estimated using laboratory and field data. In addition, as part of a vertical life table analysis, TSA plants were sampled every two weeks in pastures in Central Florida, and counts of all G. boliviana and other herbivores and predators were recorded. Survival to adulthood was similar between Central and North Florida (open cages: 12–19%). Intrinsic mortality (laboratory data) and biotic factors (predation) together accounted for 75% of the mortality of immature stages. Survival of beetles in a natural population determined from vertical life tables was 5%. A complex of three mirid species (Engytatus modesta Distant, Tupiocoris notatus Distant, and Macrolophus sp.) were the most abundant predators found in the field, and are known to feed on G. boliviana eggs and larvae. Positive growth rates (r m =0.3) during the summer and early fall allow the beetle population to increase and provide suppression of TSA in Central Florida. [Copyright &y& Elsevier]

Abstract: Life history parameters of the sap-feeding bug Ischnodemus variegatus (Signoret) (Hemiptera: Blissidae) were compared between the invasive Neotropical grass, Hymenachne amplexicaulis (Rudge) Nees and the Australian native Hymenachne acutigluma (Steudel) Guilliland. Development of immatures, adult longevity, ovipositional preference and population growth of I. variegatus were compared on H. amplexicaulis and H. acutigluma under choice and no-choice conditions. Third-instar nymphs developed on both hosts but individuals reared on H. acutigluma had a 40% lower survival rate to the adult stage, 40% longer developmental time, a 9% reduction in length and a 30% reduction in weight of females compared to those reared on H. amplexicaulis. The no-choice adult longevity and oviposition study indicated that individuals feeding on H. acutigluma had half the lifespan, 62% as many ovipositing females, 52% longer time to first oviposition and only 14% as many eggs per female. Under choice conditions, females laid only 37% as many eggs on H. acutigluma as on H. amplexicaulis. Population growth of I. variegatus was slower on H. acutigluma compared to H. amplexicaulis over a 60day period resulting in negative population increase on H. acutigluma but positive increase on H. amplexicaulis. These results reflect an overall poorer performance of I. variegatus on H. acutigluma for most life stages. [ABSTRACT FROM AUTHOR]

• Biotic and abiotic influences on weed biological control vary geographically. • Literature and a global database on weed biological control were reviewed. • Abiotic limitations such as temperature and precipitation were most common. • Biogeographical studies will inform predictions and manage control expectations. The impacts of different biotic and abiotic limiting factors on introduced biological control agents and their weed targets may result in geographically variable control, with implications for ongoing management and plans to improve efficacy. Geographic variability in control successes, however, may be underreported. Using the comprehensive catalogue, "Biological control of weeds: A world catalogue of agents and their target weeds", we assessed whether geographic variability in successful control is common, whether variability in programs could be attributed to limiting factors, and which factors were most likely responsible for variable success. In 38% of all reviewed programs, success was deemed spatially variable but nearly half of variable programs had unknown or unreported limiting factors. We discuss the factors that can contribute to geographic variability in agent abundance and associated success of weed biological control, provide case studies and current biological control practices, and finally discuss the potential ecological and evolutionary consequences of this variability. Published data to assess whether geographic patterns of variability were predictable, or to quantify variability along environmental gradients are lacking. Research that addresses the strength of agent-host interactions across environmental gradients, such as temperature or precipitation, or examines spatial variability in a metapopulation or landscape context may provide the best understanding of control failures and contribute to a biogeographic framework within which to evaluate ongoing and future biological control projects. [ABSTRACT FROM AUTHOR]

Cyrtobagous salviniae is widely used in several countries including the United States, South Africa and Australia for biological control of Salvinia molesta Mitchell (Salviniales: Salviniaceae). Despite considerable success in tropical and subtropical regions, the effectiveness of C. salviniae on S. molesta is inconsistent in temperate regions, indicating the need for populations adapted to cooler climates. The objectives of this study were to determine the regions of South America that are climatically similar to S. molesta habitats in temperate Louisiana, conduct surveys for new provenances of C. salviniae in these regions, establish the phylogenetic relationships among C. salviniae provenances, and compare the cold tolerance of populations of C. salviniae from Louisiana, USA and the Lower Paraná-Uruguay Delta (LPUD), South America. Foreign exploration of the Lower Paraná-Uruguay Delta region resulted in the first record of C. salviniae in Uruguay, and revealed the most southern distribution of this species in Argentina and Uruguay. Phylogenetic identification of this provenance indicated that it is a different biotype to the one from Brazil which was first released in the United States in 2001. Analysis of the climate in south, central, and north Louisiana revealed colder and more frequent cold fronts in the north, likely contributing to winter population crashes. Regional differences in Louisiana thermal regimes indicate that there is a need for region specific management plans, such as the inclusion of cold tolerant C. salviniae populations in the management of S. molesta in temperate regions. The cold tolerance of C. salviniae populations from Louisiana and Lower Paraná-Uruguay Delta were compared by measuring survival at 0 °C, chill coma recovery times, and supercooling points (SCP). Survival at 0 °C was 1.5-times greater, mean chill coma recovery time was 1.8-times faster, and mean SCP was 1.2-times lower in the Lower Paraná-Uruguay Delta population compared to the Louisiana population. These findings show that the Lower Paraná-Uruguay Delta provenance should be considered for managing S. molesta in temperate regions. Besides host range tests on the Lower Paraná-Uruguay Delta biotype, cross breeding between the Louisiana and Lower Paraná-Uruguay Delta populations of C. salviniae should be investigated to determine the life histories of any possible hybrids. [ABSTRACT FROM AUTHOR]

[Display omitted] • Trials demonstrate that CMBS is susceptible to several fungal biopesticides. • CMBS is more affected by Beauveria bassiana strains than Isaria fumosorosea PFR97. • Biopesticide applications in autumn and winter resulted in higher scale mortality than spring treatments. • Spore germination of all fungal strains was greatest at 28 °C. The crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae, is an important pest of crapemyrtles, Lagerstroemia spp. Biopesticides are frequently used to control soft-bodied insects; however, there is no information on their efficacy against CMBS. The objectives of this study were to test the use of selected biopesticides against CMBS under different seasons, evaluate their pathogenicity to CMBS, and determine optimum temperature for spore germination. Commercial formulations of the fungal biopesticides Isaria fumosorosea PFR97, Beauveria bassiana ANT-03, and the bacterial biopesticides Burkholderia rinojensis A396 and Chromobacterium subtsugae PRAA4-1 T were tested in greenhouse settings and did not have significant treatment effect on immature mortality. Biopesticides containing I. fumosorosea PFR97, B. bassiana ANT-03, and B. bassiana GHA were applied to mature crapemyrtles grown in the landscape and naturally infested with CMBS, and the scale survivorship was determined in two trials at different seasons. When treatments were applied in winter, scale survivorship was significantly lower in the B. bassiana ANT-03 treatment compared to the control. When treatments were applied in spring, no treatment effect was observed. During another trial conducted in autumn using container-grown crapemyrtles, B. bassiana GHA treatment reduced scales survivorship when compared to the control. Pathogen re-isolation assays confirmed that scales collected in the spring trial were had all pathogens delivered; in addition, B. bassiana ANT-03 was the most recovered pathogen. In a temperature-dependent spore germination assay, the optimum temperature range for I. fumosorosea PFR97, B. bassiana ANT-03, and B. bassiana GHA was between 22.5 and 30 °C, with peak spore germination observed at 28 °C for all three pathogens. Results from this project suggest that biopesticides containing strains of B. bassiana can be included in the toolbox for CMBS control, provided that climate and product coverage are considered. [ABSTRACT FROM AUTHOR]

[Display omitted] • Coccinellids are major predators of the crapemyrtle bark scale (Acanthococcus lagerstroemiae). • Mycopesticides reduced the survival of coccinellid adults and larvae in the laboratory. • Spores of mycopesticides were recovered from coccinellids under field conditions. • Mycopesticides might interfere with the biological control of the bark scale. Insect predators are the most important natural enemies of the crapemyrtle bark scale (CMBS) in the USA. Mycopesticides (biocontrol fungi) are considered an IPM tool to increase CMBS mortality; however, their impacts on CMBS predators are unknown. The objectives of this study were to assess the abundance and diversity of CMBS natural enemies in Louisiana; evaluate the impacts of mycopesticides on survival of CMBS predators by life stage; and determine if entomopathogenic spores delivered to crapemyrtles are transferred to predators under field conditions. The mycopesticides Ancora® (Isaria fumosorosea PFR97), BioCeres® (Beauveria bassiana ANT-03), and BotaniGard® (B. bassiana GHA) were tested against the coccinellids Chilocorus spp. and Hyperaspis bigeminata under laboratory and field conditions. Adults and larvae of the coccinellids were treated with each mycopesticide and survival recorded over a 14-day period. The most common natural enemies on CMBS infested trees were the coccinellids Chilocorus cacti, C. stigma , and Hyperaspis bigeminata (Coleoptera: Coccinellidae). In laboratory bioassays BotaniGard® reduced survival of adults and larvae of both genera by at least 57%. BioCeres® reduced the survival of Chilocorus spp. adults by 40% and Ancora® reduced survival of H. bigeminata larvae by 69%. Under field conditions, CMBS infestations were sprayed with the mycopesticides and coccinellids were collected every other day for a two-week period. Spores of the applied mycopesticides were recovered from the coccinellids; however, it is not known if infection occurred in the field trial or spores were delivered to CMBS infestations by the coccinellids. We conclude that mycopesticides negatively impacted the survival of coccinellids in laboratory trials, and coccinellids can transport pathogen spores under field conditions. [ABSTRACT FROM AUTHOR]