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This study investigated the interactions between insecticides (acephate and indoxacarb) and fungal entomopathogens (Beauveria bassiana [Bals.‐Criv.] Vuill. strain B27, Metarhizium anisopliae [Metschn.] Sorokin strain ECS1, and a commercial B. bassiana product, Velifer® Biological Insecticide) for controlling the macadamia seed weevil, Kuschelorhynchus macadamiae Jennings and Oberprieler, in the laboratory and glasshouse. In the laboratory, additive interactions between insecticides at their full field concentrations (776 mg AI/L of acephate and 75 mg AI/L of indoxacarb) and fungal entomopathogens at 107 conidia/ml (ECS1 and B27) or at full field concentration (0.5 ml of Velifer®/L) were seen at 6 days and 12 days post‐application. Under the same experimental conditions, synergistic interactions against K. macadamiae were observed 6 days post‐application when fungal entomopathogens at 2.5 × 106 conidia/ml or at 25% of full field concentration (Velifer®) were co‐applied with insecticides at 25% of their full field concentrations, whilst additive interactions were again observed at 12 days post‐application. In the glasshouse, additive interactions between insecticides (at full field concentrations) and fungal entomopathogens (at 107 conidia/ml, or at full field concentration for Velifer®) were obtained at 6 days and 12 days post‐application. The results from this study suggest that acephate and indoxacarb have both synergistic and additive effects against K. macadamiae when deployed together with fungal entomopathogens, depending on the initial concentrations of mixture components. Combined application of entomopathogens with compatible insecticides promises to provide more effective management of K. macadamiae than individual chemical applications. [ABSTRACT FROM AUTHOR]

Fuller's rose weevil (FRW; Asynonychus cervinus (Boheman)) is a pest of quarantine concern in many Asian markets for Australian citrus. We investigated vertical (tree climbing) and horizontal movements (inter-tree movements) of FRW adults in a citrus orchard during 2009-2011 with mark-recapture experiments. Trunk traps were used to intercept tree-climbing adults. The results showed that the majority of the adults released on the foliage stayed in the canopy, however considerable numbers did drop and some dropped multiple times. The rate of drops appeared to be fixed, independent of how many times the weevils had dropped before. Inter-tree movements of adults in the canopy occurred mainly within rows, probably because of touching foliage between within-row neighboring trees. Movement directions on the ground were more random, when reliance on touching foliage was not necessary. According to fitted dispersal equations, the average dispersal distance was 38 m for weevils released on foliage and 127 m for those released on the ground. Trunk banding with chemicals is an important control tactic for FRW, and based on our results, chemicals should be applied at a high enough rate (or in a wide enough band) to ensure the weevils are killed by a single crossing. For maximum reductions of FRW populations in citrus, control actions should be applied not only to infested blocks but also to neighboring blocks in the orchard. [ABSTRACT FROM AUTHOR]

Simple Summary: Horticultural crops are vulnerable to attack by many different weevil species. Fungal entomopathogens provide an attractive alternative to synthetic insecticides for weevil control because they pose a lesser risk to human health and the environment. This review summarises the available data on the performance of these entomopathogens when used against weevils in horticultural crops. We integrate these data with information on weevil biology, grouping species based on how their developmental stages utilise habitats in or on their hostplants, or in the soil. These patterns of habitat usage can help identify the stages during which pest species are at their most vulnerable, and also help to determine the most effective ways to deploy entomopathogens for their control. Weevils are significant pests of horticultural crops and are largely managed with insecticides. In response to concerns about negative impacts of synthetic insecticides on humans and the environment, entomopathogenic fungi (EPF) have been developed as an alternative method of control, and as such appear to be "ready-made" components of integrated pest management (IPM) programs. As the success of pest control requires a thorough knowledge of the biology of the pests, this review summarises our current knowledge of weevil biology on nut trees, fruit crops, plant storage roots, and palm trees. In addition, three groups of life cycles are defined based on weevil developmental habitats, and together with information from studies of EPF activity on these groups, we discuss the tactics for integrating EPF into IPM programs. Finally, we highlight the gaps in the research required to optimise the performance of EPF and provide recommendations for the improvement of EPF efficacy for the management of key weevils of horticultural crops. [ABSTRACT FROM AUTHOR]

• Both Metarhizium anisopliae and Beauveria bassiana are highly pathogenic. • Indigenous isolates performed as well as commercially available entomopathogens. • Entomopathogens in the future can be integrated into IPM programs. Macadamia seed weevil, Kuschelorhynchus macadamiae Jennings and Oberprieler, is a major pest of macadamia in eastern Australia, causing yield losses of up to 15%. Current control methods involve two applications of acephate per season but more recently have moved to a single application of indoxacarb, combined with the collection and destruction of fallen nuts that contain developing larvae. As a first step towards reducing the dependence of the industry on synthetic insecticides, we tested six isolates of M. anisopliae, six isolates of B. bassiana and one commercial B. bassiana product (Velifer® biological insecticide) against adult macadamia seed weevil under laboratory conditions. All isolates were pathogenic against adult weevils with M. anisopliae accession ECS1/BRIP 70272 and B. bassiana accession B27/BRIP 70267 causing 97.5% and 92.5% mortality 12 days after being treated at 1 × 107 conidia/mL. Isolates ECS1/BRIP 70272 and B27/BRIP 70267 had the shortest LT 50 values of 5.13 days and 5.37 days respectively. The median lethal concentrations (LC 50) for ECS1/BRIP 70272 and B27/BRIP 70267 were 1.48 × 105 and 1.65 × 105 conidia/mL respectively. Results of this study indicate that M. anisopliae accession ECS1/BRIP 70272 and B. bassiana accession B27/BRIP 70267 have considerable potential for K. macadamiae control, and should be developed into biological insecticides for integration into macadamia pest management programs. [ABSTRACT FROM AUTHOR]