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© 2019 Elsevier Inc. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (February 2019) in accordance with the publisher’s archiving policy, Rhizoctonia root rot caused by Rhizoctonia solani AG8 is a major disease in dryland cereal crops. Previous research identified a suite of microbes using in planta bioassay screening that are effective as seed-coated inoculants for control of Rhizoctonia root rot on wheat. This paper assessed 23 strains in fields in Australia with a history of naturally occurring R. solani AG8. Due to the patchy nature of Rhizoctonia root rot in the field, a 2-phase split-plot field trial system was used to allow comparison for disease control efficacy in the same disease space. Seed applied strains were first assessed for their ability to reduce Rhizoctonia using ‘microplots’ which compare adjacent treated and untreated one metre rows. Up to 10% increases in plant growth and a 32% reduction in root disease was measured at eight weeks after sowing. Selected strains were then assessed in 20 m six row (3 + 3) split plots for their effects on early season wheat growth and root damage and for grain yield. A Paenibacillus and a Streptomyces strain were identified which were able to reduce root damage by 20% and 32% and increase grain yield by 4.2% and 2.8%, respectively, compared to untreated controls. The current best registered chemical control for Rhizoctonia root rot reduced root disease by 35% and increased yield by 3.0% in the same trial.

Diachasmimorpha longicaudata (Ashmead) and Fopius arisanus (Sonan), are two of the most abundant and widely used parasitoids for biological control of Bactrocera dorsalis (Hendel) worldwide. However, interspecific competition between them frequently occurs within a single host once they coexit in same orchard, resulting in reduction of their combined impact. However, thus far, it is difficult to characterize these complex interactions. This paper demonstrates qPCR-methods for detection of parasitism for single D. longicaudata, and methods to determine interspecific interaction with F. arisanus. Utilizing qPCR-based methodologies, a species-specific probe was designed for D. longicaudata, which was coupled with a previously published probe for F. arisanus. An assay was developed that is sensitive enough to detect parasitism of solitary D. longicaudata across all developmental stages including one egg per host larva (0.01 ng/40 ng parasitoid/host DNA). The detected parasitism of D. longicaudata was higher than that of using traditional rearing-methods. For the lab-reared and wild strain of multiple species parasitization, qPCR-methods also detected higher parasitism by the above two species from one assay respectively when compared to conventional rearing-based methods. In the later experiment, the majority of D. longicaudata larvae were dying or dead within hollow-like host pupae probably due to interspecific competition. This method is a reliable and robust technique to determine parasitism by a single species or both species of parasitoid across all life stages within one host. It will be useful to evaluate parasitoid combined suppression, and to characterize complex interspecific competition between these two species of parasitoids.

Plant-mediated indirect interactions among herbivores (arthropods and pathogens) are common and extensively reported in the ecological literature. However, they are not well-documented with respect to weed biological control. Such interactions between biological control agents can have net positive or negative impacts on total weed suppression depending on the strength of the interaction(s), the relative importance of the agent indirectly impacted, and the combined weed suppression that results. A better understanding of plant-mediated interactions may improve decision-making about which agents to introduce in classical biological control programs for greatest impact on invasive weeds. This paper reviews the subject, including examples from the biological control literature; outlines the need for research on indirect effects of herbivores on other herbivores; discusses how such knowledge may strengthen classical biological control programs for invasive weeds; and provides recommendations for the kind of studies that should be done and how information about plant-mediated interactions could be integrated into agent evaluation protocols, to assist in decision-making about agents for importation and release.

Tomato crop in the Mediterranean Basin and in Europe has been recently affected by the exotic pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), which is difficult to control due to its high reproduction rate and potential to develop resistance to insecticides. In this paper, the suitability and effectiveness of the predatory bug Dicyphus errans (Wolff) (Hemiptera: Miridae), an indigenous species usually found in the IPM tomato crop of northwestern Italy, were evaluated on eggs and larvae of T. absoluta under controlled conditions. This generalist predator could be an effective biological control agent against the tomato borer. Both sexes of D. errans were proven to prey actively on T. absoluta eggs and 1st-instar larvae. In particular, compared to males, females showed a significantly higher egg consumption rate (11.0 ± 0.7 vs 8.6 ± 0.8 day−1), and were also more effective in preying on 1st-instar larvae (2.4 ± 0.5 vs 1.3 ± 0.3 day−1). The mirid was able to develop from egg to adulthood on tomato infested with eggs or with 1st-instar larvae of T. absoluta, even if a high mortality of the predator was recorded in the latter case. Moreover, in olfactometer bioassays predator adults proved to be attracted by tomato either infested or previously infested with tomato borer larvae, independently of larval instars. D. errans can be considered a promising potential candidate for controlling the pest, and further research is needed to assess its effectiveness under field conditions.

Aphids cause much damage to Chinese cabbage in northern China. Over reliance on pesticides have large environmental and human health costs that compel researchers to seek alternative management tactics for aphid control. The component of aphid alarm pheromone, E-β-Farnesene (EβF), extracted from Matricaria chamomilla L., which attracts natural enemies in the laboratory, may have significant implications for the design of cabbage aphid control strategies. The purpose of this paper is to understand the effects of EβF on natural enemies to cabbage aphid control in Chinese cabbage fields. Ladybeetles on Chinese cabbage leaves in EβF released plots and Aphidiidae in EβF released yellow traps were significantly higher than those of in controls. No significant differences were detected in the interactions of different treatments and the two years for all natural enemies. More important, lower aphid densities were found in EβF released plots. Our results suggested that the EβF extracted from M. chamomilla L. could attract natural enemies to reduce cabbage aphids in the Chinese cabbage fields.

Tetranychus urticae Koch (Acari: Tetranychidae) is a key pest of citrus that can also feed on most plant species occurring in the ground cover associated with this crop. To determine the effect of the management of the ground cover on the biological control of this mite, we have studied the dynamics of both tetranychid and phytoseiid mites in four commercial clementine mandarin orchards under three different ground cover management strategies: (1) bare soil, (2) resident wild cover and (3) a sown cover of Festuca arundinaceaSchreb. (Poaceae). Our results provide evidence that the management of ground cover can affect both Tetranychid and Phytoseiid mite populations. We hypothesize that both natural enemies (top-down mechanisms) and plant resources (bottom-up mechanisms, discussed in a previous paper) play important regulatory roles. T. urticae specialist phytoseiid mites were consistently found in the F. arundinacea cover and this may explain the better regulation of Tetranychid mite populations on trees grown in association with this cover crop. In contrast, the more regular provision of alternative food (pollen) in the wild cover relative to the F. arundinacea cover, could explain the higher abundance of generalist pollen feeder phytoseiids in the former. As a result, more efficient T. urticae-specialized phytoseiids could suffer increased competition from generalist pollen feeders in the wild cover. This fact, in combination with periods of prey scarcity, could result in their disappearance from the agroecosystem, resulting in an inadequate control of Tetranychid mites in trees grown in association with a wild cover. This work was partly funded by MICINN (projects AGL2005-07155-C03/AGR and AGL2008-05287-C04/AGR), and the Valencian Conselleria d’Agricultura, Pesca i Alimentació (ATC06/058-TS/06/UJI/03)

The fungus, Penicillium oxalicum Thom.;has been proposed as a biocontrol agent against vascular wilts caused by Verticillium spp.;Fusarium oxysporum. In this paper, we report our findings on the effects of different additives and storage conditions of varying durations, temperatures, and types on the viability and biocontrol efficacy of three different types of P. oxalicum conidial formulations. The viability of the three different P. oxalicum conidial formulations with various solvent stabilizers and moisture contents between

Fungal endophytes are quite common in nature and some of them have been shown to have adverse effects against insects, nematodes, and plant pathogens. Our research program is aimed at using fungal endophytes-mediated plant defense as a novel biological control mechanism against the coffee berry borer, the most devastating pest of coffee throughout the world. A survey of fungal endophytes in coffee plants from Hawaii, Colombia, Mexico, and Puerto Rico has revealed the presence of various genera of fungal entomopathogens, including Acremonium, Beauveria, Cladosporium, Clonostachys, and Paecilomyces. Two of these, B. bassiana and Clonostachys rosea, were tested against the coffee berry borer and were shown to be pathogenic. This paper reviews the possible mode of action of entomopathogenic fungal endophytes. Published by Elsevier Inc.

Improving the conditions for natural enemies through conservation biological control (CBC) in agricultural landscapes has the potential to be economically beneficial, but economic assessments of CBC programs are rarely conducted. In this paper, we discuss how to complete an economic assessment of CBC. We also ask what the research and development (R&D) requirements are for CBC and the likelihood of that R&D being funded. We examine the factors that may influence uptake of CBC amongst farmers and consider what policies or strategies might be introduced to increase the incentive to adopt CBC. Relative advantage of CBC over other production systems, trialability (ease of informal field experimentation and learning before adoption) of CBC and the social dynamics of CBC development and extension are key factors influencing adoption. The most important social factors are the social learning processes to support agroecological practices, and the configuration of economic incentives to reward farmers for undertaking the transition to conservation biological control. By itself, neither social pressure to reduce insecticide use nor sophisticated scientific research guarantees expanded implementation of CBC.

All introduced natural enemies present a degree of risk to nontarget species. Since most biological control programs use relatively host-specific natural enemies, the risk to nontarget species is generally very low, particularly from biological control of weeds, which uses extensively tested and validated host-specificity testing procedures to predict risk. However, many of the published comments about risks of biological control are superficial or misleading, often inappropriately lumping risk from all taxa of agents as “the risk of biological control,” and ignore the potential benefits, rather than dealing with species-by-species risk and benefits. Particularly confounding accurate predictions is the common mixing of parameters of hazard and exposure in discussions of risk. In this paper, traditional risk analysis techniques are discussed and adapted for biological control. How people perceive risk is the key to understanding their attitude to risk. Some of the criticisms of biological control relating to inadequate post-release monitoring are valid and the ethical responsibilities of biological control scientists in this area are also discussed. Biological control scientists should address objectively the criticisms of biological control, continue to review and adjust current host-specificity testing procedures and make appropriate changes. This process will result in better science, ultimately delivering more focused programs, and altering the perception of risk from biological control agents by objective observers.