Insight into the feeding behavior of predatory mites on Beauveria bassiana, an arthropod pathogen

Fungal Endophytes and Their Role in Agricultural Plant Protection against Pests and Pathogens

Virtually all examined plant species harbour fungal endophytes which asymptomatically infect or colonize living plant tissues, including leaves, branches, stems and roots. Endophyte-host interactions are complex and span the mutualist-pathogen continuum. Notably, mutualist endophytes can confer increased fitness to their host plants compared with uncolonized plants, which has attracted interest in their potential application in integrated plant health management strategies. In this review, we report on the many benefits that fungal endophytes provide to agricultural plants against common non-insect pests such as fungi, bacteria, nematodes, viruses, and mites. We report endophytic modes of action against the aforementioned pests and describe why this broad group of fungi is vitally important to current and future agricultural practices. We also list an extensive number of plant-friendly endophytes and detail where they are most commonly found or applied in different studies. This review acts as a general resource for understanding endophytes as they relate to potential large-scale agricultural applications.

Provisioning predatory mites with entomopathogenic fungi or pollen improves biological control of a greenhouse psyllid pest

BACKGROUND

Tomato/potato psyllid (TPP), Bactericera cockerelli (Šulc), is a recently established invasive pest of solanaceous crops in New Zealand. No alternative control strategies are available against TPP due to the development of insecticidal resistance. We investigated the combined use of the predatory mites Amblydromalus limonicus or Neoseiulus cucumeris with either the fungus Beauveria bassiana (suspensions and dry conidia) or with Typha orientalis pollen as a control of TPP in greenhouse bell pepper over 7 weeks.

RESULTS

All treatments significantly reduced TPP densities compared with the control. A. limonicus resulted in significantly lower TPP densities than any other combination with N. cucumeris. B. bassiana suspensions did not affect A. limonicus densities when they were combined. However, the application of dry B. bassiana conidia significantly reduced the densities of A. limonicus. The use of T. orientalis pollen resulted in significantly higher densities of A. limonicus but densities of N. cucumeris did not increase. The combined use of A. limonicus with B. bassiana suspensions or T. orientalis pollen resulted in significantly decreased TPP populations and greater crop yield.

CONCLUSION

The synergistic application of A. limonicus with B. bassiana suspensions could be a suitable strategy to control TPP in the greenhouse. © 2019 Society of Chemical Industry.

A decade of a thrips invasion in China: lessons learned

The Western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is an invasive polyphagous pest with an expanding global range that damages a wide variety of crops. F. occidentalis was first reported in China from Yunnan province during 2000, and has rapidly expanded its range since then. It is currently distributed across at least 10 provinces in China and has become a particularly devastating pest, causing substantial damage and economic losses. At present, the still heavy reliance on frequent use of insecticides for control of F. occidentalis, has lead to a series of ecological problems stemming from insecticide resistance, interspecific displacement and non-target effects. Thus, integrated pest management (IPM) programmes, multiple complementary tactics, including preventive tactics, biological controls, and judicious use of insecticides will likely provide a viable IPM strategy for control of F. occidentalis in the near future. This review provides an overview for information gained during the 10+ years since the invasion of F. occidentalis into China, reviews lessons that have been learned enhancing our overall understanding of the biology and ecology of F. occidentalis and discusses IPM practices relative to this widespread invasive insect pest.

Effects of Beauveria bassiana on predation and behavior of the predatory mite Phytoseiulus persimilis

Determination of intraguild interactions between entomopathogens and predators is important when attempting to use a combination of these two natural enemy groups for biological control of their shared arthropod pest species. This study assessed the effects of Beauveria bassiana on the predation and associated behavior of the predatory mite, Phytoseiulus persimilis, against Tetranychus urticae. The functional response tests showed that P. persimilis exhibited a Holling type II response on the spider mite, Tetranychus urticae, when treated with either a B. bassiana or Tween-80 suspension. There were no significant differences between the treatments in the number of T. urticae consumed. The laboratory choice test indicated that P. persimilis displayed a significant avoidance response to B. bassiana on bean leaves immediately following spray application. They also spent significantly longer time in self-grooming behavior on leaf disks sprayed with fungal conidia than on discs treated with Tween-80. There were no significant differences in the predation rates on T. urticae eggs between the different treatments. The potted plant investigations indicated that P. persimilis showed significant aversion behavior to the initial fungal spray, but gradually dispersed over the entire bean plants. Observations using scanning electron microscopy revealed that fungal conidia were attached to the body of P. persimilis after mounting the leaf disk treated with B. bassiana, which would account for its varied behavioral responses. Our study suggests that fungal spray did not affect the predation capability of P. persimilis and poses a negligible risk to their behavior.