Diatomaceous Earth for Arthropod Pest Control: Back to the Future

Nowadays, we are tackling various issues related to the overuse of synthetic insecticides. Growing concerns about biodiversity, animal and human welfare, and food security are pushing agriculture toward a more sustainable approach, and research is moving in this direction, looking for environmentally friendly alternatives to be adopted in Integrated Pest Management (IPM) protocols. In this regard, inert dusts, especially diatomaceous earths (DEs), hold a significant promise to prevent and control a wide range of arthropod pests. DEs are a type of naturally occurring soft siliceous sedimentary rock, consisting of the fossilized exoskeleton of unicellular algae, which are called diatoms. Mainly adopted for the control of stored product pests, DEs have found also their use against some household insects living in a dry environment, such as bed bugs, or insects of agricultural interest. In this article, we reported a comprehensive review of the use of DEs against different arthropod pest taxa, such as Acarina, Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, Ixodida, Lepidoptera, when applied either alone or in combination with other techniques. The mechanisms of action of DEs, their real-world applications, and challenges related to their adoption in IPM programs are critically reported.

Bottom-Up Forces in Agroecosystems and Their Potential Impact on Arthropod Pest Management

Bottom-up effects are major ecological forces in crop–arthropod pest–natural enemy multitrophic interactions. Over the past two decades, bottom-up effects have been considered key levers for optimizing integrated pest management (IPM). Irrigation, fertilization, crop resistance, habitat manipulation, organic management practices, and landscape characteristics have all been shown to trigger marked bottom-up effects and thus impact pest management. In this review, we summarize current knowledge on the role of bottom-up effects in pest management and the associated mechanisms and discuss several key study cases showing how bottom-up effects practically promote natural pest control. Bottom-up effects on IPM also contribute to sustainable intensification of agriculture in the context of agricultural transition and climate change. Finally, we highlight new research priorities in this important area. Together with top-down forces (biological control), future advances in understanding ecological mechanisms underlying key bottom-up forces could pave the way for developing novel pest management strategies and new optimized IPM programs. Expected final online publication date for the Annual Review of Entomology, Volume 67 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Whole Genome Sequence of a Novel Chrysovirus From Beauveria Bassiana Vuillemin, an Entomopathogenic Fungus

Beauveria bassiana, an entomopathogenic fungus, has a wide host range and is used for arthropod pest control worldwide. Here, we report the discovery and characterization of a novel double-stranded RNA (dsRNA) mycovirus Beauveria bassiana chrysovirus 2 (BbCV2), isolated from the B. bassiana from China. The genome of the virus was determined by metagenomic sequencing, RT-PCR, and RACE cloning comprises four dsRNA segments that are 3441bp, 2779bp, 2925bp, and 2688bp long, respectively, each of them contains a single ORF, the first one (ORF1) encoding a 1115-amino-acid-long protein (122.65 kDa) with a conserved RNA-dependent RNA polymerase (RdRp) motif, its sequences showed the highest identity of only 16.13% to that of the Beauveria bassiana chrysovirus 1. The second ORF (ORF-2) encoding a 807-amino-acid-long coat protein (CP) (88.77 kDa). The virus constitutes a new member of the chrysoviridea family from B. bassiana.

Interaction of the Causal Agent of Apricot bud gall Acalitus phloeocoptes (Nalepa) with Apricot: Implications in Infested Tissues

Apricot bud gall mite, Acalitus phloeocoptes (Nalepa), is a destructive arthropod pest that causes significant economic losses to apricot trees worldwide. Infested bud examination revealed that the starch granules in the bud axon were extended at the onset of the attack. During the later stages of the attack, the cytoplasm was distributed in apricot. The results also demonstrated that the accumulation of large amounts of cytokinin (zeatin, ZT) and auxin (indoleacetic acid, IAA) led to rapid bud proliferation during the rapid growth period. Abscisic acid (ABA) controls the development of gall buds and plays a vital role in gall bud maturity. The reduction of gibberellic acid (GA3) content led to rapid lignification at the later phase of bud development. Our results reveal the mechanism underlying the interaction of apricot bud gall with its parasite and provide reliable information for designing valuable breeding programs. This study will be quite useful for pest management and will provide a comprehensive evaluation of ecology-based cost-effective control, life history and demographic parameters of A. phloeocoptes.