Assessing New Tools for Management of the Pepper Weevil (Coleoptera: Curculionidae) in Greenhouse and Field Pepper Crops.

The pepper weevil, Anthonomus eugenii Cano, is an economically important pest of field and greenhouse pepper crops in North America. In this study, a series of insecticides covering a broad-spectrum of insecticidal modes of action were assessed for their potential in managing the pepper weevil under laboratory and greenhouse conditions. To accomplish this, laboratory mini-spray tower and greenhouse cage trials were conducted that evaluated the efficacy of 16 conventional, reduced-risk, and microbial insecticides. In laboratory trials, adult weevils were sprayed with insecticides, placed on treated leaves within a cup cage, and were monitored for their survival over 10 d. Of the 16 insecticides tested, 8 provided greater than 60% weevil control, a threshold considered necessary for including products in further greenhouse testing. In greenhouse trials, adult weevil mortality, bud and foliar damage, bud and fruit abortion, and subsequent weevil offspring emergence were measured following each of three weekly insecticide applications. The most efficacious insecticides included kaolin clay and mineral oil, which performed as well as the thiamethoxam-positive control, and incurred 70 and 55% of adult weevil mortality, respectively. Additionally, kaolin clay and mineral oil reduced offspring weevil emergence by 59 and 54%, respectively, compared with untreated controls. Despite the clear challenge that controlling this pest represents, this study has identified useful new tools for the integrated management of the pepper weevil, which may accelerate the rate at which these become available for use in greenhouse and field pepper production.

Comparison of Transeius montdorensis (Acari: Phytoseiidae) to Other Phytoseiid Mites for the Short-Season Suppression of Western Flower Thrips, Frankliniella occidentalis (Thysanoptera: Thripidae).

Under winter and early spring greenhouse growing conditions, suppression of thrips by predatory mites can vary considerably on a species basis. For certain mite species, shorter photoperiods, cooler temperatures, and lower vapor pressures translate to reductions in predation, oviposition, and survival. Therefore, predator species need to be assessed simultaneously to identify those most suitable for use under short-season conditions. In this study, laboratory trials were first conducted to compare rates of Frankliniella occidentalis (Pergande) thrips predation, and oviposition by the phytoseiid predator Transeius montdorensis (Schicha) under simulated summer and winter conditions. Transeius montdorensis consumed similar numbers of first instar thrips, and laid a similar number of eggs under both conditions. In short-season greenhouse cage trials, crop establishment and predatory capacity of T. montdorensis were compared to those for three other predatory mites: Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae), Amblydromalus limonicus (Garman & McGregor) (Acari: Phytoseiidae) and Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae). Over 4-5-wk trials performed in early spring in 2014 and 2016, the number of T. montdorensis mites on pepper plants was either equal or greater to levels in other treatments. In T. montdorensis cages, high levels of thrips suppression were observed, equal to those achieved by A. swirskii or A. limonicus treatments in the 2016 trial, and superior to those by N. cucumeris in both trial years. These findings show that T. montdorensis is a good thrips predator, and provides rationale for the development of this species as a new agent for greenhouse pest management in an expanded temperate area of the world.

The function of supplemental foods for improved crop establishment of generalist predators Orius insidiosus and Dicyphus hesperus.

As with many biological control agents, generalist predators rarely survive prolonged periods of prey scarcity. Towards improving crop establishment of two major predators used in North America, Orius insidiosus and Dicyphus hesperus, this study examined the role of supplemental foods in achieving greater predator survival and faster development. In controlled environment trials, developmental time and survival were compared for predators offered diets including Ephestia eggs, Artemia cysts, Typha pollen, or combinations of these. Nymphal developmental time was significantly shorter and survival greater for both predators reared on diets that included Ephestia eggs. Interestingly, D. hesperus could successfully complete nymphal development on Artemia cysts whereas O. insidiosus could not, alluding to fundamental physiological differences between these predators. In greenhouse assays, D. hesperus was more abundant after six weeks when offered diets that included Ephestia eggs either alone or in combination with pollen or Artemia cysts relative to other diets. In contrast, only diets of Ephestia eggs, Typha pollen or their combination could significantly increase O. insidiosus crop abundance relative to the unfed control. Together, this work highlights important differences in the relative values of supplemental foods for generalist predators used in crop protection. It is also meaningful in guiding biocontrol practitioners globally in the rapidly growing sector of greenhouse vegetable production.

Histone lysine demethylase (KDM) subfamily 4: structures, functions and therapeutic potential.

KDM4 histone demethylases catalyze the removal of methyl marks from histone lysine residues to epigenetically regulate chromatin structure and gene expression. KDM4 expression is tightly regulated to insure proper function in diverse biological processes, such as cellular differentiation. Mounting evidence has shown that disrupting KDM4 expression is implicated in the establishment and progression of multiple diseases including cancer. In particular, genomic regions encoding the KDM4A, B and C genes are often amplified, disrupting normal cellular proliferation. Furthermore, KDM4 demethylases are promising druggable targets. In this review, we highlight the latest advances in characterizing the structures and regulatory mechanisms of KDM4 proteins, as well as our current understanding of their alterations and roles in tumorigenesis. We also review the reported KDM4 inhibitors and discuss their potential as therapeutic agents.

A comparative transcriptomic analysis reveals conserved features of stem cell pluripotency in planarians and mammals.

Many long-lived species of animals require the function of adult stem cells throughout their lives. However, the transcriptomes of stem cells in invertebrates and vertebrates have not been compared, and consequently, ancestral regulatory circuits that control stem cell populations remain poorly defined. In this study, we have used data from high-throughput RNA sequencing to compare the transcriptomes of pluripotent adult stem cells from planarians with the transcriptomes of human and mouse pluripotent embryonic stem cells. From a stringently defined set of 4,432 orthologs shared between planarians, mice and humans, we identified 123 conserved genes that are ≥5-fold differentially expressed in stem cells from all three species. Guided by this gene set, we used RNAi screening in adult planarians to discover novel stem cell regulators, which we found to affect the stem cell-associated functions of tissue homeostasis, regeneration, and stem cell maintenance. Examples of genes that disrupted these processes included the orthologs of TBL3, PSD12, TTC27, and RACK1. From these analyses, we concluded that by comparing stem cell transcriptomes from diverse species, it is possible to uncover conserved factors that function in stem cell biology. These results provide insights into which genes comprised the ancestral circuitry underlying the control of stem cell self-renewal and pluripotency.