Phenology and Monitoring of the Lesser Chestnut Weevil (<i>Curculio sayi</i>)

With the introduction in recent years of high-yield blight-resistant chestnut varieties, the commercial chestnut industry in the United States is expanding. Accompanying this expansion is a resurgence in a primary pest of chestnut: C. sayi, the lesser chestnut weevil. This weevil damages the nut crop and infestations can surge from 0 to close to 100% in as little as two years. Understanding the dynamics of this pest has been challenging. Most work was conducted in the 1900s and only recently has this weevil garnered renewed interest. Recent work on C. sayi phenology has been completed in Missouri but conflicted with anecdotal reports from northern growers. From 2019 to 2020, we used a combination of trapping and microcosm studies to understand both C. sayi phenology and the means of monitoring this pest. C. sayi populations were univoltine and peaked in mid-October. Pyramid traps were the most effective at capturing adult C. sayi. C. sayi larvae, pupae, eclosed adults, and emerging adults were recovered from microcosm experiments. These results suggest that C. sayi emerges later in the northern US with the potential for a single generation to emerge over multiple subsequent years. Understanding C. sayi phenology along with the means of monitoring forms the basis for effective management and control in commercial chestnut orchards

The Lesser Chestnut Weevil (Curculio sayi): Damage and Management with Biological Control Using Entomopathogenic Fungi and Entomopathogenic Nematodes

The lesser chestnut weevil, Curculio sayi (Gyllenhal), can cause irreparable damage to chestnuts through direct consumption and/or introduction of secondary pathogens. With the resurgence of blight resistant American Chestnut plantings both for commercial production and for habitat restoration, C. sayi has become a similarly resurgence pest. Here, we investigated the nature and extent of C. sayi larval damage on individual nuts and collected harvests with an eye toward the quantifying impacts. Next, we explored management options using biological control including entomopathogenic fungi and entomopathogenic nematodes. Nut damage from C. sayi can be extensive with individual nuts hosting several larvae, larvae emerging from nuts several weeks post harvest, and nut weight loss even after C. sayi have emerged from the nut. Applications of entomopathogenic fungi reduced chances of chestnut infestation, while certain strains of entomopathogenic nematodes increased the probability of C. sayi larval mortality. Understanding C. sayi damage and exploring biological control management options could be a useful tool in the effective management of this resurgent pest

Ecological Impact of American Chestnut Hybrid Restoration on Invertebrate Communities Above- and Belowground

The cross-hybridization of American chestnut (Castanea dentata (Marsh.) Borkh.) with Chinese chestnut (Castanea mollissima Bl.) is a promising strategy for restoring a blight-resistant strain of this keystone species to the Appalachian mountains. To assess the ecological impacts of hybridization on invertebrate communities, we conducted a study across chestnut plots with varying degrees of hybridization (75%, 94%, or 100% American chestnut). Our findings indicate American chestnut hybridization impacted invertebrate communities above- and belowground. Aboveground insect community composition, insect herbivory, gall infestation, and belowground invertebrate diversity were all altered. While some of these differences could be explained by different growth habits or environmental differences, stark differences in Asian chestnut gall wasp infestation (Dryocosmus kuriphilus Yasumatsu.) suggest a genetic component. These results suggest that chestnut hybridization, and particularly expanded restoration efforts using chestnut hybrids, could impact invertebrate communities above- and belowground in addition to pest dynamics. Understanding these effects is crucial for successful chestnut restoration and ecosystem management

Effects of insecticides on CO2 release by entomopathogenic nematodes (Nematoda: Rhabditida) and development of their mutualistic bacteria

El presente estudio tuvo como objetivo evaluar la liberación de CO2 por juveniles infecciosos (JIs) y la viabilidad de bacterias mutualistas de nematodos entomopatógenos (NEP) expuestos a insecticidas sintéticos. Se probaron dos especies de NEP, Heterorhabditis amazonensis JPM4 y Steinernema carpocapsae All. Los insecticidas aplicados fueron Vertimec® (abamectina) y Klorpan® (clorpirifos). Se empleó cromatografía de gases para el análisis de CO2. Se aislaron las bacterias y se evaluó el desarrollo de colonias en placas de Petri estériles. Vertimec® desencadenó una mayor liberación de CO2 por los nematodos, asociado con cambios en su actividad metabólica, que el Klorpan®. Vertimec® y Klorpan® no inhibieron el desarrollo bacteriano.The present study aimed to evaluate the CO2 release by infective juveniles (IJs) and the viability of mutualistic bacteria of entomopathogenic nematodes (EPNs) when exposed to synthetic insecticides. Two species of EPNs, Heterorhabditis amazonensis JPM4 and Steinernema carpocapsae All, were tested. The applied insecticides were Vertimec® (abamectin) and Klorpan® (chlorpyrifos). Gas chromatography was employed for CO2 analysis. The bacteria were isolated and the colony development was evaluated in sterile Petri dishes. Vertimec® triggered greater CO2 release by the nematodes, associated with changes in their metabolic activity, than Klorpan®. Vertimec® and Klorpan® did not inhibit the bacterial development

Efectos de los insecticidas sobre la liberación de CO2 por nematodos entomopatógenos (Nematoda: Rhabditida) y el desarrollo de sus bacterias mutualistas.

El presente estudio tuvo como objetivo evaluar la liberación de CO2 por juveniles infecciosos (JIs) y la viabilidad de bacterias mutualistas de nematodos entomopatógenos (NEP) expuestos a insecticidas sintéticos. Se probaron dos especies de NEP, Heterorhabditis amazonensis JPM4 y Steinernema carpocapsae All. Los insecticidas aplicados fueron Vertimec® (abamectina) y Klorpan® (clorpirifos). Se empleó cromatografía de gases para el análisis de CO2. Se aislaron las bacterias y se evaluó el desarrollo de colonias en placas de Petri estériles. Vertimec® desencadenó una mayor liberación de CO2 por los nematodos, asociado con cambios en su actividad metabólica, que el Klorpan®. Vertimec® y Klorpan® no inhibieron el desarrollo bacteriano

A multi-omics approach to solving problems in plant disease ecology.

The swift rise of omics-approaches allows for investigating microbial diversity and plant-microbe interactions across diverse ecological communities and spatio-temporal scales. The environment, however, is rapidly changing. The introduction of invasive species and the effects of climate change have particular impact on emerging plant diseases and managing current epidemics. It is critical, therefore, to take a holistic approach to understand how and why pathogenesis occurs in order to effectively manage for diseases given the synergies of changing environmental conditions. A multi-omics approach allows for a detailed picture of plant-microbial interactions and can ultimately allow us to build predictive models for how microbes and plants will respond to stress under environmental change. This article is designed as a primer for those interested in integrating -omic approaches into their plant disease research. We review -omics technologies salient to pathology including metabolomics, genomics, metagenomics, volatilomics, and spectranomics, and present cases where multi-omics have been successfully used for plant disease ecology. We then discuss additional limitations and pitfalls to be wary of prior to conducting an integrated research project as well as provide information about promising future directions

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora