Sampling environmental DNA from trees and soil to detect cryptic arboreal mammals.

Environmental DNA (eDNA) approaches to monitoring biodiversity in terrestrial environments have largely focused on sampling water bodies, potentially limiting the geographic and taxonomic scope of eDNA investigations. We assessed the performance of two strictly terrestrial eDNA sampling approaches to detect arboreal mammals, a guild with many threatened and poorly studied taxa worldwide, within two central New Jersey (USA) woodlands. We evaluated species detected with metabarcoding using two eDNA collection methods (tree bark vs. soil sampling), and compared the performance of two detection methods (qPCR vs. metabarcoding) within a single species. Our survey, which included 94 sampling events at 21 trees, detected 16 species of mammals, representing over 60% of the diversity expected in the area. More DNA was found for the 8 arboreal versus 8 non-arboreal species detected (mean: 2466 vs. 289 reads/sample). Soil samples revealed a generally similar composition, but a lower diversity, of mammal species. Detection rates for big brown bat were 3.4 × higher for qPCR over metabarcoding, illustrating the enhanced sensitivity of single-species approaches. Our results suggest that sampling eDNA from on and around trees could serve as a useful new monitoring tool for cryptic arboreal mammal communities globally.

Combining surface and soil environmental DNA with artificial cover objects to improve terrestrial reptile survey detection.

Reptiles are increasingly of conservation concern due to their susceptibility to habitat loss, emerging disease, and harvest in the wildlife trade. However, reptile populations are often difficult to monitor given the frequency of crypsis in their life history. This difficulty has left uncertain the conservation status of many species and the efficacy of conservation actions unknown. Environmental DNA (eDNA) surveys consistently elevate the detection rate of species they are designed to monitor, and while their use is promising for terrestrial reptile conservation, successes in developing such surveys have been sparse. We tested the degree to which inclusion of surface and soil eDNA sampling into conventional artificial-cover methods elevates the detection probability of a small, cryptic terrestrial lizard, Scincella lateralis. The eDNA sampling of cover object surfaces with paint rollers elevated per sample detection probabilities for this species 4-16 times compared with visual surveys alone. We readily detected S. lateralis eDNA under cover objects up to 2 weeks after the last visual detection, and at some cover objects where no S. lateralis were visually observed in prior months. With sufficient sampling intensity, eDNA testing of soil under cover objects produced comparable per sample detection probabilities as roller surface methods. Our results suggest that combining eDNA and cover object methods can considerably increase the detection power of reptile monitoring programs, allowing more accurate estimates of population size, detection of temporal and spatial changes in habitat use, and tracking success of restoration efforts. Further research into the deposition and decay rates of reptile eDNA under cover objects, as well as tailored protocols for different species and habitats, is needed to bring the technique into widespread use.

El interés por la conservación de los reptiles es cada vez mayor debido a su susceptibilidad ante la pérdida del hábitat, enfermedades emergentes y la captura para el mercado de fauna. Sin embargo, las poblaciones de reptiles son difíciles de monitorear por lo frecuente que es la cripsis en sus historias de vida. Esta dificultad deja incierto el estado de conservación de muchas especies y desconocida la eficacia de las acciones de conservación. Los censos de ADN ambiental (DNAa) elevan sistemáticamente la tasa de detección de las especies que monitorean, y aunque su uso es prometedor para la conservación de los reptiles terrestres, han sido escasos los éxitos en el desarrollo de dichos censos. Analizamos el grado al que la inclusión del muestreo de DNAa superficial y del suelo a los métodos convencionales de cobertura artificial eleva la probabilidad de detección de una pequeña lagartija terrestre críptica: Scincella lateralis. El muestreo de DNAa de las superficies con cobertura de objetos con rodillos de pintura elevó las probabilidades de detección por muestra para esta especie 4-16 veces más que los censos visuales. Detectamos fácilmente el DNAa de S. lateralis bajo los objetos de cubierta hasta dos semanas después de la última detección visual y en algunos objetos de cubierta en donde no se había observado en los meses previos a S. lateralis. Con suficiente intensidad de muestreo, el análisis de DNAa del suelo bajo objetos de cubierta produjo probabilidades de detección por muestra comparables como métodos de rodillo superficial. Nuestros resultados sugieren que la combinación del DNAa y los métodos de objetos de cobertura puede incrementar considerablemente el poder de detección de los programas de monitoreo de reptiles, lo que permite estimaciones más precisas del tamaño poblacional, detección de los cambios espaciales y temporales en el uso de hábitat y el éxito de rastreo de los esfuerzos de restauración. Además, se necesita la investigación sobre las tasas de depósito y descomposición del DNAa de reptiles bajo objetos de cubierta, así como los protocolos hechos para diferentes especies y hábitats, para que la técnica entre al uso difundido.

Cranberry (Vaccinium macrocarpon) Is a Marginal Host for Brown Marmorated Stink Bug.

The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a well-documented pest of agricultural crops across the globe. However, not all crops are suitable hosts for H. halys, and it is necessary to proactively document the susceptibility of economically important specialty crops, such as cranberry (Vaccinium macrocarpon; Ericaceae), a native fruit crop that contributes millions of dollars to the North American economy. In this study, we tested whether cranberry is a suitable host for H. halys by measuring the development and feeding injury inflicted by H. halys on cranberry fruit and foliage. We found that H. halys nymphs cannot successfully develop on cranberry fruit or foliage alone, but that the fruit are susceptible to adult feeding. On the basis of these findings, cranberry does not seem to be a suitable host to support nymph development, but adult feeding could negatively impact fruit quality. Future research should consider the impacts of adult feeding on fruit quality and how adult abundance in and near agricultural crops might change the risk profile of this pest.

Life History and Damage by Systena frontalis F. (Coleoptera: Chrysomelidae) on Vaccinium macrocarpon Ait.

Pest management of emerging pests can be challenging because very little fundamental knowledge is available to inform management strategies. One such pest, the red-headed flea beetle Systena frontalis (Fabricius) (Coleoptera: Chrysomelidae), is increasingly being identified as a pest of concern in cranberries Vaccinium macrocarpon Aiton (Ericales: Ericaceae). To improve our understanding of this pest and to develop more targeted management programs, we conducted field and laboratory studies to characterize the development, seasonal emergence patterns, and density-dependent plant injury. We found that significantly more flea beetle eggs hatched when exposed to sustained cold treatment between 0 and 5°C for 15 wk than at warmer temperatures, and for shorter and longer cold-period durations. The adults emerged sporadically over the summer, were patchily distributed, fed on both fruit and foliage, and preferentially fed on new plant growth. Using soil cores, we found eggs and larvae located relatively deep (>30 cm) in the soil. These patterns indicate that S. frontalis likely overwinters as eggs, and that targeting the larval stage may be the most effective management approach. Despite the cryptic nature of the larvae, continuing to improve our understanding of this life stage will be critical to optimizing control strategies.

A Codling Moth (Lepidoptera: Tortricidae) Kairomonal Lure Is Marginally Effective at Decreasing Fruit Damage in Apple Trees Outside of Orchard Settings.

Codling moth, Cydia pomonella (L.), is a significant pest of pome fruits and walnuts worldwide. Recently, a three-chemical kairomonal lure, comprised of pear ester, acetic acid, and n-butyl sulfide, was successfully used as an attractant in a mass-trapping scheme to reduce fruit damage in commercial apple orchards. In this study, we tested whether this same attractant could be used outside of an orchard setting to decrease fruit damage in isolated, unmanaged apple (Malus spp.) (Rosales: Rosaceae) trees. Traps containing the lures were placed in trees before the first codling moth flight and maintained throughout the summer. We found that while the traps statistically reduced the percent of apples damaged near the trap, the effect was smaller than expected and limited to areas near the trap. It is currently unclear, but site-specific effects (e.g., host type, apple density, codling moth source) may be important factors in the efficacy of management tools in these systems. While kairomone-based trapping could be a practical and feasible management tool in individual trees outside of orchards, more work needs to be done to understand the limitations of this method.

Vertical and temporal distribution of spotted-wing drosophila (Drosophila suzukii) and pollinators within cultivated raspberries.

BACKGROUND: Drosophila suzukii (Diptera: Drosophilidae) is the most prominent arthropod pest of caneberries. Current management practices rely on chemical control, which has raised concerns over the sustainability of this approach. We currently understand little about D. suzukii activity, and whether activity patterns can be exploited to improve management. In this study, we investigated the vertical and temporal distribution of D. suzukii, as well as pollinators, in cultivated raspberries. RESULTS: D. suzukii were generally crepuscular, and most active in the morning within the bottom half of the crop, and in the evening within the top half of the crop. Pollinators were most active during the day and within the top half of the canopy. Humidity and temperature were correlated with insect activity. CONCLUSION: Pesticides applied during twilight that ensure coverage in the bottom half of the crop, or if applied in the late afternoon cover the entire crop, should improve the pesticide efficacy. However, previous studies suggest that specific D. suzukii (e.g. sex, mating status, age) may exploit different areas in the crop at different times, and more work needs to be done to understand how these aspects before a specific management program can be recommended. © 2019 Society of Chemical Industry.

Mass-Trapping Codling Moth, Cydia pomonella (Lepidopteran: Torticidae), Using a Kairomone Lure Reduces Fruit Damage in Commercial Apple Orchards.

Codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) is a major pest of pome fruits worldwide. Fruit is damaged by larval feeding, and numbers of larvae are directly related to the numbers of females in the preceding generation. In Pacific Northwest, apple orchards, C. pomonella are generally managed with insecticides and mating disruption. However, additional control methods are needed when these treatments fail or are undesirable. Using a three-component kairomone lure that attracts both sexes, we mass-trapped C. pomonella in 4-acre plots located within commercial apple orchards. In all cases, there were smaller increases in fruit infestation in the mass-trapped plots than in the corresponding control plots. This relative decrease in fruit infestation in the mass-trapped plots corresponded with the removal of more male and female C. pomonella. Mass-trapping using this lure has potential to be a novel and promising addition to integrated pest management of C. pomonella.

Multistate Comparison of Attractants and the Impact of Fruit Development Stage on Trapping Drosophila suzukii (Diptera: Drosophilidae) in Raspberry and Blueberry.

Spotted-wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), is an invasive pest of soft-skinned fruits across the globe. Effective monitoring is necessary to manage this pest, but suitable attractants are still being identified. In this study, we combined lures with fermenting liquid baits to improve D. suzukii trapping specificity and attractiveness. We also measured the efficiency and specificity of baits/lures during different times of the season; the reproductive status of females among baits/lures; and the effects of locations and crop type on these response variables. We developed a metric that combined mating status and fat content to determine differences in types of females attracted. Lures utilizing yeast and sugar-based volatiles trapped the most D. suzukii. The addition of a commercial lure to yeast and sugar-based lures increased catches in most locations, but was also the least specific to D. suzukii. Apple juice-based chemical lures tended to be most specific to D. suzukii, while lures comprised of a singular attractant tended to trap more D. suzukii with a higher reproductive potential than combinations of attractants. Trap catch and lure specificity was lower during fruit development than fruit ripening. While catch amounts varied by geographic location and crop type, attractants performed similarly relative to each other in each location and crop. Based on the metrics in this study, the yeast and sugar-based attractants were the most effective lures. However, further work is needed to improve early season monitoring, elucidate the effects of physiological status on bait attraction, and understand how abiotic factors influence bait attraction.

Field Experiment of a Three-Chemical Controlled-Release Dispensers to Attract Codling Moth (Cydia pomonella) (Lepidoptera: Tortricidae).

Male and female codling moths, Cydia pomonella (Lepidoptera: Tortricidae), were shown to be attracted to a three-chemical kairomonal lure consisting of pear ester, acetic acid, and n-butyl sulfide. A controlled-release device based on sachets was developed in the laboratory and field tested to optimize the attractiveness of C. pomonella to this combination of attractants, and to decrease material costs associated with the controlled-release of these chemicals. The lure was most effective when pear ester was released from a separate dispenser than when combined acetic acid and n-butyl sulfide. We found that acetic acid and n-butyl sulfide can be combined into one device without decreasing C. pomonella trap catches and that there is minimal pear release rate before trap catch is negatively affected. A sachet-based controlled-release system of pear ester, acetic acid, n-butyl sulfide is a cost-effective alternative to a vial and septa controlled-release system and allows for easier quantification of ideal release rates. A reduction in material costs associated with management are important in promoting the adoption of attract-and-kill and mass-trapping paradigms for C. pomonella management. These findings also have important consequences in interpreting studies that use different loads of pear ester, and emphasize the need to better understand the release rates of attractants.

Isolating Spermathecae and Determining Mating Status of Drosophila suzukii: A Protocol for Tissue Dissection and Its Applications.

The spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), is an emerging invasive pest, which attacks a wide variety of fruits and berries. Although previous studies have focused on different aspects of D. suzukii reproductive biology, there are no protocols available for determining the mating status of D. suzukii females and drosophilids in general. In this study, a step-by-step protocol for tissue dissection, isolating spermathecae, and determining the mating status of females was developed specifically for D. suzukii. This protocol is an effective and relatively quick method for determining female mating status. It has important applications from exploring reproductive output of D. suzukii females to understanding the biology of D. suzukii winter morph, which presumably plays the main role in the overwintering of this invasive species. We demonstrated applicability of this protocol for both field collected flies and flies reared in the lab, including fly specimens stored on a long-term basis.

Methylation of chloroplast DNA does not affect viability and maternal inheritance in tobacco and may provide a strategy towards transgene containment.

We report the integration of a type II restriction-methylase, mFokI, into the tobacco chloroplast genome and we demonstrate that the introduced enzyme effectively directs the methylation of its target sequence in vivo and does not affect maternal inheritance. We further report the transformation of tobacco with an E. coli dcm methylase targeted to plastids and we demonstrate efficient cytosine methylation of the plastid genome. Both adenosine methylation of FokI sites and cytosine methylation of dcm sites appeared phenotypically neutral. The ability to tolerate such plastid genome methylation is a pre-requisite for a proposed plant transgene containment system. In such a system, a chloroplast located, maternally inherited restriction methylase would provide protection from a nuclear-encoded, plastid targeted restriction endonuclease. As plastids are not paternally inherited in most crop species, pollen from such plants would carry the endonuclease transgene but not the corresponding methylase; the consequence of this should be containment of all nuclear transgenes, as pollination will only be viable in crosses to the appropriate transplastomic maternal background.

Left versus right nipple preference in free-ranging infant rhesus macaques (Macaca mulatta).

The examination of nonhuman primate (NHP) lateralized behaviors may provide insight into the evolution of hemispheric specialization. This study examined nipple preference in 64 infant macaques in order to consider the ontogeny of lateralized behavior. We used a focal animal sampling method to record nipple contact during 15, 30-min observation sessions collected across each infant's first year of life. Using a lateralized behavior index (LBI) we calculated individual and population preferences (LBI=(R-L)/(R+L); "R"=mean right nipple contact, "L"=mean left nipple contact). Strength of preference was calculated as the absolute value of this score. Infants exhibited no population preference for a particular nipple, but showed a significant strength of preference that developed after 48 hr. Interestingly, successive siblings preferred the nipple not used by the previous infant. These findings suggest that nipple preference is guided by external stimuli, and that nipple preference during infancy may not be a behavioral representation of hemispheric specialization.