Stephanie J. Swenson

We revise the Neotropical xanthopygine rove beetle genus Plociopterus and provide illustrated keys, distribution maps and illustration of morphological features for all 34 species. We designate two species groups, the fetialis and the venustus species groups, and we discuss the evolution of elaborate secondary sexual structures in the venustus species group. We describe 12 species as new: P. ashei Chatzimanolis & Swenson new species, Plociopterus atrypos Chatzimanolis & Swenson new species, P. campbelli Chatzimanolis & Swenson new species, P. dactylos Chatzimanolis & Swenson new species, P. dichalotos Chatzimanolis & Swenson new species, P. diploportokalis Chatzimanolis & Swenson new species, P. kolasmenos Chatzimanolis & Swenson new species, P. mesanychtos Chatzimanolis & Swenson new species, P. polychromos Chatzimanolis & Swenson new species, P. portokalenios Chatzimanolis & Swenson new species, P. syngenevon Chatzimanolis & Swenson new species, P. triploportokalis Chatzimanolis & Swenson new species. Plociopterus dimidiatus Sharp is placed into synonymy with Staphylinus scenicus Erichson, new synonymy; P. forsteri Scheerpeltz is placed into synonymy with P. zischkai Scheerpeltz, new synonymy; P. mollis Sharp is placed into synonymy with P. lugubris Sharp, new synonymy; P. miriventris Bernhauer is placed into synonymy with P. laetus Sharp, new synonymy; P. traili Sharp is placed into synonymy with P. ventralis Sharp, new synonymy; and P. virgineus Sharp is placed into synonymy with S. venustus Erichson, new synonymy. We designate neotypes for P. brasilianus Bernhauer, P. chlorocephalus Bernhauer, and P. jelskii Solsky. We designate lectotypes for P. collaris Sharp, P. columbinus Bernhauer, P. forsteri Scheerpeltz, P. histrio Sharp, P. laetus Sharp, P. lugubris Sharp, P. mirandus Sharp, P. tricolor Sharp, P. varipes, P. ventralis, P. zischkai Scheerpeltz, S. comptus Erichson, S. fetialis Erichson, S. ornatus Erichson, S. scenicus, and S. venustus Erichson.

The decline of insect abundance and richness has been documented for decades and has received increased attention in recent years. In 2017, a study by Hallmann and colleagues on insect biomasses in German nature protected areas received a great deal of attention and provided the impetus for the creation of the project Diversity of Insects in Nature protected Areas (DINA). The aim of DINA was to investigate possible causes for the decline of insects in nature protected areas throughout Germany and to develop strategies for managing the problem.A major issue for the protection of insects is the lack of insect-specific regulations for nature protected areas and the lack of a risk assessment and verification of the measures applied. Most nature protected areas border on or enclose agricultural land and are structured in a mosaic, resulting in an abundance of small and narrow areas. This leads to fragmentation or even loss of endangered habitats and thus threaten biodiversity. In addition, the impact of agricultural practices, especially pesticides and fertilisers, leads to the degradation of biodiversity at the boundaries of nature protected areas, reducing their effective size. All affected stakeholders need to be involved in solving these threats by working on joint solutions. Furthermore, agriculture in and around nature protected areas must act to promote biodiversity and utilise and develop methods that reverse the current trend. This also requires subsidies from the state to ensure economic sustainability and promote biodiversity-promoting practices.

Caraway (Carum carvi L.) is a crop species that is gaining in importance in Europe, especially as a condiment and medicinal plant. Here, we present the plant–pollinator network of caraway in a central European agricultural landscape, focusing on two diverse potential pollinator taxa, Diptera: Brachycera (= true flies) and Hymenoptera (sawflies, bees, and wasps). We specifically studied qualitative differences in interactions between the two insect taxa as well as the intraday and intraseasonal variability of the network. Insect and pollen plant species determination was done via morphological identification and DNA (meta)barcoding. In total, 121 species representing 33 families of Hymenoptera and Brachycera were found to carry caraway pollen. These taxa included many nonhoneybee and nonhoverfly species, showing a wide taxonomic breadth of potential pollinators and a higher network complexity than previously anticipated. There are distinct qualitative differences between Brachycera and Hymenoptera networks, suggesting complementary roles of both taxa in the pollination of native and crop plants. Strong intraday differences in potential pollinator diversity make it necessary to collect insects and pollen at different times of the day to compile complete plant–pollinator networks. Intraseasonal analyses of the plant–pollinator network of caraway show the potential of caraway as an important food source for insect species with an activity peak in late summer.

In recent years, the decline of insect biodiversity and the imminent loss of provided ecosystem functions and services has received public attention and raised the demand for political action. The complex, multi-causal contributors to insect decline require a broad interdisciplinary and cross-sectoral approach that addresses ecological and social aspects to find sustainable solutions. The project Diversity of Insects in Nature protected Areas (DINA) assesses insect communities in 21 nature reserves in Germany, and considers interactions with plant diversity, pesticide exposure, spatial and climatic factors. The nature reserves border on agricultural land, to investigate impacts on insect diversity. Part of the project is to obtain scientific data from Malaise traps and their surroundings, while another part involves relevant stakeholders to identify opportunities and obstacles to insect diversity conservation. Our results indicate a positive association between insect richness and biomass. Insect richness was negatively related to the number of stationary pesticides (soil and vegetation), pesticides measured in ethanol, the amount of area in agricultural production, and precipitation. Our qualitative survey along with stakeholder interviews show that there is general support for insect conservation, while at the same time the stakeholders expressed the need for more information and data on insect biodiversity, as well as flexible policy options. We conclude that conservation management for insects in protected areas should consider a wider landscape. Local targets of conservation management will have to integrate different stakeholder perspectives. Scientifically informed stakeholder dialogues can mediate conflicts of interests, knowledge, and values to develop mutual conservation scenarios.

The worldwide rapid declines in insect and plant abundance and diversity that have occurred in the past decades have gained public attention and demand for political actions to counteract these declines are growing. Rapid large-scale biomonitoring can aid in observing these changes and provide information for decisions for land management and species protection. Malaise traps have long been used for insect sampling and when insects are captured in these traps, they carry traces of plants they have visited on the body surface or as digested food material in the gut contents. Metabarcoding offers a promising method for identifying these plant traces, providing insight into the plants with which insects are directly interacting at a given time. To test the efficacy of DNA metabarcoding with these sample types, 79 samples from 21 sites across Germany were analysed with the ITS2 barcode. This study, to our knowledge, is the first examination of metabarcoding plant DNA traces from Malaise trap samples. Here, we report on the feasibility of sequencing these sample types, analysis of the resulting taxa, the usage of cultivated plants by insects near nature conservancy areas and the detection of rare and neophyte species. Due to the frequency of contamination and false positive reads, isolation and PCR negative controls should be used in every reaction. Metabarcoding has advantages in efficiency and resolution over microscopic identification of pollen and is the only possible identification method for the other plant traces from Malaise traps and could provide a broad utility for future studies of plant-insect interactions.

We surveyed the insect fauna associated with Urophora cardui L. (Diptera: Tephritidae) galls on Canada thistle, Cirsium arvense L. (Asterales, Asteraceae), in parts of the northern Great Plains, U.S., by field-collecting galls and rearing or dissecting out the insects. We also examined the relationships between gall biomass and insect density and biomass. Urophora cardui were widespread, and the gall biomass was positively correlated with fly density and fly biomass. We recovered Isohydnocera tabida (LeConte) (Coleoptera: Cleridae) from galls in two counties, which represents a new host record and provides vital information on the little-known immatures of this predatory species. Pteromalus elevatus (Walker) (Hymenoptera: Pteromalidae) was the dominant parasitoid that emerged from the U. cardui galls. Individual galls typically only had one insect species, and occasionally both U. cardui and P. elevatus were present, but it was rare for other insects to be present in galls housing I. tabida. This study adds to the taxonomic literature of gall-inhabiting insect species and provides new information on the predators of U. cardui, specifically a little-known clerid beetle species.

The declines observed in insect abundance and diversity in the past decades has also been observed in plants, and these events are most certainly correlated. Rapid largescale biomonitoring of both plants and insects can help monitor these changes and inform decisions for land management and species protection. Malaise traps have been used for nearly 80 years for passive insect sampling of primarily flying insects, and when they enter these traps, they carry the fragments of the plants they have visited, either as plant fragments and pollen on the body surface, or as digested food material in gut contents. DNA metabarcoding is a potential method to identify these plant traces in the ethanol of the malaise bottles, which is not possible with traditional microscopy. Metabarcoding could offer more insight into what plants insects are directly interacting with at a given time, and allow for the detection of rare plants, and neophyte species visited by insects. This study, to our knowledge, is the first examination of DNA metabarcoding plant traces from Malaise trap samples, we examine 105 samples from 21 sites throughout Germany collected in a 2-week period in May of 2020. Here we report on the feasibility of sequencing these sample types, analysis of the resulting taxa, the usage of cultivated plants by insects near nature conservancy areas, and the detection of rare and neophyte species.

Landscape diversification with flowering plants can benefit pollinators and natural enemies, although insect pests can also use floral resources for nutrition and chemoprotection. Corn rootworms (Coleoptera: Chrysomelidae, Diabrotica spp.) are major pests of corn (Zea mays L.), and while subterranean larvae primarily feed on corn roots, adult rootworms commonly consume floral resources from other plant species. We quantified the species, density, and sex of adult corn Diabroticite rootworm beetles on wild and cultivated sunflower, corn, and squash, quantified pollen within the bodies of adult northern corn rootworms [NCR, D. barberi (Smith & Lawrence)], and investigated how consumption of sunflower and corn pollen by NCR adults impacted predation of their eggs by two soil-dwelling mites with different feeding specialization. NCR were the most common Diabroticite species on sunflower inflorescences and western corn rootworm (WCR, D. v. virgifera LeConte) were more abundant in corn and squash blossoms. Pollen feeding by NCR adults did not impact egg predation by omnivorous Tyrophagus putrescentiae (Schrank) (Acari: Sarcoptiformes, Acaridae), but predatory Stratiolaelaps scimitus (Womersley) (Acari: Mesostigmata, Laelapidae) ate eggs less frequently and took longer to feed on eggs from NCR females that had fed on sunflower pollen. This research suggests pollen feeding by adult NCR can impact predation of their eggs. While increasing plant diversity can benefit natural enemies and pest control within agroecosystems, it is important to consider how floral resources alter dietary preferences of biocontrol agents.

Insect declines and biodiversity loss have attracted much attention in recent years, but lack of comprehensive data, conflicting interests among stakeholders and insufficient policy guidance hinder progress in preserving biodiversity. The project DINA (Diversity of Insects in Nature protected Areas) investigates insect communities in 21 nature reserves in Germany. All selected conservation sites border arable land, with agricultural practices assumed to influence insect populations. We taught citizen scientists how to manage Malaise traps for insect collection, and subsequently used a DNA metabarcoding approach for species identification. Vegetation surveys, plant metabarcoding as well as geospatial and ecotoxicological analyses will help to unravel contributing factors for the deterioration of insect communities. As a pioneering research project in this field, DINA includes a transdisciplinary dialogue involving relevant stakeholders such as local authorities, policymakers, and farmers, which aims at a shared understanding of conservation goals and action pathways. Stakeholder engagement combined with scientific results will support the development of sound policy recommendations to improve legal frameworks, landscape planning, land use, and conservation strategies. With this transdisciplinary approach, we aim to provide the background knowledge to implement policy strategies that will halt further decline of insects in German protected areas.

Pollen metabarcoding has received much attention recently for its potential to increase taxonomic resolution of the identifications of pollen grains necessary for various public health, ecological and environmental inquiry. However, methodologies implemented are widely varied across studies confounding comparisons and casting uncertainty on the reliability of results. In this study, we investigated part of the methodology, the effects of level of exine rupture and lysis incubation time, on the performance of DNA extraction and Illumina sequencing. We examined 15 species of plants from 12 families with pollen that varies in size, shape, and aperture number to evaluate effort necessary for exine rupture. Then created mock communities of 14 of the species from DNA extractions at 4 levels of exine rupture (0, 33, 67, and 100%) and two levels of increased lysis incubation time without exine rupture (2 or 24 hours). Quantities of these DNA extractions displayed a positive correlation between increased rupture and DNA yield, however increasing time of lysis incubation was associated with decreased DNA yield. Illumina sequencing was performed with these artificial community treatments with three common plant DNA barcode regions (rbcL, ITS1, ITS2) with two different primer pairings for ITS2 andrbcL. We found decreased performance in treatments with 0% or 100% exine rupture compared to 33% and 67% rupture, based on deviation from expected proportions and species retrieval, and increased lysis incubation was found to be detrimental to results.