Efficacy of synthetic lures for pine bark beetle monitoring

The Scots pine (Pinus sylvestris) plantations in central Europe are currently damaged by a large-scale infestation by bark beetles (Scolytinae). Ips acuminatus and Ips sexdentatus are among the most aggressive species causing infestations of pine trees that are currently simultaneously attacked by Ips typographus. In pine plantations prone to damage, it is therefore necessary to carry out the bark beetle monitoring. One of the used methods is the pheromone bark beetle trapping using synthetic lures. The efficacy of synthetic lures differs. We tested the efficacy of commercially available lures used in the protection of pine trees. In total, we deployed 10 trap series, each consisting of traps with eight different lures and two unbaited traps (controls). Ips acuminatus and I. sexdentatus were most abundantly captured in Pheagr-IAC- and Sexowit-baited traps. Interestingly, the spruce species I. typographus was also captured and most often found in traps with Pheagr-IAC and Erosowit Tube lures. The number of captured beetles was consistent with the gradation phase of bark beetles. Our results suggest the suitability of pheromone traps for bark beetle monitoring. The use of Sexowit can be recommended especially in southwestern Moravia, where I. sexdentatus occurs in high numbers in the long run. In other parts of the Czech Republic, Pheagr-IAC alone can be used with sufficient efficacy. The use of the Erosowit Tube lure is also suitable for I. typographus and I. sexdentatus monitoring.

DNA Barcoding of Scavenging Amphipod Communities at Active and Inactive Hydrothermal Vents in the Indian Ocean

Hydrothermal vent areas have drawn increasing interest since they were discovered in 1977. Because of chemoautotrophic bacteria, they possess high abundances of vent endemic species as well as many non-vent species around the fields. During the survey conducted by the Bundesanstalt für Geowissenschaften und Rohstoffe (Federal Institute for Geosciences and Natural Resources, BGR) to identify inactive polymetallic sulfide deposits along Central and Southeast Indian Ridges, the INDEX project studied the scavenging amphipod community at three newly discovered hydrothermal fields. A sample consisting of 463 representatives of Amphipoda (Malacostraca: Crustacea) was collected by means of baited traps in active and inactive vents of three different sites and subsequently studied by both morphological and genetic methods. Molecular methods included the analysis of two mitochondrial (cytochrome c oxidase subunit I [COI] and 16S rRNA) and one nuclear (18S rRNA) genes. By six delimitation methods, 22 molecular operational taxonomic units (MOTUs) belonging to 12 genera and 10 families were defined. The existence of potential species complexes was noted for the representatives of the genus Paralicella. The inactive site, where 19 species were found, showed higher species richness than did the active one, where only 10 taxa were recorded. Seven genera, Ambasiopsis, Cleonardo, Eurythenes, Parandania, Pseudonesimus, Tectovalopsis, and Valettiopsis, were observed only at inactive sites, whereas Haptocallisoma, was collected exclusively at active ones. The species Abyssorchomene distinctus (Birstein and Vinogradov, 1960), Hirondellea brevicaudata Chevreux, 1910, and Hirondellea guyoti Barnard and Ingram, 1990, have been previously reported from vent sites in the Atlantic or Pacific oceans. The present study provides the first report of Eurythenes magellanicus (H. Milne Edwards, 1848) and five other already described species in the Indian Ocean. The addition of 356 sequences strongly increases the number of amphipod barcodes in reference databases and provides for the first time COI barcodes for Cleonardo neuvillei Chevreux, 1908, Haptocallisoma abyssi (Oldevig, 1959), Hirondellea guyoti, Tectovalopsis fusilus Barnard and Ingram, 1990, and the genera Haptocallisoma, Pseudonesimus, and Valettiopsis.

Variability in mosquito community composition associated with estuarine wetlands in Northern NSW, Australia

The Northern Rivers region of NSW, Australia, is well documented as being impacted by nuisance-biting mosquitoes and mosquito-borne disease. Mosquitoes of greatest concern are those associated with estuarine and brackish water habitats associated with coastal wetlands and understanding the spatial variability in abundance and diversity will assist the assessment of risk and inform surveillance and control programs. Adult mosquito populations were sampled, using carbon dioxide baited traps, at four locations within the Richmond River estuary at Ballina, NSW, Australia, during January and February 2021. Concomitant sampling of habitats for immature mosquitoes was also undertaken. A total of 16,467 mosquitoes was collected at all sites across two sampling periods with the most abundant mosquitoes, Verrallina funerea, Aedes vigilax, and Culex sitiens, those typically associated with estuarine environments. Culex annulirostris, a mosquito associated with freshwater habitats, and Aedes notoscriptus, a mosquito associated with water-holding containers, were also commonly collected. The mosquito communities differed, in relative abundance and species richness, between the four locations. The result highlighted the need for authorities to understand the variability in productivity of potential mosquito habitats, beyond those determinants associated with vegetation communities alone, when assessing suitable locations of mosquito surveillance and integrated mosquito management.

Olean (1,7-dioxaspiro[5.5]undecane): A Novel Intraspecific Chemical Cue in Coraebus undatus (F.) (Coleoptera: Buprestidae)

The main aim of this work was to identify semiochemicals from the jewel beetle Coraebus undatus (F.) (Coleoptera: Buprestidae) that may aid in the improvement of current monitoring tools. First, HS-SPME collections revealed that individually sampled adults (>7 days old) of both sexes release the spiroacetal 1,7-dioxaspiro[5.5]undecane (olean). Electroantennographic recordings from both sexes exposed to increasing amounts of olean followed a dose-dependent pattern, with females being more responsive than males to the highest amount of the compound (100 µg). In double-choice assays, adults older than seven days were significantly attracted to olean, whereas this attraction was not detected in insects aged less than seven days. Indeed, a repellent effect was observed in young females. Subsequent field trials employing sticky purple prism traps revealed that there were no differences among the number of insects caught in control and olean-baited traps at two different release rates (0.75 and 3.75 mg/day). Interestingly, all the trapped specimens were determined as mated females, regardless of the presence of olean. Overall, these findings provide a basis for unraveling the chemical ecology of the species, although further research is still needed to determine the specific role of this compound within the chemical communication of the species.

Effect of Vegetation Types on Sarcophagidae (Diptera) in Ciervo de los Pantanos National Park, a Natural Remnant in a Highly Endangered Landscape

Species diversity can be affected by the structure of vegetation, which may vary in height, density, and distribution of trees, shrubs, and other plant types, configuring different types of habitats. In this study, we evaluated the diversity of sarcosaprophagous Sarcophagidae communities inhabiting the remnant representative habitats protected in Ciervo de los Pantanos National Park: grasslands, forests, and wetlands. We hypothesized that the abundance and diversity of flesh flies would be higher in the grasslands and wetlands than in the forest patches. Samplings were carried out in each habitat type using baited traps during the four seasons in 2015, 2016, and 2019. We collected 585 sarcophagid flies of 17 species. Fifteen species were recorded in grasslands, twelve in the wetlands, and seven in the forests, Tricharaea (Sarcophagula) occidua (Fabricius) (Diptera: Sarcophagidae) being the most abundant (58.3% of the total sample). As expected, the highest abundance was recorded in grasslands whereas the lowest was found in forests. In addition, flesh fly abundance was affected by season. Sarcophagid assemblages differed between habitats and the overall dissimilarity was mainly explained by nestedness. This study provides important information about sarcosaprophagous sarcophagid flies in a little-studied protected natural area in Argentina, which is fundamental for their conservation and useful in forensic investigations.

Efficiency of Different Traps and Baits for Catching Freshwater Prawn Macrobrachium Spp. for Broodstock Development

Catching of wild freshwater prawns in Palawan is done by using different fishing gears, including baited traps. However, there are only limited studies related to the efficiency of these traps on catching freshwater prawns. In this study, the efficiency of four different traps (traditional plastic traps, bamboo traps, modified traps, and rattan traps) and three baits (low-valued fish, grilled coconut, and octopus) was tested in catching live Macrobrachium spp. from the rivers of two localities in the Barangay Bagongbayan, Roxas and Sitio Catama, Dumaran, Palawan at two sampling events with 12-hr intervals along the river bank. Each trap was deployed randomly 5-8 meters apart in the collection site late afternoon and retrieved the following day. The highest catch was obtained using plastic traps with low-value fish as bait. All samples from the different traps were collected alive. Modifications are underway to improve the design of these traps to improve catch efficiency. Regulating the collection of Macrobrachium from the wild by developing it into broodstocks will support the sustainable aquaculture industry using hatchery-produced seedstocks instead of sourcing it from the wild.

Semiochemical baited traps of lepidopteran pests of economic importance can deliver reliable data also on wide range of non-target species: case study in the Hajdúság Region of East Pannonian Lowland (East Hungary)

Lepidopteran assemblages were studied at 16 sampling sites in the Hajdúság Region between 2013 and 2020. Although studies targeted development of synthetic phenylacetaldehyde-based and semi-synthetic isoamyl alcohol-based baits for pest monitoring, traps caught 179 species belonging to the Sphingidae, Thyatiridae, Geometridae, Erebidae and Noctuidae families. Most species were pests or widely distributed generalists, but there were also many rare habitat specialists, for example, silvicol species, whose appearance was unexpected in the recently less forested region. The specificity of the two bait types tested differed notably both on family and subfamily levels. Semi-synthetic baits performed better and attracted a wide range of noctuids belonging mainly to the Xyleninae and Noctuinae subfamilies, while synthetic phenylacetaldehyde-based lures showed specificity to Plusiinae subfamilies with lower number of sampled species. Our data fill a gap of knowledge since the fauna studied formerly was nearly unknown and brings attention to the alternative use of volatile traps of agricultural pests in faunistical studies.

Preferences of fruit-feeding butterfly on bait trap in Soraya Research Station, Leuser Ecosystem, Aceh, Indonesia

Butterflies are insects that live cosmopolitan. Some butterflies in tropical forests look for food sources from sucking the juice of ripe fruits that have fallen on the forest floor. Fruit-feeding butterflies can adapt in finding food sources, selecting and sucking food effectively. Fruit contains varying concentrations of sugar and nitrogen. The existence of fruit-feeding butterflies in tropical rain forests is influenced by the availability and quality of food sources as well as other supporting factors such as temperature, humidity, and light intensity. The purpose of this study was to identify fruit-feeding butterflies and their preferences for banana and pineapple baits in the Soraya Research Station Area, Leuser Ecosystem, Aceh, Indonesia from September to November 2020. Six forest trail locations were selected as trap locations. A total of 360 cylindrical gauze baited traps (80 cm high and 35 cm diameter) were installed on six trails/line transects. Baited traps were set at three different heights, that is at the understorey level (± 0-2 m), midstorey level (± 5-6 m), and overstorey level (± 10-11 m) with a distance of ± 5-10 m. The distance between location points is ± 250 m. The fruit baits used in this trap were ripe bananas and pineapples. The results obtained were 37 species with 176 individuals trapped on banana bait and 50 species with 183 individuals on pineapple bait. However, the results of the t-test using the Man-Whitney test showed no significant difference between the banana and pineapple bait used.

How to Count Bugs: A Method to Estimate the Most Probable Absolute Population Density and Its Statistical Bounds from a Single Trap Catch

Knowledge of insect population density is crucial for establishing management and conservation tactics and evaluating treatment efficacies. Here, we propose a simple and universal method for estimating the most probable absolute population density and its statistical bounds. The method is based on a novel relationship between experimentally measurable characteristics of insect trap systems and the probability to catch an insect located a given distance away from the trap. The generality of the proposed relationship is tested using 10 distinct trapping datasets collected for insects from 5 different orders and using major trapping methods, i.e., chemical-baited traps and light. For all datasets, the relationship faithfully (R=0.91) describes the experiment. The proposed approach will take insect detection and monitoring to a new, rigorously quantitative level. It will improve conservation and management, while driving future basic and applied research in population and chemical ecology.

First record of Spotted-wing drosophila Drosophila suzukii (Diptera: Drosophilidae) in Martín García Island wildlife refuge, Argentina

Here we report on the first peculiar detection of the spotted-winged drosophila, Drosophila suzukii (Matsumura) on Martín García Island, a wildlife refuge located in the Río de la Plata estuary, Argentina. Flies were collected using banana baited traps fermented with live yeast, in sandy areas with abundant presence of cactus in the interior of the island. The absence of cultivated host plants, e.g., fruit crops, and the small population of humans inhabiting the island make the presence of D. suzukii in this wildlife refuge unexpected. Previous detection of this fly in South America happened mostly within commercial fruit orchards and/or neighboring fields.