Brown marmorated stink bug overwintering aggregations are not regulated through vibrational signals during autumn dispersal

The brown marmorated stink bug, Halyomorpha halys (Heteroptera: Pentatomidae), is regarded as one of the world's most pernicious invasive pest species, as it feeds on a wide range of economically important crops. During the autumn dispersal period, H. halys ultimately moves to potential overwintering sites, such as human-made structures or trees where it will alight and seek out a final overwintering location, often aggregating with other adults. The cues used during this process are unknown, but may involve vibrational signals. We evaluated whether vibrational signals regulate cluster aggregation in H. haly s in overwintering site selection. We collected acoustic data for six weeks during the autumn dispersal period and used it to quantify movement and detect vibrational communication of individuals colonizing overwintering shelters. Both movement and vibrational signal production increased after the second week, reaching their maxima in week four, before decaying again. We found that only males produced vibrations in this context, yet there was no correlation between movement and vibrational signals , which was confirmed through playback experiments. The cues regulating the formation of aggregations remain largely unknown, but vibrations may indicate group size.

Lipid and protein utilization during lecithotrophic development in the asteroid Stegnaster inflatus, with a review of larval provisioning in lecithotrophic echinoderms

The eggs of echinoderms with lecithotrophic development provide structural and nutritional materials (lipids, proteins) to complete development without any external sources of nutrition. Previous studies have suggested that a relatively large proportion of the maternal lipid reserves remain after settlement to provision the early post-metamorphic juvenile. Here we examined lipid and protein utilization during lecithotrophic development of the asterinid starfish Stegnaster inflatus which has large (~400 µm diameter), negatively buoyant eggs. S. inflatus produces eggs with a large amount of lipid (mean ± SD: 2047 ± 315 ng egg-1), with 26% structural lipids and 74% energetic lipids dominated by diacylglycerol ether (DAGE; 66%). Similar amounts of protein were present in the egg (mean ± SD: 2143 ± 157 ng egg-1), with a lipid:protein ratio of 0.96. Approximately 80% of the egg protein is used prior to settlement. In contrast, 51.0% of the energetic lipids provided in the egg, and 40.3% of the DAGE remain for provisioning of the early juvenile. A review of lecithotrophic development in echinoderms reveals that asteroid, echinoid and ophiuroid species have an excess of 50% of the maternal lipids remaining in the settled post-larva. When considering maternal investment in offspring for lecithotrophic developers, we need to consider energetic use during the short dispersal period, as well as provisioning for post-metamorphic early juvenile life.

DISPERSAL PATTERN OF CORAL LARVAE IN KUANTAN COASTAL WATERS, MALAYSIA

Understanding source and sink pattern of coral larvae is among the key elements for effective ecosystem management and future habitat restoration. This study examined dispersal pattern of coral larvae among three known inshore reefs (Pulau Ular, Balok Reef and Raja Muda reef) in Kuantan coastal waters by simulating virtual larvae trajectories during spawning event in 2018. Dispersal pathways were modelled and constructed by incorporating biological traits (timing of spawning and pelagic larvae duration) using Langragian particle tracking module integrated with 2-dimensional, hydrodynamic, flexible network model (MIKE 21 FM). Results indicated that Acroporid larvae moved in southward direction throughout dispersal period. Source and sink dynamic suggested that Pulau Ular has high larvae retention (70%) in which most of larvae originated from natal reef. Balok reef was dominant source of larvae for Raja Muda reef. Results also indicated that patches reefs near Raja Muda was ideal sink site for coral larvae and should be prioritized for future ecosystem management action.

Integrating Kaolin Clay for Ambrosia Beetle Management in Ornamental Crops of Eastern Redbud

Invasive ambrosia beetles (Coleoptera: Curculionidae) are an important pest problem at ornamental tree nurseries. Available chemical treatments are not completely effective and, due to the length of the beetle dispersal period and insecticide breakdown, repeated treatments can become costly in terms of application expense and nontarget impacts. Additional options are needed to reduce application frequency and to provide an acceptable level of crop protection. Four treatments were tested using ethanol-injected eastern redbud trees at research sites in Mississippi (MS) and Tennessee (TN) over 2 years (2014–15), with the number of new ambrosia beetle galleries compared over time on 1) nontreated control trees, 2) kaolin-treated trees, 3) bifenthrin-treated trees, and 4) kaolin + bifenthrin (k + b)-treated trees. Kaolin-treated trees rapidly lost their coating after rain events and, at 6 days after treatment (DAT) in TN, no differences were detected in the number of beetle galleries between kaolin and nontreated control trees. Kaolin + bifenthrin-treated trees appeared to retain treatment residue longer, but were not better-protected than bifenthrin-treated trees at any time. Further research is needed to determine whether an adjuvant, such as a surfactant, spreader, or sticker, may enhance the modest impact offered by kaolin in our test, or if a reduction in rates of bifenthrin may be allowable.

Survival rate and mortality of juvenile and immature eastern imperial eagles (Aquila heliaca) from Bulgaria studied by satellite telemetry

A long-living species like A. heliaca has a natal dispersal period lasting several years. This period is crucial for the survival and conservation of the eagles. In this study we present mortality factors and the survival rate of juvenile and immature A. heliaca from Bulgaria as established by satellite telemetry. A total of 20 juvenile A. heliaca were fitted with GPS/Argos transmitters in their nests in Bulgaria. Fourteen birds were tracked till their death and the bodies were found. Tracking allows the survival rate of juvenile and immature A. heliaca to be estimated for the first time. It is 59.1% for the first calendar year, 83.3% for the second calendar year and 80.0% for the third calendar year. The main mortality factor for juvenile and immature A. heliaca from the Bulgarian population is electrocution, which caused 59.0% of the mortality cases. Other threats identified are shooting, poisoning and collisions. Most of the fatalities of these tracked eagles occurred in Bulgaria (50%) and Turkey (43%). Thus, Turkey is a key country for conservation of the Bulgarian population ofA. heliaca during its dispersal period. Eagles from Bulgaria have been recorded dispersing further south, to Sudan and Saudi Arabia. Conservation efforts are needed both inside and outside Bulgaria in order to reduce mortality. International collaboration and the exchange of experiences should be part of any conservation strategy or plans focused on the eastern imperial eagle.

Relationship between vegetation structure and abundance of Great-spotted Woodpeckers (Dendrocopos major) in a mosaic habitat

This study was made in a postglacial relic bog in the Ócsa Protected Landscape Area in Hungary. Secondary succession of vegetation began after peat extraction and a grove-like forest evolved. Among the eight woodpecker species that occur in this area, the Great-spotted Woodpecker is the most abundant with the largest amount of data, it is for this reason we chose this species to study. The aims of this work were to detect changes in the abundance of the study species in relation to forest succession; to examine the seasonal patterns of these changes in abundance, and to identify any relationship between the height of the trees near the nets and the number of captured birds. We used the data from 1411 mist-netted Great-spotted Woodpeckers (1984- 2010), which were captured at the Ócsa Bird Ringing Station (120 standard mist nets). The assessment of forest succession rates were based on aerial photos (1979-2010). We measured the height of the vegetation, at 12 points, near each 12 m long net. Population growth of Great-spotted Woodpeckers was significantly correlated with the rate of afforestation. The majority of birds occurred only during the dispersal period. The pattern of the captures correlated well with the vegetation structure, not just with height, but also with vegetation quality as well

Habitat selection, philopatry and spatial segregation in rural Irish hedgehogs (Erinaceus europaeus)

As a non-territorial species with no known dispersal period, there are no obvious factors that regulate hedgehog numbers in an area. This study aimed to examine these factors and involved the radio-tracking of rural hedgehogs over a 3-year period. Males had a significantly larger mean annual home range (56 ha) than females (16.5 ha), which was at its maximum during the breeding season. Outside of the breeding season, the home range was relatively small (4–5 ha) in both sexes. The home ranges of males completely overlapped both each other and all of the females. In contrast, females occupied more exclusive areas with little overlap between one another. On a nightly basis, both sexes occupied spatially independent areas with little overlap. Compositional analysis of the data showed that habitats were not used in proportion to their availability but were selected, and this changed seasonally, with the highest preference being for garden and arable land. Hedgehogs tagged for consecutive years exhibited site philopatry and followed the same pattern of habitat selection annually. It is suggested that the spatial separation observed amongst individual hedgehogs could restrict numbers in an area and that female numbers reach a carrying capacity before that of males.

Habitat features of settlement areas used by floaters of Bonelli’s and Golden Eagles

SummaryBonelli’s Eagle Hieraaetus fasciatus and Golden Eagle Aquila chrysaetos are two declining species, in which floaters tend to be located outside of breeding territories during the dispersal period, in so-called settlement areas. We studied settlement areas for both these long-lived raptors in the southern Iberian Peninsula, to gain a better understanding of the ecological requirements of the eagles during their long pre-adult stage, a period accounting for around 80% of the species’ mortality. Eagle abundance was calculated by road censuses, and habitat characteristics of settlement and non-settlement areas compared by General Discriminant Analysis (GDA) and Logistic Regression (LR). The best model of GDA and LR incorporated the abundance of main prey for eagles (rabbits, partridges) and orchard surface area, and explained 100% of eagle presence; the best model selected by GDA also included habitat heterogeneity. Both eagles tended to share settlement areas in the southern Iberian Peninsula and, when they did not, the mean annual temperature and slope appeared to explain the segregation between the two species. Management measures for the conservation of both threatened species during the dispersal period should be focused on identifying settlement areas, maintaining high prey densities and maximum habitat heterogeneity.