Journal of Insect Conservation

European mountain forests are unique ecosystems, and they harbour specific saproxylic beetle fauna, including relict species such as the longhorn beetle Ropalopus ungaricus (Herbst, 1784). This endangered species is endemic to European mountain forests and is considered to be monophagous on living sycamore trees (Acer pseudoplatanus L.). Insufficient knowledge of the species ecology limits its effective conservation. Hence, to investigate its habitat requirements, 175 sycamore trees (87 occupied and 88 unoccupied by the species) were surveyed in the Hrubý Jeseník Mts. and Moravskoslezské Beskydy Mts. in northern Moravia (Czech Republic) in 2016. The species strongly preferred trees with reduced vitality, including variously damaged trees. The species was also documented to be much more abundant on sun-exposed trees, and the parts of the trunk mantle (south- and east-facing quarters) with the warmest microclimates were preferred. Surprisingly, trunk diameter seems to be an unimportant characteristic for this species (the diameters of occupied trees varied between 5 and 72 cm). In conclusion, R. ungaricus is a specialised species whose survival depends upon a continuous supply of sun-exposed declining and damaged sycamores in mountain forests. Based on the results of the present study, we suggest concrete conservation measures to support the species, and these will benefit other saproxylic species associated with the same habitat.

General agri-environment schemes (AES) have been shown to benefit widespread species, but there is little information on the extent to which rare, more localised, species may also benefit. We tested whether AES options aimed at increasing general biodiversity also benefit a highly endangered moth, Polia bombycina, without species-specific tailoring. We assessed effects on its abundance of two AES options, wide field margins and hedgerow trees, using light traps at the landscape-scale and for mark-release-recapture at the farm-scale. We hypothesized that abundance would be highest at wide field margins and at hedgerow trees, and that if hedgerow trees conferred a positive effect, individuals would be more likely to follow hedgerows than crossing exposed fields while on the move. The results showed that significantly more individuals were captured at sites with a hedgerow tree. Numbers were also higher at wide margins, but this was not statistically significant, and no individuals were caught at field centres. Our study suggests that general options within appropriately designed and implemented AES aimed at increasing overall biodiversity in intensive agricultural landscapes have the potential to not only benefit common, widespread habitat generalists, but some rare and more endangered species as well. P. bombycina serves as an example of how general AES options, existing and novel ones alike, might cater for the needs of rare and localised species. As the precise ecological requirements of most invertebrate species remain unknown, we urge scientists and governments to address the challenge to research and design truly general AES, which options should be able to deliver not only for widespread species but also for the less-widespread counterpart of farmland biodiversity.

Various methods exist for collecting pollinating insects; however, colored bowl traps, vane traps, and sweep netting are among the most commonly used approaches, and may yield different estimates of insect abundance and taxa diversity depending on habitat type. Electric transmission rights-of-ways (ROWs) are found throughout the United States and provide early successional habitat which may provide an abundance of floral and nesting resources for many insect pollinators. Despite the potential for harboring pollinating insects, few researchers have focused on ROWs as important pollinator habitat. We surveyed pollinating insects (bees, wasps, flies, and lepidopterans) within ROWs and the surrounding habitat in central Alabama during spring and summer of 2018 using colored bowl traps (blue, yellow, and white), blue vane traps, and targeted sweep netting of insects on flowering plants. Overall, each collection method collected several bee genera and other pollinators that were not collected with the other methods. Blue vane traps collected more bee taxa and overall pollinating insect diversity compared to colored bowl traps and sweep netting. Sweep netting flowering plants collected the fewest pollinating insects but did document some genera that colored bowl traps and vane traps did not. Our data support the use of multiple collecting methods to document pollinator insect diversity and abundance. This study suggests that accurately assessing insect pollinator abundance and diversity should not depend solely on one type of collecting method due to potential collection biases. Alternatively, if specific pollinator taxa are sought, utilizing certain collecting methods over others may enhance the probability of collection.

We have investigated the genetic population structure within and the genetic differentiation between local populations of the large blue butterfly Maculinea alcon throughout the Jutland peninsula. Samples were collected as eggs on foodplants (Gentiana pneumonanthe), and reared to 4th instar caterpillars in the laboratory. A significant excess of homozygotes was found for all the investigated allozyme loci in most of the populations. A North-South cline was observed for the allele frequencies at some of the loci and for several linkage groups. Because some of the allele frequency clines were parallel to clines in adult morphological variation, we interpret our results as evidence for the co-existence of at least two gene pools within the Danish Maculinea alcon populations. Multilocus electrophoretic data revealed highly positive but variable FST values, which under this scenario would reflect varying frequencies of the Maculinea gene pools across the local populations. The significantly positive FIS values indicate that these gene pools are at least partly reproductively isolated (Wahlund effect). The co-occurrence of several Maculinea alcon gene pools on many local sites in Jutland is of great importance for conservation of the fragmented Maculinea populations. Our results show that there is probably more Maculinea biodiversity to conserve than was previously thought, and suggests that extant populations are more fragmented and vulnerable than counts of flying adults or eggs on foodplants indicate.

There are few papers describing long-term fluctuations and general patterns of temporal diversity in butterfly assemblages in the Neotropical region. The present paper presents a long-term study on the variation in richness and composition of butterflies in a fragment of semi-deciduous forest in Southeastern Brazil, and examines the viability of using maximized butterfly transect counts as a methodology to rapidly and adequately access the local characteristics of butterfly communities. Based on the eight annual standard lists, 518 species in six butterfly families were recorded, representing 74 % of the total butterfly fauna known from the study site. Hesperiidae was the richest family (248 species), followed by Nymphalidae (154), Lycaenidae (49), Riodinidae (29), Pieridae (26), and Papilionidae (12). The accumulation curves show that 8 years of sampling were not enough to result in stable species totals for all butterfly families, especially Hesperiidae and Lycaenidae, which are still increasing in number of species. A great similarity in species composition was observed among all the years (54 %). Comparing the similarity between two standard lists at different time intervals (from 1 to 8 years), a clear pattern of increasing dissimilarity was observed in most families. Our results show that the maximized sampling method is effective in revealing temporal patterns of diversity across several years and could be valuable in monitoring temporal variation in butterfly assemblages for conservation purposes, since the obtained standard lists can be successfully compared to temporal patterns over large periods of time.

Bees ensure 35 % of global food production, but this service is endangered due to several threats. Declines in bumblebee populations (genus Bombus) have been reported worldwide. Bombus bellicosus is one of the rare cases of reported threatened bumblebees in South America. It was once widespread in southern Brazil’s grasslands until the 1960s. During that time, that area underwent increasing land use which led to a decrease in bee abundance and richness, and to local disappearance of B. bellicosus. Climate change is also believed to cause declines in the abundance of B. bellicosus. Here we used species distribution models to assess potential effects of climate changes on the distribution of B. bellicosus in southern Brazil, considering both current and future climate scenarios. Our results show that the suitable climatic conditions for B. bellicosus will retreat southwards. A wax cover inside its nests is usually related to Bombus species inhabiting cooler climates. This cover enables the maintenance of higher temperatures inside the nest and may be deleterious for the species under future warmer climates. Continuously growing land use is the second major threat to this pollinator. The results presented here may eventually provide theoretical grounds and enable practical conservation actions for B. bellicosus protection in South America, especially given the potential adverse effects of climate changes for this species.

Species rich semi-natural grasslands are disappearing across Europe, affecting invertebrate diversity negatively. In NW Spain, the recent abandonment of traditional farming practices and the gradual decrease in grazing pressures are reducing the number and extent of montane grasslands. In this context, we investigated the composition of carabid beetle (Coleoptera, Carabidae) assemblages that inhabit semi-natural grasslands situated in long-term managed oak and beech forested landscapes. According to their spatial arrangement, the studied grasslands were classified into: (1) interior or gap grasslands (small and completely surrounded by continuous forest) and (2) exterior grasslands (large and connected to a variety of habitat types). Our results indicate that, within each forested landscape, the gap and exterior grasslands harboured particular carabid assemblages (i.e. exclusive or abundantly collected species), which were also distinct from the surrounding forest carabid fauna. Dissimilarities between gap and exterior grasslands in each landscape suggest great carabid diversity at the regional scale. We also detected species-specific responses as several carabids were mainly associated with gap or exterior grasslands. Consequently, in highly modified forested landscapes, semi-natural grassland remnants may constitute great value for the protection of the carabid fauna. Specifically, we recommend conservation strategies that preserve variety in grassland features and maintain proper management activities to prevent the loss of specialised species and a decrease in regional carabid diversity.

Threats to biodiversity are not studied equally amongst taxa leaving some groups like insects typically understudied in conservation and management research. Crane flies (Diptera: Tipuloidea) are diverse and important members of the aquatic and terrestrial biotic communities. These semi-terrestrial larval habitat preferences place crane flies at risk of habitat degradation and loss particularly from grazing by livestock. Increased grazing by livestock in the Hövsgöl region of Mongolia has impacted both terrestrial and aquatic ecosystems. The purpose of this study is to document biodiversity of crane flies along the east shore of Lake Hövsgöl, Mongolia, and to test whether crane fly diversity differs between valleys with different grazing intensity. Ninety-six species of Tipuloidea were found in this study, nine of these new to Mongolia, with 21 new to the Hövsgöl region. Rarefaction curves indicate that predicted diversity is less for moderately and highly grazed valleys than for the lightly grazed valleys and an analysis of variance indicates that Shannon’s diversity index was significantly higher in the lightly grazed valleys. Finally, a parsimonious model based on multiple regression analysis indicates that plant biomass and relative humidity are the strongest significant predicators of variation in crane fly diversity across the grazing gradient. Since crane fly larvae are an important part of the soil and leaf litter community, impaired diversity may affect ecosystem services such as decomposition of leaf litter and bioturbation, potentially exacerbating the impact of grazing.

The use of captive rearing to promote recovery of endangered butterflies has substantially increased over the last decade. These programs have the potential to play a significant role in butterfly population recovery, but the effects of captive conditions are poorly understood and rarely are traits of captive individuals assessed relative to traits in their founding populations. To develop rearing protocols and investigate possible effects of captive conditions, we reared Puget blue butterflies (Icaricia icarioides blackmorei), a subspecies closely related to the endangered Fender’s blue (I. i. fenderi) which is limited to Oregon, USA. We reared individuals from two wild populations in Washington, USA to investigate two approaches for egg collection (collect eggs in the wild vs. collect eggs from adult females which were brought to a greenhouse for oviposition) and three diapause environments (in indoor facilities at two independent locations vs. outdoors in enclosures). Survival from egg to adult was similar across all captive groups which survived past diapause and was less than 10%. Captive reared individuals were lighter and had smaller wings and shorter body lengths than their founding populations for both sites. Based on our findings, we recommend that rearing programs compare characteristics of reared individuals to individuals from the founding population to quantify possible effects of captive conditions, diapause individuals in natural environments, and for programs with survival rates similar to rates in the wild, consider alternatives to augment declining populations and reintroduce historic ones.