IntroductionEvolutionary traits acquired in response to one type of disturbance will potentially confer resilience to other disturbances that have similar environmental impacts, even if the biota has no evolutionary history of such disturbances. In grassy ecosystems the environmental impacts of grazing have important similarities to those of fire through the removal of grass biomass, and we hypothesise that high resilience to frequent fire confers high resilience to grazing.AimsWe test this hypothesis by investigating the resilience of highly fire-resilient ant communities to grazing in a mesic Australian savanna, which has not historically experienced such high levels of mammalian grazing.MethodsWe sampled ants using pitfall traps at Annaburroo Station in the Australian seasonal tropics using ten plot triplets, with each triplet representing no, low and heavy grazing. Grazing has had a major impact on the basal area of perennial grasses and the cover of bare ground. We considered large (> 4 mm) ants only, which tend to be particularly sensitive to disturbance.ResultsWe recorded 28 species of ‘large’ ants from 14 genera. Neither ant species richness nor overall composition varied significantly with grazing, and only one of the eight most common species responded to grazing.DiscussionAnt communities at Annaburoo Station are highly resilient to livestock grazing. The limited number of relevant studies suggest that ant communities in Australian savannas more generally have higher resilience than those in southern rangelands where fire frequency is relatively low. This supports our hypothesis that an evolutionary history of frequent fire confers resilience to grazing. Many more studies are required, but we suggest that resilience to grazing might be related more to evolutionary history in relation to fire, a more pervasive remover of plant biomass globally, than to grazing.Implications for insect conservationGrazing by cattle is the dominant land-use in Australian savannas and the Australian savanna ant fauna is one of the richest on Earth; our findings of high resilience is therefore good news for insect conservation. Such good news is likely to have wide applicability to other fire-prone grassy ecosystems subject to livestock grazing.

The artificial light sources are useful tools for sampling night active insects, however, they also possess potential environmental risks in their habitats. To test their applicability and evaluate environmental risk for caddisflies (Trichoptera), the attractivity of different portable light traps working with LED, UV and mixed-white light sources was studied and compared with attractivity of traditionally used mercury-vapour lamp (in Jermy-type light trap), which is tool of sampling and street-light. Analysing 1135 caught individuals of 19 species light sources emitting different wavelength spectra showed different attractivity and selectivity on caddisflies both on species and family levels. Attractivity of mercury-vapour lamp was generally lower than the other tested light sources. We found that the most attractive wavelength range for caddisflies is between 360 and 407 nm. One of the tested LED and mixed-white lamps together could cover this spectrum and a high and wide spectral peak of mixed-white light source between 375 and 391 nm resulted additional catches considering both species and number of individuals. Lamps emitting between 360 and 407 nm may be both a useful tool for sampling caddisflies and dangerous source of light pollution along lowland water courses where the sampled species are common and widespread.

As urbanization continues throughout much of the world, there is great interest in better understanding the value of urban and residential environments to pollinators. We explored how landscape context affects the abundance and diversity of bees on 50 residential properties in northern Georgia, USA, primarily in and around Athens, GA. Over 2 years of pan trap sampling we collected 4938 bees representing 111 species, from 28 genera in five families, constituting 20% of the species reported for the state. Development correlated positively with bee diversity at small (< 2.5 square km) scales, and positively with six of eight individual bee species’ abundances. Agriculture often correlated positively with bee diversity at larger spatial scales (> 2.5 square km), and negatively at smaller spatial scales. Forest cover correlated negatively with bee diversity at small spatial scales, but positively at larger scales. This trend was also largely true for individual bee species abundances. Bee communities differed between sites by predominant land cover types (agriculture, forest and development). Simper and indicator species analysis revealed which species contributed heavily to the observed patterns and helped to determine group distinctions.Implications for insect conservationOur results show that residential landscapes can support high bee diversity and that this diversity is sensitive to landscape context at different scales. Although development appears to have a negative effect on bee diversity overall, some bee species are favored by the open conditions characteristic of developed areas. Moreover, forest remnants appear to be valuable habitats for many species and are thus important to regional bee diversity. Urban planning that prioritizes and incorporates forest remnant conservation will promote bee abundance and diversity.

In 2016, the annual value of all global crops dependent upon pollination was valued at $ 235–$ 577 billion (US$). Pollination service is threatened by habitat loss, pesticides, and climate change. We collected potential pollinators with blue vane traps in native grasslands, Conservation Reserve Program (CRP) lands, and cropland (land use), and their embedded playa wetlands (land type) in the Southern High Plains of Texas (SHP). We collected vegetation data that included floral cover, floral diversity, native grass cover, introduced grass cover, canopy gap, and duff cover. Our objective was to determine if individual vegetation characteristics influenced potential pollinator abundance and richness in addition to land use or land type as a whole. The top model explaining abundance was land use, land type, and floral cover. Floral cover had a positive influence on all land uses. The top model that explained insect richness was land use x floral cover, land type, canopy gap, and duff cover. Floral cover positively influenced insect richness in native grasslands but negatively influenced cropland and CRP richness. Percent of canopy gap had a slight negative influence on insect richness, and duff cover positively influenced richness. Our recommendations to land managers are to protect playas to preserve undisturbed areas and native floral resources and seed all future CRP contracts with floral rich plantings to provide for pollinators over the entire growing season.Implications for insect conservationOur results show that vegetation characteristics shared by all land uses such as floral cover, canopy gap and duff cover influence pollinator abundance and richness. Therefore, conserving playa wetlands and programs such as the CRP have the potential for enhancing pollinator habitat in working landscapes of the SHP of Texas.