Insect Community Composition Research Articles

Biodiversity and plant-insect interactions in fragmented habitats: A systematic review

Abstract Fragmentation is threatening insect biodiversity and intricate interactions in various ecosystems. Ecological interactions – especially those involving plants and insects – are significantly impacted by fragmented habitats. Because of fragmentation, edge effects and reduced habitat connectivity and quality affect insect species diversity, abundance, behavior, movement, life cycles, and interactions with plants, e.g., pollination, herbivory, and seed distribution. To a large degree, ecosystem services or processes are mediated by these interactions. While fragmented habitats create suitable conditions for invasive alien plants (IAPs), such invasions modify native plant composition and herbivorous insect communities because they cause a decline or loss in insect biodiversity. A systematic review was conducted by reviewing eighty-eight (88) articles to gather evidence for fragmentation effects on insect biodiversity, insects’ behavior and adaptations, plant-insect interactions (i.e., pollination, herbivory, and seed dispersal), and its influence on IAP invasions. This review deduced that any change in insect community composition and diversity due to fragmentation can have cascading effects on ecosystem processes within habitats. It further contends that successful conservation and management of fragmented habitats requires an understanding of the intricate dynamics of plant-insect interactions. However, the long-term resilience and health of ecosystems can be guaranteed by supporting sustainable land use, improving connectivity, and restoring habitats. These actions may help stop and/or reduce the effects of fragmentation on insect biodiversity and support the livelihoods and well-being of millions of people.

Impact of urban disturbance on soil insect communities in a Brazilian Atlantic Forest biological station

Urbanization constitutes a major threat to biodiversity. Understanding its effects on insect communities is relevant because they are key elements of trophic interactions, and indicators and targets of conservation. Herein, we investigated the influence of meteorological and habitat factors on the soil entomofauna in three areas with distinct levels of urbanization at the Parque Estadual da Pedra Branca, Brazil. We investigated whether community structure differs among areas with different levels of urbanization, and how changes in the environment affect soil insect community composition and distribution. We systematically monitored communities for 12 months in three areas along a gradient of anthropogenic disturbance, representing preserved secondary forest, disturbed forest and peridomicile areas. The results revealed that the degree of urbanization affects insect communities, with a strong effect of habitat factors, such as canopy cover, presence of flooded areas, quantity of fallen trunks and mean temperature. Insect abundance did not show significant differences among areas, while biomass was higher in disturbed forest than in preserved forest and peridomicile areas. Additionally, insect richness and diversity were higher in preserved and disturbed forests than in peridomicile areas, with no significant difference between preserved and disturbed forests. Our results can be used to enhance the understanding of the effects of urbanization on taxonomically and functionally diverse groups of insects, and to advise residents and urban planners about the consequences of urbanization on biodiversity and ecosystem services in urban-sylvatic interface areas.

Insect community structure in young and productive coffee farms under leucaena shade of Jember Regency, East Java, Indonesia

The developmental phase of Robusta coffee plantations with agroforestry systems exhibits varying ecosystem characteristics (biotic and abiotic), therebyinfluencing the dynamics of insect community composition within them. One of the major coffee-producing centers in East Java is Jember Regency, where coffeecultivation commonly employs agroforestry systems with various shade trees. Understanding the abundance of insect species in agroforestry coffee plantations is important for determining insect pest control measures. This research aims to study the insect community structure in young coffee and productive coffee farms. Insect sampling was conducted in young coffee farms and productive coffee farms at the Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute (ICCRI), by using road sampling methods with insect nets and pitfall traps. Both types of plantations utilize Leucaena sp. var L2 as shade trees, forming agroforestry coffee plantation systems. Data analysis was performed by calculating the Shannon-Wiener diversity index (H’) to assess insectdiversity and the independent sample t-test to determine differences in insect abundance based on functional roles between the two farms. The results indicatethat the composition and abundance of insects in productive coffee farms are higher than in young coffee farms, resulting in a higher insect diversity index valuefor productive coffee farms (categorized as high), while young coffee farms fall into the moderate category. Furthermore, based on their functional roles, productive coffee farms positively influence the abundance of herbivorous, predatory, parasitoid, and detritivorous insects.

Ecological Impact of American Chestnut Hybrid Restoration on Invertebrate Communities Above- and Belowground

The cross-hybridization of American chestnut (Castanea dentata (Marsh.) Borkh.) with Chinese chestnut (Castanea mollissima Bl.) is a promising strategy for restoring a blight-resistant strain of this keystone species to the Appalachian mountains. To assess the ecological impacts of hybridization on invertebrate communities, we conducted a study across chestnut plots with varying degrees of hybridization (75%, 94%, or 100% American chestnut). Our findings indicate American chestnut hybridization impacted invertebrate communities above- and belowground. Aboveground insect community composition, insect herbivory, gall infestation, and belowground invertebrate diversity were all altered. While some of these differences could be explained by different growth habits or environmental differences, stark differences in Asian chestnut gall wasp infestation (Dryocosmus kuriphilus Yasumatsu.) suggest a genetic component. These results suggest that chestnut hybridization, and particularly expanded restoration efforts using chestnut hybrids, could impact invertebrate communities above- and belowground in addition to pest dynamics. Understanding these effects is crucial for successful chestnut restoration and ecosystem management.

Crop type rather than production method determines functional trait composition of insect communities on arable land in boreal agricultural landscapes

Abstract To understand the potential consequences of arable land use changes for insect conservation and ecosystem functioning, it is fundamental to know how insect species with different functional traits respond to crop choice and production method. This study examined the effects of crop type and production method on functional traits of butterfly, bumblebee and carabid beetle communities using species abundance data from 78 fields in Southern Finland. Surrounding landscape composition was also accounted for. The studied traits were associated with dispersal capacity, habitat or diet specialization and phenology—the key determinants modifying species responses to agricultural disturbances and land use changes. Butterfly habitat breadth was narrowest and wingspan shortest in long‐term fallows. Fallows also supported the highest share of butterflies overwintering in early development stages and bumblebees with late‐emerging queens. The tongue length of bumblebees was longest in organic oat fields, probably due to flowering weeds with long corolla. For carabid beetles, the proportion of poor flyers and carnivores was highest in perennial crops and fallows. Carabid beetles overwintering as adults were relatively more abundant in organic than in conventional production, probably due to more intensive tillage in organic fields. In all insect groups, poor dispersers and/or specialists decreased with increasing arable land cover in the surrounding landscape. Increasing the area of long‐term fallows and perennial crops and enhancing within‐field plant diversity while maintaining landscape heterogeneity would promote insect species sensitive to agricultural disturbances and land use changes and their associated ecosystem services in boreal farmland.

Anthropogenic disturbance affects specialist, but not generalist, endophagous insects associated with two African grasses: implications for biological control

ABSTRACT The specialisation-disturbance hypothesis (SDH) predicts that specialist and generalist taxa respond differently to disturbance, with generalists more tolerant of disturbance, while habitat stability (i.e. no/limited disturbance) should favour specialist species. If the SDH holds true, this would have implications for the design and implementation of biological control programmes, in terms of performing native-range surveys in search of candidate agents and subsequent development of management programmes for their release in the weeds invaded range. We assessed the effect of anthropogenic disturbance (mowing/slashing and fire) on the endophagous insect communities associated with two African grasses, Sporobolus pyramidalis and Sporobolus natalensis (Poaceae), that are targets for biological control in Australia. Comparisons, of insect community structure and presence/abundance of each species between disturbed and undisturbed sites, were made at 19 sites in South Africa. Disturbance caused a shift in insect species composition and abundance, whereby specialist insects were less frequently encountered and less abundant at disturbed versus undisturbed sites. If the potential agents for Sporobolus spp. are released in Australia they may be negatively affected by disturbance and may therefore be incompatible with certain integrated management strategies, such as mowing and prescribed burning. Moreover, our results suggest that field sites with limited disturbance should be prioritised during native-range surveys to maximise the chances of locating specialist natural enemies. The effect disturbance has on insect community composition may be particularly relevant for the biological control of invasive grasses, due to the intensity of disturbance of grasslands worldwide.

Shifting taxonomic and functional community composition of rivers under land use change.

Land use intensification has led to conspicuous changes in plant and animal communities across the world. Shifts in trait-based functional composition have recently been hypothesized to manifest at lower levels of environmental change when compared to species-based taxonomic composition; however, little is known about commonality in these responses across taxonomic groups and geographic regions. We investigated this hypothesis by testing for taxonomic and geographic similarities in the composition of riverine fish and insect communities across gradients of land use in major hydrologic regions of the conterminous United States. We analyzed an extensive dataset representing 556 species and 33 functional trait modalities from 8,023 fish communities, and 1,434 taxa and 50 trait modalities from 5,197 aquatic insect communities. Our results demonstrate abrupt threshold changes in both taxonomic and functional community composition due to land use conversion. Functional composition consistently demonstrated lower threshold responses compared to taxonomic composition for both fish (urban p = 0.069; agriculture p = 0.029) and insects (urban p = 0.095; agriculture p = 0.043) communities according to gradient forest models. We found significantly lower thresholds for urban versus agricultural land use for fish (taxonomic and functional p < 0.001) and insects (taxonomic p = 0.001; functional p = 0.033). We further revealed that threshold responses of functional composition were more geographically consistent than those of taxonomic composition to both urban and agricultural land use change. Traits contributing the most to overall functional composition change differed along urban and agricultural land gradients, and conformed to predicted ecological mechanisms underpinning community change. This study points to reliable early-warning thresholds that accurately forecast compositional shifts in riverine communities to land use conversion, and highlight the importance of considering trait-based indicators of community change to inform large scale land use management strategies and policies. This article is protected by copyright. All rights reserved.

Elevational variation of spider and insect communities in the Swedish mountains

AbstractMountain topography gives rise to often dramatic climate‐driven elevation gradients in primary productivity, which can generate substantial biodiversity variation. Therefore, mountain areas may be particularly useful for evaluating the ecological consequences of climate change. Arthropods are the most diverse animal phylum, which play important roles in most ecosystems. However, despite their ecological importance, we have limited information on how arthropods vary along elevation gradients. We investigated how taxonomic richness, taxonomic composition, and spatial structuring of spider and insect communities varied along elevation gradients and among three geographic locations in a mountain region of northern Sweden. The locations provided a latitude gradient spanning approximately 3° (from 62° N to 65° N), but were otherwise selected to contain similar environmental characteristics. Taxonomic richness of both spiders and insects declined monotonically with increasing elevation, and there were limited differences between the geographic locations in such declines. Taxonomic composition varied with elevation for both taxonomic groups, but also differed among the three sites. Linyphiid spiders were more widely distributed along the elevation gradients than other spider taxa, whereas a broad taxonomic range of insects occurred over almost all elevations. We observed nested as well as modular spatial distributions of both spider and insect communities along the elevation gradients. While the modular patterns suggest that species turnover has generated distinct communities at different elevations, some generalist species were still widespread throughout large parts of the gradients. Our results point to smaller differences among geographic locations than among taxonomic groups in how taxonomic richness and community structuring varied with elevation. We interpret these results as support for taxonomically specific adaptations to environmental conditions being important for structuring arthropod communities. We also suggest that climate‐driven changes to arthropod communities in mountain environments may be regulated by two not mutually exclusive processes, one in which generalist species may become more dominant and shift their ranges upward and one in which high‐elevation specialists may go extinct because of increasingly fragmented habitats.

Multiple and contrasting pressures determine intraspecific phytochemical variation in a tropical shrub.

Intraspecific phytochemical variation across a landscape can cascade up trophic levels, potentially mediating the composition of entire insect communities. Surprisingly, we have little understanding of the processes that regulate and maintain phytochemical variation within species, likely because these processes are complex and operate simultaneously both temporally and spatially. To assess how phytochemistry varies within species, we tested the degree to which resource availability, contrasting soil type, and herbivory generate intraspecific chemical variation in growth and defense of the tropical shrub, Piper imperiale (Piperaceae). We quantified changes in both growth (e.g., nutritional protein, above- and below-ground biomass) and defense (e.g., imide chemicals) of individual plants using a well-replicated fully factorial shade-house experiment in Costa Rica. We found that plants grown in high light, nutrient- and richer old alluvial soil had increased biomass. High light was also important for increasing foliar protein. Thus, investment into growth was determined by resource availability and soil composition. Surprisingly, we found that chemical defenses decreased in response to herbivory. We also found that changes in plant protein were more plastic compared to plant defense, indicating that constitutive defenses may be relatively fixed, and thus an adaptation to chronic herbivory that is common in tropical forests. We demonstrate that intraspecific phytochemical variation of P. imperiale is shaped by resource availability from light and soil type. Because environmental heterogeneity occurs over small spatial scales (tens of meters), herbivores may be faced with a complex phytochemical landscape that may regulate how much damage any individual plant sustains.

Monitoring insect biodiversity and comparison of sampling strategies using metabarcoding: A case study in the Yanshan Mountains, China.

Insects are the richest and most diverse group of animals and yet there remains a lack, not only of systematic research into their distribution across some key regions of the planet, but of standardized sampling strategies for their study. The Yanshan Mountains, being the boundary range between the Inner Mongolian Plateau and the North China Plain, present an indispensable piece of the insect biodiversity puzzle: both requiring systematic study and offering opportunities for the development of standardized methodologies. This is the first use of DNA metabarcoding to survey the insect biodiversity of the Yanshan Mountains. The study focuses on differences of community composition among samples collected via different methods and from different habitat types. In total, 74 bulk samples were collected from five habitat types (scrubland, woodland, wetland, farmland and grassland) using three collection methods (sweep netting, Malaise traps and light traps). After DNA extraction, PCR amplification, sequencing and diversity analysis were performed, a total of 7427 Operational Taxonomic Units (OTUs) at ≥97% sequence similarity level were delimited, of which 7083 OTUs were identified as belonging to Insecta. Orthoptera, Diptera, Coleoptera and Hemiptera were found to be the dominant orders according to community composition analysis. Nonmetric multidimensional scaling (NMDS) analysis based on Bray-Curtis distances revealed highly divergent estimates of insect community composition among samples differentiated by the collection method (R = .524802, p = .001), but nonsignificant difference among samples differentiated according to habitat (R = .051102, p = .078). The study therefore appears to indicate that the concurrent use of varied collection methods is essential to the accurate monitoring of insect biodiversity.

Is less simply less? A comparison of abundance and biomass losses in auchenorrhynchan grassland communities and their different impacts on trait composition and taxonomical diversity

Declines in insect biomass and individual numbers have been demonstrated in many parts of the world, including central European dry grasslands. It is, howver, unclear if biomass data or individual numbers are superior as measures of change in species composition, and in trait composition of insect communities. We revisited a former study of ours demonstrating severe losses in abundance of planthoppers and leafhoppers in Central European grasslands since the 1960s. We performed a series of univariate, multivariate and trait-based tests to investigate the relationship between biodiversity change and environment, and compared the results for number-weighted and biomass-weighted community data.While both individual numbers and biomass declined strongly over time, no changes in species diversity (Jost's D) were observed irrespective of the measure used for weighting. Surprisingly, metrics for trait diversity tended to increase over time in both the number-weighted and biomass-weighted data. For both measures, community composition changed strongly over time for species and trait data, and was also associated with landscape structure and mean annual precipitation. Of the tested traits, we only found associations between an early phenology and time, and a temporal increase of species over-wintering in a nymphal stage, but again there was no major difference between the measure used for weighting.Our study shows that declining assemblage size (regardless of the measure used) does not necessarily translate in concomitant changes in functional diversity or trait diversity. From a methodological perspective, no clear evidence emerged for either biomass or individual number as measure of assemblage size being more sensitive to environmental change. This implies that conversion of widely used data of individual numbers to biomass values is unlikely to bring much additional insights. With respect to the general scarcity of quantitative data on insect communities, the focus should be on using whatever data is available.

Insect biodiversity in urban tree pit habitats

Urban green spaces are important for urban insects, providing both habitat space as well as stopover locations within the urban landscape. Street tree pits in cities are small, heterogeneous, and understudied green spaces that may be important for supporting urban insect communities. The purpose of this study was to investigate the composition of insect communities within tree pits in New York City, New York, USA (NYC) and compare tree pit insect communities across NYC neighborhoods. Tree pits in NYC are part of the New York City Parks system but are primarily managed by residents of each street. We postulated that insect assemblages within tree pits would contain both permanent (habitat) and transient (stopover) members and those communities would vary among neighborhoods. Insects were collected from understory plants in tree pits in four NYC neighborhoods during the summer of 2019. We found that the tree pits provided habitat for nine orders and 51 families of insects, the majority of which were herbivores and their associated predators or parasitoids, which were likely utilizing the tree pits as habitat space. Few clearly transient species (e.g. pollinators) were collected. Furthermore, insect communities were similar both within neighborhoods and among neighborhoods, suggesting that while tree pits management is not strictly regulated in NYC, tree pits in all neighborhoods provided habitat to sustain similar insect assemblages. At the neighborhood level, urban tree pits can harbor a diverse insect community and that capability is similar throughout the urban landscape.

Specialised chemistry affects insect abundance but not overall community similarity in three rare shrub willows: Salix myrtilloides, S. repens and S. rosmarinifolia

Willows serve as a keystone host-plant genus for insect herbivores. The diversity of insect herbivore assemblages harboured by willows is typically affected by the diversity of specialised metabolites that willows produce. Here, we studied three small, shrubby willow species (Salix myrtilloides, S. repens and S. rosmarinifolia) that primarily occur at sites of high conservation value in the Czech Republic. We explored if associated insect communities reflect the specialised chemistry in these uncommon host plants. We measured the three willow species for overall metabolomic profiles and salicinoids using non-targeted metabolomics and sampled them for caterpillars, leaf-chewing beetles (adults and larvae), sawfly larvae, and sap-sucking Hemiptera. We detected 2,067 metabolites across the three willow species. Most of them were shared by S. repens and S. rosmarinifolia, while S. myrtilloides showed a distinct chemical profile. Salix repens and S. rosmarinifolia also had significantly higher concentration and richness of salicinoids than S. myrtilloides. The abundance of all insect species and generalists that also feed on host-plants outside Salicaceae was higher on S. myrtilloides than on S. rosmarinifolia or S. repens. The abundance of Salicaceae specialists did not differ among the three willow species. Insect community composition, in contrast, did not show pronounced differences among the three willows. Our results suggest that salicinoids may be responsible for the low abundance of generalist herbivores. Furthermore, our study indicates that herbivore community composition does not reflect the specialised chemistry in the three willows we studied. Therefore, we hypothesise that the presence of some of the insect species is primarily determined by other factors, such as the habitat type where the respective willow species occur. Although the studied willows possess some characteristic specialised chemistry, we conclude that their importance as hosts of specific and sometimes threatened insect fauna may be mediated by willow habitat preference.

Dynamics of insect communities across a unique network of hydrologically altered riparian habitats in central China

AbstractThe establishment of hydroelectric dams can lead to major changes in hydrology for habitats within the reservoir drawdown zones. The Three Gorges Dam (TGD) in China is the world's largest hydroelectric facility, with a reservoir covering 1080 km2 and a drawdown zone covering 350 km2. Since the TGD's establishment in 2008, the formerly terrestrial habitats within the dam's drawdown zone have effectively been converted to riparian habitats. A strong understanding of ecological dynamics in these novel habitats is critical to their ongoing management. Given the major contribution of insects to ecosystem function and biodiversity, we surveyed riparian insect communities semi‐annually from 2011 to 2018 across a 600‐km network of 18 sites in the TGD's drawdown zone. During this period, the total abundance of insects increased 4.4‐fold, and the composition of insect communities shifted significantly, with Diptera increasingly dominant in later years. Insect abundance trajectories were coupled with concomitant changes in local climate and soil chemistry, which have in turn been brought on by the novel hydrological regime in the drawdown zone. Revegetation efforts had limited impacts on riparian insect abundances. Overall, riparian insect communities have undergone marked shifts since the TGD started operating. We cannot explicitly attribute these effects to the TGD's establishment, but our results indicate that they might have been shaped by—or are at least coupled with—the profound changes in hydrological conditions associated with the TGD's establishment.

The impact of wildfire and mammal carcasses on beetle emergence from heathland soils

Abstract Wildfires alter the composition of insect communities due to fire‐induced mortality, and the post‐fire vegetation and soil conditions also affect the initial re‐colonisation and subsequent local emergence of adults from burnt soils. However, the impact of wildfires on re‐colonisation and emergence of carrion‐associated scavenging species from soils has previously been neglected. We established an experiment in an unmanaged heathland area that was affected by a severe wildfire in 2017 by adding wild boar carcasses to burnt and unburnt areas 204 days after the wildfire. Adult beetles were then collected with emergence tents at paired sites with and without carcasses and in burnt and unburnt areas from 27 April to 10 August 2018. The wildfire did not significantly affect the diversity or abundance of soil‐emerging beetles. Community composition in the burnt area differed significantly from the unburnt area with higher numbers of Staphylinidae and lower numbers of phytophagous beetle families (Curculionidae and Elateridae) emerging from soils, probably reflecting the structurally simpler vegetation and reduced litter one year after the wildfire. Scavenging beetles generally colonise mammal carcasses in burnt areas to the same extent as in unburnt areas, but the post‐fire conditions favoured some species with very specialised habitat preferences. A few rare species of conservation concern almost exclusively occurred in the burnt area and in most cases in combination with the presence of a carcass. This result highlights the joint importance of heathland wildfires and carcass resources for species conservation in beetle communities.

Insect community composition varies between temperate and tropical regions but functional structure remains conserved

Insect community composition varies between temperate and tropical regions but functional structure remains conserved

Intensive grazing alters the diversity, composition and structure of plant-pollinator interaction networks in Central European grasslands.

Complex socio-economic, political and demographic factors have driven the increased conversion of Europe’s semi-natural grasslands to intensive pastures. This trend is particularly strong in some of the most biodiverse regions of the continent, such as Central and Eastern Europe. Intensive grazing is known to decrease species diversity and alter the composition of plant and insect communities. Comparatively little is known, however, about how intensive grazing influences plant functional traits related to pollination and the structure of plant-pollinator interactions. In traditional hay meadows and intensive pastures in Central Europe, we contrasted the taxonomic and functional group diversity and composition, the structure of plant-pollinator interactions and the roles of individual species in networks. We found mostly lower taxonomic and functional diversity of plants and insects in intensive pastures, as well as strong compositional differences among the two grassland management types. Intensive pastures were dominated by a single plant with a specialized flower structure that is only accessible to a few pollinator groups. As a result, intensive pastures have lower diversity and specificity of interactions, higher amount of resource overlap, more uniform interaction strength and lower network modularity. These findings stand in contrast to studies in which plants with more generalized flower traits dominated pastures. Our results thus highlight the importance of the functional traits of dominant species in mediating the consequences of intensive pasture management on plant-pollinator networks. These findings could further contribute to strategies aimed at mitigating the impact of intensive grazing on plant and pollinator communities.

Seasonal and spatial dynamics of the aquatic insect communities of an intermittent Mediterranean river

Although intermittent rivers are present in all climate regions, their biodiversity and ecosystem functions were largely overlooked in the past. Recently, considerable effort has been made to improve our understanding of these, however, many data gaps still remain. We conducted a study to improve knowledge of the community patterns and processes in intermittent rivers in the Dinaric Western Balkan ecoregion. We studied spatial and temporal variation of aquatic insect community composition and structure in the intermittent Krčić River over two seasons (June and December) in three river sections (spring, upper/middle and lower reaches), encompassing dominant microhabitats (phytal, boulders, cobbles, sand and xylal). Community was primarily composed of aquatic insects (92 % of the community) and seasonality was inferred as the most important factor determining its composition, diversity and abundance. This was also supported by the ecological trait information, i.e. trophic and dispersal-related community structure. The most diverse and abundant insect group were the under-investigated chironomids, thus, we discussed tolerance and intermittency indicator potential of some of these taxa. By providing new insights into temporal and spatial dynamics of aquatic insect communities, a major bioindicator component of the macroinvertebrate community used in water quality monitoring in intermittent rivers, our data support development of the intermittent river-specific and adequate management and monitoring procedures.

Effects of aerial adulticiding for mosquito management on nontarget insects: A Bayesian and community ecology approach

AbstractDiseases transmitted by mosquitoes are emerging across the globe in a broad range of urbanized, rural, and natural environments inhabited by their vector species. Because applications of insecticides remain the most effective, and often the only available tool to prevent or control mosquito‐borne disease outbreaks, their use and scope continue to expand. However, the effects of multiple insecticide applications targeting adult mosquitoes on nontarget insect communities remain poorly characterized. To remedy this knowledge gap, we conducted an evaluation of five aerial insecticide applications on insect communities in a natural environment near Salt Lake City, Utah. Employing a before–after–control–impact approach, we assessed abundance and community composition changes over the study period utilizing Bayesian and community ecology analytical methods. We observed no discernible effects on most insect taxa, and there were no changes in the overall insect community composition. The abundance of Diptera, Coleoptera, and Hemiptera declined in control and treatment sites, Odonata increased over the period of the study, and Hymenoptera and Lepidoptera remained similar, suggesting seasonal trends rather than treatment effects. The only consistently detectable treatment effect was on nonbiting midges (Diptera: Chironomidae), that are closely related to mosquitoes taxonomically and have similar body size and diel activity. Midge abundance declined by 79.9% (95% credible interval: 58.4–91.9). Overall posttreatment abundance decline of 62.2% (95% credible interval: 22.5–87.8) was also detected for leafhoppers (Hemiptera: Cicadellidae), but, these declines were inconsistent and may be attributed to natural variability rather than the treatment effect. Treatment frequency, location, life‐stage targeting, and application techniques may mitigate the effects of mosquito control on nontarget insects to allow protecting human health while limiting environmental impacts.

My home is your home: Nest boxes for birds and mammals provide habitats for diverse insect communities

Abstract Cavity‐bearing trees are important nesting sites for many birds and mammals but have become rare due to anthropogenic modification of natural environments. Nest boxes are often used to compensate for the loss of these microhabitats. Nest boxes contain amounts of organic debris exploited by a variety of organisms, mainly insects. We studied the largely unexplored group of nest‐dwelling insects by rearing them from plant detritus and animal remains accumulated in nest boxes of six bird and two mammal species, distributed in forest, farmland and urban environments in Poland. We recorded 119 species representing eight insect orders. Nest substrates composed of plant detritus and animal remains supported similar insect species richness but differed significantly in terms of the insect community composition. Nests of Falco tinnunculus and Tyto alba and also Parus spp. and Strix aluco had very similar insect communities. The structural compositions of insect communities were also similar in nests of Parus spp. and Sturnus vulgaris, and of F. tinnunculus and S. aluco. Flies and earwigs were associated with nests of Parus spp. and Sciurus vulgaris and were more abundant in forests and urban environments, whereas wasps preferred S. aluco nests in forests. Our study shows that nest boxes may serve as replacement habitats for a variety of nest‐associated insects. Therefore, we suggest a more flexible approach to nest boxes maintenance and management, for example, less frequent cleaning or providing more than one nest box in a given place to enhance conservation of nest‐associated insects.