Current opinion in insect science最新文献

Predicting how insects will respond to stressors through time is difficult because of the diversity of insects, environments, and approaches used to monitor and model. Forecasting models take correlative/statistical, mechanistic models, and integrated forms; in some cases, temporal processes can be inferred from spatial models. Because of heterogeneity associated with broad community measurements, models are often unable to identify mechanistic explanations. Many present efforts to forecast insect dynamics are restricted to single-species models, which can offer precise predictions but limited generalizability. Trait-based approaches may offer a good compromise that limits the masking of the ranges of responses while still offering insight. Regardless of the modeling approach, the data used to parameterize a forecasting model should be carefully evaluated for temporal autocorrelation, minimum data needs, and sampling biases in the data. Forecasting models can be tested using near-term predictions and revised to improve future forecasts.

Insects are important elements of terrestrial ecosystems because they pollinate plants, destroy crops, transmit diseases to livestock and humans, and are important components of food chains. Here, I used Gephebase, a manually curated database of genetic variants associated with natural and domesticated trait variation, to explore current knowledge about the genes and the mutations known to contribute to natural phenotypic variation in insects. Analysis of over 600 mutations reveals that data are concentrated toward certain species and traits and that experimental approaches have changed over time. The distribution of coding and cis-regulatory changes varies with traits, experimental approaches, and identified gene loci. Recent studies highlight the important role of standing variation, repeated mutations in hotspot genes, recombination, inversions, and introgression.

Increase in soil salinization due to climate change is a global phenomenon that can induce significant changes in plant growth, physiology, and chemistry, exacerbating growing threats to insect biodiversity. Insects that rely on plants are likely to be indirectly impacted by changes in soil salt content through changes in plant chemistry, yet few studies link changes in plant metabolism to impacts on higher trophic levels. Some salinity-mediated changes in specialized metabolites may be predictable due to highly conserved metabolic pathways shared between herbivore defense and stress resistance, but recent studies also suggest substantial variation across plant species and habitats. To date, most of the research on salinity and chemically mediated plant–insect interactions has focused on herbivores, particularly in agricultural systems. Published effects of salinity on pollinators and parasitoids are scarce. Future research will need to focus more on the role of plant chemistry to bridge the divide between studies of plant and insect responses to salinization.

Blattodea, which includes cockroaches and termites, possesses high developmental plasticity that is mainly controlled by nutritional conditions and insect hormones. Insulin/insulin-like growth factor signaling (IIS), target of rapamycin complex 1 (TORC1), and adenosine monophosphate-activated protein complex are the three primary nutrition-responsive signals. Juvenile hormone (JH) and 20-hydroxyecdysone (20E) constitute the two most vital insect hormones that might interact with each other through the Met, Kr-h1, E93 (MEKRE93) pathway. Nutritional and hormonal signals interconnect to create a complex regulatory network. Here we summarize recent progress in our understanding of how nutritional and hormonal signals coordinately control the developmental plasticity of metamorphosis, reproduction, and appendage regeneration in cockroaches as well as caste differentiation in termites. We also highlight several perspectives that should be further emphasized in the studies of developmental plasticity in Blattodea. This review provides a general landscape in the field of nutrition- and hormone-controlled developmental plasticity in insects.

The rise of megafires and extreme fire behaviors poses a significant threat to insect populations, affecting their survival and postfire recolonization. Megafires threaten the entire insect communities by changing fire regimes and habitats. These fires are now burning non-fire-prone ecosystems, endangering non-fire-adapted insects and habitats. While implementing prescribed burn programs can reduce the chances of megafires from developing, some megafires will be unpreventable. Land managers can mitigate the fire impacts by creating refugia and promoting heterogeneity in burn severity through fire control measures. Last, these post-megafire landscapes can provide an opportunity to restore historical fire regimes through subsequent prescribed burn management. This will revitalize ecosystems, benefit insects, and reduce the likelihood of future megafires and subsequent insect loss.

Recent studies have continued to shed light on the ecology of monarch butterflies (Danaus plexippus) in western North America. These studies have documented a declining overwintering population over several decades, punctuated by unexpected variability in recent years. Understanding this variability will require grappling with the spatial and temporal heterogeneity of resources and risks presented to western monarchs throughout their annual life cycle. Recent changes in the western monarch population further illustrate how interacting global change drivers can create complex causes and consequences in this system. The complexity of this system should inspire humility. However, even recognizing the limits of our current understanding, there is enough scientific common ground to take some conservation actions now.

Population dynamics, persistence, and distribution are emergent properties of animal movement behavior and the spatial configuration of resources. Monarch butterflies are a vagile species with an open-population structure. Selecting locations for monarch butterfly- breeding habitat restoration that aligns with natural movement behavior will facilitate efficient habitat utilization across the landscape, increase realized fecundity, and ultimately support increases in the overwintering population size in Mexico. Obtaining and interpreting empirical movement and space-use data through field and laboratory studies are fundamental to this effort. To gain insights into population responses at larger, spatially explicit landscape scales, the results from empirical studies can be incorporated into simulation models. Together, empirical and simulation studies can inform options for creating functional connectivity of monarch butterfly-breeding habitats. Given currently available information, we synthesize studies for the eastern monarch butterfly to illustrate how an improved understanding of movement ecology can assist in planning conservation practices.

Rearing monarch butterflies in captivity for later release is a popular but contentious activity due to concerns about its potential negative effects on the wild population. In this review, I discuss how captive rearing and breeding could impact monarch fitness in the wild, the current evidence for such impacts in monarchs and other captive-reared/released organisms, and how this should inform our efforts to conserve monarchs and other species.

Monarch butterflies have emerged as a model system in migration genetics. Despite inherent challenges associated with studying the integrative phenotypes that characterize migration, recent research has highlighted genes and transcriptional networks underlying aspects of the monarch’s migratory syndrome. Circadian clock genes and the vitamin A synthesis pathway regulate reproductive diapause initiation, while diapause termination appears to involve calcium and insulin signaling. Comparative approaches have highlighted genes that distinguish migratory and nonmigratory monarch populations, as well as genes associated with natural variation in propensity to initiate diapause. Population genetic techniques demonstrate that seasonal migration can collapse patterns of spatial structure at continental scales, whereas loss of migration can drive differentiation between even nearby populations. Finally, population genetics can be applied to reconstruct the monarch’s evolutionary history and search for contemporary demographic changes, which can provide relevant context for understanding recently observed declines in overwintering North American monarch numbers.

Insects have to navigate a complex and rich olfactory environment consisting of mixtures of odors at varying ratios. However, we understand little of how the olfactory system represents these complex blends. This review aims to highlight some of the recent results of studying this mixture code, in the Drosophila melanogaster olfactory system, as well as gives a short background to one of the most challenging questions in olfaction — how are mixtures encoded in the brain?