Protecting an ecosystem service: approaches to understanding and mitigating threats to wild insect pollinators

Insect pollination constitutes an ecosystem service of global importance, providing significant economic and aesthetic benefits as well as cultural value to human society, alongside vital ecological processes in terrestrial ecosystems. It is therefore important to understand how insect pollinator populations and communities respond to rapidly changing environments if we are to maintain healthy and effective pollinator services. This paper considers the importance of conserving pollinator diversity to maintain a suite of functional traits to provide a diverse set of pollinator services. We explore how we can better understand and mitigate the factors that threaten insect pollinator richness, placing our discussion within the context of populations in predominantly agricultural landscapes in addition to urban environments. We highlight a selection of important evidence gaps, with a number of complementary research steps that can be taken to better understand: i) the stability of pollinator communities in different landscapes in order to provide diverse pollinator services; ii) how we can study the drivers of population change to mitigate the effects and support stable sources of pollinator services; and, iii) how we can manage habitats in complex landscapes to support insect pollinators and provide sustainable pollinator services for the future. We advocate a collaborative effort to gain higher quality abundance data to understand the stability of pollinator populations and predict future trends. In addition, for effective mitigation strategies to be adopted, researchers need to conduct rigorous field-testing of outcomes under different landscape settings, acknowledge the needs of end-users when developing research proposals and consider effective methods of knowledge transfer to ensure effective uptake of actions

First large-scale quantification study of DNA preservation in insects from natural history collections using genome-wide sequencing

Insect declines are a global issue with significant ecological and economic ramifications. Yet, we have a poor understanding of the genomic impact these losses can have. Genome-wide data from historical specimens have the potential to provide baselines of population genetic measures to study population change, with natural history collections representing large repositories of such specimens. However, an initial challenge in conducting historical DNA data analyses is to understand how molecular preservation varies between specimens. Here, we highlight how Next-Generation Sequencing methods developed for studying archaeological samples can be applied to determine DNA preservation from only a single leg taken from entomological museum specimens, some of which are more than a century old. An analysis of genome-wide data from a set of 113 red-tailed bumblebee Bombus lapidarius specimens, from five British museum collections, was used to quantify DNA preservation over time. Additionally, to improve our analysis and further enable future research, we generated a novel assembly of the red-tailed bumblebee genome. Our approach shows that museum entomological specimens are comprised of short DNA fragments with mean lengths below 100 base pairs (BP), suggesting a rapid and large-scale post-mortem reduction in DNA fragment size. After this initial decline, however, we find a relatively consistent rate of DNA decay in our dataset, and estimate a mean reduction in fragment length of 1.9 bp per decade. The proportion of quality filtered reads mapping to our assembled reference genome was around 50%, and decreased by 1.1% per decade. We demonstrate that historical insects have significant potential to act as sources of DNA to create valuable genetic baselines. The relatively consistent rate of DNA degradation, both across collections and through time, mean that population-level analyses—for example for conservation or evolutionary studies—are entirely feasible, as long as the degraded nature of DNA is accounted for

Measurement of the t(t)over-bar production cross section in pp collisions at root s=7 TeV in dilepton final states containing a tau

The top quark pair production cross section is measured in dilepton events with one electron or muon, and one hadronically decaying tau lepton from the decay t (t) over bar -> (l nu(l))((sic)(h)nu((sic)))b (b) over bar, (l = e, mu). The data sample corresponds to an integrated luminosity of 2.0 fb(-1) for the electron channel and 2.2 fb(-1) for the muon channel, collected by the CMS detector at the LHC. This is the first measurement of the t (t) over bar cross section explicitly including tau leptons in proton- proton collisions at root s = 7 TeV. The measured value sigma(t (t) over bar) = 143 +/- 14(stat) +/- 22(syst) +/- 3(lumi) pb is consistent with the standard model predictions

Data from: Mechanisms and fitness effects of antibacterial defenses in a carrion beetle

Parents of many species care for their offspring by protecting them from a wide range of environmental hazards, including desiccation, food shortages, predators, competitors, and parasites and pathogens. Currently, little is known about the mechanisms and fitness consequences of parental defenses against bacterial pathogens and competitors. Here we combine approaches from microbiology and behavioural ecology to investigate the role and mechanistic basis of antibacterial secretions applied to carcasses by parents of the burying beetle Nicrophorus vespilloides. This species rears its larvae on vertebrate carcasses, where larvae suffer significant fitness costs due to competition with bacterial decomposers. We first confirm that anal secretions produced by parents are potently bactericidal, and that their effects are specific to gram-positive bacteria. Next, we identify the source of bacterial killing as a secreted lysozyme, and show that its concentration changes throughout the breeding cycle. Finally, we show that secreted lysozyme is crucial for larval development, increasing survival by nearly two-fold compared to offspring reared in its absence. These results demonstrate for the first time that anal secretions applied to carrion is a form of parental care, and expand the mechanistic repertoire of defenses used by parent insects to protect dependent offspring from microbial threats

Data from: Late-life and intergenerational effects of larval exposure to microbial competitors in the burying beetle Nicrophorus vespilloides

Intergenerational effects can have either adaptive or nonadaptive impacts on offspring performance. Such effects are likely to be of ecological and evolutionary importance in animals with extended parental care, such as birds, mammals and some insects. Here, we studied the effects of exposure to microbial competition during early development on subsequent reproductive success in the burying beetle Nicrophorus vespilloides, an insect with elaborate parental care. We found that exposure to high levels of microbial competition both during a female’s larval development and during her subsequent reproduction resulted in females rearing smaller broods than those exposed to lower levels of microbial competition. To determine whether these differences arose before or after offspring hatching, a cross-fostering experiment was conducted. Our results demonstrate that the impact of larval competition with microbes for resources extends into adult life and can negatively affect subsequent generations via impacts on the quality of parental care provided after hatching. However, we also find evidence for some positive effects of previous microbial exposure on pre-hatch investment, suggesting that the long-term results of competition with microbes may include altering the balance of parental investment between pre-hatch and post-hatch care

Arce et al data

Arce et al dat

Egg data – Experiment 2

Average volume and number of eggs produced by Nicorphorus vespilloides females on mouse carcasses aged for seven days and on fresh carcasses, collected for Experiment 2 in the linked publication. ‘History’ refers to the mother’s natal environment. The weight of the female beetle (‘Mother_weight’) is also given

Brood weight data – Experiment 1

Brood size and weight produced by Nicorphorus vespilloides females on mouse carcasses aged for seven days and on fresh carcasses, collected for Experiment 1 in the linked publication. ‘History’ refers to the mother’s natal environment, ‘Treatment’ to the carcass provided for her first breeding attempt. ‘Family’ indicates which sister females were mated to the same male. The weight of the female beetle (‘Mother_weight’) and the mouse carcass (pre-aging) (‘Mouse_weight’) are given. Brood size refers to the number of successfully dispersing offspring