Land sparing or sharing: strategies for conservation of arable plant diversity

Strategies to achieve agricultural production and biodiversity conservation fall into two categories, land-sparing or land-sharing. Plant species richness under organic arable (land sharing) versus conventional arable with land set-aside for conservation (land sparing) was evaluated on adjacent farms to compare these strategies. Sampled plant species richness was significantly higher under organic than conventional arable, as expected, but very similar to set-aside. Nevertheless, the Chao1 estimator of total plant species richness indicated that the larger area available to plants under organic arable may sustain more scarce species leading to a higher species richness. It appears that the conservation value of sparing versus sharing depends on the relative species richness of the portion of land spared (set-aside) compared to the larger area of shared land (organic), and not with the species richness on conventionally cropped land. Furthermore, in theory the land-shared use will have greater capacity to sustain populations of scarce low-density species simply due 100% of the land area being available to these species. These are important principals for assessing land sparing versus sharing strategies seeking to balance production and biodiversity conservation not just for arable land but all agricultural land uses

Buzzing benefits: how multi-species pollination boosts strawberry yield, quality, and nutritional value

A diverse assemblage of insect visitors can provide functional complementarity within plant pollination due to differences in characteristics such as their physical traits, visitation rate and foraging time of day or year. In a horticultural context, greater functional complementarity may play a crucial role in enhancing fruit yield and quality by improving pollination. We tested whether the identity of the crop pollinators (bumblebee Bombus terrestris and hoverfly Eupeodes corollae) independently and additively influenced commercial strawberry yield, quality, and nutritional parameters such as vitamin C and sugar concentration. Fragaria x ananassa “Malling Champion” plants received pollination treatments of either a) “control”: self-pollination where pollinators were excluded, b) “bee”: bumblebee Bombus terrestris, c) “hoverfly”: Eupeodes corollae, d) “combined”: both B. terrestris and E. corollae. Hoverflies and bumblebees exhibited distinct visitation patterns throughout the day, establishing a functional complementary relationship that enhances pollination success and crop output as well as vitamin C concentrations. Strawberries from plants receiving pollination by bumblebees, or bumblebees and hoverflies combined, had higher yields of higher marketable quality. They also had measurably higher vitamin C content than strawberries from plants pollinated by hoverflies alone, or the control (self-pollinating) plants. This study advances our understanding of niche complementarity and its impact on fruit yield and quality. By elucidating the behavioural and temporal dynamics of pollinators, we provide valuable insights for optimizing pollination strategies in agricultural contexts. Our findings highlight the significance of behavioural factors, such as handling time and number of visits, in determining fruit quality

Enhanced West Nile virus surveillance in the North Kent marshes, UK

Background As part of efforts to more fully understand the potential risks posed by West Nile virus (WNV) and Usutu virus (USUV) in the UK, and following on from previous reports of a potential bridge vector Culex modestus for these viruses, at wetland sites in North Kent, mosquito surveillance was undertaken more widely across the Isle of Sheppey, the Hoo Peninsula and the Kent mainland. Methods Larval surveys were conducted and Mosquito Magnet® adult traps were used to collect adult mosquitoes. Pools of female mosquitoes were tested for the presence of WNV using real-time reverse transcriptase polymerase chain reaction. A subset of samples was tested for USUV. Results Culex modestus was found in both the pre-imaginal and imago stage at all five locations surveyed, accounting for 90% of adult mosquitoes collected. WNV or USUV were not detected in any sample. Conclusions Although no mosquitoes have been shown to be virus positive, the field survey data from this study demonstrated the dominance of an important bridge vector species for WNV in this region. Its wide geographical distribution highlights the need to update risk assessments on WNV introduction, and to maintain vigilance for WNV in the South East of England

Global perspectives and transdisciplinary opportunities for locust and grasshopper pest management and research

Locusts and other migratory grasshoppers are transboundary pests. Monitoring and control, therefore, involve a complex system made up of social, ecological, and technological factors. Researchers and those involved in active management are calling for more integration between these siloed but often interrelated sectors. In this paper, we bring together 38 coauthors from six continents and 34 unique organizations, representing much of the social-ecological-technological system (SETS) related to grasshopper and locust management and research around the globe, to introduce current topics of interest and review recent advancements. Together, the paper explores the relationships, strengths, and weaknesses of the organizations responsible for the management of major locust-affected regions. The authors cover topics spanning humanities, social science, and the history of locust biological research and offer insights and approaches for the future of collaborative sustainable locust management. These perspectives will help support sustainable locust management, which still faces immense challenges such as fluctuations in funding, focus, isolated agendas, trust, communication, transparency, pesticide use, and environmental and human health standards. Arizona State University launched the Global Locust Initiative (GLI) in 2018 as a response to some of these challenges. The GLI welcomes individuals with interests in locusts and grasshoppers, transboundary pests, integrated pest management, landscape-level processes, food security, and/or cross-sectoral initiatives

The cabbage whitefly, aleyrodes Proletella: causes of outbreaks and potential solutions

The cabbage whitefly, Aleyrodes proletella, has in recent years become a primary pest of several brassica crops in Europe. In the UK, its greatest impact has been on kale, where nymphs, wax deposits and sooty mould caused by honeydew excretion reduce the marketable portion of the crop, particularly later in the year. In order to test the contribution of insecticide resistance to these outbreaks, a leaf-dip bioassay method was developed. Resistance to several pyrethroids was found in multiple populations in Lincolnshire and Kent, with similar patterns between compounds but differing magnitudes of resistance. This resistance was expressed to a similar degree by both adults and nymphs. The host plant used in bioassays influenced lethal concentrations but not resistance factors. A diagnostic concentration of lambda-cyhalothrin was identified and used to screen further populations over successive years. No cross-resistance to neonicotinoid insecticides was evident in highly pyrethroid-resistant populations. Bioassays with the synergist piperonyl butoxide provided no evidence of mixed-function oxidase or associated nonspecific esterase involvement in pyrethroid resistance. Attempts to sequence the sodium channel gene of susceptible and resistant whiteflies to check for target-site resistance were unsuccessful. Field surveys of whitefly populations on wild cabbage were carried out to identify candidate native biological control agents for use in IPM strategies in field crops. These identified several parasitoid wasps and a coccinellid beetle, Clitostethus arcuatus. One of the parasitoids, Encarsia tricolor, and C. arcuatus were successfully cultured at NRI and tested in outdoor cage trials. In 2011, a multiple generation trial demonstrated the superiority of parasitoid release during the development of the first generation of whiteflies over later releases of E. tricolor or C. arcuatus. A Horticultural Development Company funded field trial in 2012 showed that insecticide application early in a whitefly infestation could provide prolonged control equivalent to regular spraying. This research will contribute to the development of future integrated pest IV management programmes for A. proletella through avoiding ineffective pyrethroid applications, facilitating insecticide resistance management and identifying non-chemical approaches

The cabbage whitefly Aleyrodes proletella and its natural enemies on wild cabbage Brassica oleracea on the Kent coast

Field surveys of Aleyrodes proletella populations on wild cabbage Brassica oleracea on the Kent coast were carried out in 2009 and 2010 in order to investigate the ecology of the whitefly in this habitat, to identify native natural enemies and to quantify their impact. Whiteflies were found to overwinter largely as adults on the most sheltered plants in a location and, while dispersal to other plants was evident, reached the greatest numbers on these plants. Three putative generations of juvenile whiteflies were monitored throughout 2010. It was found that more frequent monitoring would be necessary to estimate survival to eclosion; this, along with the loss of puparial exuviae from wild cabbage leaves under field conditions prevented conclusive estimates of survival to be calculated. Observations of potential predators and estimates of parasitism were possible; observed parasitism peaked in the second generation at 2.75% of all juveniles monitored. Limited sampling identified several chalcid parasitoid wasp species (Encarsia tricolor, Encarsia inaron and Euderomphale chelidonii) and a coccinellid beetle, Clitostethus arcuatus, as antagonists