1. Agricultural pollinator management requires knowledge on pollinator-crop interactions, including information on pollinator visits to crop flowers. Time-lapse trail cameras may provide an efficient and simple tool to collect such information. However, research evaluating their performance against traditional direct observation of crop pollinators is scarce. 2. Here, we compare trail camera and human observer performance for collecting flower visitation data in two crops, apple and caraway, in boreal farmland. Five commercially available trail cameras recorded time-lapse images of crop flowers throughout one flowering season. Near each camera, a human observer monitored flower visits five times per crop. 3. In apple, cameras recorded more diverse pollinator assemblages than the human observer. This was due to better detection of less conspicuous flower visitors, as well as to a larger time window for the camera monitoring. 4. Honeybees dominated flower visits in apple but with a lower proportion in the camera monitoring. 5. In caraway, hoverflies dominated flower visits in both methods. Their proportion was similar between the methods during similar observation periods, but lower in the camera monitoring when using full camera data with larger temporal coverage. 6. Detecting pollinators from images was harder for caraway than for apple. 7. Time-lapse photography with manual image analysis was more time- and cost-efficient than human observation. 8. In conclusion, trail camera photography appears as a competitive method for monitoring pollinator flower visits in apple but not in caraway. Automated pollinator detection from images can improve the method's efficiency in the future.
1. Invasive species pose major threats to biodiversity, crop production and rural livelihoods worldwide. The red gum lerp psyllid Glycaspis brimblecombei Moore is an invasive pest that causes significant damage to Eucalyptus trees globally. Because the species is highly host-specific and develops exclusively on Eucalyptus spp., its establishment outside its native range depends not only on climatic suitability but also on host availability. However, spatially explicit habitat suitability models that can guide targeted surveillance and monitoring remain limited. 2. In this study, the global potential distribution of G. brimblecombei was estimated using the MaxEnt model. Model performance was robust (AUC = 0.880; TSS = 0.634; CBI = 0.803), indicating strong discriminatory capacity and balanced predictive accuracy. Annual mean temperature (Bio01) was the most influential predictor, contributing approximately 35% to model performance, followed by annual temperature range (Bio07; similar to 20%). 3. Under current climatic conditions, highly suitable areas are concentrated in tropical and subtropical regions, including parts of South America, Africa, and Oceania, with additional suitable areas predicted in Europe, North America, and Asia. Future projections for 2041-2060 under SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios indicate moderate contractions in highly suitable habitats, although core distribution regions are expected to persist. 4. These findings provide spatially explicit insights to support surveillance and management of G. brimblecombei under ongoing climate change. However, the predicted suitable areas represent climatic suitability and should be interpreted in conjunction with the distribution of Eucalyptus plantations and ornamental plantings, as host availability remains a prerequisite for species establishment.
Entomopathogenic fungi (EPF) can suppress aphid populations through biological control, but whether EPF-associated volatile cues influence aphid behaviour remains poorly understood. We investigated the olfactory response of apterous Myzus persicae to Beauveria bassiana and to conspecifics infected with B. bassiana. Aphid responses were assessed using four-arm olfactometer assays. In the first assay, aphids were exposed to B. bassiana-colonised agar, sterile agar and two blank-air controls. In the second, aphids were exposed to odours from EPF-infected conspecifics, healthy conspecifics, an agar control and a blank-air control. Time spent within each odour field was converted to compositional proportions and analysed following centred log-ratio transformation. Aphids showed no detectable olfactory response to B. bassiana-colonised agar alone. In contrast, aphids responded positively to odours associated with infected conspecifics, spending significantly more time in this odour field than in those containing healthy aphids, agar or blank air. These findings demonstrate that the behavioural response of M. persicae to EPF-associated cues is context dependent, with cues generated during host infection appearing more salient than fungal odours presented in isolation. The results extend our understanding of pathogen-mediated chemical communication in aphids and suggest that EPF infection may influence host-pathogen interactions and potentially pathogen transmission in ways that are not predicted by repellency-based models alone.
Barley yellow dwarf virus (BYDV) causes major yield losses in temperate cereals. In many regions, management of BYDV has focused on Rhopalosiphum padi as the primary vector of BYDV-PAV and Sitobion avenae as the primary vector of BYDV-MAV. By contrast, the significance of Metopolophium dirhodum beyond its summer feeding damage is less clear. Although M. dirhodum can transmit both BYDV species, its role in driving disease outbreaks has received limited attention in management discussions, and its field occurrence and population biology under Irish conditions remain poorly studied. This study addresses this gap by examining the seasonal presence and life-history parameters of M. dirhodum in temperate barley systems. National field monitoring (2022-2025) using yellow-pan traps and in-field tiller assessments confirmed regular occurrence of M. dirhodum in Irish barley crops, with consistent spring barley establishment and occasional winter barley colonization, demonstrating distinct seasonal phenology compared to S. avenae. In terms of life-history, all clones showed high fecundity and extended adult longevity. Population parameters indicated strong reproductive potential, with intrinsic (r) and finite (lambda) rates of increase consistent with a capacity for rapid population growth under favourable conditions. This study provides the first integrated assessment of M. dirhodum population biology and seasonal dynamics in Ireland, and our findings demonstrate that the species maintains stable field presence and strong reproductive capacity on barley, reinforcing its status as an important component of national aphid-monitoring and integrated pest management programmes.
Abstract Pollinator diversity is declining worldwide, mainly due to agricultural habitat loss, threatening wild plant reproduction and crop pollination. Although natural habitat supports pollination services in agricultural landscapes, the amount needed remains unclear. We assessed how the percentage of natural habitat (NH) and distance from the orchard edge (DFE) influence pollinator richness and abundance in sweet cherry and apple orchards in Mediterranean central Chile. Twenty‐seven orchards of each crop were sampled over 2 years, classified by NH within a 1‐km buffer (<35%, 35%–70%, >70%). Pan traps surveyed pollinators at three distances from the orchard edge to the crop interior (0, 70 and 140 m). Both crops were modelled jointly, as crop identity did not affect pollinator richness, abundance, or honey bee abundance. Wild pollinator richness and abundance were higher with more surrounding natural habitat and decreased with distance from the edge. This decline was steeper in orchards with less natural habitat, buffering the edge effect. Honey bee abundance was unaffected by NH or DFE, and both wild pollinator and honey bee metrics were lower in the second year. Species composition differed significantly among NH categories, crops and years, although crop‐ and year‐related differences were each driven by only a small subset of taxa. Most species contributing to compositional differences among NH categories increased in abundance with NH, and none were more abundant in orchards with less than 35% NH. Our results suggest that landscapes with at least 35% of NH may better maintain wild pollinator diversity, although this value should not be interpreted as a biological threshold.
