Pollination services from wild insects contribute to crop productivity around the world, but are at risk of decline in agricultural landscapes. Using highbush blueberry as a model system, we tested ...whether wildflower plantings established adjacent to crop fields would increase the abundance of wild pollinators during crop bloom and enhance pollination and yield. Plantings were seeded in 2009 with a mix of 15 perennial wildflower species that provided season‐long bloom and increased plant density and floral area during the subsequent 3 years. Honeybees visiting blueberry flowers had similar abundance in enhanced and control fields in all 4 years of this study, whereas wild bee and syrphid abundance increased annually in the fields adjacent to wildflower plantings. Crop pollination parameters including percentage fruit set, berry weight and mature seeds per berry were significantly greater in fields adjacent to wildflower plantings 3 and 4 years after seeding, leading to higher crop yields and with the associated revenue exceeding the cost of wildflower establishment and maintenance. Synthesis and applications. We suggest that provision of forage habitat for bees adjacent to pollinator‐dependent crops can conserve wild pollinators in otherwise resource‐poor agricultural landscapes. Over time, these plantings can support higher crop yields and bring a return on the initial investment in wildflower seed and planting establishment, also insuring against loss of managed pollinators. Further understanding of the importance of planting size, location and landscape context will be required to effectively implement this practice to support crop pollination.
Recent evidence highlights the value of wild-insect species richness and abundance for crop pollination worldwide. Yet, deliberate physical importation of single species (eg European honey bees) into ...crop fields for pollination remains the mainstream management approach, and implementation of practices to enhance crop yield (production per area) through wild insects is only just beginning. With few exceptions, studies measuring the impacts of pollinator-supporting practices on wild-insect richness and pollination service success - particularly in relation to long-term crop yield and economic profit - are rare. Here, we provide a general framework and examples of approaches for enhancing pollinator richness and abundance, quantity and quality of pollen on stigmas, crop yield, and farmers' profit, including some benefits detected only through long-term monitoring. We argue for integrating the promotion of wild-insect species richness with single-species management to benefit farmers and society.
Urban trees are at risk of stress due to heat island effects and the increased proportion of impervious areas surrounding them. Among pests of trees, insect borers such as bark beetles (Coleoptera: ...Curculionidae) and flatheaded borers (Coleoptera: Buprestidae) are some of the most devastating, frequently colonizing stressed trees. The objective of this study was to explore the effects of biotic and abiotic risk factors on borer attacks on trees in urban areas. In the summer of 2021 and 2022, this study was conducted in 50 urban sites in Atlanta and Augusta, Georgia (USA). Specific factors explored include overall tree health, differentially warmer maximum and minimum temperatures of sites compared to surrounding areas, tree species, and the percentage of impervious surface surrounding trees. Generalized linear models and zero-inflated models explored how these factors were related to damage from these borers. The number of borer attacks on trees increased with higher percentage impervious area. As the two most commonly encountered trees, Acer rubrum was found to be significantly more susceptible to attack from borers than Ulmus parvifolia. Unhealthy trees were more likely to experience more frequent and more severe borer attack. Trees with increased impervious cover around them as well as those with differentially warmer daily maximum and minimum temperatures relative to surrounding were more likely to be attacked.
Native wildflower plantings can be used to provide nutritional resources to support pollinating insects, yet the effects of planting size and bloom richness on the density, diversity, and function of ...these insects are not well understood. We established stands of twelve native flowering perennial plant species in replicated plots ranging in size from 1 to 100m2. These plots were sampled for insect pollinators, bloom richness, and seed production by three wildflower species. Honeybees, wild bees, and hoverflies all responded positively to increasing flower richness, whereas particular insect pollinator groups responded differently to the size of the flowering plant area. The density of honeybees and hoverflies was not affected by increasing flowering patch size, whereas in general, wild bees were observed at higher density and diversity in the 30 and 100m2 patches. Increasing wildflower patch size, and thus wild bee density, resulted in greater seed set in the sampled wildflowers. These results indicate that wild bees are sensitive to the area and richness of floral resources in patches, even at relatively small scales. Therefore, larger wildflower plantings with more diverse flower species mixes are more suitable for the conservation of wild pollinators and reproduction of sown species.
Mit dem Anpflanzen von einheimischen Wildkräutern können Nahrungsressourcen bereitgestellt werden, um bestäubende Insekten zu unterstützen, aber die Effekte von Größe der Anpflanzung und Vielfalt der Blüten auf Dichte, Diversität und Funktion dieser Insekten sind wenig bekannt. Wir bepflanzten replizierte Plots unterschiedlicher Größe (1 – 100m2) mit zwölf einheimischen ausdauernden Blütenpflanzenarten. Auf diesen Plots wurden Beobachtungen zu den blütenbesuchenden Insekten und zur Vielfalt der blühenden Arten gemacht und die Samenproduktion von drei Arten bestimmt. Honigbienen, Wildbienen und Schwebfliegen reagierten positiv auf zunehmende Blütenvielfalt, während die einzelnen Bestäubergruppen unterschiedlich auf die Größe der Plots reagierten. Die Dichte der Honigbienen und Schwebfliegen wurde nicht von der Größe der Plots beeinflusst, während die Wildbienen im Allgemeinen auf den 30- und 100m2-Plots höhere Dichte und Diversität erreichten. Zunehmende Plot-Größe und damit Wildbienendiversität ergaben höheren Samenansatz bei den untersuchten Pflanzenarten. Diese Ergebnisse zeigen, dass Wildbienen empfindlich auf das Areal und die Vielfalt der Blütenressourcen reagieren, sogar auf relativ kleinen Skalen. Deshalb sind größere Wildblumenanpflanzungen mit diverseren Artenmischungen besser für den Schutz von wilden Bestäubern und die Reproduktion der ausgesäten Arten geeignet.
1. An important means of conserving beneficial insects in resource‐limited habitats is to meet their ecological requirements, which may be achieved by providing areas containing flowering plants that ...bloom throughout the season, but little is known about the importance of wildflower plot size for supporting natural enemies or the biological control they provide.
2. Wildflowers were established in plots of sizes ranging from 1 to 100 m
2
, and found that natural enemy density, group richness, and diversity of natural enemy groups increased with plot size.
3. The density of insect herbivores was lower in all flower plots than in the control samples, whereas the diversity of herbivore groups was significantly higher in flower plots.
4. Comparing population growth of sentinel soybean aphids (
Aphis glycines
Matsumura) among plot sizes, aphid colonies were smaller as plot size increased.
5. Providing beneficial insects with flowering resources resulted in significantly more natural enemies and greater pest control than in smaller flower plots or mown grass areas.
6. These results indicate that the density, diversity, and function of natural enemies are sensitive to the size of wildflower plantings, even at relatively small scales. Therefore, larger wildflower plots are more suitable for the conservation of beneficial insects and their provision of natural pest control.
There have been notable and significant advances in elucidating the chemical ecology of the invasive
Halyomorpha halys
(Hemiptera: Pentatomidae), brown marmorated stink bug. This highly destructive ...and polyphagous pest is originally from Korea, China, and Japan, but was accidentally introduced into North America and Europe. Prior to its invasion into these regions, little was known about its chemical ecology. However, since then, researchers have identified and synthesized its aggregation pheromone, documented its synergism with the pheromone of another Asian stink bug,
Plautia stali
, developed monitoring traps of various designs, and lures with reliable attractants have become commercially available. Furthermore, plant volatiles have been shown to have attractive, neutral, and repellent effects on attraction and retention of
H. halys
, and
H. halys
-derived volatiles have been shown to play a role in recruiting natural enemies. Finally, management strategies based on pheromone-based technology have been evaluated, including insecticide applications based on a cumulative threshold of adult captures in pheromone-baited traps, and the use of intensively baited trees in an attract-and-kill strategy to manage this pest. This review summarizes the available literature on the chemical ecology of
H. halys
and concludes with several research areas that should be explored in future research.
In this study we focus on the invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), which has a strong dispersal capacity and has had a significant impact on ...several cropping systems, including peach (Prunus persica (L.)). Management of H. halys has relied on intensive insecticide use, and thus a better understanding of its dispersal behavior may assist in developing improved management strategies. In order to investigate H. halys movement and distribution patterns within a peach orchard we applied ecologically safe, food protein markers to the trees along the orchard border (chicken egg albumin in the form of liquid egg whites) and to the trees within the orchard interior (bovine casein in the form of cow's milk). We used enzyme-linked immunosorbent assays (ELISA) to assess whether collected H. halys were "marked" with either of the two protein markers, revealing where in the orchard the bugs had visited. From the density data we determined that H. halys is a perimeter-driven pest in peaches, with a significantly higher density of bugs collected along the orchard border. Interestingly, this trend is primarily driven by the distribution of male bugs. The protein marking data revealed that a small proportion of male H. halys move equally between the orchard border and interior, while a small proportion of females move predominately to the border after visiting the interior. The verification of a strong edge-effect, although potentially sex-specific, implies that H. halys displays a dispersal behavior that may also be exploited for management, which may help growers more efficiently and more effectively manage H. halys.
Crop pollination and natural biological control provided by beneficial insects have an economic worth of hundreds of billions of dollars annually. Apple and peach production in North Georgia are ...economically important industries that benefit from these ecological services. Hover flies are dual ecosystem service providers that have been relatively understudied in orchard ecosystems. We investigated the diversity and seasonal activity of hover flies in apple and peach orchards at 2 sites in North Georgia from March to October 2020 and 2021. Bowl traps were used to sample hover flies in orchard edge and interior habitats. The aphidophagous species Toxomerus geminatus (Say) (Diptera: Syrphidae) and Toxomerus marginatus (Say) (Diptera: Syrphidae) comprised 86.6% of the total hover flies collected. Apple orchards yielded the greatest hover fly presence, species richness, and Toxomerus spp. abundance. Hover fly richness and diversity were greatest during postbloom, but Toxomerus spp. abundance was greatest during the bloom period. No differences in presence, richness, diversity, or Toxomerus spp. abundance were found between edge and interior habitats. Toxomerus geminatus and T. marginatus were dominant from March through August, with T. geminatus being more abundant than T. marginatus in March, early April, and August. October sampling produced the greatest hover fly richness. Our results suggest that hover flies are abundant in North Georgia orchards and exhibit substantial spatial and temporal variation in richness and diversity. Expanded studies incorporating additional sampling efforts and methods are needed to further characterize the hover fly fauna and their impact on North Georgia apple and peach orchards.
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