•Pollinators and natural enemies compared across 217 semi-natural habitats (SNH).•Areal herbaceous SNH most important for pollinators; woody edges for enemies.•Pollinators well predicted by SNH type ...and floral abundance of plant trait groups.•SNH type important to better predict pollinators and enemies in agroecosystems.•Crucial to promote agroecosystems with diverse SNH of complementary plant traits.
Semi-natural habitats (SNH) are vital to sustain pollinators and natural enemies, and the ecosystem services they provide in agroecosystems. However, little is known about the relative importance of different SNH types and their vegetation traits for pollinators and natural enemies. Yet, such knowledge is essential for effective habitat management to promote both functional arthropod groups and associated multiple ecosystem services. We quantified vegetation traits and abundances of pollinators (bees) and natural enemies (predatory flies and parasitic wasps) in 217 SNH differing in type (woody or herbaceous) and shape (linear or areal habitats), for edge and interior locations within each SNH patch with respect to adjacent crops, across 62 agricultural landscapes in four European countries. Pollinators and natural enemies responded distinctively to major SNH types and within-habitat location of SNH: abundance of natural enemies (predatory flies and parasitic wasps) was higher along woody habitat edges than herbaceous SNH or the interior of woody habitats. In contrast, bee abundances, especially of honey bees, were generally higher in areal herbaceous compared to woody SNH. Abundances of both wild bees and managed honey bees were lowest for the interior sampling location in areal woody habitats. These findings reflected divergent key vegetation traits driving pollinator and natural enemy abundances across SNH: bee pollinators increased with herbaceous plant cover and were well predicted by SNH type and the floral abundance of identified key plant trait groups. In contrast, floral abundances of these plant groups were poor predictors of the studied natural enemies, which were better predicted by SNH type and sampling location within SNH. Our findings stress the need to move beyond the simplistic pooling of SNH types and highlight the importance of considering their vegetation traits to more reliably predict pollinators and natural enemies in agroecosystems. They suggest that the floral abundance of key groups of flowering plants is crucial for habitat management to promote bee pollinators, while vegetation-structural traits appear more important for predatory flies and parasitoids. The distinct importance of different SNH types and associated vegetation traits for pollinators and natural enemies calls for agroecosystem management ensuring diverse SNH with complementary vegetation traits to concomitantly foster pollination and pest control services.
•Sown wildflower strips strongly reduced cereal leaf beetle numbers in nearby crops.•This resulted in a 40% reduction of pest-induced crop damage near wildflower strips.•Moreover, crop yield was ...increased by 10% in fields next to wildflower strips.•Broadleaved cover, flower density and diversity were positive predictors of yield.
The effectiveness of agri-environment schemes (AES) such as wildflower strips in promoting farmland biodiversity has been relatively well studied. Their effects on biodiversity-mediated ecosystem services, such as natural pest control, in contrast, remain poorly evaluated and their consequences on crop yield largely unexplored. We assessed the effect of sown, species-rich, perennial wildflower strips, promoted through the Swiss AES, on pest control services and their consequences for crop yield in nearby winter wheat. We found strong reductions in cereal leaf beetle Oulema sp. (CLB) density (eggs: 44%, larvae: 66%) and crop damage (40%) caused by CLB in winter wheat besides wildflower strips (N=10) compared with control fields without wildflower strip (N=10). Moreover, average crop yield was increased by 10% in winter wheat next to wildflower strips up to 10m into the fields. Wheat yield was positively associated with broad leaved plant cover, flower density and diversity of nearby flower strips, yet collinearity with wheat density made these effects difficult to disentangle. Our study demonstrates that diverse wildflower strips with known benefits for farmland biodiversity can also promote biological pest control and crop yield. This creates a win-win situation for crop production and biodiversity conservation, through which such AES may contribute to ecological intensification.
Conservation biological controls utilizing native natural enemies need to comprehend the natural enemy fauna in the area. While green lacewings（Neuroptera: Chrysopidae）are an important group of ...natural enemies in agriculture, their distribution remains unclear in Japan, particularly in the Nansei Islands. This study reports newly recorded green lacewing species found in the Nansei Islands, and summarizes the distribution information of lacewing species. Four species were newly recorded from the Amami Islands, 2 from the Okinawa Islands, 5 from the Miyako Islands, 2 from the Yaeyama Islands, and 4 from the Daito Islands. A total of 25 species of green lacewings were recognized including one species newly found in the Nansei Islands.
Crop domestication is the process of artificially selecting plants to increase their suitability to human requirements: taste, yield, storage, and cultivation practices. There is increasing evidence ...that crop domestication can profoundly alter interactions among plants, herbivores, and their natural enemies. Overall, little is known about how these interactions are affected by domestication in the geographical ranges where these crops originate, where they are sympatric with the ancestral plant and share the associated arthropod community. In general, domestication consistently has reduced chemical resistance against herbivorous insects, improving herbivore and natural enemy performance on crop plants. More studies are needed to understand how changes in morphology and resistance-related traits arising from domestication may interact with environmental variation to affect species interactions across multiple scales in agroecosystems and natural ecosystems.
Tuta absoluta is the most serious insect pest of tomato crops. It control is mainly based on the extended use of insecticides that causes resistance development and increased production cost, and ...thus, there is an urgent need to develop more environmentally friendly methods for its control. Essential oils (EOs) have several advantages that make them valuable alternatives in insect pest control. Data presented in this review show that research conducted so far has proved the insecticidal and repellent effects of EOs against T. absoluta. Their efficacy depends on the application method with fumigation being more effective and on the stage tested with eggs being less susceptible than larvae or adults. In addition, studies have indicated the selectivity of EOs on the natural enemies of T. absoluta, i.e. the mirid predator Nesidiocoris tenuis and the egg parasitoids, Trichogramma spp. Recently scientific interest focuses on the improvement of EOs’ physicochemical properties and the enhancement of their activity applying various nanotechnological approaches. Based on the positive evidence gained, this review concludes that EOs hold promise as alternative means to control T. absoluta and suggests several aspects on which future research should focus toward their commercialization as effective and eco-friendly insecticides.
•Essential oils (EOs) of several plant families are effective against Tuta absoluta.•Eggs and larvae inside their mines suffer less mortality.•Nanotechnology approaches may improve and extend the bioactivity of EOs.•EOs show compatibility with main T. absoluta natural enemies.•Efficacy, selectivity and phytotoxicity of EOs should be further evaluated.
•Emerald ash borer (EAB) from Asia kills most overstory ash trees in North America.•Ash recovery in infested forests requires saplings to mature and produce fertile seed.•Biological control is being ...evaluated for management of EAB in forested ecosystems.•A biocontrol agent Tetrastichus planipennisi reduces EAB populations in ash saplings.•EAB biocontrol enhances ash survival and promotes ash recovery in aftermath forests.
In many parts of North America, ash (Fraxinus) stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees, saplings, basal sprouts, and seedlings. Without a soil seed bank for Fraxinus spp., tree recovery will require survival and maturation of these younger cohorts to reproductive age. Here we report and analyze the population dynamics of emerald ash borer and its associated natural enemies in ash saplings (2.5–5.8cmDBH) in six deciduous forest stands in southern Michigan. At these sites, the outbreak population of the pest collapsed during the study, and a biocontrol agent introduced from China, the larval parasitoid Tetrastichus planipennisi, became widely established and increased in rates of parasitism. To assess the potential for ash recovery in these stands, we also quantified the abundance and crown condition of the ash saplings and surviving ash trees at the study sites. We found that T. planipennisi was the dominant biotic mortality factor in saplings, killing 36–85% of the late instar borer larvae. Neither woodpecker predation nor native parasitoids caused more than minor levels (<20%) of borer mortality in saplings. Life table analyses of these data further showed that the net population growth rate of the pest in saplings was near or under replacement levels, and that the introduced biocontrol agent reduced the pest’s net population growth rate in saplings at our study sites by over 50%. In addition, stand inventories found that healthy ash saplings (4–16 per 100m2) and smaller (pole size) trees (2–9 per 100m2) remained in the six study sites, despite an early high density population of the pest at the sites. These findings indicate that the introduced biocontrol agent T. planipennisi is providing significant biocontrol services, enhancing ash survival and promoting recovery of the ash in southern Michigan.
In the present study, the relative abundance and species diversity indices of family Tachinidae were evaluated based on continuous and regular sampling using Malaise traps in seven regions of ...Mazandaran province during 2011. A total of 280 specimens belonging to 48 species, 38 genera and 4 subfamilies of this family were collected and identified. Species of subfamily Tachininae are the most abundant in the studied areas, followed by Phasiinae. Subfamilies Exoristinae with 16 species and 15 genera and Tachininae with 14 species and 12 genera had the highest number of species and genera in this study. Among the 48 species collected in Mazandaran province, 26 species were single samples. Biodiversity indices showed a significantly difference between studied areas of Mazandran province (P≤ 0.05) based on Simpson and Shannon & Wiener diversity indices. Ghaznasera the elevated area with diverse vegetation, had the highest values of species richness and species diversity indices among the studied areas, followed by Tanghevaz region (forest vegetation). The lowest values of these indices and highest value of Pielou-J evenness, belonged to Jorband, including areas near the sea and rice fields. Also, a positive correlation between biodiversity indices and altitude of studied areas was observed.
Agri-environmental schemes (AES) aim to restore biodiversity and biodiversity-mediated ecosystem services in landscapes impoverished by modern agriculture. However, a systematic, empirical evaluation ...of different AES types across multiple taxa and functional groups is missing. Within one orthogonal design, we studied sown flowering AES types with different temporal continuity, size, and landscape context and used calcareous grasslands as seminatural reference habitat. We measured species richness of 12 taxonomic groups (vascular plants, cicadas, orthopterans, bees, butterflies, moths, hoverflies, flower visiting beetles, parasitoid wasps, carabid beetles, staphylinid beetles, and birds) representing 5 trophic levels. A total of 54,955 specimens were identified using traditional taxonomic methods, and bulk arthropod samples were identified through DNA metabarcoding, resulting in a total of 1,077 and 2,110 taxa, respectively. Species richness of most taxonomic groups, as well as multidiversity and richness of pollinators, increased with temporal continuity of AES types. Some groups responded to size and landscape context, but multidiversity and richness of pollinators and natural enemies were not affected. AES flowering fields supported different species assemblages than calcareous grasslands, but assemblages became more similar to those in seminatural grasslands with increasing temporal continuity. Our results indicate that AES flowering fields and seminatural grasslands function synergistically. Flowering fields support biodiversity even when they are relatively small and in landscapes with few remaining seminatural habitats. We therefore recommend a network of smaller, temporally continuous AES flowering fields of different ages, combined with permanent seminatural grasslands, to maximize benefits for biodiversity conservation and ecosystem service delivery in agricultural landscapes.
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