Monitoring Arthropods in Azorean Agroecosystems: the project AGRO-ECOSERVICES

The data we present are part of the AGRO-ECOSERVICES project (Assessing ecosystem services and disservices provided by arthropod species in Azorean agroecosystems). The project aims to evaluate the relative importance of native and non-native organisms as ecosystem services (ES) and disservices (ED) providers, by combining novel, direct and quantitative tools for monitoring agro-biodiversity. Ecosystem services include evaluation of natural pest control by predation, seed predation on weed plants, pollination, decomposition and ecosystem disservices, herbivory and seed predation on crop plants. Active Aerial Searching (AAS) (only in maize-fields) and pitfall traps were used to sample the arthropod biodiversity (predatory spiders, true-bugs and beetles and main insect pests) on four agricultural habitats of Terceira Island, namely citrus orchards, low and high elevation maize fields and vineyards. We provided an inventory of all arthropods recorded in four Azorean agroecosystems (citrus orchards, low and high elevation maize fields and vineyards) from Terceira Island. A total of 50412 specimens were collected, belonging to four classes, 20 orders, 81 families and 200 identified species of arthropods. A total of 127 species are considered introduced (n = 22646) and 69 native non-endemic (n = 24117). Four endemic species were recorded with very few specimens (n = 14) and 3635 specimens belong to unidentified taxa recorded only at genus or family level. Five species are new records for Terceira Island, with Lagria hirta (Linnaeus, 1758) (Coleoptera, Tenebrionidae) being also a new record for the Azores. This publication contributes to a better knowledge of the arthropods communities present in agro-ecosystems of Terceira Island and will serve as a baseline for future monitoring schemes targeting the long-term change in arthropod diversity and abundance.

Effects of Temporal Crop β Diversification of a Cereal-Based Cropping System on Generalist Predators and Their Biocontrol Potential

In agroecosystems, crop diversification plays a fundamental role in maintaining and regenerating biodiversity and ecosystem services, such as natural pest control. Temporal diversification of cropping systems can affect the presence and activity of natural enemies by providing alternative hosts and prey, food, and refuges for overwintering. However, we still lack studies on the effects of temporal diversification on generalist predators and their biocontrol potential conducted at field scale in commercial agricultural settings. Here, we measured proxies of ecosystem functions related with biological pest control in 29 commercial agricultural fields characterized by cereal-based cropping system in Lower-Saxony, northern Germany. The fields differed in the number of crops and cover crops cultivated during the previous 12 years. Using the Rapid Ecosystem Function Assessment approach, we measured invertebrate predation, seed predation and activity density of generalist predators. We aimed at testing whether the differences in the crop rotations from the previous years would affect activity of predators and their predation rates in the current growing season. We found that the length of the crop rotation had neutral effects on the proxies measured. Furthermore, predation rates were generally lower if the rotation comprised a higher number of cover crops compared to rotation with less cover crops. The activity density of respective taxa of predatory arthropods responded differently to the number of cover crops in the crop rotation. Our results suggest that temporal crop diversity may not benefit the activity and efficiency of generalist predators when diversification strategies involve crops of very similar functional traits. Adding different resources and traits to the agroecosystems through a wider range of cultivated crops and the integration of semi-natural habitats are aspects that need to be considered when developing more diverse cropping systems aiming to provide a more efficient natural pest control.

Inventory of refugia plants potentially medicinal in the agricultural area of Plandaan Subdistrict, Jombang Regency, East Java Province

Agricultural and plantation areas dominate the Plandaan subdistrict, so the majority of the livelihoods of its residents are engaged in agriculture. In practice, in addition to using pesticides, crop pest control in the Plandaan subdistrict is to make use of refugia plants. The refugia technique is economical and environmentally friendly because it does not use synthetic chemicals that damage the environment. In addition to acting as natural pest control, refugia plants are also known to have potential as medicines. This study aimed to inventory or collect medicinal plants refugia in the agricultural area of ​​the Plandaan subdistrict. This study used descriptive explorative methods. Data collection techniques were carried out through observation and directly documenting species of refugia plants with potential drugs found in the area of observation plots. In this study, the subject was a potentially medicinal refugia plant found on an observational plot with a plot size of 10 × 10 meters. The observations were three plots of agriculture fields and three plots of telajakan (open space). The frequency of refugia plants found from the study on the plot of agriculture fields as many as 1035 plants, while in the plot of telajakan as many as 1007 plants consisting of 37 types of species that each has different medicinal potentials, such as heat and fever lowering, treating cough, flu, skin diseases, and wounds. Agriculture field plots had more frequency of potentially medicinal refugia plants than telajakan plots.

How effective are frogs in regulating crop pest population in a natural multi-trophic system??

Potential of frogs as important natural pest control agents has been highlighted earlier. But the effectiveness of frogs in regulating the pest load in intensive agricultural landscape in a multi-trophic system is not clear. We performed controlled field experiment in paddy field with a varying density (observed in high and low agricultural intensity (AI) areas) of a commonly found frog species and compared the pest and pest predator build-up. The consumption rate of the model amphibian was studied using enclosure experiment. The consequent trophic cascade effect of frogs on both crop pest and other arthropod pest predator was analyzed using mathematical population growth models. Although frogs consumed pests, they could not reduce crop pest abundance. Although a lesser frog density found in high AI areas significantly affected the pest predator abundance. Based on the functional response result, mathematical growth models demonstrated that with a constant harvesting factor (Holling Type II) frogs will always have a negative impact on the beneficial natural enemy population due to intraguild predation thereby limiting its potential as a pest regulator. Our study challenges the notion of frogs as an effective pest control agent and argues that increasing habitat diversity might improve overall biological pest suppression.

Identification of Entomopathogenic Nematode-Associated Bacteria Originating from Mojokerto

Entomopathogenic nematodes (EPN) are one of the soil worms that have been widely used as a natural pest control. EPN has its pathogenic capability because of the mutualistic interactions between nematodes and symbiotic bacteria inside the digestive tract of nematodes. Symbiotic bacteria capable of producing exoenzymes that are toxic to insects. The isolation of symbiotic bacteria accomplished by infection of obtained EPN (Belik II isolate) into Tenebrio molitor larvae. Symbiotic bacteria were isolated from the hemolymph of dead larvae on NBTA media. Isolation of symbiotic bacteria was successfully obtained two morphologically distinct bacteria: B 3.1 isolate and B 4 isolate. Both bacteria were further identified using PCR analysis of the 16S rRNA gene. Based on the sequencing results, the B 3.1 isolate was in accordance with Acinetobacter pittii strain ATCC 19004, while B 4 isolate was in accordance with bacteria Enterobacter aerogenes strain KCTC 2190. The characterization of B 3.1 isolate was shown to have similarities with Acinetobacter sp., i.e.: gram-negative, non - motile, rod-shaped, and some other characteristics of biochemical tests. While the characterization of B 4 isolate was shown to have similarities with E. aerogenes i.e.: gram-negative, rod-shaped, motile, and some other characteristics of biochemical tests. These findings will be the potential to be applied as biological agents in pest control.

Proportion of Grassland at Landscape Scale Drives Natural Pest Control Services in Agricultural Landscapes

Managing regulating ecosystem services delivered by biodiversity in farmland is a way to maintain crop yields while reducing the use of agrochemicals. Because semi-natural habitats provide shelter and food for pest enemies, a higher proportion of semi-natural habitats in the landscape or their proximity to crops may enhance pest control in arable fields. However, the ways in which the spatial arrangement of these habitats affects the delivery of this beneficial ecosystem service to crops remains poorly known. Here, we investigated the relative effects of the amount of grassland in the landscape versus the distance to the nearest grassland on the predation rates of weed seeds and aphids into 52 cereal fields. We found that both seed and aphid predation levels increased with the proportion of grassland in a 500 m radius buffer while the distance to the nearest grassland displayed no effect. We show that increasing from 0 to 50% the proportion of grasslands in a 500 m radius, respectively, increased seed and aphid predation by 38 and 20%. In addition to the strong effect of the proportion of grassland, we found that seed predation increased with the proportion of forest fragments while aphid predation increased with the proportion of organic farming in the landscape. Overall, our results reveal that natural pest control in cereal crops is not related to the distance to the nearest grassland, suggesting that natural enemies are not limited by their dispersal ability. Our study indicates that maintaining key semi-natural habitats, such as grasslands, is needed to ensure natural pest control and support food production in agricultural landscapes.

Management to Promote Flowering Understoreys Benefits Natural Enemy Diversity, Aphid Suppression and Income in an Agroforestry System

Agroforestry systems, where productive trees are integrated into agricultural land, can deliver benefits to biodiversity, natural pest control, and pollination, but the effects are highly variable. Recent advances in our understanding of flower strips in agricultural systems suggest that the management of the tree row understorey could be an important contributor to this variation. Here, we compare two cutting regimes for an understorey, originally seeded with the same flower mix, in the tree rows of an apple-arable agroforestry system: (i) uncut vegetation to promote a flowering understorey, and (ii) regularly mown vegetation. We recorded the effects of management on invertebrate pests, natural enemies, and pollinators, in both the apple and arable components. Apple trees above flowering understoreys supported significantly: (i) more natural enemies early in the season, (ii) fewer aphid colonies, (iii) fewer aphid-damaged fruits, and (iv) higher pollinator visitation, compared with those above mown understoreys. In the arable crop alleys, both the taxonomic richness and Shannon diversity of ground-based natural enemies were significantly higher adjacent to flowering understoreys, compared with those adjacent to mown understoreys, early in the season. Financial modelling based on aphid damage to apples, mowing costs, and income from Countryside Stewardship grants, indicated that flowering understoreys increased farm income by GBP 231.02 per ha of agroforestry compared with mown understoreys. Our results provide the first empirical evidence that management to promote flowering understoreys in agroforestry systems can be a win-win option to improve invertebrate diversity, associated ecosystem services, and farm income.

Prey removal in cotton crops next to woodland reveals periodic diurnal and nocturnal invertebrate predation gradients from the crop edge by birds and bats

Factors influencing the efficacy of insectivorous vertebrates in providing natural pest control services inside crops at increasing distances from the crop edge are poorly understood. We investigated the identity of vertebrate predators (birds and bats) and removal of sentinel prey (mealworms and beetles) from experimental feeding trays in cotton crops using prey removal trials, camera traps and observations. More prey was removed during the day than at night, but prey removal was variable at the crop edge and dependent on the month (reflecting crop growth and cover) and time of day. Overall, the predation of mealworms and beetles was 1-times and 13-times greater during the day than night, respectively, with predation on mealworms 3–5 times greater during the day than night at the crop edge compared to 95 m inside the crop. Camera traps identified many insectivorous birds and bats over crops near the feeding trays, but there was no evidence of bats or small passerines removing experimental prey. A predation gradient from the crop edge was evident, but only in some months. This corresponded to the foraging preferences of open-space generalist predators (magpies) in low crop cover versus the shrubby habitat preferred by small passerines, likely facilitating foraging away from the crop edge later in the season. Our results are in line with Optimal Foraging Theory and suggest that predators trade-off foraging behaviour with predation risk at different distances from the crop edge and levels of crop cover. Understanding the optimal farm configuration to support insectivorous bird and bat populations can assist farmers to make informed decisions regarding in-crop natural pest control and maximise the predation services provided by farm biodiversity.