Enemies Of Pests Research Articles

Selected flowering plants as a habitat for pollinators and natural enemies in field margins of a watermelon crop—implications for crop yield

The practice of field margins management using mixtures of selected plants to provide habitats for pollinators and natural enemies of pests, and possible impact on crop yield, was studied for two mixtures (mixture A: Borago officinalis, Coriandrum sativum, Glebionis coronaria; mixture B: Vicia sativa, Sinapis alba, Phacelia tanacetifolia) in watermelon, cv. Karistan. The sown margins attracted primarily Apis mellifera and Halictidae bees (Lasioglossum spp.), and a few other Apidae (Anthophora sp., Eucera sp., Bombus sp.) over a flowering period of 6 weeks (beginning of April to mid-May). Pollinators on watermelon flowers were mainly Halictidae (Lasioglossum spp.) and fewer honey bees, from mid-May to mid-June. Shannon’s (Η) diversity index of parasitoids was higher in mixture B while their abundance did not differ between the plant mixtures, although it varied during the season. Higher weight/fruit, lower proportion of undeveloped/mature seeds per fruit, and higher Brix level in the field with the sown margins compared to a commercial watermelon, cv. Karistan, field, under common agronomic practices, suggest a positive effect of the sown margins on the crop yield.

Using motifs in ecological networks to identify the role of plants in crop margins for multiple agriculture functions

Advances in network ecology offer new tools for the sustainable management of agroecosystems. Plants in field margins may be involved in different processes of agronomic importance - indirectly affecting crops by supporting shared pollinators, hosting natural enemies of pests or acting as pest reservoirs. In this work, we explored the use of motifs (patterns of interaction between a subset of species) in agricultural ecological networks incorporating multiple types of trophic interactions to identify plant species with a key role in field margins. We searched for plant species benefiting crops via (1) shared pollinators and (2) supporting parasitoids of crop pests; or (3) negatively affecting crops through attracting pest herbivore species. We focused on determining whether species’ showed consistent affiliation with these roles across the landscape and evaluated the potential of plant species to influence crops indirectly via shared insect partners. To showcase our framework, we used a unique data set of antagonistic and mutualistic interactions recorded in soybean crops and wild plant species in field margins, that despite its limitations (e.g., spanning one growing season) allowed us to test our approach using multiple types of interactions simultaneously. Here, we support the use of motifs in multi-trophic interaction networks in agroecosystems to reveal the role of key plant species in sustaining ecological functions involving crops and other plant species, enhancing the evidence base for management recommendations in the future.

Effects of soil mitigation on lawn-dwelling invertebrates following residential development

Abstract Residential areas are the most rapidly expanding land use type in the southeastern USA. Residential development impairs soil functions primarily through compaction and the removal or burial of topsoil and natural vegetation, which reduces water infiltration and retention, root penetration, and plant establishment. Plant stress reduces plant-derived ecosystem services and increases vulnerability to pests, often leading to supplemental management inputs in the form of irrigation, fertilizers, pesticides and labor. Soil-dwelling invertebrates, including detritivores and natural enemies of pests, drive valuable ecosystem functions that facilitate plant establishment and reduce maintenance inputs. Although poorly understood, soil disturbance during residential development likely disturbs these communities and reduces the services provided by soil-dwelling invertebrates. Here, we compare the effects of two soil compaction mitigation techniques, tillage with and without compost incorporation, on invertebrate communities and the services they provide over 2 years following residential development. We focus on the relationships between detritivores and detritus decomposition rates, entomopathogenic nematodes and the activity density of a key turfgrass pest and other arthropod herbivores and predators. We found that soil mitigation had no detectable benefit for epigeal arthropods within 1 year after disturbance, but that compost-amended soils supported greater arthropod richness and predator activity density than unmitigated soils in the second year after disturbance. In contrast, we found reduced insect-parasitic nematode activity associated with compost amendment. All taxa increased in abundance with time after development. These results can inform more sustainable residential development and landscape maintenance practices for more biodiverse and functional urban and residential ecosystems.

Occurrence of entomopathogenic fungi in muck-glial soils of the Liwiec river valley

For the preservation of biological diversity of soil microorganisms, including entomopathogenic fungi which are natural enemies of pests, areas that are subject to anthropogenic transformation as little as possible are of great importance. River valleys may be such areas. The aim of the study was to identification of types of entomopathogenic fungi, as well as to investigate the intensity of their occurrence in the upper genetic levels of meadow muck-glial soils located in the Liwiec river valley. The material for the research was soil samples collected in October 2018 and May 2019, in the upper reaches of the Liwiec river. Insecticidal fungi were isolated from individual genetic levels of the soils under study using the selective substrate isolation method. In the course of the research, insecticidal fungi of the genus were isolated: Beauveria spp., Metarhizium spp., Isaria spp. and Lecanicillium spp., with only Beauveria spp. and Lecanicillium spp. being found in the autumn. The greatest number of infection units was formed by the fungus Beauveria spp. and the greatest intensity of its occurrence was found in the turf level of the soils studied.

Predstavnici roda "Trissolcus" (Hymenoptera: Scelionidae) prirodni neprijatelji štetnih stenica (Hemiptera: Pentatomidae) i preliminarna istraživanja u Srbiji

Different types of polyphagous true bug pests are present in Serbia and countries in the region, many of which stand out as significant pests of agricultural crops. Among the harmful true bugs, the green vegetable bug, Nezara viridula Linnaeus, 1758 and the brown marble bug Halyomorpha halys Stål, 1855 (Hemiptera: Pentatomidae) are the species that currently attract attention the most, primarily because of their invasive and polyphagous nautre and ability to migrate rapidly from one crop to another. In many regions, where harmful bugs cause large economic losses, control strategies are primarily based on the application of chemicals. In addition to chemical control measures, biological control measures are increasingly present, which are based on the application of natural enemies of pests. Species from the genus Trissolcus (Hymenoptera: Scelionidae) show the best results in the biological control of polyphagous true bug. The species that has been commercially used for many years to control harmful Hemiptera is Trissolcus basalis Wollaston, 1958, which is one of the most important natural enemies of the green vegetable bug in the World. The species Trissolcus japonicus Ashmead, 1904 and Trissolcus mitsukurii Ashmead, 1904 have been identified as the predominant parasitoids of the brown marble bug and show great potential in the biological control of this harmful species. Representatives of the genus Trissolcus are also registered on the territory of Serbia, which opens the possibility of including native species of the genus Trissolcus in the strategies of biological control of true bug pests on the territory of Serbia and the region.

Consistency of attack level of coffee berry borer (Hypotenemus hampei Ferr.) on organic and conventional arabica coffee plantation in Aceh Tengah District, Aceh Province, Indonesia

A study has been conducted for 3 consecutive years since 2019 to 2021 to investigate the influence of cultivation system of Arabica coffee against the attack of the coffee berry borer (Hypothenemus hampei Ferr.) in Arabica coffee plantations in Aceh Tengah District, Aceh Province, Indonesia. We observed the attack level of H. hampei on Arabica coffee plants that were cultivated both organically and conventionally. The results showed that for three years observation, in general, the attack level of coffee berry borer (CBB) on organic and conventional coffee plantations was not significantly different. Observations in 2019 showed that the attack level of CBB on organic coffee plantations ranged from 27-34 % and on conventional coffee plantations ranging from 33-49 %. Observations in 2020 showed that the attack rate of CBB on organic and conventional coffee ranged from 20-40 % and 28-41%, respectively, while observations in 2021 were 25-26 % and 27-28 %. The results of these studies indicate that the level of CBB attack on organic coffee plantations is no different from conventional coffee plantations that routinely use synthetic pesticides. This indicates that in organic coffee plantations, natural enemies have played an important role in suppressing the development of CBB populations. Although the use of synthetic pesticides in conventional coffee plantations can suppress pest populations, it is suspected that these pesticides also play a role in reducing the population of natural enemies of pests. Therefore, organic coffee cultivation is much more profitable, especially it can reduce the cost of buying synthetic pesticides and fertilizers, besides ensuring the safety of coffee farmers, workers, and consumers from harmful chemical contamination from pesticides.

ARENA: Assessment of pest biocontrol in arable crops by naturally ocuring pest enemies: sampling network and tools to integrate this ecosystem service into integrated crop management

ARENA: Assessment of pest biocontrol in arable crops by naturally ocuring pest enemies: sampling network and tools to integrate this ecosystem service into integrated crop management

Annual flower strips and honeybee hive supplementation differently affect arthropod guilds and ecosystem services in a mass-flowering crop

Intensively managed agricultural landscapes have degraded the provisioning of diverse and continuous forage and shelter habitats for arthropods and weakened the delivery of ecosystem services such as insect crop pollination and biological pest control. In response, farmers are incentivised to sow flower strips along field margins to counteract resource bottlenecks. Yet, it is poorly understood how effective this diversification practice is when combined with the supplementation of honeybee (Apis mellifera L.) hives, which is commonly used to boost insect pollination in flowering crops. Honeybees share floral resources with wild pollinators and natural enemies of pests, which could lead to competition for food resources. We sampled pollinators, natural enemies and their pests as well as estimated the benefit of insect pollination in 17 organic faba bean (Vicia faba minor L.) fields in southern Sweden either with or without sown annual flower strips and with or without added honeybee hives. In fields with flower strips, bumblebee (Bombus spp.) densities were redistributed from field edges to interiors but without affecting their overall densities. Flower strips enhanced silver Y moth (Autographa gamma L.) densities and carabid beetle Shannon diversity along the field edge, and overall spider activity density. The supplementation of honeybee hives enhanced honeybee densities, overall ladybird beetle densities, black bean aphid (Aphis fabae Scop.) densities along field edges, but deterred silver Y moths and pushed bumblebees towards the field interior. Bean mass per plant was higher in insect pollinated plants compared with bagged, self-pollinated plants. This insect pollination benefit was independent of honeybee hive supplementation and the flower strip treatment suggesting that faba bean fields were not deficient in pollinator visits. We conclude that flower strips did not provide sufficient floral resources to increase overall wild pollinator densities in faba bean fields. Yet, annual flower strips attracted and facilitated ground-dwelling predators, especially spiders, to faba bean fields, likely by providing beneficial shelter habitats. It is worth noting that 2018, in which we collected our data, was characterised by late frosts in spring followed by an unusually hot and dry summer. While these unforeseen weather conditions together with a relatively small sample size might limit the generalisation of our results, we argue that conducting experiments under such conditions provide insights into the effectiveness of agri-environmental schemes under climate change, especially considering that such weather conditions are becoming increasingly more frequent.

Pengenalan dan pengendalian hama dan penyakit pada tanaman Ubi Kayu di Unit Pelaksana Teknis Badan Penyuluhan Pertanian (UPTBPP) Kulim

Cassava (Manihot utilissima) is the third food source in Indonesia. Cassava commodity has economic value and is widely planted in the Technical Implementation Unit of the Agricultural Extension Agency (UPTBPP) Kulim, Pekanbaru City. This service aims to provide knowledge and skills to cassava farmers in the Technical Implementation Unit of the Kulim Agricultural Extension Agency (UPTBPP) of Pekanbaru Municipality about the types of pests and diseases that attack, symptoms of attacks, and their control techniques. The target of service is mainly cassava farmers in the Technical Implementation Unit of the Agricultural Extension Agency (UPTBPP) Kulim Pekanbaru Municipality so that farmers' incomes become better and more prosperous. The service method used the method of counseling and demonstration. The extension method uses LCD and infocus, pictures of pests, life cycles, damage are presented, along with explanations of control techniques. The demonstration method includes the practice of control techniques consisting of first introducing natural enemies in the form of videos, making glumon traps and making forest betel leaf and soursop vegetable pesticides. The measuring instrument for achieving the goals of service was the understanding and knowledge of farmers about pests and diseases of cassava plants, controlling cassava pests and changing farmers' views on pest control no longer prioritizing the use of synthetic pesticides and the ability of farmers to recognize the types of natural enemies of pests. Achievement is measured by distributing questionnaires to determine changes and increase in farmer knowledge. The results of the service program in the form of counseling and demonstrations were very well responded by cassava farmers. Participants paid close attention, asked many questions. The results of the questionnaire assessment of farmers showed an increase in farmers' understanding of controlling pests and diseases of cassava plants after service activities. Thus this service will provide great benefits to cassava farmers in controlling pests and diseases in cassava cultivation.

More pests but less pesticide applications: Ambivalent effect of landscape complexity on conservation biological control.

In agricultural landscapes, the amount and organization of crops and semi-natural habitats (SNH) have the potential to promote a bundle of ecosystem services due to their influence on ecological community at multiple spatio-temporal scales. SNH are relatively undisturbed and are often source of complementary resources and refuges, therefore supporting more diverse and abundant natural pest enemies. However, the nexus of SNH proportion and organization with pest suppression is not trivial. It is thus crucial to understand how the behavior of pest and natural enemy species, the underlying landscape structure, and their interaction, may influence conservation biological control (CBC). Here, we develop a generative stochastic landscape model to simulate realistic agricultural landscape compositions and configurations of fields and linear elements. Generated landscapes are used as spatial support over which we simulate a spatially explicit predator-prey dynamic model. We find that increased SNH presence boosts predator populations by sustaining high predator density that regulates and keeps pest density below the pesticide application threshold. However, predator presence over all the landscape helps to stabilize the pest population by keeping it under this threshold, which tends to increase pest density at the landscape scale. In addition, the joint effect of SNH presence and predator dispersal ability among hedge and field interface results in a stronger pest regulation, which also limits pest growth. Considering properties of both fields and linear elements, such as local structure and geometric features, provides deeper insights for pest regulation; for example, hedge presence at crop field boundaries clearly strengthens CBC. Our results highlight that the integration of species behaviors and traits with landscape structure at multiple scales is necessary to provide useful insights for CBC.

Dynamics of a pest management model with mate‐finding Allee effect induced by sterile release

Using sterile insect release to guide the occurrence of the mate‐finding Allee effect in pest populations is considered a pest management strategy. In this paper, a pest management model is established with the mate‐finding Allee effect induced by releasing sterile pests. In addition, the natural enemies of pests and spraying insecticide are also taken into account to achieve integrated pest management. For the model without delay, although the origin is not well‐defined in our model, we pay attention to the dynamics near the origin and find it is always an attractor. This means the extinction of pests is closely related to their initial scale. Based on that, we conduct a detailed qualitative study on other equilibria. Furthermore, the model with a time delay is also observed. The stability of equilibrium points, Hopf bifurcation, and Bogdanov–Takens bifurcation are all carried out. Through numerical simulation, the results indicate that adding the mate‐finding Allee effect can significantly reduce the demand for pesticides and reduce the environmental damage from pesticides, comparing with the traditional approach (i.e., combining natural enemies and pesticides). We also find that a time delay can switch the stability of the equilibrium points and promote the extinction of pests.

Agrobiodiversity of using refugia plants towards several plant gardens at Tulung Rejo, East Java

A study and identificiation on agrobiodiversity of refugia plant as alternative solution by farmers towards their several plant gardens to repel pest was conducted at Tulung Rejo, East Java, Indonesia in March 2021. Refugia plants are biodiversity plants that grow around cultivated plants, which have the potential as a place of protection and a source of food for natural enemy insects (both predators and parasitoids). The principle of refugia pants is that these plants can attract and become a place of life and a source of life for insects, natural enemies of pests. the reseach was using a survey method with interview with farmers who have a land and using refugia plant as a natural pesticides to repel pests of their plants. besides, this research was also using a physical indentification of several refugia plants. Among several locations in Tulung Rejo, the results show that on average farmers use refugia plants of the type of kenikir flower Cosmos caudatus. This has evident because from 20 garden locations, 18 of them use Cosmos caudatus. The needs of farmers in Tulung Rejo, East Java to repel pests naturally.

Ant diversity inhabited oil palm plantations in a peatland in Sumatra, Indonesia

Abstract. Johari A, Hermanto MA, Wulandari T. 2021. Ant diversity inhabited oil palm plantations in a peatland in Sumatra, Indonesia. Nusantara Bioscience 13: 158-163. Ant community is one of the soil biotic components with diverse roles, including pollinators, predators, decomposers, parasites, and herbivores. Changes in land use from natural habitats to plantations affect the diversity and composition of ants because these groups are very vulnerable to environmental changes. The purpose of the study was to analyze the diversity of ants (Formicidae) found in peatland planted with oil palm. The study was conducted on peatland in Gambut Jaya village, Sungai Gelam sub-district, Muaro Jambi district, Indonesia from October 2019 to May 2020. The research was conducted through surveys in two peatland locations (natural peatland and oil palm plantation) using the purposive sampling technique through the stages of transect making, field sampling, sample preparation, and identification. A total of 2636 individuals of ants were collected from natural peatland, while 3183 individuals were found in oil palm plantations. Eight ant species were identified from both study sites belong to four subfamilies, namely Dolichoderinae, Formicinae, Myrmicinae, and Ponerinae. Among the species, Dolichoderus thoracicus were most dominant, composed 63.6% in natural peat-land and 73.6% in oil palm plantation. The diversity index of ant species in natural peatland was higher (0.97) than that in oil palm plantations (0.88), indicate the change in the abundance and diversity of ant species in oil palm plantations. Therefore, efforts to preserve the habitat of ants by maintaining their microhabitat and resource, as well as conserving the important species such as natural enemies of pests, need to be taken into account in peatland management.

Aboveground and belowground biodiversity responses to seed mixtures and mowing in a long-term set-aside experiment

Set-asides sown to wildflowers are introduced to promote agrobiodiversity. Often, sown seed mixtures have been used to enhance aboveground biodiversity while belowground biodiversity has received less attention. We studied in a 15-year-old set-aside experiment, the impact of seed mixtures (grass vs. meadow) and mowing (mown vs. unmown) on the abundance and diversity of plants, two aboveground invertebrate groups (pollinators and natural enemies of pest species) and one key belowground group, earthworms. We also studied the treatment effects on selected soil chemical properties. In general, a sown meadow seed mixture mostly benefitted aboveground biodiversity, whereas the impacts of late-season mowing were most discernible for earthworms. Plant species richness or coverage did not differ between seed mixtures, but plant coverage showed a positive response to mowing, while the impact on species richness was minor. The meadow seed mixture was dominated by Centaurea jacea. A non-mown meadow treatment supported the highest earthworm density and species richness, while the values were lowest in the mown meadow, where earthworm total mass was also at its lowest. In a grass seed mixture of intermediate density and richness, the mowing had no measurable effect on the earthworm community. Topsoil carbon, nitrogen and soluble phosphorus concentrations showed a typical gradient for non-inverted soils, with the highest concentrations in the 0–2.5 cm layer. The two uppermost soil layers (to 5 cm depth) had higher soluble phosphorus content under grass than under meadow seed mixture. Abundance of natural enemies of pests was not significantly different between the treatments, but for carabids there was a marginally significant positive response to mowing. Bumblebee species richness and the abundance of bumblebees and honeybees were highest in the mown meadow seed mixture plots. Butterfly species richness was marginally significantly higher in mown than in non-mown treatments in both seed mixtures. The results showed the potential of set-asides to promote both aboveground and belowground biodiversity through increased plant diversity.

Natural Pest Regulation and Its Compatibility with Other Crop Protection Practices in Smallholder Bean Farming Systems.

Common bean (Phaseolus vulgaris) production and storage are limited by numerous constraints. Insect pests are often the most destructive. However, resource-constrained smallholders in sub-Saharan Africa (SSA) often do little to manage pests. Where farmers do use a control strategy, it typically relies on chemical pesticides, which have adverse effects on the wildlife, crop pollinators, natural enemies, mammals, and the development of resistance by pests. Nature-based solutions -in particular, using biological control agents with sustainable approaches that include biopesticides, resistant varieties, and cultural tools-are alternatives to chemical control. However, significant barriers to their adoption in SSA include a lack of field data and knowledge on the natural enemies of pests, safety, efficacy, the spectrum of activities, the availability and costs of biopesticides, the lack of sources of resistance for different cultivars, and spatial and temporal inconsistencies for cultural methods. Here, we critically review the control options for bean pests, particularly the black bean aphid (Aphis fabae) and pod borers (Maruca vitrata). We identified natural pest regulation as the option with the greatest potential for this farming system. We recommend that farmers adapt to using biological control due to its compatibility with other sustainable approaches, such as cultural tools, resistant varieties, and biopesticides for effective management, especially in SSA.

Organic farming supports lower pest infestation, but fewer natural enemies than flower strips

Abstract Agricultural intensification has led to dramatic losses of species and associated ecosystem services. In the European Union, agri‐environment schemes (AESs) have been developed to mitigate these challenges. There are two opposing AES strategies, targeting either production or non‐production areas. Organic farming focuses on production and conservation on the same land‐use area, whereas flower strips adjacent to crop fields are in favour of intensified conventional production combined with conservation strips outside the cultivated area. We investigated pest and natural enemy abundances of organic farming versus establishing flower strip in 10 agricultural landscapes in Central Germany along a gradient of mean field size (1.24–6.78 ha). We focused on three winter wheat fields per landscape: conventional field (control), conventional field with adjacent flower strip and organic field. We sampled crop pests such as cereal leaf beetles (CLBs) and cereal aphids as well as their natural enemies. Our results indicated that the abundance of CLB larvae was more than two times higher in conventional farming with and without flower strip than that in the organic farming. The abundance of natural enemies was supported by landscapes with small mean field size, that is their numbers increased c. threefold when field size decreased from 7 to 2 ha. Aphid abundance was lower in organic fields and conventional control fields than in conventional fields with flower strips suggesting a potential disservice of flower strips. Parasitoids and natural enemies benefited from flower strips, but they were obviously not able to control the aphids. Synthesis and applications. The major pests in cereals, aphids and CLBs infested organic farming less than flower strips along conventional fields. However, the abundance of natural enemies of pests benefited from flower strips and, in addition, from decreasing field size in agricultural landscapes. Hence, enhancing predator populations for more effective biological pest control may be best with decreasing field sizes combined with organic farming and flower strips. Altogether, organic farming might contribute much more to low pest damage than a conventional farming strategy with flower strips.

Tracing the distribution of natural enemies of non-native invasive eucalypt insect pests in sub-Saharan Africa

Eucalypt forestry in sub-Saharan Africa is challenged by non-native eucalypt-feeding insects. In recent studies, six invasive eucalypt insect pests, namely Blastopsylla occidentalis, Glycaspis brimblecombei, Gonipterus sp.n.2, Leptocybe invasa, Thaumastocoris peregrinus and Ophelimus maskelli were confirmed present in sub-Saharan Africa. We investigated the diversity and distribution of natural enemies of these pests in six countries in the region. Plant parts (leaves, petioles and stem) infested with the insect pests were sampled from multiple sites in each country. The emerged natural enemies were identified using morphological characteristics and DNA sequence data. Nine species of natural enemies were confirmed present in the surveyed countries, namely Anaphes nitens, Closterocerus chamaeleon, Megastigmus sp., M. pretorianensis, Psyllaephagus blastopsyllae, P. bliteus, Quadrastichus mendeli, Selitrichodes kryceri and S. neseri. No natural enemies were found in Ghana and Sierra Leone despite the presence of L. invasa in both of those countries. Interestingly, most of these natural enemies were unintentionally introduced into the surveyed countries. Results of this study showed that both insect pests and natural enemies introduced into one country are likely to affect many other countries in the region. These findings call for a more coordinated approach to the management of plantation pests in the region.

Utilizing local plant extracts to control Diamondback moth in round cabbage

Diamondback moth (Plutella xylostella L.) with abbreviation DBM is a detrimental pest that mostly attacks cabbage and other vegetables in Brassicaceae family. The build-up of resistance in DBM due to continuous and indiscriminate use of synthetic insecticides have refocused farmer’s perspectives to plant based extracts. Plant extracts are generally compatible with natural enemies of pests therefore are considered eco-friendly. This study was done to evaluate the push effect of Garlic (Allium sativum L.), Chili (Capsicum frutescens L.) and Seaweed extract on the activity of DBM. All three treatments; chili extract, garlic extract, and seaweed extract were generally effective in controlling DBM than the reference group (control treatment). Separation of means by Student-newman-keuls (SNK) test showed that Diamondback moth (DBM) abundance under seaweed extract was significantly low (2.18±0.32, p< 0.05) followed by chili extract (3.22±0.43, p< 0.05). There was no significant difference in DBM abundance under garlic extract and control treatment. For defoliation, only control treatment recorded a significant increase in DBM population (5.40±0.64, p< 0.05). The other three plant extracts had similar low non-significant abundances (p> 0.05). Data on LAI did not show any significant differences in all the treatments meaning treatments did not affect LAI (p> 0.05). This study found that both seaweed and chili extracts were effective in controlling P. xylostella in round cabbage. Both extracts are recommended for use since they differ in their mechanism pathways to protect crops.

Biochemistry of Terpenes and Recent Advances in Plant Protection.

Biodiversity is adversely affected by the growing levels of synthetic chemicals released into the environment due to agricultural activities. This has been the driving force for embracing sustainable agriculture. Plant secondary metabolites offer promising alternatives for protecting plants against microbes, feeding herbivores, and weeds. Terpenes are the largest among PSMs and have been extensively studied for their potential as antimicrobial, insecticidal, and weed control agents. They also attract natural enemies of pests and beneficial insects, such as pollinators and dispersers. However, most of these research findings are shelved and fail to pass beyond the laboratory and greenhouse stages. This review provides an overview of terpenes, types, biosynthesis, and their roles in protecting plants against microbial pathogens, insect pests, and weeds to rekindle the debate on using terpenes for the development of environmentally friendly biopesticides and herbicides.

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.