Insect Pest Suppression Research Articles

Cover crops dismantle keystone ant/aphid mutualisms to enhance insect pest suppression and weed biocontrol

Abstract Cover crops are multifunctional tools that mitigate environmental impacts of agriculture, enhance resilience to weather extremes and suppress weeds and arthropod pests. Cover crops provide non‐crop food and habitat resources that attract natural enemies of pests, but their outcomes for pest management are less clear in regions where keystone mutualisms between red imported fire ants and aphids dominate. Here, we manipulate ant exclusion treatments and cover crop treatments (living mulches and terminated cover crops) that vary in food/habitat resources and examine responses of ants, aphids, other herbivores and predators in a cotton agroecosystem. Living mulches reduced both ants and aphids in the crop canopy by 97% and 93%, respectively, relative to bare soil treatments, and terminated cover crops reduced them as well by a lesser degree (~50%). Non‐aphid herbivores occurred in low densities system‐wide and increased in living mulches, whilst native predators had variable responses to cover crops and ant exclusion. Cover crops had no effect on prey removal in the crop canopy, but living mulches tripled rates of weed seed biocontrol, relative to bare soils. Cover crops elicited a shift in fire ant foraging from cotton foliage downward to the soil‐surface, preventing competitive exclusion by keystone ant/aphid mutualists that dominate crop monocultures. Cover crops altered the system‐wide impacts of fire ants: reducing ecosystem disservices (i.e. aphid tending) and enhancing ecosystem services (i.e. weed seed biocontrol). These results provide incentives for cover crop adoption as a regenerative practice in large‐scale commercial agriculture.

Long-term suppression of turfgrass insect pests with native persistent entomopathogenic nematodes

Entomopathogenic nematodes (EPNs) can control several important turfgrass insect pests including white grubs, weevils, cutworms, and sod webworms. But most of the research has focused on inundative releases in a biopesticide strategy using EPN strains that may have lost some of their ability to persist effectively over years of lab maintenance and / or selection for virulence and efficient mass-production. Our study examined the potential of fresh field isolate mixes of endemic EPNs to provide multi-year suppression of turfgrass insect pests. In early June 2020, we applied isolate mixes from golf courses of the EPNs Steinernema carpocapsae, Heterorhabditis bacteriophora, and their combination to plots straddling fairway and rough on two golf courses in central New Jersey, USA. Populations of EPNs and insect pests were sampled on the fairway and rough side of the plots from just before EPN application until October 2022. EPN populations increased initially in plots treated with the respective species. Steinernema carpocapsae densities stayed high for most of the experiment. Heterorhabditis bacteriophora densities decreased after 6 months and stabilized at lower levels. Several insect pests were reduced across the entire experimental period. In the fairway, the combination treatment reduced annual bluegrass weevil larvae (59 % reduction) and adults (74 %); S. carpocapsae reduced only adults (42 %). White grubs were reduced by H. bacteriophora (67 %) and the combination (63 %). Black turfgrass ataenius adults were reduced in all EPN treatments (43–62 %) in rough and fairway. Sod webworm larvae were reduced by S. carpocapsae in the fairway (75 %) and the rough (100 %) and by H. bacteriophora in the rough (75 %). Cutworm larvae were reduced in the fairway by S. carpocapsae (88 %) and the combination (75 %). Overall, our observations suggest that inoculative applications of fresh field isolate mixes of endemic EPNs may be a feasible approach to long-term suppression of insect pests in turfgrass but may require periodic reapplications.

Communication between undamaged plants can elicit changes in volatile emissions from neighbouring plants, thereby altering their susceptibility to aphids.

Plant volatiles play an important role in intra- and interspecific plant communication, inducing direct and indirect defenses against insect pests. However, it remains unknown whether volatile interactions between undamaged cultivars alter host plant volatile emissions and their perception by insect pests. Here, we tested the effects of exposure of a spring barley, Hordeum vulgare L., cultivar, Salome, to volatiles from other cultivars: Fairytale and Anakin. We found that exposing Salome to Fairytale induced a significantly higher emission of trans-β-ocimene and two unidentified compounds compared when exposed to Anakin. Aphids were repelled at a higher concentration of trans-β-ocimene. Salome exposure to Fairytale had significant repulsive effects on aphid olfactory preference, yet not when Salome was exposed to Anakin. We demonstrate that volatile interactions between specific undamaged plants can induce changes in volatile emission by receiver plants enhancing certain compounds, which can disrupt aphid olfactory preferences. Our results highlight the significant roles of volatiles in plant-plant interactions, affecting plant-insect interactions in suppressing insect pests. This has important implications for crop protection and sustainable agriculture.

Morphometric Analysis, Feeding Capacity and Proteobacteria Wolbachia Screening in the Yellow-Assassin Bug Cosmolestes picticeps

The yellow-assassin bug, Cosmolestes picticeps (Hemiptera: Reduviidae) is a generalist predator that has potential use as biological control agent in oil palm agroecosystem. They are known to feed on insect pests like bagworm. To facilitate understanding on the suitability of C. picticeps as an alternative means to manage oil palm pests, and little impact on beneficial insects, this study investigated the morphological variations, feeding capacity and proteobacteria in C. picticeps. To examine the relationships between morphology and feeding capacity of C. picticeps, a total of 90 male and 90 female individuals of C. picticeps collected were measured, and then provided with weevil individuals in captivity. The results showed no significant correlation between the size of C. picticeps with the number of weevil individuals consumed. Meanwhile, the present study also want to determine whether there are proteobacteria Wolbachia sp. in female C. picticeps gut content using Polymerase Chain Reaction (PCR) amplification. The result showed absent of Wolbachia surface protein and Wolbachia citrate synthase coding gene amplification. Based on the present study, more information on the C. picticeps should be assessed as they have the potential as biological control agent to suppress insect pests in agricultural ecosystem.

Seed priming with Beauveria bassiana improves growth and salt stress response in rice

One of the most important abiotic factors that hinder plant development, growth, and production is salt stress. In recent years, there has been a lot of interest in the biological treatment of salt stress in plants using beneficial microbes. The fungal endophyte Beauveria bassiana provides a wide variety of ecosystem services, like suppressing insect pests and pathogens and enhancing plant growth. However, the role of B. bassiana in reducing salt stress in plants has not yet been clarified. This study was undertaken to evaluate the performance of B. bassiana isolate BeauA1 primed rice under salt stress by estimating rice growth, stress parameters, and mitigator characteristics. Primarily, rice seeds were primed with BeauA1 and placed in an agar medium with 120 mM NaCl (≈12 dS m−1 salt solution) to observe the role of BeauA1 in the early establishment of rice seedlings in salt conditions. Seed priming with BeauA1 resulted in an enhancement of rice growth attributes under both control and NaCl stress conditions. In the pot experiment, the BeauA1 primed rice seedlings were planted in soil with different concentrations of salt, viz. 8, 10, and 12 dS m−1. The BeauA1 primed rice plants showed improvement in leaf succulence, leaf area, photosynthetic pigments, and shoot relative water content (RWC), leading to enhanced growth under both salt stress and control conditions. The biochemical study found that BeauA1 considerably increased proline content, total soluble sugars, total carbohydrates, and K+/Na+ in leaves. The antioxidant enzymes catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), glutathione S-transferase (GST), and nonenzymatic antioxidants phenol and flavonoid were upregulated in BeauA1-primed plants under both control and stressed conditions. Further significant reductions of the lipid peroxidation products malondialdehyde (MDA) and hydrogen peroxide (H2O2) by BeauA1 under salt stress were consistent with higher antioxidant activities in salt stress conditions. Principal component analysis (PCA) further validated BeauA1-primed plants' modulation of growth, antioxidant defense, and reduction of MDA and H2O2 in rice under salt-stress conditions. Our findings indicated that utilizing BeauA1 to reduce salt stress would be a useful strategy to increase rice yield in salt-affected regions.

Edge-based wireless imaging system for continuous monitoring of insect pests in a remote outdoor mango orchard

Mango production is a prominent tropical fruit industry worldwide. However, outdoor mango cultivation is susceptible to crop damage caused by insect pests and harsh environmental conditions. Integrated pest management (IPM) has emerged as a proposed solution to this problem. IPM utilizes data-driven and environmentally-friendly methods to suppress insect pest populations. Nevertheless, the collection of insect pest population data remains a laborious process, necessitating automation. This paper presents an image-based monitoring system to automatically record insect pest populations and environmental conditions in mango orchards. The system comprises solar-powered sensor nodes capable of periodically acquiring and analyzing sticky paper trap images. A modular deep learning-based algorithm was developed to detect and classify insect pests into seven classes, including major insect pests of mango such as thrips, mango leafhopper, and oriental fruit fly, with an average classification F1-score of 0.96. Unlike other insect counting algorithms, the algorithm reliably classifies insect pests according to different taxonomic levels even in non-laboratory environments. The monitoring system was tested and deployed in a remote mango orchard for over two years. The collected spatiotemporal information was analyzed to demonstrate the benefits of using the proposed system and recommend new IPM strategies. Temporal data analysis revealed a significant decrease in the count of selected insect pests after using the system, enabling identification of insect hotspots through statistical methods. This work presents a breakthrough in hardware and software solutions for developing smarter insect pest monitoring systems, leading to better IPM strategies.

Toxicity assessment of common acaricides and mineral oils on Anagyrus vladimiri, an effective biocontrol agent of citrus mealybug.

Chemical pesticides, while playing an important role in the suppression of insect pests, should be used in a manner that minimizes negative effects on natural enemies. The parasitoid, Anagyrus vladimiri Triapitsyn (Hymenoptera: Encyrtidae), plays an important role in the management of mealybug pests of citrus groves in the Mediterranean region. This study was conducted to evaluate the effect of commonly used acaricides (Spirodiclofen, Spirotetramat, Sulfur, Fenpyroximate, Abamectin) and mineral oils (Levanola, EOS, JMS, and Ultrapaz) on acute mortality of A. vladimiri. Toxicity was assessed in 4 cases: (i) direct spray application on adults, (ii) pesticide application on the mummified host, (iii) feeding with contaminated food, and (iv) contact with pesticide residue. The pesticide Abamectin, applied alone and with Levanola oil was highly toxic to adults in all bioassays, with the exception of direct spray application on the mummified host. Fenpyroximate was found to be highly toxic only when sprayed directly on adults, and sulfur was slightly harmful. Mineral oils were harmful when ingested with food; otherwise, they did not cause appreciable adult mortality. The findings of the present study suggest that all tested materials, with the exception of Abamectin and Fenpyroximate, are compatible with the survival of A. vladimiri. Direct ingestion of oils can, however, cause a degree of mortality. Given that indiscriminate use of these pesticides may affect the population ecology of A. vladimiri, they should be used with caution.

Fighting caterpillar pests and managing agricultural insecticide resistance with Lepidoptera-associated <i>Enterococcus casseliflavus</i>

<p>Probiotics are live microorganisms that are intended to benefit the health of metazoan hosts. Mutualism in insects (both pests and beneficial insects) provides a vital contribution to host fitness. With the development and demand for healthy modern agriculture, bacterial symbionts are considered to be an important toolbox for pest control and beneficial insect protection. <i>Enterococcus casseliflavus</i> is a widespread symbiont in most Lepidoptera insect pests. Recent studies indicated that <i>E. casseliflavus</i> provides beneficial phenotypes to the host, including supplying a diet lacking amino acids and enhancing insecticide resistance. We propose that <i>E. casseliflavus</i> should have enormous biotechnological potential awaiting further exploitation for Lepidoptera insect pest control or beneficial insect protection through symbiont-targeted insecticide resistance management, because this symbiont is widespread in natural caterpillar hosts, easily isolatable and cultured, and rapidly spreadable within the caterpillar population. We outline the rationales for why <i>E. casseliflavus</i> is suitable for application in pest management and envision possible plans of symbiont-targeted therapeutics via four potential approaches: genome modification, phage engineering, predatory biocontrol, and synthetic microbiome. This perspective opens up a grand blueprint for the future of symbiont-targeted insect pest suppression or economic insect promotion.</p>

Applications of gene drive systems for population suppression of insect pests.

Population suppression is an effective way for controlling insect pests and disease vectors, which cause significant damage to crop and spread contagious diseases to plants, animals and humans. Gene drive systems provide innovative opportunities for the insect pests population suppression by driving genes that impart fitness costs on populations of pests or disease vectors. Different gene-drive systems have been developed in insects and applied for their population suppression. Here, different categories of gene drives such as meiotic drive (MD), under-dominance (UD), homing endonuclease-based gene drive (HEGD) and especially the CRISPR/Cas9-based gene drive (CCGD) were reviewed, including the history, types, process and mechanisms. Furthermore, the advantages and limitations of applying different gene-drive systems to suppress the insect population were also summarized. This review provides a foundation for developing a specific gene-drive system for insect population suppression.

Draft Genome Sequence of Pseudomonas protegens Strain MWU12-2233, Isolated from Wild Cranberry Fruit in Provincetown, Massachusetts.

ABSTRACTPseudomonas protegens strain MWU12-2233 was isolated from wild cranberry fruit surfaces in Provincetown, MA. The genome contains putative hydrogen cyanide synthase and type VI secretion systems which can act symbiotically on plant health by suppressing competitors, indicating a role in indigenous microfloral disease and insect pest suppression.

Semi‐natural habitat surrounding farms promotes multifunctionality in avian ecosystem services

Abstract Farmland birds can suppress insect pests, but may also consume beneficial insects, damage crops and potentially carry foodborne pathogens. As bird communities shift in response to farming practices, so too do the benefits (services) and costs (disservices) from birds. Understanding how and why ecosystem services and disservices covary can inform management interventions that enhance synergies, avoid trade‐offs and promote multifunctionality. We investigated how farmland diversification practices influence the services and disservices provided by wild birds on 21 California strawberry farms. Specifically, we coupled 285 bird surveys, metabarcoding and other molecular analyses of ~1,000 faecal samples representing 55 bird species (mostly passerines) to determine which individuals consumed pests, natural enemies, and crops and carried foodborne pathogens. Then, we explored how farming practices shape ecosystem service bundles, or suites of consistently co‐occurring services/disservices. Avian services and disservices were shaped by interactions between local farming practices and landscape context. We found that the amount of semi‐natural habitat surrounding each farm was the single most important driver of ecosystem services, with the best outcomes (highest multifunctionality) occurring on farms surrounded by semi‐natural habitat. Bundles were primarily influenced by landscape context. Increasing semi‐natural habitat around farms was associated with more multifunctional bird communities that maximized services and minimized disservices. However, not all trade‐offs were minimized in landscapes with more semi‐natural habitat, suggesting that specific farming contexts can exacerbate or mitigate trade‐offs as bird communities shift in response to diversification practices. Synthesis and applications. Though growers are often pressured to remove non‐crop habitat to reduce food‐safety risks, our work suggests that conserving habitat can support bird conservation, mitigate food‐safety risks and decrease crop damage from birds. More broadly, by considering the multiple roles that communities play in ecosystems, managers can simultaneously maximize services and minimize disservices to achieve multifunctionality.

Recently introduced Wolbachia reduces bacterial species richness and reshapes bacterial community structure in Nilaparvata lugens.

Wolbachia has been developed as an effective tool to suppress insect pests and arbovirus transmission. Recently, the brown planthopper Nilaparvata lugens, a serious agricultural pest, has been successfully transinfected with Wolbachia wStri strain from Laodelphax striatellus. However, before conducting the field experiments, the impacts of wStri on the bacterial microbiota in N. lugens and how it differs from native Wolbachia wLug strain have not been clarified. Here, we found that wStri reduced bacterial diversity and shaped bacterial community structure more than wLug in both developmental stage and different adult tissues. Overall, the relative abundance of Wolbachia was negatively correlated with bacterial diversity, but the bacterial diversity gradually decreased only when the relative abundance of Wolbachia was higher than 60%. Further analysis found that wStri reduced species richness of other bacteria but not their evenness. wStri infection also affected many bacterial functions (e.g., amino acid metabolism & signaling and cellular processes) in the developmental stages, with a stronger effect than wLug in nymphs. Moreover, although Wolbachia occupied a high relative abundance in infected individuals, Acinetobacter was consistently a core part of microbiome. These results showed the significant impacts of recently introduced wStri on bacterial microbiota in N. lugens, with the effects differing from native wLug. This study will aid in understanding the relationship between Wolbachia, its host and the host's microbiota, and provide a reference for future field experiments.

Cultivar Mixture Enhances Crop Yield by Decreasing Aphids

The reduction in biodiversity owing to agricultural intensification has brought negative effects on sustainable crop production in the agro-environment. Plant diversity can help regulate insect pests; however, research that demonstrates that genotypic diversity of multiple varieties with prominent agroecological practices to suppress insect pests and benefit crop yield at agricultural landscapes is limited. To examine the effects of diversity of wheat varieties on aphids and crop productivity, we performed field experiments by designing plots of single (resistant/susceptible) and cultivar mixtures in 2018–2020. The effects of population abundance of cereal aphids (Sitobion miscanthi and Rhopalosiphum padi) and crop yield on resistant and susceptible wheat varieties and mixture of wheat cultivars were determined to reveal the most dominant mixed broadcasting mode in Kaifeng of China. The results showed that cultivar mixture significantly decreased aphid abundance compared with the single varieties (resistant/susceptible). Cultivar mixture had a higher yield compared with the single varieties (resistant/susceptible). Additionally, cultivar mixture had significantly higher thousand-grain weights than susceptible and resistant wheat varieties in 2019 and 2020. Cultivar mixture enhanced wheat yield by decreasing cereal aphids, indicating a bottom-up or top-down effect from genetic diversity to pest abundance. Our results indicated that appropriate cultivar mixtures could manage insect pests to some extent and stabilize crop yield.

Organic fertilisation enhances generalist predators and suppresses aphid growth in the absence of specialist predators

Abstract Biological control by natural enemies is a valuable ecosystem service. The predator community in a crop field is a combination of predators dwelling in the field and those moving into it from the surrounding landscape. The former is mainly affected by field management, the latter more by the composition of the surrounding landscape. Yet, separate and combined effects of local and landscape management on pest suppression have seldom been investigated. We set‐up mesocosms within an existing long‐term agricultural field experiment to investigate the effects of local management of organic manure or inorganic mineral fertilisation, and simulated the spillover from the surrounding landscape of different predator types: no predators, generalist predators (wolf spiders) and specialist predators (ladybirds). We examined whether aphid density was driven by top‐down or bottom‐up processes under different fertilisation treatments, and how the magnitude of pest suppression was affected by predator community composition. We found positive synergistic effects between manure fertilisation and predator spillover on the suppression of aphid growth. Top‐down suppression of aphids was more effective under manure fertilisation and in presence of specialist predators (ladybirds). Bottom‐up effects on the plant biomass growth dominated in inorganically fertilised plots. Organic and inorganic fertilisation gave the same yield, but through different mechanisms. The abundance of locally emerging predators in the manure treatment increased top‐down pest suppression yielding plant biomass levels comparable with inorganically fertilised plants, being the latter driven by bottom‐up effects. Synthesis and applications. Organic fertilisation enhanced local emergence of predators increasing top‐down pest suppression. In contrast, local predator communities were unable to suppress aphid populations in inorganic and no fertilisation treatments. Here, predator inflow from outside the crop field was essential for lowering aphid population growth. Managing landscapes to promote mobile predators emerges as particularly important for crop fields without manure amendments. We advise the active promotion of both local predators in the crop field and mobile predators in the landscape to secure the conservation of biological insect pest suppression.

Chemical diversity rather than cultivar diversity predicts natural enemy control of herbivore pests.

Cultivar mixtures have been studied for decades as a means for pest suppression. The literature, however, shows a large variability in outcomes, suggesting that we are unable to create mixtures that consistently suppress insect pests and attract natural enemies. A key gap in our understanding of how cultivar mixtures influence pest control is that few studies have examined the plant traits or mechanisms by which cultivar diversity affects pests and their interactions with natural enemies. The diversity of plant chemistry in a cultivar mixture is one trait dimension that is likely influential for insect ecology because chemical traits alter how predators and herbivores forage and interact. To understand how plant chemical diversity influences herbivores and their interactions with predators, we fully crossed predator presence or absence with monocultures, bicultures, and tricultures of three chemotypes of tomato that differed in odor diversity (terpenes) or surface chemistry (acyl sugars) in a caged field experiment. We found that the direct effects of plant chemotype diversity on herbivore performance were strongest in bicultures and depended on herbivore sex, and these effects typically acted through growth rather than survival. The effects of chemotype diversity on top-down pest suppression by natural enemies differed between classes of chemical diversity. Odor diversity (terpenes) interfered with the ability of predators to hunt effectively, whereas diversity in surface chemistry (acyl sugars) did not. Our results suggest that phytochemical diversity can contribute to pest suppression in agroecosystems, but that implementing it will require engineering cultivar mixtures using trait-based approaches that account for the biology of the pests and natural enemies in the system.

White pupae phenotype of tephritids is caused by parallel mutations of a MFS transporter

Mass releases of sterilized male insects, in the frame of sterile insect technique programs, have helped suppress insect pest populations since the 1950s. In the major horticultural pests Bactrocera dorsalis, Ceratitis capitata, and Zeugodacus cucurbitae, a key phenotype white pupae (wp) has been used for decades to selectively remove females before releases, yet the gene responsible remained unknown. Here, we use classical and modern genetic approaches to identify and functionally characterize causal wp− mutations in these distantly related fruit fly species. We find that the wp phenotype is produced by parallel mutations in a single, conserved gene. CRISPR/Cas9-mediated knockout of the wp gene leads to the rapid generation of white pupae strains in C. capitata and B. tryoni. The conserved phenotype and independent nature of wp− mutations suggest this technique can provide a generic approach to produce sexing strains in other major medical and agricultural insect pests.

Diversity and Abundance of Insect in Conventional Apple (Malus sylvestris (L.) Mill) Plantation at Kota Batu, East Java

Apple is a plant that susceptible toward pests and diseases. Application of pesticide to suppress insect pest population gave negative impact toward natural enemies and insect pollinators. The purpose of this research was to determine the diversity and dominance of insect pests, pollinators, and natural enemies of each phase of apple plant development in conventional plantations in Kota Batu, East Java. This research was conducted in February to May 2016 in each phase of apple growth namely, after defoliation, early flower, late flower, early fruit, and late fruit. Plot size was 10x10 m2 with total 5 plots and total plants in each plot were 60 trees. Collection methods were active collection (hand picking, insect net, and beating tray) and passive collection (yellow trap, pitfall trap, light trap, and stainer trap). Preservation methods used in this research were dry preservatoin and wet preservation. Identification was conducted in Laboratorium of Entomology, Faculty of Biology UGM and Laboratorium Entomology, Zoology Division, Research Centre for Biology Indonesian Institute of Sciences, Cibinong. Data analyzed by using Shannon-Wiener Diversity Index, Simpson Dominance Index and Abundance Formulation. The results showed that total insects that was caught consist of 38 species belong to 9 orders. Diversity index in each phase of apple growth were: after defoliation (0.69), early flower (1.39), late flower (1.86), early fruit (0.66), and late fruit (1.24). Domination index each phase of apple growth were after defoliation (0.50), early flower (0.34), late flower (0.21), early fruit (0.75), and late fruit (0.40). Diversity index of potential insect as pest (1.46), as pollinator (1.29), and as natural enemies (1.18). The highest abundance of insect as pollinator was Apis cerana, as natural enemy was Pantala flavescens, and as pest was Aphis gossypii.

Influence of Trap Crops on Tomato and Squash Insect Pests

Influence of Trap Crops on Tomato and Squash Insect Pests

Crop Varietal Mixtures as a Strategy to Support Insect Pest Control, Yield, Economic, and Nutritional Services

Most on-farm diversification strategies to enhance ecosystem services, such as insect pest control and yield, have focused on expanding crop species diversity. While polycultures often provide valuable services, logistical constraints with planting and harvesting can hamper implementation on large scales. An alternative diversification strategy is to increase within-field intraspecific crop diversity through the use of crop varietal mixtures. Here, we evaluate an interdisciplinary body of research to determine the potential for crop varietal mixtures to support food security by providing ecological, economic, and nutritional services. Previous literature has synthesized the link between varietal mixtures and yield and insect pest suppression services. We expand on prior analyses by considering hypotheses generated from species-level research and assessing whether they also provide a useful framework for predicting how varietal mixtures affect crop productivity and insect pest suppression. In addition, we evaluate the potential for varietal mixtures to increase farm resilience and growers’ profits. While there is a growing effort to quantify the economic value of ecosystem services provided by agrobiodiversity in terms of enhanced yield or revenue, much less attention has been given to quantifying the production costs associated with diversification schemes. Consequently, we know little about the effect of diversification practices on farm profitability, the metric of ultimate importance to farmers. We address this issue by evaluating the ability of varietal mixtures to reduce production costs associated with other types of agrobiodiversity and outline areas for future research to better understand the profit implications of varietal mixtures. Further, we review evidence that varieties of some crop species differ in phytochemical content—a functional trait important for insect pest suppression and human dietary diversity—suggesting that varietal mixtures could be designed to simultaneously support insect pest control and human nutrition services. Given that little research has explicitly addressed the capacity for varietal mixtures to support human nutrition, we outline predictions for where we would expect to see the greatest nutritional impact of mixtures, providing a foundation for future human nutrition research. Taken together, our review suggests that varietal mixtures are a promising and logistically feasible strategy that could simultaneously support multiple services.

The impact of bioinsecticide overdoses of Beauveria bassiana on species diversity and abundance of not targeted arthropods in South Sumatra (Indonesia) freshwater swamp paddy

Abstract. Hanif KI, Herlinda S, Irsan C, Pujiastuti Y, Prabawati G, Hasbi, Karenina T. 2020. The impact of bioinsecticide overdoses of Beauveria bassiana on species diversity and abundance of not targeted arthropods in South Sumatra (Indonesia) freshwater swamp paddy. Biodiversitas 21: 2124-2136. Bioinsecticides have been shown to reduce insect pest populations, but it is necessary to monitor the effect of bioinsecticide overdoses on non-target arthropods because they are abundant in rice fields. This study aimed to analyze the impact of bioinsecticide overdoses of B. bassiana on species diversity and abundance of non-target arthropods. Bioinsecticides derived from Beauveria bassiana were sprayed on the paddy every two weeks until the ripening stage, at a dose of 1, 2, 3, 4 L.ha-1, control (without insecticide), and abamectin as prescribed. The abundance of spiders and predatory arthropods did not decrease when bioinsecticides were applied but the abundance of spiders, especially Lycosidae and Salticidae dropped significantly when abamectin was applied. The abundance of the parasitoid decreased significantly when abamectin was applied, but the abundance of parasitoids applied by bioinsecticide was not significantly different from those of control. The abundance of insect pests started to decrease when bioinsecticide was applied to 2, 3 or 4 L.ha-1. The diversity species of non-target arthropods (spiders, predatory arthropods, and parasitoids) tended to decrease when it was applied bioinsecticides 3 and 4 L.ha-1 or abamectin, but their abundance remained high and no species dominance was found. For this reason, the correct dosage for suppressing insect pests abundance by not decreasing the abundance and diversity of non-target species is 2 L.ha-1 and applied when herbivore abundance is high.