Insect Predators Research Articles

Insecticidal activities of three recombinant venom proteins of the predatory stink bug, Arma custos.

Widespread resistance of insect pests to insecticides and transgenic crops in the field is a significant challenge for sustainable agriculture, and calls for the development of novel alternative strategies to control insect pests. One potential resource for the discovery of novel insecticidal molecules is natural toxins, particularly those derived from the venoms of insect predators. In this study, we identified three insecticidal proteinaceous toxins from the venom glands (VGs) of the predatory stink bug, Arma custos (Hemiptera: Asopinae). Transcriptomic analysis of A. custos VGs revealed 151 potentially secreted VG-rich venom proteins. Three VG-rich venom proteins (designated AcVP1 ~ 3) were produced by overexpression in Escherichia coli. Injection of the recombinant proteins into tobacco cutworm (Spodoptera litura) larvae showed that all of the three recombinant proteins caused paralysis, liquefaction and death. Injection of recombinant proteins into rice brown planthopper (Nilaparvata lugens) nymphs showed higher insecticidal activities, among which a trypsin (AcVP2) caused 100% mortality postinjection at 1.27 pmol mg-1 body weight. A natural toolkit for the discovery of insecticidal toxins from predatory insects has been revealed by the present study. © 2024 Society of Chemical Industry.

New Eucalyptus (Myrtaceae) species host of Blastopsylla occidentalis (Hemiptera: Aphalaridae) and its parasitism by Psyllaephagus blastopsyllae (Hymenoptera: Encyrtidae) in Indonesia

Blastopsylla occidentalis Taylor (Hemiptera: Aphalaridae), native to Australia, causes damage to an increasing number of Eucalyptus (Myrtaceae) species and their hybrids in a growing number of countries. This is partly because predatory insects and spiders have low potential to reduce B. occidentalis populations. The purpose of this study was to report a new host of B. occidentalis and the parasitism of this insect by Psyllaephagus blastopsyllae Tamesse, Soufo, Tchanatame, Dzokou, Gumovsky, & Coninck (Hymenoptera: Encyrtidae) in Indonesia. Blastopsylla occidentalis nymphs parasitized were collected from five Eucalyptus pellita F. Muell. trees on October 3rd, 2023, in Senoni, East Kalimantan, Indonesia, and reared in a laboratory until their adults or P. blastopsyllae emerged. The adults recovered from this parasitoid were identified by morphological analysis of their bodies. Eucalyptus pellita is a new host for B. occidentalis. This is the first time in Asia (Indonesia) that P. blastopsyllae has been reported. This new insect-host association alerts the world to the need to develop management strategies for B. occidentalis on E. pellita plantations. The recovery of P. blastopsyllae also opens up new perspectives for the development of biological control programs in Indonesia.

A Double-edged Sword: Evolutionary Novelty along Deep-time Diversity Oscillation in An Iconic Group of Predatory Insects (Neuroptera: Mantispoidea).

Evolutionary novelties are commonly identified as drivers of lineage diversification, with key innovations potentially triggering adaptive radiation. Nevertheless, testing hypotheses on the role of evolutionary novelties in promoting diversification through deep time has proven challenging. Here we unravel the role of the raptorial appendages, with evolutionary novelties for predation, in the macroevolution of a predatory insect lineage, the Superfamily Mantispoidea (mantidflies, beaded lacewings, thorny lacewings, and dipteromantispids), based on a new dated phylogeny and quantitative evolutionary analyses on modern and fossil species. We demonstrate a single origin of the raptorial foreleg and its associated novelties as key innovations triggering an early radiation of raptorial mantispoids from the Late Triassic to the Early Jurassic. Subsequently, the evolution of the raptorial foreleg influenced the diversification in different modes among lineages. At times, it might have limited the morphological diversity of other body parts and lead to lineage constraint by intensifying competition and lowering environmental resilience, e.g., in thorny lacewings, whose extant diversity is meagre. Conversely, in mantidflies, reduced emphasis on foreleg novelties and increased plasticity in other body parts may lead to better adaptation to predator-prey interactions and environmental shifts, thus maintaining a stable or accelerated level of diversification. We also reveal how major environmental change and lineage interactions interplayed with raptorial novelties in shaping the significant oscillations of mantispoid diversification over deep time, especially the abrupt shift near the mid-Cretaceous. However, by excluding a substantial portion of samples from the mid-Cretaceous of Myanmar, these shifts of some evolutionary parameters, such as morphological disparity, body size, and diversification rates, became inconspicuous and might be overestimated due to sampling bias. Our results uncover the intricate evolutionary patterns and profound significance of raptorial specializations, providing new insights into the role of novelties in forming evolutionary trajectories, both for the better and worse. [evolutionary novelty; macroevolution; diversification; raptorial foreleg; fossil; insect; Mantispoidea].

Seasonal phenology of anuran larvae and predatory aquatic insects in human-modified landscapes of the NW montane forest of Argentina

Seasonal phenology of anuran larvae and predatory aquatic insects in human-modified landscapes of the NW montane forest of Argentina

Biological control of locusts and grasshoppers: A review

Locusts and grasshoppers (Orthoptera: Acrididae) are pests of agricultural importance, devastating crops and pastures. This group includes hundreds of pest species and affects the livelihoods of one in every ten people worldwide. Their outbreaks can be chronic or episodic, with alternating periods of invasion and recession. Here, we review the natural enemies of locusts and grasshoppers in both their native and invaded ranges across the globe to assess the need for their conservation and maintenance as part of the natural suppression of outbreaks and to augment outbreak suppression as potential biological control agents. More than 70 natural enemies have been reported to attack locusts and grasshoppers, including entomopathogenic fungi, bacteria, nematodes, predatory insects, birds, reptiles, and mammals. Particular attention is given to the well-studied species of locusts and grasshoppers for which more information is available and to natural enemies in the locust-affected countries as part of the recent trend of looking for indigenous natural enemies. Such organisms can play a vital role in integrated pest management strategies for locusts and grasshoppers, particularly entomopathogens that can be incorporated with chemical pesticides into the management system. Among the organisms considered, Metarhizium acridum is noteworthy for inclusion in integrated pest management programs.

Garden Snail Predatory Insects' Modus Operandi Under Laboratory Conditions.

Heliciculture farms are susceptible to significant biotic issues that can impact snail breeding, among them, the entomofauna predation of snails. Predatory insects can cause damage to snail shells during predation, and sometimes, the specific type of damage may be characteristic of certain insect families or species. Under laboratory conditions, we analysed the predatory activity of the species Silpha tristis Illiger, 1798 (Coleoptera: Silphidae), Ocypus olens (Müller, 1764) (Coleoptera: Staphylinidae), Carabus (Macrothorax) morbillosus constantinus Kraatz, 1899 (Coleoptera: Carabidae), and Lampyris sardiniae Geisthardt, 1987 (Coleoptera: Lampyridae) against the gastropod Cornu aspersum (Müller, 1774) reared on snail farms located in the Sardinian region. The adult and larval stages of each species were tested, except for L. sardiniae, as only the larval stage preys upon snails. This study showed that among all of the species considered, only two insects were able to damage the shell of C. aspersum: C. morbillosus constantinus and O.olens. This may prove valuable in C. aspersum breeding for the recognition of specific lesions, even in the absence of the predator.

Dietary Ecology of Predatory Insects Examining the Role of Prey and Non Prey Foods of Ladybird Beetle

Ladybird beetles consume a wide variety of non-prey items in their natural habitats, including aphids, fruits, plants, fungi, honeydew, and nectar. These non-prey foods play several critical roles, such as boosting fertility, decreasing mortality during dormancy, supporting migration, and enhancing survival during times when prey is scarce. Larval ladybird beetles have more specialized nutritional needs compared to adults, with simple carbohydrates being crucial nutrients that can improve adult beetle function and reproductive success. Non-prey foods often provide similar or greater nutritional and caloric content compared to prey. Each non-prey item has distinct defense mechanisms and nutritional benefits, influencing its suitability for ladybird beetles. Research comparing diets consisting solely of prey with mixed diets that include non-prey foods revealed that while pollen improved larval and adult performance, a diet high in sugar alone was less effective for reproduction compared to an aphid-based diet. Wheat, which lacks essential nutrients such as proteins, could not adequately support egg production and larval development. Although pollen did enhance overall performance, it could not completely offset the nutritional shortcomings of a diet high in sugar. Adding sugar to a diet did not markedly enhance the performance of ladybird beetles compared to a diet composed entirely of prey. This review underscores the need to understand the varied diet of ladybird beetles within their ecological context, as it has significant implications for the success of conservation-oriented biological control effort.

Positive association between foliar silicon and extrafloral nectar in Vicia faba with application of methyl jasmonate

Plants have evolved direct and indirect defences against herbivores, which may come at a cost to other plant functions. Many plants can uptake and deposit large amounts of silicon within plant tissue, creating structures which can reduce herbivore performance. Silicon uptake can increase plant defenses against herbivores, but it has also been shown to trade-off with defensive phenolic compounds due to interference with jasmonic acid (JA) signaling. Additionally, plants can recruit predacious insects with extrafloral nectar (EFN), a sugar secretion not involved in pollination. It is currently unclear whether silicon uptake reduces other putative defences associated with the JA pathway, like EFN production. We used faba bean (Vicia faba) to identify potential trade-offs between silicon accumulation, phenolic content, and EFN production. We grew four genotypes of faba bean that varied in tannin content in control soil, or soil supplemented with silicon. After five weeks of growth, we exposed plants to either a buffer or methyl jasmonate (MeJA) solution to simulate an herbivory response. We measured EFN production at 24 and 48 hours after treatment, and harvested leaves to quantify silicon and phenolic content. We found silicon supplementation, but not MeJA treatment, increased foliar silicon concentration. Silicon supplementation did not affect foliar phenolic content or EFN sugar content. Silicon concentration (ppm) and MeJA treatment did not decrease foliar phenolic content or EFN sugar content. However, we found an interaction between silicon concentration (ppm) and MeJA treatment with EFN sugar content: across MeJA-treated plants, we detected a positive association between foliar silicon concentration and the amount of sugar (mg) in EFN. This study is the first to show MeJA can interact with leaf silicon concentration to alter EFN response, with the potential for cascading effects on other trophic levels.

Adaptive trade-offs between vertebrate defence and insect predation drive Amazonian ant venom evolution.

Stinging ants have diversified into various ecological niches, and selective pressures may have contributed to shape the composition of their venom. To explore the drivers underlying venom variation in ants, we sampled 15 South American rainforest species and recorded a range of traits, including ecology, morphology and venom bioactivities. Principal component analysis of both morphological and venom bioactivity traits reveals that stinging ants display two functional strategies where species have evolved towards either an exclusively offensive venom or a multi-functional venom. Additionally, phylogenetic comparative analysis indicates that venom function (predatory, defensive or both) and mandible morphology correlate with venom bioactivity and volume. Further analysis of the venom biochemistry of the 15 species revealed switches between cytotoxic and neurotoxic venom compositions among species. Our study supports an evolutionary trade-off between the ability of venom to deter vertebrate predators and to paralyse insect prey which are correlated with different venom compositions and life-history strategies among Formicidae.

New Records of Insect Predators of Invasive Fluted Scales (Hemiptera: Monophlebidae: Iceryini) in Ecuador

Population outbreaks of invasive fluted scales in urban areas of Ecuador have become frequent in recent years. Despite the negative impact that these scale insects cause on the native flora, little is known about the natural enemies that control their populations in Ecuador. During collections and observations carried out between July and October 2021 in the province of Guayas, in western Ecuador, high infestations caused by the invasive pests Crypticerya genistae (Hempel, 1912), Crypticerya multicicatrices Kondo & Unruh, 2009, and Icerya purchasi Maskell, 1879 (Hemiptera: Coccomorpha: Monophlebidae: Iceryini) were found. Hence, this study aimed to determine the natural enemies of these fluted scales using taxonomic keys based on their morphological characteristics. As a result, five species of predators were identified, i.e., Novius punicus (Gordon, 1972), Novius cardinalis (Mulsant, 1850) (Coleoptera: Coccinellidae), Syneura cocciphila (Coquillet, 1895) (Diptera: Phoridae), Ceraeochrysa sp. (Neuroptera: Chrysopidae), and Cardiastethus sp. (Hemiptera: Anthocoridae); the latter is reported preying on C. multicicatrices for the first time. Knowledge of natural enemies is crucial for developing more effective, eco-friendly pest management strategies that could help mitigate the adverse effects of these invasive scale insects.

Functional response and control potential of adult Arma chinensis on Colorado potato beetle in Xinjiang, China

AbstractPotato is an important food crop. The Colorado potato beetle (CPB) is its key pest. CPBs are now resistant to several chemical pesticides, making their control more difficult. The predatory insect, Arma chinensis, is a natural enemy of other plant pests. We studied the predation of adult A. chinensis on CPB eggs and young larvae under indoor controlled conditions and its control of CPB in cages under outdoor conditions. Adult A. chinensis effectively reduces CPB egg and larva populations, and its predatory functional response aligns with Holling’s Type II model. A. chinensis adults released within outdoor cages reduced CPB populations. Based on the predation behavior of the adults of A. chinensis to CPB eggs and young larvae, A. chinensis is an efficient and potential predator.

The Influence of Habitat Diversity on Bat Species Richness and Feeding Behavior in Chilean Vineyards: Implications for Agroecological Practices

Agriculture is a leading cause of biodiversity loss, making the transition to sustainable agroecological practices crucial. Insectivorous bats play a crucial role as biological controllers in regard to agricultural crops, serving as important insect predators. The purpose of this study is to assess bat communities in three distinct habitats, namely the interior of a vineyard, native vegetation, and the transitional edge between them, by analyzing the echolocation patterns of different species. Generalized linear mixed models were used to evaluate the influence of landscape characteristics on bat communities and at the species level, allowing the incorporation of variables at different scales (at 10 m, 100 m, and 1000 m radius) from each sampling site. Our results show that edges enhance bat richness, their general activity, and feeding patterns, and are of particular benefit to certain species: Tadarida brasiliensis, Myotis chiloensis, and Lasiurus varius. Implementing agroecological practices, such as the maintenance of tree hedgerows at the landscape scale, along with native vegetation at the landscape scale, can amplify feeding activity in vineyards, thereby enhancing the provision of ecosystem services in agroecosystems. The edges of vineyards and natural vegetation are crucial for providing habitats for bats and increasing their foraging activity, as well as providing a way to enhance agroecological practices in vineyards to bolster ecosystem services.

Diversity of Butterflies in Guindy National Park-Butterfly Garden in Guindy Children’s Park

Guindy National Park is the only protected forest oasis holding good tropical dry evergreen forest vegetation sheltering many wild Fauna, and flora amidst the city. The literature survey provides a limited information analysis earlier before, on various aspects of Ecology & Conservation Management, Habitat analysis & assessment, distribution of Vegetation, diversity of fauna like Black buck, spotted deer, Birds, Jackal including lower vertebrates & Butterflies. Butterflies are the sensitive insects which react quickly to any kind of disturbances like changes in the habitat quality and environmental variation. Apart from pollinators they play a major key role in food chain, being prey for birds, reptiles, spiders and predatory insects. Many species of butterflies are strictly seasonal in their occurrence and prefer a particular set of habitats and host plants for their survival. Notably these biological indicators are slowly disappearing due to changes in land pattern and habitat as they are closely dependent on plants.

Identifying insect predators using camera traps reveal unexpected predator communities in oilseed rape fields

Cameras are common tools for ecologists studying species abundance, richness, and interactions. They are mainly used to study large animals but are increasingly used to study invertebrates. Camera traps could be a powerful tool to identify and quantify the natural enemies, such as predators, of specific agricultural pests. This knowledge can then be applied to adapt farming practices to favour the predators identified and improve conservation biocontrol.Here, cameras were used to identify predators of two insect pests of oilseed rape (Brassica napus): the pollen beetle (Brassicogethes aeneus) and the brassica pod midge (Dasineura brassicae). These insects are spring pests of oilseed rape and are both susceptible to predation by ground-dwelling arthropods during their development cycle. The objectives of this study were to 1) identify the predators of the pest species, and 2) investigate the hypothesis that the diel activity periods of the predators match the timing of pest larval presence on the ground. Field observations were conducted in two locations over two consecutive years in the UK.In contrast to previous reports, our data collected using cameras showed that larval stages of predatory beetles are responsible for most of the predation events and that adult stages were not frequently observed feeding on the prey. Our data also showed that the traditional method, using pitfall traps, failed to detect the presence of large numbers of beetle larvae. Interestingly, the pests dropped to the ground and were therefore most susceptible to predation at the time when predators were most active.These results give new insight on the predators of the two most important spring pests of oilseed rape in Europe. This knowledge can be used by practitioners to develop framing practices targeted on enhancing the abundance of the larval stages of these beneficial arthropods to better control the pests in a more sustainable way.

Pathways for accidental biocontrol: The human-mediated dispersal of insect predators and parasitoids.

Introductions of insect predators and parasitoids for biological control are a key method for pest management. Yet in recent decades, biological control has become more strictly regulated and less frequent. Conversely, the rate of unintentional insect introductions through human activities is rising. While accidental introductions of insect natural enemies can potentially have serious ecological consequences, they are challenging to quantify as their movements go largely unobserved. We used historical border interception records collected by the US Department of Agriculture from 1913 to 2018 to describe the diversity of entomophagous insects transported unintentionally, their main introduction pathways, and trends in host specificity. There were 35,312 interceptions of insect predators and parasitoids during this period, representing 93 families from 11 orders, and 196 species from these families. Commodity associations varied, but imported plants and plant products were the main introduction pathway. Most interceptions originated with commodities imported from the Neotropical, Panamaian, and Western Palearctic regions. Among the intercepted species, 27% were found in material originating from more than one country. Two thirds of species were polyphagous host generalists. Furthermore, 25% of species had already been introduced intentionally as biological control agents internationally, and 4.6% have documented negative impacts on native biodiversity or human society. Most of the intercepted species that have not established in the United States are host generalists or have at least one known host species available. The unintentional transport of diverse natural enemy insects has the potential to cause substantial ecological impacts, both in terms of controlling pests through accidental biocontrol and disrupting native communities. Characterizing the insects being transported and their introduction pathways can inform biosecurity practices and management.

Enhancing pest management - Utilizing supplementary food spray to harness predatory insects against fall armyworm in maize crop of Vinh Phuc Province, Vietnam

The effect of supplementary food spray on the fall armyworm (Spodoptera frugiperda) and beneficial insects (predominantly predatory insects) was studied in commercial maize field experiments from 2020 to 2022. The food spray formulation was developed from local ingredients in Vietnam, both with and without neem extract. The sugar-based rice dough product attracted and sustained beneficial insects, significantly reducing fall armyworm populations. Compared to conventional insecticide treatments, the net margin achieved in plots treated with food spray was higher ($3,467) to $3,394 in the conventional insecticide-treated plots demonstrating its economic viability (1 AUD=17.28 VND). Our study observed an average predator-to-prey ratio of 9.2:1 per plant in the food-spray-treated plots, and that was effective in managing the fall armyworm throughout the season. We propose that this ratio can serve as a valuable parameter and decisionmaking tool in food spray-based Integrated Pest Management (IPM) programs against fall armyworm in maize fields. Therefore, we suggest that food sprays can be incorporated into IPM strategies to successfully manage fall armyworm infestation in maize crop.

The Role of (E)-β-Farnesene in Tritrophic Interactions: Biosynthesis, Chemoreception, and Evolution.

(E)-β-farnesene (EBF) stands out as a crucial volatile organic compound, exerting significant influence on the complex interactions between plants, aphids, and predator insects. Serving as an alarm signal within aphids, EBF is also emitted by plants as a defense mechanism to attract aphid predators. This review delves into EBF sources, functions, biosynthesis, detection mechanisms, and its coevolutionary impacts on aphids and insect predators. The exploration underscores the need to comprehend the biophysical and structural foundations of EBF receptors in aphids, emphasizing their role in unraveling the intricate patterns and mechanisms of interaction between EBF and target receptors. Furthermore, we advocate for adopting structure-based or machine-learning methodologies to anticipate receptor-ligand interactions. On the basis of this knowledge, we propose future research directions aiming at designing, optimizing, and screening more stable and efficient active odorants. A pivotal outcome of this comprehensive investigation aims to contribute to the development of more effective aphid-targeted control strategies.

Variations of pest and disease attacks on horticultural and non-horticultural crops in South Sumatra

Horticultural crops of olericultural types that were given a lot of chemical pesticides cause many negative impacts such as the emergence of pests and pathogens that were immune to pesticides, the emergence of new pests, increased pest populations and secondary pathogens, reduced populations of beneficial insects (predators). The study aimed to consider the use of pesticides by farmers to eradicate pests and diseases in horticulture and non-horticulture in South Sumatra. The research was conducted in South Sumatra Province. The research was conducted in 7 districts and 1 city, namely Indralaya District, North Indralaya District, Air Kumbang District, South Pemulutan District, Gelumbang District, Belitang Mulya District, Tanjung Batu District, and Palembang City, which was conducted from May to September 2022. Data were collected using the Secondary Variables method with Purposive sampling technique and processed into analyzed data. The results of this study showed that the most horticulture cultivated by farmers was eggplant(Solanum melongena L.). While for non-horticulture the most widely cultivated by farmers was corn(Zea mays). The percentage of pest attacks on non-horticultural land was 57.36%, the percentage of pest attacks on horticultural land was 68.28%. Variations in pest and disease attacks that occur in 180 farms on horticultural and non-horticultural crops in South Sumatra. Horticultural crops that are widely cultivated in South Sumatra include cucumber, long beans, and eggplant. Meanwhile, non-horticultural crops are corn, rice, and rubber. Spodoptera frugiperda was a pest that has been found to damage corn crops and Leptocorisa sp species that damage food crops (No Horticulture). Counseling was provided to farmers to find out the types of pests that could attack and the symptoms and diseases in plants to know how to control them.

Birds and bats reduce herbivory damage in Papua New Guinean highland forests.

Insectivorous predators, including birds and bats, play crucial roles in trophic cascades. However, previous research on these cascades has often relied on permanent predator exclosures, which prevent the isolation of specific effects of birds and bats, given their different activity patterns throughout the day. Moreover, limited knowledge exists regarding the variations in individual effects of these predators under different biotic and abiotic conditions, such as changes in elevation. To address these uncertainties, our study aimed to investigate the distinct effects of bats and birds on arthropod densities in foliage and herbivory damage in lowland and highland rainforests of Papua New Guinea (PNG). Predator exclosures were established for one month to exclude diurnal or nocturnal predators across 120 saplings (ca. 2.5-4 m tall) selected from two lowland and two highland forests (i.e., 30 saplings per study site) along the Mt. Wilhelm transect in PNG. Arthropods were collected and measured, and herbivory damage was analyzed at the end of the experiment. Birds significantly reduced arthropod densities by 30%, particularly in arthropods longer than 10 mm, regardless of elevation. Additionally, both birds and bats appeared to mitigate herbivory damage in highland forests, with protected saplings displaying up to 189% more herbivory. Our results support previous studies that have demonstrated the ability of insectivorous predators to reduce leaf damage through the control of arthropods. Furthermore, our approach highlights the importance and necessity of further research on the role of seasons and elevations in trophic cascades.

Volatile organic compound profile for the search of rejection markers in protein baits used as Vespa velutina control method

The invasive species Vespa velutina nigrithorax (Lepeletier 1836), commonly known as the Asian hornet, constitutes an economic and environmental threat, as it is a predator of fruits and insects, especially Apis mellifera (Linnaeus, 1758) (honey bees).Different methods have been developed for its control. Among of them, biocidal protein baits are included, which have a limited time of use. Oxidation of their components, enzymatic activity and microorganisms lead to the formation of spoilage compounds.The aim of this work was to determine the optimal conditions for storing and preserving the baits without losing efficacy. Furthermore, a search of rejection markers will be carried out based on field studies results in the apiary on the acceptance and rejection of the baits by hornets under different storage conditions.Volatile organic compound profiles of these baits were obtained by solid phase microextraction/gas chromatography/mass spectrometry (SPME-GC–MS). The data were processed using different statistical and chemometric tools.The identification of potential rejection markers belonging to the families of ketones, esters, alcohols and amines was carried out by partial least squares discriminant analysis (PLS-DA). The four markers with the highest VIP scores were 2-butanone, 2-heptanone, 1-butanol, 3-methyl and 1-butanol, 3-methyl, acetate.