Insect Bait Research Articles

Whitefly‐Pathogenic Beauveria bassiana JEF‐507 as a Competitive Biopesticide, Chongchae‐Stop

ABSTRACTSilverleaf whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a destructive insect pest damaging to diverse crops by vectoring several plant pathogenic viruses, which consequently causes economic losses in crop production. As the resistance of whiteflies to chemical insecticides is increasing, this study aimed to investigate the potential of entomopathogenic fungi as an alternative. A total of 72 entomopathogenic fungal isolates, collected from soils using Tenebrio molitor larvae as an insect baiting method, were assessed for their virulence against 2nd nymphs of whitefly. Their virulence was assayed by dipping whitefly‐infested tomato leaves in fungal conidia suspensions at 1.0 × 107 conidia/mL. Among the tested isolates, two isolates of Beauveria bassiana JEF‐462 and JEF‐507 showed high virulence. In the assessment of virulence depending on conidia concentrations, the estimated LC50 values for JEF‐462 and JEF‐507 were similarly 8.7–14.0 × 107 conidia/mL. However, B. bassiana JEF‐507 showed higher conidial productivity and thermotolerance on most of tested 12 grain substrates than B. bassiana JEF‐462, and millet was the most suitable grain substrate. Additionally, siloxane as a surfactant was able to sufficiently exhibit the insecticidal activity of JEF‐507 against whitefly nymphs compared with other surfactants. In a pot‐based greenhouse trial, JEF‐507 showed higher control efficacy than chemical insecticides, dinotefuran and spinetoram. This work suggests that B. bassiana JEF‐507 could be competitively used as a biopesticide to control silverleaf whiteflies while overcoming current resistance issues. The JEF‐507 isolate has been registered in Korea, 2022 and successfully commercialised as the name of Chongchae‐Stop in this local market to control whitefly and thrips.

Laboratory Evaluation of Indigenous and Commercial Entomopathogenic Nematodes against Red Palm Weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae).

The red palm weevil (RPW) is a significant threat to date palms. Conventional pest control has been ineffective. This study aims to evaluate entomopathogenic nematodes (EPNs) indigenous to Saudi Arabia and commercial against RPW. We used 33 soil samples collected from four areas of Saudi Arabia. The indigenous EPNs were isolated and cultured using an insect baiting method to obtain infective juveniles. Pathogenicity bioassays were conducted against different stages of RPW, including eggs, larvae, and adults. The bioassay was performed using all the isolates at 1 × 106 IJ/mL. Distilled water was used as a control. The results revealed that only 9.09% of soil samples contained positive EPNs. Through DNA sequencing analysis, the positive samples were identified as indigenous isolates belonging to Heterorhabditis indica and Steinernema carpocapsae EPN species. In pathogenicity tests, 90% mortality of RPW eggs was observed after five days. Similar mortality trends were seen in RPW larvae and adults, with 90% mortality recorded after ten days for all the EPN treatments. Mortality increased with the duration of post-EPN inoculation exposure. The 1 × 106 IJ/mL concentrations of EPN effectively killed various stages of RPW in the laboratory. More research is needed to test EPNs against RPW in the field.

Cordyceps sp. WZFW1, a novel entomopathogenic fungus to control Ectropis grisescens (Lepidoptera: Geometridae)

AbstractEctropis grisescens is a notorious pest in tea plantations. The control of E. grisescens relies on synesthetic pesticides but the resurgence is always accompanied by increasing resistance. Therefore, it is crucial to use biological control to reduce the damage caused by E. grisescens. Here, we collected soil from a tea plantation, used Galleria mellonella as a bait insect and successfully isolated one entomopathogenic fungus. The isolated colony was initially identified as Cordyceps sp. using morphological observation. ITS‐rDNA sequence amplification and sequencing, molecular database comparisons, and phylogenetic analysis proved this fungus as a new species and thus named Cordyceps sp. WZFW1. Further virulence test of Cordyceps sp. WZFW1 against E. grisescens was evaluated under laboratory conditions. Lethal concentration was 5.74 × 106 spore/mL with a confidence level of 2.32 × 106 ~ 1.79 × 107 and lethal time was 2.98 days at 108 spore/mL and 7.47 days at 107 spore/mL, indicating Cordyceps sp. WZFW1 was effective at controlling E. grisescens. Our findings are significant as they contribute to the application of new entomopathogenic fungi (EPF) species as biocontrol agents, promoting eco‐friendly pest management practices.

Ant protection effectiveness in myrmecophytes and extrafloral nectary plants

AbstractExtrafloral nectaried plants and myrmecophytes offer resources to ants that engage in protective mutualisms. The role of different ant species in herbivore deterrence has long been analyzed by using insect baits, and ants are regarded as effective plant guards if they attack the insects. Here, by performing a literature review, we conducted a comparative investigation on which ants display aggression toward experimental prey, which ants are better plant guards, and which plants (extrafloral nectaried plants or myrmecophytes) are better defended by ants. Data revealed that studies evaluating ant aggression toward insect baits have been performed on 37 extrafloral nectaried plant species and 19 myrmecophytes, and have involved over 30 genera of ants. Extrafloral nectaried plants and myrmecophytes rely on specific ant fauna to defend them from herbivores. In extrafloral nectaried plants, Camponotus and Crematogaster were regarded as the best plant protectors, as they attacked insects in nearly all plants. In myrmecophytes, Azteca, Pheidole, and Pseudomyrmex were the most important insect attackers. Myrmecophytes were better protected by ants, as all insects were attacked; in extrafloral nectaried plants, some ants failed to attack the insects. Plants are patrolled by several different ants, but there is a core of ants that excel in protection, and this varies according to plant type (extrafloral nectaried plants and myrmecophytes). With this knowledge, it may be possible to label different ants as effective plant guards, to anticipate their effects on plant performance, and even to understand their potential role as biological control agents.

Hidden diversity within Beauveria and Metarhizium – Comparing morphology, barcoding, multilocus phylogenies and whole-genome sequences

Accurately identifying entomopathogenic fungi is crucially important, but the current approach of analysing four genes might not provide sufficient resolution. In this study, we investigated the different resolution provided by multilocus phylogenies and approaches based on whole genome sequence data. Fungi were isolated from soil samples that were collected from five different vegetation types (dry sclerophyll forest, agricultural grassland, rainforest, suburban parkland, and sugar cane fields) and across four different suburban soil habitat types in southeast Queensland. Three different agricultural pests were used as live baits, cotton stainer bug, diamondback moth, and rust-red flour beetle. Whole-genome sequencing was conducted for all 83 isolates recovered, and the ITS2 region was extracted from the genome assemblies to make initial species identifications with the UNITE database. We also extracted tef1a 3′, tef1a 5’, rpb1 and rpb2 genes from the Metarhizium genomes and the bloc, tef1a and rpb1 genes from Beauveria genomes to construct multilocus phylogenies and obtain species identification. To investigate the genetic relationships across 14 isolates of Beauveria bassiana and (independently) across 43 isolates of Metarhizium based on whole-genome data, we genotyped single nucleotide polymorphism (SNP) markers and conducted principal components analysis on the whole-genome SNP data. The multilocus methods identified isolates to species more precisely than ITS2, except in the one unresolved clade in the Metarhizium phylogeny. The whole-genome approach identified more genetic clusters than the multilocus phylogenies identified species among the isolates, and the morphological results correlated with some of the genetic clusters, so they likely represent distinct species not detected by the other methods. The genetic clusters were not associated with vegetation type or bait insect species. This is the first comparison of the resolution of multilocus phylogenetics with that of whole-genome SNP data for these genera. We suggest how the genetic clusters identified here may be investigated further to determine whether they represent unrecognised species within these groups.

Entomopathogenic fungi associated with cultivated honeybush, Cyclopia spp., in South Africa and their pathogenicity towards a leafhopper pest, Molopopterus sp. (Hemiptera: Cicadellidae)

The southern and eastern parts of the African Fynbos region favour the production of honeybush tea. Honeybush biomass and extracts are used to prepare a beverage both locally and internationally, mainly as herbal tea with health benefits. Honeybush tea is mostly grown organically requiring natural control measures for pests and diseases. The leafhopper, Molopopterus sp., is one of the most important pests of cultivated honeybush in South Africa, as its feeding compromises the quality and quantity of the yield through leaf discolouration and reduction of the photosynthetic area. Local entomopathogenic fungi (EPF) can provide a pool of potential biocontrol agents for this pest. Therefore, a total of 98 soil samples were collected from organically grown honeybush fields and vegetation surrounding the honeybush fields in the Western Cape province of South Africa. Entomopathogenic fungi were isolated using the insect bait method and were characterised using molecular techniques. Twenty fungal isolates of Metarhizium anisopliae and Fusarium oxysporum were recovered from soil samples, of which 70% were from honeybush fields and 30% were from surrounding vegetation. Fusarium oxysporum isolates comprised 20% of the recovered isolates; M. anisopliae the remainder. Laboratory bioassays of the recovered isolates against adults and nymphs of the leafhopper, showed that F. oxysporum isolates caused 10–45% mortality and M. anisopliae isolates 30–80% mortality. Metarhizium anisopliae isolates J S1, KF S3, KF S11, KF S13, LS1 and LS2 were the most virulent and induced over 60% mortality in both nymphs and adults at a concentration of 1 × 107 conidia/ml.

First report on the enzymatic and immune response of Metarhizium majus bag formulated conidia against Spodoptera frugiperda: An ecofriendly microbial insecticide.

Entomopathogenic fungi from microbial sources are a powerful tool for combating insecticide resistance in insect pests. The purpose of the current study was to isolate, identify, and evaluate bag-formulated entomopathogenic fungal conidial virulence against insect pests. We further investigated the enzymatic responses induced by the entomopathogenic fungi as well as the effect on a non-target species. Entomopathogenic fungi were isolated from the Palamalai Hills, India, using the insect bait method, and the Metarhizium majus (MK418990.1) entomopathogen was identified using biotechnological techniques (genomic DNA isolation and 18S rDNA amplification). Bag-formulated fungal conidial efficacy (2.5 × 103, 2.5 × 104, 2.5 × 105, 2.5 × 106, and 2.5 × 107 conidia/ml) was evaluated against third instar larvae of Spodoptera frugiperda at 3, 6, 9, and 12 days of treatment, and acid and alkaline phosphatases, catalase, and superoxide dismutase enzymatic responses were evaluated at 3 days post-treatment. After 12 days of treatment, non-target assays on the earthworm Eudrilus eugeniae were performed using an artificial soil assay. Results of the bag formulated fungal conidial treatment showed that S. frugiperda had high susceptibility rates at higher concentrations (2.5 × 107 conidia/ml) of M. majus. Lower concentration of 2.5 × 103 conidia/ml caused 68.6% mortality, while 2.5 × 107 conidia/ml caused 100% mortality at 9 days post treatment. Investigation into enzymatic responses revealed that at 3 days post M. majus conidia exposure (2.5 × 103 conidia/ml), insect enzyme levels had significantly changed, with acid and alkaline phosphatases, and catalase enzymes significantly reduced and superoxide dismutase enzymes significantly raised relative to the control. After 12 days of treatment, no sublethal effects of M. majus conidia were observed on E. eugeniae, with no observed damage to gut tissues including lumen and epithelial cells, the nucleus, setae, coelom, mitochondria, and muscles. This study offers support for the use of fungal conidia in the target-specific control of insect pests.

Identification of locally isolated entomopathogenic Fusarium species from the soil of Changa Manga Forest, Pakistan and evaluation of their larvicidal efficacy against Aedes aegypti.

Dengue fever vectored by the mosquito Aedes aegypti is one of the most rapidly spreading insect-borne diseases. Current reliance of dengue vector control is mostly on chemical insecticides. Growing insecticide resistance in the primary mosquito vector, Aedes aegypti, limits the effectiveness of vector control through chemical insecticides. These chemical insecticides also have negative environmental impacts on animals, plants and human health. Myco-biocontrol agents are naturally occurring organisms and are found to be less damaging to the environment as compared to chemical insecticides. In the present study, entomopathogenic potential of local strains of fungi isolated from soil was assessed for the control of dengue vector. Local fungal isolates presents better alternative to introducing a foreign biocontrol strain, as they may be better adapted to environmental conditions of the area to survive and may have more entomopathogenic efficacy against target organism. Larvicidal efficacy of Fusarium equiseti and Fusarium proliferatum was evaluated against Aedes aegypti. Local strains of F. equiseti (MK371718) and F. proliferatum (MK371715) were isolated from the soil of Changa Manga Forest, Pakistan by using insect bait method. Larvicidal activity of two Fusarium spp. was tested against forth instar larvae of A. aegypti in the laboratory, using concentrations 105, 106, 107 and 108 conidia /ml. LC50 values for F. equiseti after 24h, 48h, 72h and 96h of exposure were recorded as 3.8x 108, 2.9x107, 2.0x107, and 7.1x106 conidia /ml respectively while LC50 values for F. proliferatum were recorded as 1.21x108, 9.6x107, 4.2x107, 2.6x107 conidia /ml respectively after 24h, 48h, 72h and 96h of exposure. The results indicate that among two fungal strains F. equiseti was found to be more effective in terms of its larvicidal activity than F. proliferatum against larvae of A. aegypti.

Eksplorasi Potensi Bakteri Entomopatogen di Areal Tanaman Perkebunan Provinsi Kalimantan Utara

Plantation areas have the potential as a source of biological agents for entomopathogenic bacteria. This study aims to determine the potential of entomopathogenic bacteria from various locations in plantation crop cultivation areas, and compare their potential in North Kalimantan Province. This study carried out soil sampling, bacterial isolation, and selection of entomopathogenic bacteria using insect baits. This type of research uses a survey method on the potential of entomopathogenic bacteria. The survey was conducted at three plantation crop cultivation locations, namely coffee cultivation areas in Malinau, cocoa in Sebatik, and oil palm in Sebuku. The potency is distinguished based on the number and macroscopic characteristics of the bacterial isolate colonies obtained from each location. Furthermore, selection was carried out through testing, namely comparing bacterial isolates with a dilution of 10-1, stock, and control. Analysis of survey results using descriptive analysis and potential testing using t-test. The results showed that there were 13 bacterial isolates, and the coffee cultivation area in Malinau had the highest bacterial isolates. The selection results found 7 (seven) bacterial isolates that had the potential to be entomopathogenic bacteria, and coffee cultivation locations in Malinau had a higher number of isolates that had the potential to be entomopathogenic compared to other locations. However, isolate ST6-4U2 at dilution 10-1 from soil in the oil palm plantation area in Sebuku has the highest virulence potential as an entomopathogenic bacteria.

Entomopathogenic infection ability of low land rice (Oryza sativa L.) cultivation from Ogan Komering Ilir regency

Entomopathogenic fungi are biological agents important in suppressing or regulating pest populations in agricultural ecosystems. This study aimed to determine the ability to infect entomopathogens from lowland rice (Oryza sativa L.) cultivation from the Ogan Komering Ilir District. This research was conducted in the Pest and Plant Diseases Laboratory, Faculty of Agriculture, the University of Palembang, from February to May 2022. The study used a Completely Randomized Design (CRD) method consisting of 5 treatments, namely PS1 = mortality of bait insects three days after infestation (dai), PS2 = bait insect mortality six dai, PS3 = bait insect mortality nine dai, PS4 = bait insect mortality 12 dai, PS5 = bait insect mortality 15 dai and five replicates. This study concluded that the entomopathogenic fungus found in lowland rice (O. sativa L.) from Ogan Komering Ilir Regency was Beauveria bassiana and could infect the highest bait insect mortality on day nine after infestation.

Evaluation of Indigenous Entomopathogenic Nematodes from Tea Soil of Assam as Potential Biocontrol Agents against Termite and Cockchafer Grub in Tea

This study aimed to isolate native entomopathogenic nematodes (EPN) in the tea growing areas of Assam and to determine their potential for control of Termite and Cockchafer grub Soil samples were collected from three tea estates of jorhat, Assam for EPN isolation.A total of 30 soil samples were tested for the study. Larva of meal moth, Corcyra cephalonica was use as insect bait. Out of 30 samples 9 were found to be positive for EPNs. The infected host larvae were separated for extraction using “white trap method”. All the isolates were evaluated to ascertain their pathogenicity against Termite and cockchafer grub. From the experiment the isolated strain @ 50IJ, 75IJ and 100 IJ was found to be highly pathogenic to Termite and cockchafer grub, which recorded 94- 100% mortality in termite and 100% in all concentrations against cockchafer grub. After infection to prove the cause of mortality EPN could be recovered from the termite and cockchafer cadavers.

Evaluation of the Efficacy of Beetle Lure (BFL 225) and Bullet Synthetic Multi-Attractant as Insect Baits in Untreated Grain Storehouses

An experiment was carried out to evaluate the efficacy of synthetic general beetle lure and bullet synthetic multi attractant in trapping insects in untreated grain stores. Four grain stores (two each) in two major markets within Calabar metropolis, were sampled at random and selected for this research. Three groups of four traps each with sticky bases were treated as follows: Trap group “A” was treated with BFL225 pheromone multi-attractant, Trap group “B” was treated with bullet lure multi-attractant pheromone and Trap group “C” was untreated (control). This experiment was replicated on monthly basis for a period of eight months to also ascertain the influence of weather conditions on trapped insect population. Insects caught were identified base on the different trap efficacy and recorded following the method in Ukeh and Mordue, (2009). All traps were re-treated monthly for efficient trapping. Data obtained from the experiment were laid out as factorial in CRD and subjected to analysis of variance using GenStat statistical software (Version 6). Significant means were compared using LSD and DNMRT at 5 percent level of probability. Insects trapped and identified include Sitophilus spp , Corcyra ciphilonica, Tribolium castaneum and Callosobrochus maculatus. The treated trap groups (A and B) significantly (p<0.05) caught more insects than the untreated trap group (control). However, between the treated trap groups, the BFL 225 significantly (p<0.05) caught more insects than the bullet lure treated trap. The number of insets caught also varied significantly (p<0.05) with different months. The wet month of August significantly had the highest number of insects followed by June. The dry months of January and February also had high number of insects relative to the other months. The least number of insects caught were obtained in the months of April and May. The interaction between the trap treatment type and month was significant (p<0.05). Generally, higher number of insects were caught in both treated and untreated trap groups in the wet month (June – August) compared to other months. BFL 225 treated trap groups significantly caught the highest number of insects in August, followed by the bullet treated trap group and the untreated in the same month. The bullet lure treated traps caught the least number on insects in April and May and was not significantly (p<0.05) different from the number caught by untreated trap (control) in the month of April. The trap treated with BFL225 caught the highest number of insect. Hence, this research supports the use of BFL 225 as an efficient tool in integrated pest management approach for stored grains. Keywords: Beetle lure, Bullet synthetic, Insects, Pheromone, Treated traps. DOI: 10.7176/JBAH/12-20-03 Publication date: October 31 st 2022

Biodiversity and virulence characterization of entomopathogenic fungi isolated from soils in different regions of Nigeria

BackgroundStudying the diversity of the indigenous entomopathogenic fungi (EPF) is a prerequisite to effective insect pest control. The distribution and occurrence of EPF from the soil across Nigeria were evaluated. Three subsoil samples from three locations in each of the 11 states were used to isolate the fungi by the insect bait method. Three fungal rates, 1.0 × 102, 5.0 × 101 and 7.5 × 101 spores/ml, were applied to the Galleria larvae.ResultsEPF occurred in 41.1% of the soil sampled. These fungi belong to five and an unidentified genus. High species diversity was observed in Abuja with 6 species, and a uniform diversity of 5 species in Gombe, Ibadan, Jos, Kano, Lagos, Nasarawa and Port Harcourt. The Shannon–Wiener index ranges from 2.48 to 1.84. Similarly, species evenness showed a distinct similarity across the 11 sampling states and ranges from 0.99 to 0.92. Simpson Diversity Index was found to be highest in Bauchi with 0.31 and lowest in Abuja with 0.19. The mortality of the Galleria mellonella (L.) larvae differed significantly (P < 0.01) with EPF species and time of exposure. There was also a strong (P < 0.001) relationship between larval mortality and conidial concentration within and among the species. The virulence of the isolated fungi on Galleria mellonella larvae based on LC50 differs with states (sampling site) even within the same species.ConclusionsThe present study uncovered the diversity and occurrence of EPF in soil across Nigeria. In addition, the results can be useful in selecting the suitable soils and best adapted EPF in a particular soil across the study area, or it could be the beginning of a molecular study.

Field Tests of Three Alternative Insecticides with Protein Bait for the Development of an Insecticide Rotation Program to Control Melon Flies, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae).

Simple SummaryMelon flies in Hawaii have developed high levels of resistance to a widely used insecticidal bait containing the active ingredient spinosad. Since farmers relied heavily on this product and have few alternatives, we tested three other insectides mixed with a bait spray called Nu-Lure. The three products (Agri-Mek SC, Mustang Maxx, and Malathion 5EC) were all found to be effective in either decreasing melon fly numbers or suppressing the growth of the population in the field. When used one-by-one in rotation for two weeks per product at one-week intervals on a commercial zucchini farm, melon fly populations were dramatically reduced and the yield of zucchinis harvested was substantially increased.High levels of resistance to the spinosad-based insecticidal protein bait GF-120 have been detected in some populations of melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), in Hawaii in 2017. To provide cucurbit farmers in Hawaii with alternative insecticides, we field-tested the effectiveness of Agri-Mek SC (a.i., abamectin), Mustang Maxx (a.i., zeta-cypermethrin), and Malathion 5EC (a.i., malathion), added to a protein bait spray (Nu-Lure Insect Bait). The insecticide and protein bait combinations were applied to the roosting plants of Z. cucurbitae around the perimeter of the cucurbit fields at one-week intervals. When individually tested, all three insecticides in combination with protein bait significantly reduced or suppressed the numbers of female flies caught in torula yeast traps. A two-week rotation of weekly applications of the three insecticides and GF-120 significantly reduced Z. cucurbitae numbers on a commercial zucchini farm on Maui. The percentage of marketable fruits harvested increased from 51% to 98% after implementing the insecticide rotation. Our findings will be used to provide cucurbit farmers with additional products to control Z. cucurbitae. The future focus will be on educating cucurbit farmers to use the insecticide rotation strategy to prevent or delay resistance development.

Organic mulching modulated native populations of entomopathogenic nematode in vineyard soils differently depending on its potential to control outgrowth of their natural enemies

The entomopathogenic nematodes (EPNs) are biological control agents that are widespread in crop soils. However, traditional agricultural management practices such as cultivation and agrochemical usage can alter the soil balance that enables their occurrence and activity. Alternative strategies like mulching are commonly employed to prevent weed growth, enhance below-ground biodiversity by improving soil, organic matter content, fertility, and moisture. We hypothesized that organic mulches would favor biotic conditions for nematofauna development in crop soil, including EPNs, compared to herbicide application or tillage. Traditional (insect baits) and molecular (qPCR analysis) tools were used in this study to assess the abundance and activity of native EPNs, and the abundance of potential natural enemies, such as free-living nematode (FLN) competitors, nematophagous fungi (NF), and ectoparasitic bacteria, in soils managed with different organic mulches or traditional practices. As a model agroecosystem, we selected the vineyard, one of the most intensively managed crop systems. We compared mulches of grape pruning debris (GPD-M), straw (Str-M), and spent mushroom compost (SMC-M) in two commercial vineyards, which employed either integrated or organic pest and disease management. Following a completely randomized design, we retrieved two composite samples per plot (n = 3 per treatment in each vineyard) in April, June, and October 2020. Numbers of EPNs and selected members of their soil food web were higher in the organic than the integrated managed vineyard. Supporting our hypothesis, organic mulching overall favored nematode occurrence in both vineyards. We found higher NF abundance for Str-M, and GPD-M in the organic vineyard, which plausibly explained the lower EPN activity and occurrence compared to SMC-M in both vineyards. We conclude that the organic mulches can provide appropriate conditions for increasing nematofauna numbers but, depending on the mulch type, may also adversely affect EPNs by increasing their natural enemies. Our findings highlight the need to explore alternative farming practices to unravel complex biotic interactions that affect beneficial soil organisms in agroecosystems.

Sugar alcohols have the potential as bee-safe baits for the common wasp.

BackgroundPest insects are often baited with poisoned feeding stimulants, the most common of which are sugars. However, sugars are attractive for most animal species, which makes it difficult to target only a specific pest insect species. Here, we assessed different sugar alcohols for their potential as more species‐selective feeding stimulants for pest insects.ResultsWe tested the attractiveness of the sugar alcohols sorbitol, xylitol and erythritol with a capillary feeder assay in wasps (as potential pest insects, because introduced wasps are a pest in many regions) and bees (as non‐target insects). For the common wasp (Vespula vulgaris), sorbitol and xylitol acted as nutritive feeding stimulants, and erythritol acted as a non‐nutritive feeding stimulant. For the buff‐tailed bumble bee (Bombus terrestris), sorbitol acted as a feeding stimulant, while for the honey bee (Apis mellifera), none of the sugar alcohols acted as feeding stimulant.ConclusionThe species‐specific preferences for sugar alcohols suggest their potential as species‐selective insect baits. The wasp‐specific preference for xylitol suggests its potential as a bee‐safe alternative to sugar‐containing bait for controlling the common wasp. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Abundance of Beauveria spp. and Metarhizium spp. in maize and banana agroecosystems in central Cuba

Entomopathogenic fungi are an ecological alternative for the control of agricultural pests. These fungi live in organic matter in the soil and can cause natural epizootics in many arthropods associated with the rhizosphere. The aim of this study was to evaluate the abundance of Beauveria and Metarhizium spp. in maize and banana agroecosystems in central Cuba. Selective medium and insect baiting methods were used to isolate the entomopathogenic fungi from the soil. Metarhizium spp. were significantly more abundant than Beauveria spp. in both types of fields of agroecosystems. The abundance of Metarhizium spp. was higher in Sagua la Grande than in Santa Clara and Camajuaní municipalities. The insect bait method resulted as the most successful way to isolate entomopathogenic fungi from soil. These results show the composition of the entomopathogenic fungi in different agroecosystems, and they are an advance in the understanding of their ecology.

Entomopathogenic Fungus from Rice Rhizosphere Soil in Politeknik Negeri Lampung Land

The killing of non-target insects such as predators, natural enemies, and pest resistance to pesticides are negative impacts of pesticide application. Entomopathogenic fungi may be environmentally friendly biological controllers. This study aimed to conduct entomopathogenic fungi from rice plants in the Politeknik Negeri Lampung field using the insect bait method. Sampling was done by taking the rhizosphere soil of rice plants using the diagonal sampling method. Isolation and characterization of the morphology macroscopic and microscopic of entomopathogenic fungi were carried out at the Plant Laboratory of the Food Crops Production Study Program, Politeknik Negeri Lampung. The study started from June to November 2021. The stages of rearing T. molitor bait insects, fishing for entomopathogenic fungi, isolation and purification and propagation of entomopathogenic fungi, observing macroscopic and microscopic morphology. The research results from the exploration of entomopathogenic fungi in the rhizosphere of rice plants obtained that the fungus that infects the insect bait T. molitor with white, green, black hyphae and then microscopically observed the shape of the conidia and hyphae. Macroscopic and microscopic results showed that the entomopathogens obtained from insect bait using T. molitor larvae from the rhizosphere soil of rice plants were Aspergillus flavus, A. niger and Fusarium sp. Aspergillus spp. macroscopic, the mycelium of the fungus was green-white and black-white colours as for the mycelium Fusarium sp. white colour. The history of land use against insecticide applications can affect entomopathogens in rhizosphere soils.

Comparison of Methods for Isolating Entomopathogenic Fungi from Soil Samples

The goal of the present study is to compare the effectiveness of using insect baits versus artificial selective medium for isolating entomopathogenic fungi (EPF) from soil samples. The soil is a rich habitat for microorganisms, including EPF particularly belonging to the genera Metarhizium and Beauveria, which can regulate arthropod pests. Biological products based on fungi are available in the market mainly for agricultural arthropod pest control. Nevertheless, despite the high endemic biodiversity, only a few strains are used in commercial bioproducts worldwide. In the present study, 524 soil samples were cultured on potato dextrose agar enriched with yeast extract supplemented with chloramphenicol, thiabendazole, and cycloheximide (CTC medium). The growth of fungal colonies was observed for 3 weeks. All Metarhizium and Beauveria EPF were morphologically identified at the genus level. Additionally, some isolates were molecularly identified at the species level. Twenty-four out of these 524 soil samples were also surveyed for EPF occurrence using the insect bait method (Galleria mellonella and Tenebrio molitor). A total of 51 EPF strains were isolated (41 Metarhizium spp. and 10 Beauveria spp.) from the 524 soil samples. All fungal strains were isolated either from croplands or grasslands. Of the 24 samples selected for comparison, 91.7% were positive for EPF using Galleria bait, 62.5% using Tenebrio bait, and 41.7% using CTC. Our results suggested that using insect baits to isolate the EPF from the soil is more efficient than using the CTC medium. The comparison of isolation methods in addition to the identification and conservation of EPF has a positive impact on the knowledge about biodiversity. The improvement of EPF collection supports scientific development and technological innovation.

Screening and Identification of Indigenous Entomopathogenic Fungal Isolates from Agricultural Farmland Soils in Nile Delta, Egypt.

The compound negative impact of insect pests attacking agricultural ecosystems includes (i) direct yield losses from damaged crops, (ii) the economic cost of the attempt to prevent these losses and (iii) the negative short- and long-term hazard effects of chemical pesticides on human and environmental health. Entomopathogenic fungi (EMPF) are a group of microorganisms that represent the natural enemies of a number of crop pests, presenting an opportunity to harness their evolutionary fine-tuned relationship with their insect hosts as biocontrol agents in integrated pest management programs. The aim of this study was to establish an indigenous EMPF collection via the Galleria mellonella (greater wax moth) entrapment method from the soils of Nile Delta, Egypt. Obtained insect associated fungal isolates were bio-assayed for pathogenicity against the serious pest Spodoptera litura and Tenebrio molitor, and the seven outperforming isolates were selected for molecular identification and thermotolerance assay. Based on ITS sequence analysis and phylogeny, selected isolates were identified as Beauveria bassiana (four isolates), Metarhizium anisopliae (two isolates) and one isolate of Cordyceps javanica. The obtained results demonstrated (i) the efficacy of using insect baiting coupled with molecular identification and pathogenicity screening to isolate EMPF to control insect pests, and (ii) the availability of indigenous virulent EMPF in Nile Delta’s soil, which can be exploited for the development of sustainable crop protection strategies.