Natural Biological Control Agents Research Articles

Biodiversity of Trichoderma species of healthy and Fusarium wilt-infected banana rhizosphere soils in Tenerife (Canary Islands, Spain).

Banana (Musa acuminata) is the most important crop in the Canary Islands (38.9% of the total cultivated area). The main pathogen affecting this crop is the soil fungal Fusarium oxysporum f. sp. cubense subtropical race 4 (Foc-STR4), for which there is no effective control method under field conditions. Therefore, the use of native biological control agents may be an effective and sustainable alternative. This study aims to: (i) investigate the diversity and distribution of Trichoderma species in the rhizosphere of different banana agroecosystems affected by Foc-STR4 in Tenerife (the island with the greatest bioclimatic diversity and cultivated area), (ii) develop and preserve a culture collection of native Trichoderma species, and (iii) evaluate the influence of soil chemical properties on the Trichoderma community. A total of 131 Trichoderma isolates were obtained from 84 soil samples collected from 14 farms located in different agroecosystems on the northern (cooler and wetter) and southern (warmer and drier) slopes of Tenerife. Ten Trichoderma species, including T. afroharzianum, T. asperellum, T. atrobrunneum, T. gamsii, T. guizhouense, T. hamatum, T. harzianum, T. hirsutum, T. longibrachiatum, and T. virens, and two putative novel species, named T. aff. harzianum and T. aff. hortense, were identified based on the tef1-α sequences. Trichoderma virens (35.89% relative abundance) and T. aff. harzianum (27.48%) were the most abundant and dominant species on both slopes, while other species were observed only on one slope (north or south). Biodiversity indices (Margalef, Shannon, Simpson, and Pielou) showed that species diversity and evenness were highest in the healthy soils of the northern slope. The Spearman analysis showed significant correlations between Trichoderma species and soil chemistry parameters (mainly with phosphorus and soil pH). To the best of our knowledge, six species are reported for the first time in the Canary Islands (T. afroharzianum, T. asperellum, T. atrobrunneum, T. guizhouense, T. hamatum, T. hirsutum) and in the rhizosphere of banana soils (T. afroharzianum, T. atrobrunneum, T. gamsii, T. guizhouense, T. hirsutum, T. virens). This study provides essential information on the diversity/distribution of native Trichoderma species for the benefit of future applications in the control of Foc-STR4.

Citrus Aphids in Algarve Region (Portugal): Species, Hosts, and Biological Control

Aphids affect citrus by causing leaf deformations and reducing fruit production. Additionally, aphids are a great concern due to their ability to transmit Citrus tristeza virus (CTV), the cause of tristeza, one of the main citrus diseases. In the last four years, citrus orchards in the south of Portugal (Algarve region) were sampled for aphid species identification and counting. Aphis spiraecola was the most abundant species, representing more than 80% of all identified aphids, and the damage (leaf deformation) it causes was directly proportional to its density. A. gossypii was the second most common species, followed by A. aurantii and Macrosiphum euphorbiae. The number of aphids in nymph stages was predominant over the adult stages (both wingless and winged) in all species. A. citricidus, the most efficient CTV vector, was not detected. The largest populations of A. spiraecola were observed in lemon and orange trees during spring (>100 individuals per shoot), with great damage observed in orange, lemon, and mandarin trees. A. gossypii was observed mainly in mandarin and tangor trees. There was a low activity of natural biological control agents, with the parasitism of A. spiraecola by Lysiphlebus spp. and Binodoxys spp. ranging from 0.3 to 1.5%. The numerical ratio ranged from 150 to 440 aphids per predator, and among these, syrphids were the most abundant, followed by lacewings and coccinellids (Scymnus).

Isolation and Characterization of Bacteriophage VA5 against Vibrio alginolyticus.

Bacteriophages, or phages, can be used as natural biological control agents to eliminate pathogenic bacteria during aquatic product cultivation. Samples were collected from seafood aquaculture water and aquaculture environmental sewage, and phage VA5 was isolated using the double-layer agar plate method, with Vibrio alginolyticus as the host bacteria. The purified phage strain was subjected to genome sequencing analysis and morphological observation. The optimal multiplicity of infection (MOI), the one-step growth curve, temperature stability, and pH stability were analyzed. Phage VA5 was observed to have a long tail. Whole-genome sequencing revealed that the genome was circular dsDNA, with 35,866 bp length and 46% G+C content. The optimal MOI was 1, the incubation period was 20 min, the outbreak period was 30 min, and the cleavage amount was 92.26 PFU/cell. The phage showed good activity at -20 °C, 70 °C, and pH 2-10. Moreover, the phage VA5 exhibited significant inhibitory effects on V. alginolyticus-infected shrimp culture. The isolated phage VA5 has a wide range of host bacteria and is a good candidate for biological control of pathogenic bacteria.

Genomic Characterization of Endosymbiotic Bacteria Associated With Helicoverpa armigera in Iran Using Next-Generation Sequencing.

Several species of the Helicoverpa genus have been recognized as major agricultural pests from different regions of the world, among which Helicoverpa armigera species has been reported as the most destructive and cosmopolitan species in most regions of the world, including Iran. This pest is a polyphagous species and can cause damage to more than 120 plant species. Studying the internal microbiome of pests is very important in identifying species' weaknesses and natural enemies and potential biological control agents. For genomic characterization of the microbial community associated with H armigera, the whole genome of insect larvae collected from vegetable fields in the northwest of Iran was sequenced using next-generation sequencing Illumina platform. Finally, about 2 GB of raw data were obtained. Using the MetaPhlAn2 pipeline, it was predicted that 2 endosymbiont bacterial species including Buchnera aphidicola and Serratia symbiotica were associated with H armigera. Alignment of reference strains sequences related to both endosymbiotic bacteria with raw data and subsequently, assembly analyses resulted in 2 genomes with 657 623 bp length with GC content of 27.4% for B aphidicola and 1 595 135 bp length with GC content of 42.90% for S symbiotica. This research is the first report on the association of B aphidicola and S symbiotica as endosymbiotic bacteria with H armigera worldwide.

Discovery of novel natural products for mosquito control

Vector control plays a key role in reducing the public health burden of mosquito-borne diseases. Today’s vector control strategies largely rely on synthetic insecticides that can have a negative environmental impact when applied outdoors and often become inefficient because of the mosquitoes’ ability to develop resistance. An alternative and promising approach to circumvent these challenges involves the implementation of insecticides derived from nature (biopesticides) for vector control. Biopesticides can constitute naturally occurring organisms or substances derived from them that have lifespan-shortening effects on disease vectors such as mosquitoes. Here we present the discovery and evaluation of natural product-based biological control agents that can potentially be developed into biopesticides for mosquito control. We screened a natural product collection comprising 390 compounds and initially identified 26 molecules with potential ability to kill the larval stages of the yellow fever mosquito Aedes aegypti, which is responsible for transmitting viruses such as dengue, Zika, chikungunya and yellow fever. Natural products identified as hits in the screen were further evaluated for their suitability for biopesticide development. We show that a selection of the natural product top hits, bactobolin, maytansine and ossamycin, also killed the larval stages of the malaria-transmitting mosquito Anopheles gambiae as well as the adult form of both species. We have further explored the usefulness of crude extracts and preparations from two of the best candidates’ sources (organisms of origin) for mosquitocidal activity, that is extracts from the two bacteria Burkholderia thailandensis and Streptomyces hygroscopicus var. ossamyceticus.Graphical abstract

Urban green roofs can support a diversity of parasitoid wasps

Green roofs are often installed atop buildings to provide ecological services such as mitigating storm water runoff and cooling air within urban heat islands. We found that green roofs in Portland, Oregon, also can support biodiversity, including a diverse assemblage of parasitoid wasps, with 20 morphospecies from 10 families present on the four roofs we surveyed. The roofs with greater plant diversity and structural complexity harbored comparatively more parasitoid morphospecies than the structurally simpler Sedum-dominated roofs. The oldest green roof supported much greater diversity than the younger roofs, including a comparably planted roof three times its size. Parasitoid wasps from the Hymenopteran families we found are high-trophic-level organisms known to feed on a variety of arthropods, including many insects commonly considered to be pests in urban areas. We suggest that green roofs have the potential to provide an often-overlooked ecological service by supporting parasitoid wasps that can act as natural biological control agents.

Native natural enemies in Mediterranean melon fields can provide levels of pest control similar to conventional pest management with broad-spectrum pesticides

Pest control in Mediterranean open-field melon crops currently relies on repeated pesticide applications. A lack of IPM programs that take into account naturally occurring biological control agents in the crop could be due, in part, to a lack of knowledge of the natural enemies associated with melon and their pest control potential. We estimated the abundance of pests and natural enemies in fields managed with a conventional insecticide regime (CPR) and a ‘no insecticide’ regime (NPR), with all fields receiving fungicide applications (sulphur or triadimenol), as required. In a two-year study, six melon fields were sampled periodically during spring and early summer by visual observations of leaves and the extraction of arthropods from flowers using Berlese funnels. The most abundant phytophagous arthropods on melon leaves were thrips (38.9% of total counts), aphids (31.5%), spider mites (26.8%) and whiteflies (2.8%). Aphis gossypii was significantly more abundant in CPR than in NPR fields, whereas whiteflies and thrips had similar abundance in the two treatments. Spider mites were more abundant in NPR than in CPR fields. The main groups of natural enemies on leaves were Orius spp. (76.1% of total counts), phytoseiids (7.4%), predatory thrips (7.1%) and cecidomyiids (5.6%), and all were significantly more abundant in NPR than in CPR fields. The primary predators in flowers were Orius spp. (67.4%) and Aeolothrips spp. (32.6%), and both were significantly more abundant in NPR than in CPR fields. Orius spp. was inferred to be the primary biological control agent of aphids, as few aphids were mummified by parasitoids. The control of aphids by Orius spp. was probably mediated by apparent competition with thrips, which are a preferred prey of Orius spp. In summary, elimination of pesticides from the management regime enhanced the abundance of natural enemies in the melon crop, and natural biological control limited pest infestations in NPR fields as well as did broad-spectrum insecticides in CPR fields. Therefore, IPM strategies for melon production should consider conservation of natural biological control agents as an effective alternative to conventional regimes that rely primarily upon insecticides.

Identification of mealybugs, soft scale insects and their predators in vineyards across the savannah agro-ecological region of Nigeria

Insect-vectored viruses are a major threat to grapevine production but there is a dearth of information on the occurrence and distribution of key grapevine pests in Nigeria. The recent detection of grapevine leafroll associated virus-1 (GLRaV-1), a known insect-vectored ampelovirus, in Nigeria elevates the importance of the identification of its potential vectors as a precursor to assessing the risk of grapevine leafroll disease spread. This study was conducted to determine the occurrence and diversity of potential vectors of grapevine viruses and their natural enemies in vineyards across the savannah agro-ecological region of Nigeria. Forty vineyard and nursery locations were surveyed during 2016 and 45 arthropod samples were collected. The samples were first morphologically identified, and DNA barcoding was conducted on a subset of 16 representative samples using universal primers specific to the Mitochondrial Cytochrome Oxidase subunit I (mtCOI) gene of most insects. The results indicated the presence of two species of scale insects (Parasaissetia nigra and Saissetia coffeae) and two mealybug species (Maconellicoccus hirsutus and Ferrisia virgata), some ofwhich are potential grapevine virus vectors, in Nigerian vineyards. In addition, the natural enemies of these insect species were detected which includes three species of parasitoids (Anagyrus kamali, Anagyrus pseudococci and Encarsia inaron) and one predator (Hyperaspidius mimus). While the detection of mealybugs and scale insects underscore the risk of vector-mediated virus spread in Nigerian vineyards, the identification of their natural enemies indicates presence of natural biological control agents to facilitate an integrated management of economically important grapevine virus diseases in the country.
 Keywords: Mealybugs; scale insects; parasitoids and predators; insect vectors; grapevine viruses.

Studies on the antimicrobial activity of a locally isolated lactic acid bacterium and its application on fusarium solani-infected plants

Background Lactic acid bacteria (LAB) have proven a great inhibitory effect toward phytopathogenic bacteria and fungi, giving them the importance as natural biological control agents without hazards to the surrounding eco-system. Objective This study aims for the local isolation of a lactic acid bacterial strain active against different microorganisms especially phytopathogens. Materials and methods Of the 40 isolated bacterial strains, 36 were preliminarily characterized as LAB using both Gram staining and catalase test methods. Their antimicrobial activities were then tested against different bacterial and fungal strains. The most potent isolate was molecularly identified and tested, in vitro, on different pathogens, and then, in vivo, against infected Phaseolus vulgaris plants. Results and conclusion Results revealed that 17 isolates showed antimicrobial activities against Pectobacterium carotovorum and four of them were solely effective against Staphylococcus aureus (inhibition zones of diameters ranging between 0.4 and 0.8 cm). However, only isolate 32 showed satisfactory antimicrobial activity (inhibition zones of ∼0.8 cm) against both of the two aforementioned test microorganisms. Moreover, isolate 32, molecularly identified as Enterococcus faecium, was also found to be active against Fusarium solani phaseoli, a common phytopathogen fungus that affects many economically important crops. The addition of 1.5% (v/v) of the 24-h old fermentation broth of this isolate, in vitro, resulted in a shrinking percent of the fungus growth of more than 51% and gave very promising results when applied in the field experiment. Therefore, the use of the selected LAB culture broth as a bioagent to control some plant pathogens, as well as a plant growth stimulator, could be a promising approach to reduce the economic losses in agricultural crops.

KEANEKARAGAMAN HYMENOPTERA PARASITOID PADA PERKEBUNAN KELAPA SAWIT (Elais guineensis Jacq.) YANG BERBATASAN DENGAN HUTAN SEKUNDER

Secondary forest is primary forest that managed for forest exploitation purposes, so there are many oil palm plantations that are directly adjacent to secondary forest. Hymenopteran parasitoid is a group of the most important insect in the Hymenoptera order, because of its role as natural enemies or biological control agents against insect pests in agricultural ecosystems, including oil palm plantations. The objective of this study was to understand the diversity, species richness and abundance of Hymenopteran parasitoids in oil palm plantations which adjacent to secondary forests. The research was a survey, the purposive sampling method to determine the research location, while to determine the sample points used a systematic random sampling method. For insect collection, insect nets and yellow pan traps were used. The research was carried out in oil palm plantations located in Gunung Selasih and Siguntur Village. In each research unit there were 10 sample points with a distance of each sample point was 100 m along the transect line. The results showed that the total number of Hymenopteran parasitoids collected was 199 individuals belonging to 23 families and 94 morphospecies. Braconidae and Ichneumonidae were the Hymenopteran parasitoids family which its members were found many in the present study.

Compatibility of the Predatory Beetle, Delphastus catalinae, with an Entomopathogenic Fungus, Cordyceps fumosorosea, for Biocontrol of Invasive Pepper Whitefly, Aleurothrixus trachoides, in Florida.

Simple SummaryThe solanum whitefly, Aleurothrixus trachoides, is a polyphagous pest known to attack > 70 crops worldwide. Endemic to the Neotropical region, in the past few years, it has emerged as a significant pest of several horticultural crops including pepper in the United States. To develop an eco-friendly sustainable management strategy for this pest, in this study, we evaluated the efficacy and compatibility of two commercially available biological control agents, predatory beetle Delphastus catalinae (Dc) and entomopathogenic fungi Cordyceps fumosorosea (Cfr) under laboratory conditions. Results showed both Cfr, treatments (alone or in combination with Dc) were efficacious, and Cfr did not negatively impact the beetle longevity. This study’s outcome is important not only for organic horticultural growers, but also for conventional growers as it offers a low-risk alternative tool for solanum whitefly integrated pest management in Florida and other affected regions.Aleurothrixus (formerly known as Aleurotrachelus) trachoides Back (Hemiptera: Aleyrodidae), commonly known as pepper or solanum whitefly, is a new emerging whitefly pest of several horticultural crops in the United States. During the preliminary survey for pepper whitefly infestation in Florida, a whitefly-specific predatory beetle Delphastus catalinae Horn (Coleoptera: Coccinellidae) was observed associated with this pest in the natural ecosystem. The current study was undertaken to determine the efficacy of this naturally occurring predator, D. catalinae, and an entomopathogenic fungus, Cordyceps (formerly known as Isaria) fumosorosea (Cfr) (Wize) (Hypocreales: Cordycipitaceae), alone or in combination, under controlled laboratory conditions. Whitefly mortality for Cfr (88%), beetle (100%) and Cfr + beetle (100%) treatments were similar and significantly higher compared to control. In the combination treatment, Cfr did not impact D. catalinae longevity and daily food intake, indicating a neutral interaction between the two treatments. Results showed that both of these natural biological control agents could potentially offer an effective alternative in the battle against invasive whiteflies such as pepper whitefly in U.S. horticulture production, either as a stand-alone strategy or in an integrated approach. Although these findings are promising, compatibility of the two treatments needs to be evaluated further under greenhouse and semi-field conditions before recommending to commercial growers.

Dual ecosystem services of syrphid flies (Diptera: Syrphidae): pollinators and biological control agents

With increasing worldwide pressure on bee pollinator populations and an increase in insecticide resistance amongst pest insects, there is a growing need for diversification of pollinator and pest control systems. Syrphid flies (Diptera: Syrphidae) contribute ecosystem services to agroecosystems through their supporting roles as crop pollinators and predators of pests. Adult syrphids are important pollinators with high floral visitation rates and pollen carrying capacity, while predatory syrphid larvae are natural biological control agents, reducing aphid populations in both field and laboratory conditions. The present challenge is to determine whether syrphid flies have the potential for application as pollinators and in integrated pest management (IPM) schemes as biological control agents. Currently, there are gaps in research that are hindering the use of syrphids as dual service providers. Such gaps include a lack of knowledge of syrphid floral preferences, the role and viability of adult syrphids as pollinators in natural and agro-ecological pollinator networks, and the predatory efficiency of larvae in field and greenhouse conditions. By reviewing relevant literature, we demonstrate syrphids flies have the potential to be used as pollinators and biological control agents. This article is protected by copyright. All rights reserved.

Does experimental evolution produce better biological control agents? A critical review of the evidence

AbstractBiological control of crop pests is considered a good alternative or complement to the use of pesticides. However, legislation restricts the importation of natural enemies of pests. A potential way to circumvent this limitation is by using experimental evolution and/or artificial selection to improve native biological control agents. Here, we review studies that have used these methodologies and evaluate their success. Experimental evolution or artificial selection has been used on a wide range of traits, with most focusing on improving the performance of natural enemies in ecologically relevant environments, such as in the presence of pesticides or at different temperatures. Although most studies were poorly replicated, the selected traits generally improved following the selection process. However, correlated responses (often in the form of trade‐offs) with other traits of interest were common. We suggest that the selection procedure can be improved by increasing replication and performing experimental evolution under more semi‐natural environments, to ensure that the most useful traits are being selected.

Genome mining identifies cepacin as a plant-protective metabolite of the biopesticidal bacterium Burkholderia ambifaria.

Beneficial microorganisms are widely used in agriculture for control of plant pathogens but a lack of efficacy and safety information has limited the exploitation of multiple promising biopesticides. We applied phylogeny-led genome mining, metabolite analyses and biological control assays to define the efficacy of Burkholderia ambifaria, a naturally beneficial bacterium with proven biocontrol properties, but potential pathogenic risk. A panel of 64 B. ambifaria strains demonstrated significant antimicrobial activity against priority plant pathogens. Genome sequencing, specialized metabolite biosynthetic gene cluster mining and metabolite analysis revealed an armoury of known and unknown pathways within B. ambifaria. The biosynthetic gene cluster responsible for the production of the metabolite, cepacin, was identified and directly shown to mediate protection of germinating crops against Pythium damping-off disease. B. ambifaria maintained biopesticidal protection and overall fitness in soil after deletion of its third replicon, a non-essential plasmid associated with virulence in B. cepacia complex bacteria. Removal of the third replicon reduced B. ambifaria persistence in a murine respiratory infection model. Here we show that by using interdisciplinary phylogenomic, metabolomic and functional approaches, the mode of action of natural biological control agents related to pathogens can be systematically established to facilitate their future exploitation.

Potential Biological Control of Schistosomiasis by Fishes in the Lower Senegal River Basin.

.More than 200 million people in sub-Saharan Africa are infected with schistosome parasites. Transmission of schistosomiasis occurs when people come into contact with larval schistosomes emitted from freshwater snails in the aquatic environment. Thus, controlling snails through augmenting or restoring their natural enemies, such as native predators and competitors, could offer sustainable control for this human disease. Fishes may reduce schistosomiasis transmission directly, by preying on snails or parasites, or indirectly, by competing with snails for food or by reducing availability of macrophyte habitat (i.e., aquatic plants) where snails feed and reproduce. To identify fishes that might serve as native biological control agents for schistosomiasis in the lower Senegal River basin—one of the highest transmission areas for human schistosomiasis globally—we surveyed the freshwater fish that inhabit shallow, nearshore habitats and conducted multivariate analyses with quantitative diet data for each of the fish species encountered. Ten of the 16 fish species we encountered exhibited diets that may result in direct (predation) and/or indirect (food competition and habitat removal) control of snails. Fish abundance was low, suggesting limited effects on schistosomiasis transmission by the contemporary fish community in the lower Senegal River basin in the wild. Here, we highlight some native species—such as tilapia, West African lungfish, and freshwater prawns—that could be aquacultured for local-scale biological control of schistosomiasis transmission.

Diversidad de picudos (Coleoptera: Curculionidae) en huertas de nogal pecanero en el norte de Coahuila, México


 
 
 La región norte de Coahuila es una de las zonas productoras de nuez más importantes en México. Euplatypus segnis (Chapuis, 1865) y Xyleborus ferrugineus (F. 1801) curculiónidos plaga asociados a nogales en el país, desconociéndose si hay otros presentes en las huertas. De julio de 2015 a septiembre de 2016 y agosto de 2017 se realizaron muestreos en el Banco de Germoplasma del INIFAP-Sitio Experimental Zaragoza, ocho huertas comerciales y árboles nativos de nogal. Utilizando como métodos de muestreo red entomológica estándar y manteo- aspersión del follaje con Cipermetrina. Se recolectaron 1 174 especímenes adultos de insectos, determinando seis órdenes, 49% fueron coleópteros, siendo Coccinellidae la familia más abundante, 17% fueron curculiónidos (203 adultos y 32 especies identificadas). Pandeleteius cinereus (Horn, 1876), Compsus auricephalus (Say, 1824) y Conotrachelus leucophaetus Fahraeus, 1837 se recolectaron en follaje de nogales, actualmente estas especies no son de importancia económica para el cultivo. Smicronyx interruptus (Blatchley, 1916), S. sculpticollis (Casey, 1892) y Thecesternus hirsutus (Pierce, 1909) son posibles agentes de control biológico natural para Cuscuta L., 1753, Acacia (Mill, 1754) y Parthenium L., 1753. Es importante que no se recolecto ningún ejemplar de Curculio caryae (Horn, 1873), Euplatypus segnis ni Xyleborus ferrugineus, curculiónidos consideradas plagas del nogal pecanero en México.
 
 

Larvicidal potential of selected indigenous lichens against three mosquito species–Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi

ObjectiveMosquitoes are the major transmitting vectors of serious human diseases, causing millions of deaths every year with undesirable effects, including toxicity to non-target organisms. Some plants with insecticidal properties have been used in recent years for the control of a variety of pest insects and vectors. In the quest for alternative natural biological control agents against mosquito larvae lichens were selected. MethodLarvicidal activity was assessed with methanolic extracts of Parmotrema reticulatum, Parmotrema kamatti, Parmotrema tinctorum, Parmelia erumpens, Leptogium papilosum, and Roccella montagnei against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. The standard WHO protocols with minor modifications were adopted and the bioassay was evaluated at the concentrations of 100–500 µg/mL for each lichen. Since all the lichen extracts showed complete mortality against C. quinquefasciatus in 100 µg/mL, the concentrations were decreased to 100, 50, 25, 12.5, and 6.25 µg/mL for C. quinquefasciatus. Larval mortality was observed for 24 h after treatment. ResultsAll the lichen extracts exhibited activity against third instar larvae of A. aegypti and A. stephensi at 100 µg/mL, and 100% mortality was observed against the vector C. quinquefasciatus at 100 µg/mL. The highest larvicidal activity was found with L. papilosum against A. aegypti (LC50 = 81.127 µg/mL) and A. stephensi (LC50 = 89.10 µg/mL). Similarly, P. tinctorum and R. montagnei when tested against C. quinquefasciatus with minimum concentration <100 µg/mL exhibited significant activity with LC50 values of 5.32 and 6.97 µg/mL. ConclusionThe bioassay results revealed larvicidal potential of lichens especially against C. quinquefasciatus with high mortality even at lower concentration. Hence, lichens can be used as an ideal sustainable approach for the control of lymphatic filariasis caused by vector C. quinquefasciatus.

First Report of NativeAstata unicolor(Hymenoptera: Crabronidae) Predation on the Nymphs and Adults of the Invasive Brown Marmorated Stink Bug (Hemiptera: Pentatomidae)

Summary Native insect predators and parasitoids can help regulate invasive insect pest species. The brown marmorated stink bug, Halymorpha halys (Hemiptera: Pentatomidae), is an introduced pest of fruits and vegetables in the eastern USA that originated in Asia. Surveys for native biological control agents of this pest detected the crabronid predatory wasp Astata unicolor (Hymenoptera: Crabronidae) and the generalist predatory bug Arilus cristatus (Hemiptera: Reduviidae) using the nymphs and adults of this introduced pest as prey. Temporal distribution of the wasp was determined from water pan traps and net collections over 5 years in floral provisioning strips that were established for pollinator conservation programs in tree fruit farms. Blue vane traps used for bee monitoring did not capture A. unicolor in pollinator plantings. Astata unicolor was not found in 6 commercial apple orchards that were monitored concurrently using either pan or blue vane traps over a 4 yr period.

The Biochemical Effects of Beauveria bassiana and Metarhizium anisopliae on 3rd instar Larvae of Culex pipiens L. (Diptera: Culicidae)

The biochemical effects of twoentomopathogenic fungi, Beauveriabassiana and Metarhiziumanisopliae,were studied in the 3rdinstar larvae of Culex pipiens in the laboratory. Results revealed significantreduction in the total proteins of the treated larvae compared to the controllarvae. Thebiochemical studies using (SDS-PAGE) revealed that there was a reduction in thenumber of protein bands due to the treatment with either of the two fungi. The obtained results indicated that the applicationof entomofungi as larvicidal agents against mosquito larvae caused significantchanges in the total protein profile of Cx. pipiens larvae suggesting thattoxins secreted by these pathogens caused damage to the larval proteins whichfinally leads to larval death. Theconclusion is that the fungal pathogens are important as natural biologicalcontrol agents of manyinsect and other arthropods and frequently cause epizootics that significantlyreduce host population. This study recommends the use of B.bassianaand M.anisopliae as biological control agents to the control of Cx.pipiens larvae in order tosuppress this medical vector for publichealth.

Parameters affecting plant defense pathway mediated recruitment of entomopathogenic nematodes

ABSTRACTEntomopathogenic nematodes are natural enemies and effective biological control agents of subterranean insect herbivores. Interactions between herbivores, plants, and entomopathogenic nematodes are mediated by plant defense pathways. These pathways can induce release of volatiles and recruit entomopathogenic nematodes. Stimulation of these plant defense pathways for induced defense against belowground herbivory may enhance biological control in the field. Knowledge of the factors affecting entomopathogenic nematode behaviour belowground is needed to effectively implement such strategies. To that end, we explore the effect of elicitor, elicitor dose, mechanical damage, and entomopathogenic nematode release distance on recruitment of entomopathogenic nematode infective juveniles to corn seedlings. Increasing doses of methyl jasmonate and methyl salicylate elicitors recruited more entomopathogenic nematodes as did mechanical damage. Recruitment of entomopathogenic nematodes was higher at greater release distances. These results suggest entomopathogenic nematodes are highly tuned to plant status and present a strategy for enhancing biological control using elicitor-stimulated recruitment of entomopathogenic nematodes.