Compatibility of indigenous isolates HR1, HR2 of entomopathogenic nematodes, with low-toxicity insecticides for control of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) and tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Invasive species are a major danger to agronomic and natural ecosystems, and due to environmental concerns about pesticide use, EPNs have the potential to replace larvicidal action in pest management. The goal was to see how well local isolates of Steinernema feltiae (HR1) and Heterorhabditis bacteriophora (HR2) controlled invasive species when combined with low-toxicity pesticides. HR1 + Spinosad, chlorantraniliprole produced over 90% mortality in larvae at 96 hours, while HR2 + Spinosad, chlorantraniliprole caused over 95% mortality at 96 hours. After treatment, the high dose was regarded the least hazardous technique for controlling fall armyworm. At the high dose, HR1 + Spinosad, chlorantraniliprole produced larvae death of over 100 percent at 96 hours, and HR2 + Spinosad, chlorantraniliprole caused mortality of over 97.50 percent at 96 hours, and should be considered as a least hazardous strategy for T. absoluta management. Controlling larvae mortality of above 100% at 96 hours in combination with low-toxicity insecticide dosages should be included as a least harmful technique to control T. absoluta. The results showed that these HR2 strains have high pathogenicity against T. absoluta and S. frugiperda and have potential for control in integrated approaches, causing 100 percent and 90.00 percent mortality of T. absoluta and S. frugiperda at 96 hours at the high dose as a least toxic strategy to control.

Steinernema Feltiae- Xenorhabdus Bovienii: More Information about this Bactohelminthic Complex from Iran

Background: Entomopathogenic nematodes (EPNs) of the families Steinernematidae and Heterorhabditidae that are symbiotically associated with Xenorhabdus and Photorhabdus bacteria are one of the effective biological control agents of insect pests. Native isolates can probably be more efficacious to control insect pests than exotic ones due to their adaptability to indigenous environmental conditions. Results: In this study, Steinernema feltiae isolate FUM221 was recovered from soil samples collected from the Fandoghloo pasture, Ardabil province, Iran. Morphological investigations of the first and second-generation adults, infective juveniles, and molecular characterizations were given based on ITS and 18S rDNA genes. Besides, molecular analysis based on the 16S rRNA region and phenetic data recognized Xenorhabdus bovienii as its symbiont bacterium. The scanning electron microscopy (SEM) images verified the identification of this isolate.Conclusion: The molecular characterization using two loci and phylogenetic analyses provided more evidence for the classification of this steinernematid and its difference of the same species from other countries. Moreover, molecular and phenetic characterizations of its symbiotic bacterium were provided with low variations compared to other isolates. Herein, the comprehensive taxonomic data of this steinernematid from Iran is presented.

Biocontrol in practice in Canadian floricultural greenhouses

The environment inside Canadian prairie greenhouses differs from greenhouses built in other northern latitude locations in terms of lighting, temperature, humidity, and photoperiod. Since the performance of biocontrol agents depends upon several interactive environmental variables, their effectiveness to control pests in a particular crop growing under certain climatic conditions does not directly translate to another crop or location. So, we analyzed research trials assessing the efficacy and compatibility of various biocontrol agents (Amblyseius cucumeris, Amblyseius cucumeris, Phytoseiulus persimilis, Encarsia formosa, Aphidius colemani, Aphidius ervi, and Steinernema feltiae) on key pests (Western flower thrips, two-spotted spider mites, greenhouse whiteflies, and aphids) of spring bedding plants grown in a commercial floricultural greenhouse. Were analyzed several compatible combinations of biocontrol agents and observed a significant reduction in pest densities and plant damage symptoms as compared to untreated control plants. The results demonstrate that P. persimilis controlled two-spotted spider mites successfully in calibrachoa crop. The combination of Amblyseius cucumeris and S. feltiae resulted in significantly better control of Western flower thrips than the use of Amblyseius cucumeris alone in sweet potato vine plants. The application of E. formosa and Amblyseius cucumeris individually reduced greenhouse whiteflies on calibrachoa plants as compared to control, but their combination performed better resulting in a significantly lower number of whiteflies on plants. Another combination of Aphidius colemani and Aphidius ervi controlled green peach aphids and foxglove aphids effectively on the pansy crop. The biocontrol agents were effective for managing a variety of pests in a commercial greenhouse setting.

VIRULENCE OF ENTOMOPATHOGENIC NEMATODES TO THREE SOFT SCALE INSECT SPECIES

Virulence of commercial strains of entomopathogenic nematode (EPN) Steinernema carpocapsae (Weiser), Steinernema feltiae Filipjev and Heterorhabditis bacteriophora Poinar (Rhabditida: Steinernematidae, Heterorhabditidae), were tested on young females of Pulvinaria hydrangeae Steinweden, Partenolecanium corni (Bouché) and Coccus pseudomagnoliarum (Kuwana) (Hemiptera, Coccidae) and a native strain of H. bacteriophora was tested on citricola scale, C. pseudomagnoliarum. The laboratory tests were carried out in small plastic Petri dishes with infective juveniles (IJ) applied on filter paper covering the bottom. Results showed that all EPN tested were virulent to all three soft scale insect species. Recorded mortality of insects at the highest concentration of approximately 50 IJ per cm2 exceeded 64% in all combinations of nematode and scale species tested. Within the same nematode concentration, scales’ mortality of 90% and above was recorded for P. corni with all nematode species, P. hydrangeae with S. carpocapsae (Nemastar) and C. pseudomagnoliarum with native H. bacteriophora strain. All scale species were good hosts for all nematode species. This is the first report of EPNs to parasitize soft scale insects and one of the few among Coccoidea. The level of parasitism recorded is promising for potential use in management of scale insects.

Synthesis, Structural Characterization, and Biological Activities of Organically Templated Cobalt Phosphite (H2DAB)[Co(H2PO3)4]·2H2O

A novel hybrid cobalt phosphite, (H2DAB)[Co(H2PO3)4]·2H2O, has been synthesized by using slow evaporation method, in the presence of cobalt nitrate, phosphorous acid and 1,4- dia-minobutane (DAB= 1,4- diaminobutane) as a structure-directing agent. Single crystal X-ray diffraction analysis showed that the compound crystallizes in the P-1(n.2) triclinic space group, with the following unit cell parameters (Å, °) a = 5.4814 (3), b = 7.5515 (4), c = 10.8548 (6), α = 88.001 (4), β = 88.707 (5), γ = 85.126 (5), and V= 447.33 (4) Å3. The crystal structure was built up from cor-ner-sharing [CoO6] octahedra, forming chains parallel to [001], which are interconnected by H2PO3 pseudo-tetrahedral units. The deprotonated cations, residing between the parallel chains, interacted with the inorganic moiety via hydrogen bonds leading thus to the formation of the 3D crystal structure. The Fourier transform infrared spectrum showed characteristic bands corresponding to the phosphite group and the organic amine. The thermal behavior of the compound consisted mainly of the loss of its organic moiety and the water molecules. The biological tests exhibited significant activity against Candida albicans and Escherichia coli strains in all used concentrations, while less inhibitory activity was pronounced against Staphylococcus epidermidis and Saccharomyces cerevisiae, and in the case of multi-cellular organisms, no activity against the nematode model Steinernema feltiae was detected.

Potential of two indigenous strains of entomopathogenic nematodes, (Steinernema feltiae and Heterorhabditis bacteriophora) against the tomato leafminer (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), under laboratory and greenhouse environmental bioassay

The tomato leafminer (Tuta Absoluta) is an important pest of tomato crops which have features like; high reproductive potential, Invasive species are major threats to agronomic and natural ecosystems. Based on the pathogenicity of strains, only two isolates effectively show larvicidal activity. The native isolate was obtained from soil samples, collected from Rajgarh, Hamachi Pradesh, India. Petri dish bioassay use nematodes S. feltiae HR1 and H. bacteriophora HR2 species dose (0, 10, 20, 40, 80, 160/ IJs/cm2). The (%) 1st instar larval mortality was ranged from 24.15 to 85.38 %. 2nd instar from 29.87 to 90.00 %. 3rd instar from 24.15 to 90.00 %. 4th instar from 31.53 to 90.00 % and pupae stage mortality was ranged from 31.53 to 85.38 %. Larvicidal activity after 48- and 72-hours exposure, the S. feltiae and H. bacteriophora (1.0, 1.30, 1.60, 1.90, 2.20/IJs/cm2) showed potent larvicidal activity with LC50, LC75 and LC90 of all instars and pupa show high mortality. The strain inhibits the larval and pupal development 48 to 72 hr exposer time with LC50 range from 05.42 to 23.67, LC75 20.29 to 83.12, LC90 16.52 to 98.89. Green house test is using the seam isolate of EPNs (HR1, HR2) on foliar application it caused by significant mortality results. These studies demonstrate the challenge for invasive species. The local indigenous strains of EPNs (S. feltiae HR1, H. bacteriophora HR2) as a good biocontrol agent against invasive pest of T. absoluta.

Potent Ant Deterrents Emitted from Nematode-Infected Insect Cadavers

Most known species of entomopathogenic nematodes (EPNs) are generalist obligate parasites of insects. They kill their hosts within days after infection and mortality is mainly caused by toxins produced by bacteria that co-infect the hosts and serve as food for the nematodes. EPNs can infect a very broad spectrum of insects and these insects can therefore be expected to have evolved strategies to avoid infection. Indeed, ants are known to avoid feeding on EPN-infected insect cadavers, most likely because they are repelled by semiochemicals that emanate from the cadavers. The source and nature of these repellents are so far unknown. In a series of behavioral and chemical analytical experiments we identified hexadecanal and 2-heptadecanone as two compounds that are emitted by insect larva that are infected by the EPN Steinernema feltiae, but not by uninfected larvae. When spiking honey water with the two semiochemicals, they were confirmed to be highly deterrent to the ant Lasius niger. The environmentally benign hexadecanal and 2-heptadecanone could be employed to ward off ants and possibly other pests. Additional experiments are needed to fully determine their application potential.

Bio-efficacy of entomopathogenic nematodes, Steinernema feltiae and Heterorhabditis bacteriophora against the Cabbage butterfly (Pieris brassicae [L.]) under laboratory conditions

Background Entomopathogenic nematodes (EPNs) have the potential to supersede larvicidal activity for the management of various insect pests. Result Lab experiments were conducted to test the pathogenicity of 2 EPNs local species; Steinernema feltiae and Heterorhabditis bacteriophora at different (IJs/cm2) concentrations against the cabbage butterfly, Pieris brassicae (L.). The native isolate was obtained from soil samples, collected from Rajgarh, Hamachi Pradesh, India. Petri dish bioassay used the EPNs species (S. feltiae HR1 and H. bacteriophora HR2) at the concentrations (0, 10, 20, 40, 80, 160 IJs/cm2). Based on the pathogenicity of the strains, only 2 isolates effectively showed larvicidal activity. The highest (%) (72.08 and 67.42%), at the 2nd instar larval mortality was recorded in the treatments with H. bacteriophora and S. feltiae at160 IJs/cm2, respectively. At the 4th instar larvae, respective larval mortality (85.38, 69.50%) was recorded in treatment with H. bacteriophora, and S. feltiae, respectively, at160 IJs/cm2. In case of pupae, the mortality rates were (62.12, 58.58%) for H. bacteriophora and S. feltiae, respectively, at 160 IJs/cm2; (74 and 12%) for both the tested EPNs, respectively, at 80 IJs/cm2. Percent of P. brassicae larval mortality treated with the tested EPN isolates was significantly higher than the untreated control. Results revealed that the percent of larval mortality significantly increased with the increase in time periods, being maximum at 72 h. S. feltiae and H. bacteriophora, strains showed potent larvicidal activity at low concentration even at 48 and 72 h of exposure. Conclusion This study revealed that the local strains of EPNs (S. feltiae HR1 and H. bacteriophora HR2) were found as a biocontrol agent against P. brassicae.

Comparison of Biological Activity of Field Isolates of Steinernema feltiae with a Commercial S. feltiae Biopesticide Product

Insect trap studies were carried out to determine the presence of entomopathogenic nematodes (EPN) from the family Steinernematidae in the soils of Poland and to compare the biological activities of field nematode isolates with nematodes from commercial biopesticide. The fauna of these organisms in central Poland is poorly studied in both taxonomic and biological terms. Tilled soils representative of this region were sampled from cultivated fields. EPN were isolated from soil samples under laboratory conditions and identified using a key for species identification and molecular analysis. Basic morphometric parameters of infective juveniles and adult males of the first generation were determined. The research showed that males and infective juveniles Steinernema feltiae from Łoniów were the largest. The smallest infective juveniles were found in the isolate from Oblasy, and the smallest males in the isolate from Danków. In Poland, new field isolates showed close genetic similarity to other S. feltiae isolates. The research showed that the field isolates from Poland had greater infectivity and rate of reproduction compared with nematodes from the commercial biopesticide. The findings indicate the potential use of field S. feltiae isolates from Poland (iso1Lon, iso1Dan and iso1Obl) to develop new biopesticide products.

Microbial Control Agents for Fungus Gnats (Diptera: Sciaridae: Lycoriella) Affecting the Production of Oyster Mushrooms, Pleurotus spp.

Infestations of fungus gnats (Diptera: Sciaridae) can reduce the production of oyster mushrooms (Pleurotus spp.) grown as food crops within controlled environments. The objectives of this study were to assess the efficacy of Bacillus thuringiensis var. israelensis (Bti) and Steinernema feltiae against fungus gnat larvae. A bioassay was developed, whereby pasteurized straw was inoculated with Pleurotus columbinus and treated with Bti (Gnatrol®), S. feltiae (Nemashield®), or water. Fungus gnats (Lycoriella sp.) were released into each bioassay container for ovipositing onto the straw, thereby exposing the F1 larvae to treated or untreated substrate. Sticky cards within the containers entrapped fungus gnats emerging from the substrate as an indicator of larval survivorship. Following three bioassays, fewer fungus gnats emerged from straw treated with Bti compared to S. feltiae and the water control. Three additional bioassays using Pleurotus ostreatus also demonstrated that fewer fungus gnats emerged from straw treated with Bti compared to S. feltiae and the untreated control. Steinernema feltiae was generally ineffective. Monitoring substrate weight in the bioassay containers over time indicated that Bti and S. feltiae did not impede colonization by P. ostreatus. Incorporating Bti into straw substrate is a promising approach for managing fungus gnats infesting Pleurotus spp.