Chemical Insecticide Treatments Research Articles

Validation of the methodology of the germination test using a rolled paper plus vermiculite for treated soybean seeds

ABSTRACT: The use of an appropriate germination method is crucial to allow expression of the germination potential of the seed lot, especially when the seeds are treated with phytosanitary products, since phytotoxicity can occur in some substrates and under some conditions and the germination values will be underestimated. In this context, the aim of this study was to evaluate the methodology of germination in a rolled paper plus vermiculite (RP+V) and the possibility of its statistical validation for routine use in laboratories. Four seed lots of two cultivars with different vigor levels and chemical insecticide treatments (control, thiamethoxam + cyantraniliprole, clothianidin + fipronil, and imidacloprid + thiodicarb, all seeds were treated with fungicide) were used. The samples were prepared and sent to 13 laboratories accredited by the Ministério da Agricultura e Pecuária (MAPA) for germination assessment with RP+V. The collected data were analyzed using statistical methodologies to assess the repeatability and reproducibility of the method, as well as its precision and accuracy. The data from normal soybean seedlings evaluated using the rolled paper plus vermiculite (RP+V) methodology show repeatability, reproducibility, precision, and accuracy within the critical parameters of 1% and 5%. The proposed methodology is reliable and can be routinely implemented in evaluation of soybean seeds, especially those treated with phytosanitary products.

Nanoemulsion-based plant essential oil formulations: in vitro evaluation of pesticidal activity against ectoparasites in poultry

Ectoparasite infestations significantly impact the health and productivity of poultry. Chemical applications, although common for pest control, lead to pesticide residues and parasite resistance in poultry. Nanoemulsion-based plant essential oil formulations (NEOFs) provide a promising alternative for controlling poultry ectoparasites. This study aimed to assess the efficacy of NEOFs from clove, cinnamon, and turmeric essential oils (EOs) against ectoparasites, Menopon gallinae and Megninia ginglymura, under laboratory conditions. The toxicity and repellent properties of the NEOFs were examined, with the major chemical compounds of the EOs analyzed using chromatography mass spectrometer. Results identified eugenol as the dominant component in clove and cinnamon EOs (84.60 and 75.19%, respectively), while turmerone (68.46%) was the major compound in turmeric EO. NEOFs with clove:cinnamon:turmeric ratios of 4:0:0, 2:2:0, and 2:0:2 had particle size of 20.76 nm, 20.66 nm, and 89.56 nm, respectively, while those based on eugenol and turmerone standards had sizes <21.0 nm. In addition, NEOFs at 0.3% concentration with ratios of 4:0:0 and 2:2:0 achieved full control of both ectoparasites. These formulas demonstrated exceptional potency in exterminating ectoparasites, with LC50 and LC90 at <0.160 and <0.250%, respectively, 6 h after treatments. Furthermore, both NEOFs showed higher repellence responses in M. gallinae compared to M. ginglymura. The toxicities of these NEOFs were comparably effective against both parasites, showing no significant difference compared with chemical insecticide treatment. Therefore, further research will explore the practicality of using clove and cinnamon-derived NEOFs under farm conditions.

Regional selection of insecticides and fungal biopesticides to control aphids and thrips and improve the forage quality of alfalfa crops

The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa (aphids and thrips) were compared in three sites across China’s alfalfa belt. In addition, the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined. Efficacy varied among the different biological and chemical insecticides. The chemical insecticides were significantly more effective than biopesticides in a short time-frame. The efficacy period of biopesticides was significantly longer than that of chemical insecticides, and the corrected mortality rate of aphids in all regions was above 50% at 14 days after application. The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period. The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei. The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments. Compared with chemical insecticides, the yield of alfalfa hay was higher in the biopesticides treatments. Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides. This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China, and for reducing chemical insecticide usage and improving forage quality.

Control Efficacy of Entomopathogenic Fungus Purpureocillium lilacinum against Chili Thrips (Scirtothrips dorsalis) on Chili Plant.

Simple SummaryChili thrips (Scirtothrips dorsalis) is an important pest of chili crops and a major vector of viral plant pathogens. Due to the widespread outbreak of thrips, chemical insecticides have been heavily used in the last few decades. To reduce the utilization of chemical pesticides, alternative biocontrol agents such as entomopathogenic fungi have been screened against the thrips. Laboratory screening revealed that 2 insect fungi isolates, Purpureocillium lilacinum TBRC 10638 and Beauveria bassiana BCC48145 were the most effective isolates against chili thrips. The fungus, P. lilacinum TBRC 10638 exhibited the highest efficacy against chili thrips in greenhouse and field trials and thus would be developed as a thrips control agent.In a laboratory assay, it was shown that B. bassiana BCC48145, BCC2660, and P. lilacinum TBRC10638 were the three strains that exhibited the highest insecticidal activity against chili thrips, causing 92.5% and 91.86% and 92.3% corrected mortality, respectively. The fungi B. bassiana BCC48145 and P. lilacinum TBRC10638 were selected for greenhouse spraying. Cytotoxicity test of the extracts from both fungi evaluated against 4 animal cell lines: KB; human oral cavity carcinoma, MCF7; human breast adenocarcinoma, NCI-H187; human small cell lung carcinoma and GFP-expressing Vero cells, showed none-cytotoxic to all cell lines. An efficacy validation in the greenhouse showed that P. lilacinum TBRC 10638 was more effective than B. bassiana BCC48145 and could control the thrips up to 80% when using the fungus at 108 spores/mL. The LC50 values of P. lilacinum TBRC 10638 against chili thrips based on total thrips count from two experiments were 1.42 × 108 and 1.12 × 107 spores/mL when the fungal spores were sprayed once a week. The optimal concentration of P. lilacinum TBRC 10638 spores for effective control of chili thrips was determined at 1.41 × 109 spores/mL. The average efficacy of P. lilacinum TBRC 10638 for thrips control from 3 field trials was 30.08%, 14.39%, and 29.92%. This result was not significantly different from that of the chemical insecticide treatment group, which showed efficacy at 19.27%, 14.92%, and 19.97%. Furthermore, there was no difference in productivity among the different treatment groups. Our results demonstrated that P. lilacinum TBRC 10638 is a promising biocontrol agent that could be used as an alternative to chemical insecticide for controlling chili thrips.

SUSTAINABLE CONTROL OF CODLING MOTH, CYDIA POMONELLA L. IN SOME APPLE ORCHARDS OF BULGARIA

The codling moth (CM), Cydia pomonella L., is the key pest of pome fruits in Bulgaria. Reduction of pesticide use is an important consideration for human health as well as for conservation of biodiversity. Environmentally friendly methods such as semiochemicals are among the most promising. These trials were carried out during the years 2020 and 2021 in southeast Bulgaria to test the effectiveness of microencapsulated sprayable pheromones in apple orchards using CIDETRAK® CM MEC (pheromone) liquid formulations as well as the effectiveness of mating disruption (MD) using CIDETRAK® CMDA COMBO™ MESO™ -A dispensers at rate of 80 dispensers per ha. Monitoring of CM flights was implemented using pheromone or pheromone and kairomone lures with traps during the years of the study. The traps baited with standard PHEROCON® CM L2 lures were changed at 4-week intervals. We also used PHEROCON® CMDA COMBO™ - P + AA lures, which is a new product developed by Trécé Inc., USA for use in orchards with MD. The traps baited with PHEROCON® CM DA COMBO - P + AA lures were changed at 8-week intervals. The damage in the treatment plot increased slowly over time and even in late cultivars, fruit damage by CM was below the economical threshold from 0.1 to 0.2% in both years of the study. Comparatively, ten insecticide treatments were applied to the reference orchard located in the region during the season, targeting CM and other pests. Correspondingly, fruit damage at harvest in the reference orchard by CM was from 2.2 to 2.5%. The significance of differences in the damage rate between the trial and the reference orchard was estimated by Chi-square tests. These new products developed by Trécé Inc., USA can be used in organic farming and fits perfectly into any IPM system. The use of CIDETRAK® CM MEC and CIDETRAK® CMDA COMBO™ MESO™ - A dispensers will help growers to decrease the number of chemical treatments in the field. Introduction of these products for pest management should result in reduction of the use of conventional chemical insecticide treatments, thus resulting in less environmental pollution and improved food quality.

Comparison of Mineral Oil, Insecticidal, and Biopesticide Spraying Regimes for Reducing Spread of Three Potato virus Y Strains in Potato Crops.

In-field management of Potato virus Y (PVY) faces challenges caused by the changing availability and environmental acceptability of chemical agents to control aphid vectors of the virus and by proliferation of PVY strains with different symptoms and rates of spread. From 2018 to 2020, foliar spray treatments were compared in field experiments in New Brunswick, Canada, to measure effectiveness at reducing spread of PVYO, PVYN:O, and PVYNTN strains. Mineral oil, insecticide, combined oil and insecticide spray, and a biopesticide (i.e., LifeGard WG) were compared. Insecticide-only and mineral oil-only treatments were not effective, but several combined oil and insecticide treatments and biopesticide treatments significantly reduced PVY spread. The biopesticide was proportionately more effective with recombinant PVYN:O and PVYNTN strains, possibly by exciting the plant's hypersensitive resistance response, caused naturally only in cultivar 'Goldrush' by PVYO. Pesticide residue analysis showed that mineral oil increased the retention of pyrethroid insecticide in the potato foliage longer than with insecticide applied alone, which may explain the beneficial synergistic effect of combined sprays for reducing PVY spread. Tuber yields were generally unchanged in chemical insecticide treatments but were slightly lower in biopesticide treatment. The cost per PVY treatment was competitive across all effective treatments, including biopesticide; however, there was some revenue loss from lower yield with the biopesticide. This biopesticide is certified organic, however, and thus a small premium on the price for organic production could offset this yield deficit.

Potential Use of Coconut Shell Liquid Smoke as an Insecticide on Soybean and the Impact on Agronomic Performance

One of the limiting factors in increasing soybean production is the high infestation of pests and diseases. Coconut shell liquid smoke has potential as a botanical insecticide on soybeans. This study was conducted to determine potential use of coconut shell liquid smoke on growth and yield of soybean compared to biological insecticide (entomopathogenic fungi) and chemical insecticide on acidic dry land in South Lampung, Lampung Province, Indonesia. The treatments were arranged with three insecticide treatments and two fertilization method (organic and inorganic fertilization), and control without insecticides and fertilizers. The intensity of pest attacks (I) was calculated using Townsend–Heuberger formula. The results showed that there was no significant difference between the treatment of three insecticide applications and two fertilization methods on the agronomic performance and yield of soybeans. Different results were shown in the control without fertilization with lower yield. Pest infestation in coconut shell liquid smoke treatment was smaller than other treatments. Coconut shell liquid smoke has the potential to be developed as a botanical insecticide, with the same results compared to chemical insecticide treatments.

Effect of some natural products on productivity and some pests of cabbage

The study were conducted during two consecutive seasons of 2018 and 2019 in a private farm at Marsa Matrouh Governorate which located in on Egypt northwest Mediterranean coast (latitude 31o 21’ N, longitude 27o 14’ E) to evaluate the effects of Kaolin (Aluminum phyllosilicate [Al2Si2O5 (OH)4]), Bentonite (Calcium aluminosilicate [Al2O3SiO2H2O]), Atabouglite (Magnesium aluminosilicate [Al2Mg3O18Si6]) products as well as chloropyrophose pesticide as foliar spraying and potassium fertilizers as soil additives on cabbage growth, yield, quality and pests control. Although foliar spray treatments did not have any significant effect on growth characters, chemical insecticide treatment produced the highest average head weight and highest yield compared with other foliar spray treatments. High rate of potassium supply as 75 kg gave the best value of growth and yield as well as quality characters followed by 50 kg then 25 kg compared with control treatment which produced the lowest values. Cabbage plants treated as foliar spraying with atabouglite, kaoline formulations exhibited high decrease of aphid population compared with bentonite application which gave the least potential towards adult of aphid insects. Also, atabouglite had a superior effect on average cumulative cotton leaf worm Spodoptera littoralis (Boisd) infestations of leaves and larvae followed by Kaolin. Bentonite had the lowest effect. While, chloropyrophos (chemical treatment) reduced the infestations in highly effect compared with all treatments.

The Diversity of Pest Generalist Predator in Potato Plants (Solanum tuberosum L.) Treated By Non-Synthetic Chemistry Insecticide on The Medium Plain of Lombok Island

This study aims to determine the diversity, abundance, and dominance of predators in potato plants treated by synthetic non-chemical insecticides on the medium plain of Lombok Island. The research used Randomized Block Design with ten different synthetic non-chemical insecticide treatments such as Metarhizium anisopliae, Beauveria bassiana, and Bacillus thuringiensis, Neem extract, tobacco stem extract, soursop leaf extract, babandotan leaf extract, chemical insecticide treatment, and one treatment without insecticide as a control. The insecticide was applied after 37 days of planting eight times at 7-day intervals. The type and population of predators were observed five days after the treatments. The diversity index (H'), abundance (K), and dominance (D) of the predators are then identified and determined. Data were analyzed by using a Diversity analysis followed by a 5% beda nyata jujur (BNJ). The yield shows six predatory families: Formicidae, Coccinellidae, Mantidae, Lycosidae, Oxyopidae, and Aranedae. H' and K values are generally classified as the low category, and no species dominates in each treatment (D &lt;0.5). The value of H' and K in B. thuringiensis treatment was higher than other treatments. The highest D value was obtained from chemical insecticide treatment. Formicidae is the family with the highest population compared to other families

Chemical vs entomopathogenic control of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) via aerial application in eucalyptus plantations

The Thaumastocoris peregrinus spread to eucalyptus plantations in many countries. Chemical control is a questionable measure, mainly due to the environmental impact, high cost and moreover has the use restricted by the forest certifications. Bio-insecticides may have similar efficiency to chemical products to control T. peregrinus. The chemical thiamethoxam, thiamethoxam + lambda-cyhalothrin, acephate and the microbial Beauveria bassiana and Metarhizium anisopliae insecticides were tested at different doses to manage T. peregrinus. The products were sprayed on eucalyptus plants using aircraft and populations of this insect were counted before application and at 1, 14 and 21 days afterwards (DAA). Ten eucalyptus trees were evaluated per plot, with the collection of ten leaves from the middle third of the crown of each tree, and the number of T. peregrinus nymphs and adults obtained per leaf was determined. All the chemical insecticides had similar control at 1 DAA for T. peregrinus nymphs and adults. At 14 DAA, the number of T. peregrinus nymphs and adults on eucalyptus leaves was similar for the chemical and microbial insecticide treatments. At 21 DAA the control efficiency of T. peregrinus nymphs and adults was higher than 80% with all insecticides. The entomopathogenic insecticides have potential for aerial application to control T. peregrinus nymphs and adults and provide viable and environmentally-friendly alternative to manage this pest.

ROLE OF Chrysoperla carnea (Stephens) RELEASE IN THE BIOCONTROLLING OF Cassida vittata Vill. AND Scrobipalpa ocellatella Boyd. LARVAE AS WELL AS ENHANCING THE ASSOCIATED ARTHROPOD PREDATOR POPULATIONS IN COMPARISON WITH CONVENTIONAL INSECTICIDES APPLICATIONS IN SUGAR BEET FIELDS

The current study was carried out at the Experimental Farm of Sakha Agricultural Research Station, Kafr El-Sheikh Governorate during 2016/2017 and 2017/2018 seasons for investigating the efficacy of Chrysoperla carnea (Stephens) larvae release against Cassida vittataVill. and Scrobipalpa ocellatella Boyd.larvae in sugar beet fields, at the same time in conserving arthropod predators (true spiders “Araneae”, C. carnea, Coccinellidae, Anthocoridae and Formicidae), in comparison with conventional insecticides (Tac 48% EC, Diracomel 90% SP and Shalinger-Super 24% SC). The results indicated that the conventional insecticides induced reduction in the mean number of S. ocellatella larval population with 91.00, 86.00 and 89.03%, respectively in 2016/2017 season, and 92.00, 90.00 and 92.13%, respectively in 2017/2018 season. While in case of C. vittata the chemical insecticide treatments induced reduction in the mean number of larval population with 91.00, 93.40 and 94.00%, respectively in 2016/2017 season as well as 92.40, 94.10 and 94.33%, respectively in 2017/2018 season. Also, the mean of reductions in the surveyed and associated arthropod predators as a result of using conventional insecticides against S. ocellatella larvae were 96.71, 96.55, and 96.55%, respectively in 2016/2017 season as well as 95.30, 94.00 and 92.00%, respectively in 2017/2018 season. While in case of using chemical insecticides against C. vittata larvae, the reductions in the mean population of the surveyed and associated arthropod predators in sugar beet fields were 97.40, 96.30 and 95.00%, respectively in 2016/2017 season as well as 96.00, 94.00 and 93.30%, respectively in 2017/2018 season. While in the treatment of release the predatory insect, C. carnea larvae against S. ocellatella larvae induced reduction in the mean number of the larval population by 57.13 and 43.40% in 2016/2017 and 2017/2018 seasons, respectively. While in case of C. vittata larvae, the reduction in the mean number of larval population recorded 49.00 and 45.13% in 2016/2017 and 2017/2018 seasons, respectively. Also, the surveyed and associated arthropod predator populations increased by 25.13 and 70.00% in 2016/2017 and 2017/2018 seasons, respectively. While the increasing in C. carnea populations were 22.00 and 44.13% in 2016/2017 and 2017/2018 seasons, respectively as a result of release the predatory insect, C. carnea for controlling both of S. ocellatella and C. vittata, respectively. Finally, these results show the important role of releasing C. carnea larvae as a biocontrol agent for controlling C. vittata and S. ocellatella larvae, at the same time in enhancing arthropod predator populations in comparison with conventional insecticides.

PERBANDINGAN METODE APLIKASI JAMUR ENTOMOPATOGEN BEAUVERIA BASSIANA UNTUK PENGENDALIAN CYLAS FORMICARIUS (COLEOPTERA: CURCULIONIDAE)

Comparing application methods of entomopathogenic fungus Beauveria bassiana to control Cylas formicarius (Coleoptera: Curculionidae). Cylas formicarius is a major pest of sweet potatoes. The tuber damage caused by C. formicarius reaches 100%. The research objective was to compare application methods of entomopathogenic fungi Beauveria bassiana to control C. formicarius. The research was conducted at the entomology screen house of Indonesian Legume and Tuber Crops Research Institute (ILETRI) at Malang, East Java, from January to September 2013. The treatment consisted of 12 application methods, each was repeated three times. The results showed that application of B. bassiana into the planting pit, soaking the sweet potato cuttings into the conidial suspension of B. bassiana for 30 minutes before planting, followed by spray application with two week interval (2 to 12 weeks after planting, WAP) or P4 was effective in suppressing C. formicarius population and tuber damage. Tuber weight obtained from P4 treatment was 1.4 kg plant-1, while from the chemical insecticide was only 1.1 kg plant-1. Tuber damage from P4 treatment was lower ( 5%) than that from chemical insecticide treatment (42%). Therefore, application of B. bassiana conidial suspension in the planting pit, continued by soaking the sweet potato cuttinginto the B. bassiana conidial suspension for 30 minutes before planting, and followed by spray applications of B. bassiana conidial suspension at two-week intervals ( 2-12 WAP) or P4 method can be recommended to control C. formicarius.

The effect of foliar fertilizer and pesticide methomyl in tea plantation after infested by pest: (2) The effect on population and attack intensity of Empoasca flavescens

The aim of this research was to obtain the effect of insecticide combination with nitrogen and zinc foliar fertilizers to Empoasca flave-scens. An experiment was conducted at Gam-bung Experimental Garden, Bandung, West Java. The trial was arranged in a randomized complete block design with nine treatments (A)methomyl; (B) methomyl + ZnSO4 1%; (C) me-thomyl + ZnSO4 2%; (D) methomyl + N 1%; (E) methomyl + N 1% + ZnSO4 1%; (F) metho-myl + N 1% + ZnSO4 2%; (G) methomyl + N 2%; (H) methomyl + N 2% + ZnSO4 1%; and (I) methomyl + N 2% + ZnSO4 2%, replicated three times. Each unit consisted of experiments is 40 plants. The treatments comprised: concen-tration of methomyl 0,5 gram/l with sprayed volume 200 l/ha. The level concentrations of nitrogen and zinc were 1% and 2%. The appli-cation of treatments was sprayed six times after plucking with 12 days interval, respectively. The population and intensity of E. flavescens attack were measured at the time of plucking. The effectiveness of treatment on the population as well as attack intensity of Empoasca con-ducted by measuring the rate of decline through a linear regression approach. The results showed that all of the treatments could reduce the population as well as the attack intensity of E. flavescens but there were no significantly different among others and were comparable to the chemical insecticide treatment. The fastest rate of decline were indicated by the treatment methomyl + N 2% + ZnSO4 1% and methomyl + N 2% + ZnSO4 2%.

Risk assessment of the cultivation of a stacked Bt-maize variety (MON89034 × MON88017) for nematode communities

Genetically modified Bt-maize MON89034 × MON88017 contains three different genes derived from Bacillus thuringiensis (Bt) which enable protection against insect pests, due to expression of three different insecticidal crystal proteins (Cry proteins), i.e., Cry1A.105 and Cry2Ab2 against the European corn borer and Cry3Bb1 against the Western corn root worm. Nematodes are important organisms in agricultural soil ecosystems, and on fields with Bt-maize cultivation they will be exposed to Cry proteins released into the soil from roots or plant residues. The objective of this study was to analyze in a field experiment the effect of Bt-maize MON89034 × MON88017 on nematodes as non-target organisms. Nematode communities from soil planted with the Bt-maize were compared to those from soil planted with the near-isogenic cultivar (with and without chemical insecticide treatment) and two conventional maize cultivars. The experimental field consisted of 40 plots in a completely randomized block design (eight plots for each treatment), which were monitored over two growing seasons (2008 and 2009) at six sampling dates for nematode diversity at the genus level in the rhizosphere soil. Physicochemical soil properties and Cry protein concentrations were also analyzed. Nematodes showed very high abundances, as well as a high diversity of taxa and functional guilds, indicating the relevance of maize fields as their habitat. Neither Bt-maize cultivation, nor insecticide treatment adversely affected abundance or community structure of nematode assemblages in field plots compared to several non-Bt cultivars including a near-isogenic cultivar. This confirmed the risk estimations based on the analyzed soil concentrations of extractable Cry protein, not exceeding 4.8 ng g−1 soil dry weight and thus revealing a safe toxicity-exposure ratio of >20.

Evaluation of Metarhizium brunneum F52 (Hypocreales: Clavicipitaceae) for Control of Japanese Beetle Larvae in Turfgrass.

Experimental and commercial preparations of Metarhizium brunneum (Petch) strain F52 were evaluated for control of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarbaeidae), larvae (white grubs) in the laboratory and under field conditions. Experimental preparations consisted of granule and liquid formulations made using in vitro produced microsclerotia, which are intended to produce infective conidial spores after application. These formulations were compared against commercial insecticides (imidacloprid and trichlorfon), and commercial formulations of M. brunneum F52 (Met 52) containing only conidia. Field-collected grubs were susceptible to infection in a dosage-dependent relationship when exposed to potting soil treated with experimental microsclerotia granules in the laboratory. The LC(50) for field-collected larvae was 14.2 mg of granules per cup (∼15 g granules/m(2)). Field plots treated with experimental and commercial formulations of M. brunneum F52 after 10 September (targeting second and third instar grubs) had significantly lower grub densities compared with untreated plots, providing 38.6-69.2% control, which sometimes equaled levels of control with chemical insecticides. Fungal treatments made prior to 21 August provided 14.3-69.3% control, although grub densities resulting from these treatments were often not significantly lower than those in untreated control plots. By comparison, chemical insecticide treatments provide 68-100% grub control, often providing better control when applied earlier in the season. In conclusion, P. japonica larvae are susceptible to infection by M. brunneum, and grub densities were reduced most consistently by fall applications targeting later instars.

Endophytic Bacillus subtilis enriched with chitin offer induced systemic resistance in cotton against aphid infestation

Endophytic bacterial strains EPCO 102 and EPCO 16 were effectively reduced the aphid population under greenhouse conditions. Biochemical characterisation and 16S rRNA sequence analysis confirmed as Bacillus subtilis. Talc-based powder formulation for Bacillus subtilis strains EPCO 102, EPCO 16 and Pseudomonas fluorescens Pf1 (with and without chitin amendments) were tried and its effect in inducing systemic resistance were tested under greenhouse conditions. The combined application of bioformulation as seed, soil and foliar spray significantly reduced the aphid infestation. Chitin addition in the formulation showed additional reduction in the infestation by the aphids. Application of Pf1 culture along with chitin showed less aphid infestation and this efficacy was on par with the chemical insecticide treatment, followed by EPCO 16 + Chitin. In addition, these endophytic bacterial strains along with chitin induced the activity of peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, chitinase, β-1.3-glucanase and phenol accumulation in cotton, which favours reduction in aphid infestation.

ISOLATION AND IDENTIFICATION OF NOVEL LOCAL ISOLATES OF Bacillus thuringiensis ACTIVE AGAINST RED PALM WEEVIL (RPW)

The gram-positive bacterium B. thuringiensis is well-known as sources of insecticidal proteins, most of which accumulate in crystalline inclusions during sporulation, these parasporal inclusions contain various types of insecticidal crystal protein (ICP). The crystal proteins from B. thuringiensis are among the most successful biological control agents for the suppression of agriculturally and medically important insect pests (Roh et al., 2007), being toxic to the larvae of lepidopteron, dipteran, and coleopteran insects (Johnson et al., 1998), as well as certain hymenoptera, homoptera, and mallophaga, in addition to many nematodes, flatworms, and Sarcomastigophora (Walters and English, 1995; Horak et al., 1996). At present, more than 130 B. thuringiensis crystal proteins have been described based on their gene sequences and amino acid homologies (Crickmore et al., 1998). Recently, all crystal proteins show some relatedness is grouped into four main groups. B. thuringiensis isolates are distributed worldwide, and more than 60,000 have already been collected by various industries in an effort to obtain novel crystal proteins (Martin and Travers 1989; Li et al., 2007). In addition, B. thuringiensis isolates showing different crystal protein gene patterns from the reference strains have also been reported (Li et al., 2002). The red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier), a concealed tissue borer, is a lethal pest of palms and is reported to attack 17 palm species worldwide. Although the weevil was first reported on coconut (Cocos nucifera) in South Asia during the last two decades it has gained a foothold on date palm Phoenix dactylifera in several Middle Eastern countries from where it has moved to Africa and Europe, mainly due to the movement of infested planting material. In the Mediterranean region, RPW also severely damages Phoenix canariensis. Infested palms, if not early detected and treated, often declined and die. However, palms in the early stages of infestation usually respond to chemical insecticide treatments. RPW has been managed in several countries through an integrated pest management (IPM) program (Faleiro, 2006). The search for effective natural enemies (biological control) for RPW still continues. A novel Bacillus thuringiensis strain, NCIMB 40152, was isolated from dead Tenebrio molitor L. Larvae. The isolate is endowed with specific insecticide activity against the Colorado potato beetle (Leptinotarsa decemlineata (Say), Coleoptera, Crysomelidae), but has no effect against lepidopteran or dipteran insects (Cidaria et al., 1991). Bacillus thuringiensis strains C-4, C-9, GM-7, and GM-10, with high toxicity against lepidopteran and coleopteran pests have been isolated from Northeast Mexico (Tamez-Guerra et al., 2004). Bacillus thuringiensis soil isolates A21, A51 and C17 isolated from different regions of the Cuban archipelago showed higher larvicide activity than Bactivec's isolated reference strain, against both Aedes aegypti and Culex quinquefasciatus (Gonzalez et al., 2011). Accordingly, This study describe the isolation and identification of novel isolates of B. thuringiensis, in order to study insecticidal activity of isolates produced proteins against Red Palm Weevil insect.

Effect of irradiation and insect pest control on rots and sensory quality of two varieties of stored ware white yams in Ghana

The coffee bean weevil, Araecerus fasciculatus Degeer (Coleoptera: Curculionidae) is associated with rots in stored yam tubers. The current study was designed to assess the effect of irradiation and other insect pest control strategies on rots and sensory quality of stored yams. 450 tubers each of two varieties of white yam (Dioscorea rotundata Poir) namely ‘Puna’ and ‘Asana’ were divided into two groups with half irradiated and the other half not irradiated. The two groups were then further divided into three sub-groups. The first sub-group was treated with a chemical insecticide ‘Superguard’ (400g/l Pirimiphos-methyl and 75 g/l Permethrin) against A. fasciculatus infestation whilst the second sub-group was placed in insect-proof boxes with no chemical treatment. The third sub-group was neither chemically treated nor placed in insect-proof boxes. They were all then stored in improved yam barns for four months after curing in February. Sprouts that developed on the non-irradiated tubers were broken off weekly. They were examined for rots and weight loss over the storage period. Sensory evaluation was conducted on the tubers at the end of storage to determine whether the treatments affected their sensory quality. It was observed that the irradiation and chemical insecticide treatments did not have significant effect (p>0.05) on percent rots and weight loss while the effect of storage on these parameters was significant (P

고추를 가해하는 담배나방[Helicoverpa assulta (Guenée)]의 효과적 방제를 위한 쌀좀알벌(Trichogramma evanescens Westwood)과 미생물제제의 종합생물방제 효과

Due to internal feeding behavior, the oriental tobacco budworm, Helicoverpa assulta (), infesting hot pepper has been regarded to be effectively controlled by targeting egg and neonate larval stages just before entering the fruits. This study aimed to develop an efficient biological control method focusing on these susceptible stages of H. assulta. An egg parasitoid wasp, Trichogramma evanescens Westwood, was confirmed to parasitize the eggs of H. assulta. A mixture of Gram-positive soil bacterium, Bacillus thuringiensis subsp. kurstaki, and Gram-negative entomopathogenic bacterium, Xenorhabdus nematophila ANU101, could effectively kill neonate larvae of H. assulta. A sex pheromone trap monitored the occurrence of field H. assulta adults. The microbial insecticide mixture was proved to give no detrimental effects on immature development and adult survival of the wasp by both feeding and contact toxicity tests. A combined treatment of egg parasitoid and microbial pesticide was applied to hot pepper fields infested by H. assulta. The mixture treatment of both biological control agents significantly decreased the fruit damage, which was comparable to the chemical insecticide treatment, though either single biological control agent did not show any significant control efficacy. This study also provides morphological and genetic characters of T. evanescens.

A novel approach to biological control with entomopathogenic nematodes: Prophylactic control of the peachtree borer, Synanthedon exitiosa

Generally, microbial control agents such as entomopathogenic nematodes are applied in a curative manner for achieving pest suppression; prophylactic applications are rare. In this study, we determined the ability of two Steinernema carpocapsae strains (All and Hybrid) to prophylactically protect peach trees from damage caused by the peachtree borer, Synanthedon exitiosa, which is a major pest of stone fruit trees in North America. In prior studies, the entomopathogenic nematodes S. carpocapsae and Heterorhabditis bacteriophora caused field suppression when applied in a curative manner to established S. exitiosa populations. In our current study, nematodes were applied three times (at 150,000–300,000 infective juveniles/tree) during September and October of 2005, 2006, and 2007. A control (water only) and a single application of chlorpyrifos (at the labeled rate) were also made each year. The presence of S. exitiosa damage was assessed each year in the spring following the treatment applications. Following applications in 2006, we did not detect any differences among treatments or the control (possibly due to a low and variable S. exitiosa infestation of that orchard). Following applications in 2005 and 2007, however, the nematode and chemical treatments caused significant damage suppression. The percentage of trees with S. exitiosa damage in treated plots ranged from 0% damage in 2005 to 16% in plots treated with S. carpocapsae (Hybrid) in 2007. In control plots damage ranged from 25% (2005) to 41% (2007). Our results indicate that nematodes applied in a preventative manner during S. exitios’s oviposition period can reduce insect damage to levels similar to what is achieved with recommended chemical insecticide treatments.