Biopesticide Application Research Articles

Effects of Temperature on Development of Lymantria dispar asiatica and Lymantria dispar japonica (Lepidoptera: Erebidae).

Periodic introductions of the Asian subspecies of gypsy moth, Lymantria dispar asiatica Vnukovskij and Lymantria dispar japonica Motschulsky, in North America are threatening forests and interrupting foreign trade. Although Asian gypsy moth has similar morphology to that of European and North American gypsy moth, it has several traits that make it a greater threat, the most important being the flight capability of females. Asian gypsy moth is not yet established in North America; however, infestations have been detected multiple times in Canada and the United States. To facilitate detection and eradication efforts, we evaluated the effect of a range of temperatures on development time, survivorship, and fertility of eight populations of Asian gypsy moth. There were significant impacts of temperature and population on these life history characteristics. The larval developmental rate increased with temperature until it reached an optimum at 29 °C. Larvae experienced significant molting problems at the highest and lowest temperatures tested (10 °C and 30 °C). At 30 °C, female fitness was markedly compromised, as evidenced by reduced fecundity and fertility. This suggests that development and survival of Asian gypsy moth may be limited by summer temperature extremes in the Southern United States. We also determined the degree-day requirements for two critical life stages and two populations of Asian gypsy moth, which represent the extremes in latitude, to predict the timing for biopesticide application and adult trap deployment. Our data will benefit pest managers in developing management strategies, pest risk assessments, and timing for implementation of management tactics.

Effect of Bio-Rational Approaches on the Larval Population and Pigeonpea Pod Damage by Exelastis atomosa (Wlsm.)

Effect of bio-rational approaches such as intercropping and application of bio-pesticide on the larval population, pod damage, grain damage and grain weight loss by plume moth (Exelastis atomosa (Wlsm.)) infesting pigeonpea (Cajanus cajan (L.) Millsp.) was studied. Pigeonpea intercropped with maize, pearl millet, sorghum, rice and black gram had significant effect on the larval population of plume moth when compared with pigeonpea sole crop infestation. The pigeonpea pod damage, grain damage and grain weight loss due to larval infestation in different pigeonpea intercrops and pigeonpea sole crop differed significantly however few exceptions were also recorded. The average larval population, pod damage, grain damage and grain weight loss in different intercrops varied from 0.25 to 0.39 larva/plant, 1.29 to 1.79%, 0.41 to 0.55% and 0.25 to 0.35%, respectively. The pigeonpea sole crop had recorded relatively higher larval population (0.39 larva/plant), pod damage (2.03%), grain damage (0.85%) and grain weight loss (0.59%) than the intercropped pigeon pea. The two sprays of NSKE 5% (first at flowering and pod formation stage and second after 20 days) were found superior in reducing larval population, pod damage, grain damage and grain weight loss. However, the plots devoid of any biopesticidal treatment had maximum larval population (0.68 larva/plant), pod damage (2.75%), grain damage (0.86%) and grain weight loss (0.60%) by E. atomosa.

UJI PESTISIDA NABATI TERHADAP HAMA DAN PENYAKIT TANAMAN

The Loss of crop productivity can reach 30-35% if not use pesticide. The other hand, to use of pesticides can be caused environmental problems and human healthy. This research aims to develop biopesticides for pests and plant diseases. It was conducted at the PEM laboratory UIN Suska Riau and on land, from July to November 2015. The sourches were extracts from Andropogon nardus, Annona muricata leaves, Ageratum conyzoides, Piper aduncun fructus, Nicotiana tabacum leaves, Tinospora crispa, Azadirachta indica leaves, Allium sativum and Piper betle leaves. Each the source was macerated in alcohol 50% for 24 hours and then distilled at a temperature of 60 °C until all the alcohol evaporates. The experimental Design was complete random design with 7 treatments (control, 20%, 40%, 60%, 80%, 100% and chemical pesticides as positif control) and 3 replicates. Parameters of the test biopesticides to disease performed in vitro with measure the resistance zones and for mealybugs and Gryllus assimilis in vivo with the pest mortality. Biopesticide test in vitro for the bacteria that causes carrot root rot has not been able to kill microbes. The mortality rate mealybugs begins before 1 hour observation at the treatment biopesticide concentration of 80%, 100% and control positif. Provision of different concentrations of biopesticides, does not the increased mortality of Gryllus assimilis. This shows that the power to kill biopesticide still well below chemical pesticides, but the pest is still alive no appetite as antifeedant effect of the biopesticide. So biopesticide application does not have to kill the target pest. Need follow-up and development of this research and other pests.

Microbial communities and nutrient dynamics in experimental microcosms are altered after the application of a high dose of Bti

Summary Bacillus thuringiensis subsp. israelensis (Bti) is the most widely used biopesticide against mosquitoes and blackflies, with a history of high specificity and efficacy. High doses of Bti have been suggested for extended vector control in some environments; however, the effects of Bti application on the native microfauna in the environment are poorly understood. Two Bti (VectoBac G) treatments (high = 48·1 kg ha−1; low = 0·6 kg ha−1), in addition to an untreated control, were assigned to replicate 300 L microcosms. Culex abundance, phytoplankton biomass, sestonic particulates and nutrients were reduced significantly in the high Bti treatment. These changes affected other physicochemical variables in the water column during the 44‐day field study. Bacterial communities present in the water column were assessed by Illumina sequencing of 16S rRNA genes. The most abundant aquatic bacteria in microcosms subject to a low dose of Bti and untreated control, Cyanobacteria, Cytophagales, Cyclobacteriaceae (phylum Bacteroidetes) and Sphingomonas (class Alphaproteobacteria), were suppressed in microcosms subject to a high dose of Bti. Bacteria in the high Bti treatment were dominated by Mucilaginibacter, Sediminibacterium (phylum Sphingobacteria) and Polaromonas (class Betaproteobacteria) and were more diverse than in the other treatments. Synthesis and applications. The biotic and abiotic changes resulting from a biopesticide application that significantly reduced mosquito abundance by more than 50% persisted longer than the period during which larval mosquito numbers were reduced. This warranted further investigation into the ecosystem‐level effects of Bti application rates used routinely for mosquito control. Application rates greater than the label rate for a Bti biopesticide can reduce mosquito abundance for an extended period of time and therefore lessen the operational cost of repeated application, but they could exceed manufacturer's recommendations and might violate country‐specific regulations governing biopesticide applications in natural habitats. Results of our study suggest that the widespread adoption of Bti application above the recommended label rate should be discouraged in habitats where algal abundance and its effect on primary production, microbial communities and nutrient cycling could affect the functioning of aquatic food webs.

Insecticidal properties of pyrolysis bio-oil from greenhouse tomato residue biomass

Fast pyrolysis is a recognized technology for the thermochemical conversion of biomasses into bio-oils that may contain valuable chemicals, including solvents, pharmaceuticals and biopesticides. The composition of the bio-oils is partly determined by the biomass feedstock. Bio-oil produced from the residues of greenhouse tomato plants has been investigated as a potential source of bioactive and pesticidal compounds. Fast pyrolysis of dried tomato residue biomass was performed in a bubbling bed reactor at 300 and 500°C. The condensable vapors were collected using a condenser followed by an electrostatic precipitator (ESP). Bio-oil collected from the ESP exhibited a much greater insecticidal activity based on tests carried out using the Colorado potato beetle (CPB) Leptinotarsa decemlineata leaf disc bioassay. After an extraction with 1:1 water/dichloromethane, most of the activity remained in the organic phase. To further fractionate the components, amino solid phase extractions (SPE) followed by reversed phase LC separation were performed. Six LC fractions were collected and analyzed by GC–MS. Neophytadiene, phytol and a number of fatty acids were identified in the most active fraction, but only with combinations of these compounds was the greatest insecticidal activity obtained. Pyrolysis of tomato plant biomass affords a cost-effective source of bioactive compounds that can be further developed for biopesticide application.

Combining bio-pesticides with chemical pesticides to manage legume pod borer (Maruca vitrata) on yard-long bean in Thailand

This study aims to confirm the potential of bio-pesticide application under field conditions in combination with chemical pesticides against the pest moth Maruca vitrata on yard-long bean. Four field trials were conducted at two locations (AVRDC East and Southeast Asia Regional Research and Training Station, and farmers’ fields in Kamphaeng Saen, Thailand) from March to May 2012 and May to August 2012. The yard-long bean pod damage by M. vitrata was significantly reduced by 23–85%, with substantial yield increases (22–190%) in Bacillus thuringiensis-based treatments in combination with cypermethrin, when compared with the untreated check. Although the combined effect of cypermethrin with Beauveria bassiana or neem-based treatments was better than the untreated check, the pod damage was still higher in these treatments, recording up to 26.87% compared with B. thuringiensis subsp. aizawai-treated plots. Based on these results, B. thuringiensis is a promising component for integrated pest management strategies against M. vitrata on yard-long bean in Thailand.

Performance experiments of rotary cage atomizer for biological pesticide application

To combat plant pests and diseases, spraying pesticide is an efficient and timely control method. The increasing use of a wide range of toxic chemical pesticides deliberately released into the environment can cause important problems such as human health threats, bioaccumulation and pest resistance, and soil and groundwater pollution. In response to concerns about the effects of chemical pesticides on environments and human health, there have been significant interests in biological pesticide technology with low toxicity, less residue, and reduced pest resistance. Biopesticide technology is limited in real applications, due to the lack of appropriate sprayer and standard technology. In this paper, a rotary cage atomizer for biopesticide was developed. The influence of biopesticide atomizer structure (cage diameter and cage mesh number), operational parameters (flow rate and rotational speed), and liquid types (bacillus thuringiensis and beauveria bassiana) on atomization performance and biopesticide application efficacy was investigated using PIV and a Winner laser diffraction particle analyzer. The pattern of liquid inlet was fixed experimentally by the droplet's flow field uniformity. The impacts of individual factors on droplet size were analyzed using a T-test to eliminate inter-correlation among the variables of interest. A multiple linear regression model, which predicted the volume median diameters (VMD), was established. The model showed a high degree of correlation with the experimental results. The model took into account not only the cage diameter, but its number of cage meshes, the liquid flow rate, and rotational speed of the cage. Furthermore, a histogram and normal P-P plot of standardized residuals were used to assess the model's goodness-of-fit and the measured data were also analyzed to prove model fitness and feasibility. Finally, the optimal combination of biopesticide rotary atomizer structure and operational parameters was implemented. The results indicated that the cage atomizer's liquid inlet of bilateral symmetry is better than the unilateral pattern to improve the distribution uniformity of droplets. The rotational speed of the rotary cage atomizer should not be too high to maintain the viability and infectivity of biopesticides. Results from this paper provide a case study showing how to spray biopesticide to treat plant pests and diseases effectively by using proper sciences and technologies.

Characterization of Alcaligenes faecalis strain AD15 indicating biocontrol activity against plant pathogens

Bacterial strain possessing both bacteriostatic and fungistatic activity (biocontrol activity) against pathogens of cyclamen (Cyclamen sp.) was isolated from the soil in Gifu Prefecture, Japan, and characterized with respect to its taxonomic and biocontrol properties. The sequence of its 16S rRNA gene, morphology, biochemistry, and fatty acid composition demonstrated that it is a strain most closely related to Alcaligenes faecalis subsp. faecalis LMG 1229(T). The isolate was named A. faecalis strain AD15. A. faecalis AD15 produced hydroxylamine at maximum yields of 33.3±1.7mg/L after 16 h cultivation in LB medium and 19.0±0.44mg/L after 19h cultivation in synthetic medium. Moreover, minimum inhibitory concentrations of hydroxylamine against the cyclamen pathogens Pantoea agglomerans and Colletotrichum gloeosporioides were 4.20±0.98 and 16.5±0.67mg/L. These results indicated that the biocontrol activity of strain AD15 might be attributed to hydroxylamine, a metabolite in the culture medium, and it had the potential for biopesticide application.

Combining Fungal Biopesticides and Insecticide-Treated Bednets to Enhance Malaria Control

In developing strategies to control malaria vectors, there is increased interest in biological methods that do not cause instant vector mortality, but have sublethal and lethal effects at different ages and stages in the mosquito life cycle. These techniques, particularly if integrated with other vector control interventions, may produce substantial reductions in malaria transmission due to the total effect of alterations to multiple life history parameters at relevant points in the life-cycle and transmission-cycle of the vector. To quantify this effect, an analytically tractable gonotrophic cycle model of mosquito-malaria interactions is developed that unites existing continuous and discrete feeding cycle approaches. As a case study, the combined use of fungal biopesticides and insecticide treated bednets (ITNs) is considered. Low values of the equilibrium EIR and human prevalence were obtained when fungal biopesticides and ITNs were combined, even for scenarios where each intervention acting alone had relatively little impact. The effect of the combined interventions on the equilibrium EIR was at least as strong as the multiplicative effect of both interventions. For scenarios representing difficult conditions for malaria control, due to high transmission intensity and widespread insecticide resistance, the effect of the combined interventions on the equilibrium EIR was greater than the multiplicative effect, as a result of synergistic interactions between the interventions. Fungal biopesticide application was found to be most effective when ITN coverage was high, producing significant reductions in equilibrium prevalence for low levels of biopesticide coverage. By incorporating biological mechanisms relevant to vectorial capacity, continuous-time vector population models can increase their applicability to integrated vector management.

Biofuels from Jatropha curcas oil – Perspectives for tropical regions

Almost 40% of the world’s population of 6,7 billion people do not have access to affordable energy resources and drinking water of acceptable quality. But nothing is more important than the alleviation of hunger. The number of hungry people, according to the newest FAO statistics, has risen to close to one billion in 2008. Therefore, special attention needs to be given to research in food and agriculture. To this stock of global problems new challenges are added through the increase in human population of 80 million persons a year and the concomitant loss of large areas of former fertile agricultural land, mostly in the poorest countries. Jatropha curcas is the most primitive member of the large genus Euphorbiaceae. The name is derived from the Greek iatros (doctor) and trophe (food). Jatropha curcas is a perennial plant, native and widely spread throughout the tropics. It is not grazed by animals, grows readily on degraded lands, is drought and to some extent disease resistant. It is a multipurpose plant. There are two genotypes of Jatropha curcas, a toxic and a non-toxic one. The latter genotype is found in Mexico only. Well developed dry seeds from Jatropha curcas weigh between 650- 750 mg and contain 30-35% of oil that is suitable for conversion into biodiesel of high quality by the conventional, proven processes. The kernel forms around 65% of the seeds. The de-oiled kernel meal has a crude protein content of between 58% and 60% and a favourable amino acid profile. Extracts of the toxic genotype provide chemicals with potential in medicinal, pharmaceutical and bio-pesticide application. In contrast to other fossil fuel alternatives, like biofuels from food crops such as maize, soybean, sugar cane and palm, bioenergy from Jatropha curcas grown on wasteland incurs no carbon debt and thus, offers immediate and sustained greenhouse gas advantages. Potential benefits of large scale Jatropha plantations on degraded land are expected to be : availability of CO<sub>2<sub/> neutral fuel in remote rural areas ; potential availability of high protein concentrates and biofertilizer locally ; wasteland reclamation for food production ; carbon sequestration for emission trading ; employment generation and socioeconomic development for impoverished farmers and rural labourers. Because of the wild nature of the plant, productivity reports vary considerably from less than 100 kg to more than 10.000 kg of seeds per ha. This huge variation is of importance from a breeder’s point of view for future selection and breeding programmes. Such programmes coupled with the development of agronomical practices, are essential prerequisites for economic exploitation to give Jatropha curcas a bright future.

Genetic engineering of Periplaneta fuliginosa densovirus as an improved biopesticide

The smoky-brown cockroach (Periplaneta fuliginosa) densovirus (PfDNV) has previously shown potential in urban pest control. To improve its efficacy as a biopesticide, the genome of PfDNV was engineered by inserting the insect-specific toxin gene BmKIT1 in the open reading frame encoding the major structural proteins. A green fluorescent protein (GFP) marker was tagged to the BmKIT1 at its C-terminus for in vivo imaging using Confocal laser scanning microscopy (CFSM). Using a virion rescue strategy, the genomes of recombinant and wild-type (wt) PfDNV were then cotransfected in P. fuliginosa nymphs. Reverse transcription PCR (RT-PCR) showed that the inserted BmkIT1 genes were expressed in the P. fuliginosa nymphs 48 h after cotransfection. CFSM and transmission electron microscopy also confirmed the generation of virus particles and expression of BmKIT1-GFP fusion protein in the cotransfected nymphs. The recombinant viruses remained infective to P. fuliginosa nymphs in feeding tests. Using the LT(50) bioassay method, the coninfection of the recombinant and wt PfDNV killed the P. fuliginosa nymphs approximate 32% faster than wt PfDNV only. This is the first report showing the improvement of engineered densovirus for the potential application of biopesticide.

STRATEGIES FOR THE USE OF ENTOMOPATHOGENS IN THE CONTROL OF THE DESERT LOCUST AND OTHER ACRIDOID PESTS

AbstractLarge-scale applications of non-persistent but broad-spectrum chemical insecticides in Africa during the 1980s for control of acridoid pests, particularly the desert locust (Schistocerca gregaria Forskål) and Sahelian pest grasshoppers, raised concern about environmental damage and human safety. Similar concerns have been expressed in Australia, the United States, and Canada and have led to a search for alternative strategies. To lessen dependence on chemicals, an integrated pest management (IPM) approach for grasshopper control has been encouraged in the United States with emphasis on biological control as an important component and this is also desirable elsewhere, but additional biocontrol components are needed. Current strategies for most pest acridoids rely on short-term destruction of outbreak populations. Nymphs are the preferred target wherever possible and inundative augmentation of entomopathogenic deuteromycete fungi formulated as biopesticides could replace chemical spraying in some cases, especially where the major threat is to crops remote from the pest breeding areas. Entomopathogens are slower acting than chemicals and thus best suited for use where the pest is not immediately threatening to crops. Schistocerca gregaria and Oedaleus senegalensis Krauss pose particularly difficult problems because of the very large area and inaccessibility of their potential breeding grounds, their very sudden upsurges, and their great mobility as adult swarms. Fast-acting chemicals are likely to be needed when rapid intervention is required to control these pests, but an IPM strategy could incorporate biopesticide application in the early stages of upsurges and also be used for swarm control in some cases. However, improved prediction and monitoring are needed to facilitate the use of biopesticides and other IPM techniques against these pests.