Secondary Pest Outbreaks Research Articles

Presence of a Non-Pest Mite Tarsonemus confusus Ewing (Acari: Tarsonemidae), in Florida Strawberry Fields

This publication aims to benefit growers and Extension agents by increasing awareness of a fungus-feeding mite, Tarsonemus confusus, commonly found in strawberry fields. Tarsonemus confusus may be misidentified as other pest mites. In fact, without help from an expert mite taxonomist, incorrect species identification can be a major concern. Although this mite species typically does not achieve pest status on most crops, an incorrect pest identification may lead to unnecessary application of miticides, triggering a secondary pest outbreak.

Biology and Management of Eggplant (Solanum melongena L.) Shoot and Fruit Borer: A Review

Eggplant (Solanum melongena Linnaeus) is a vital crop in South Asia, valued for its use in both raw and cooked dishes. However, its cultivation is severely threatened by the eggplant shoot and fruit borer, Leucinodes orbonalis (Guen.), which damages the plant from the seedling stage to harvest. The larval phase of this pest bores into shoots and fruits, potentially causing up to 90% loss and a decline in quality. Farmers often use excessive insecticides to combat L. orbonalis, leading to residue accumulation in food, insecticide resistance, pest resurgence, secondary pest outbreaks, and harm to beneficial organisms and the environment. In South Asia, this pest is the primary threat to eggplant fields, attracting significant research attention. This review paper examines biology, damage and control measures of eggplant shoot and fruit borer including resistant and tolerant varieties, sex pheromone traps, physical and mechanical barriers, biopesticides, biocontrol agents, and cultural and chemical methods, supported by previous studies and research findings. J Bangladesh Agril Univ 22(3): 267-276, 2024

Using stink bug migration behavior for physical exclusion.

Stink bugs have become an increasing concern for tree fruit growers due to changing management strategies and the introduction of an invasive species. The use of broad-spectrum insecticides for stink bug control disrupts biological control and leads to secondary pest outbreaks. To seek alternative tactics, we investigated the physical exclusion of native stink bugs with single-wall net barriers at orchard borders. First, stink bug capture on clear sticky panels along orchard edges showed that movement between the native shrub-steppe vegetation and the orchard occurs for much of the growing season instead of the presumed single migration event in August. Most stink bugs were captured between 1 m and 3 m heights, signifying a 4 m exclusion barrier would intercept migrating bugs. We tested large net barriers (4 m × 23 m) constructed of plain netting with or without deltamethrin-infused netting in flaps compared to a no-net control. The capture of target and nontarget arthropods was determined with plastic tarps below the nets or on the open ground of the control. Net barriers did not directly affect stink bug densities in the orchards, although orchard populations were low overall. Barriers did intercept stink bugs, and the addition of deltamethrin flaps enhanced stink bug mortality but at the price of nontarget arthropod mortality. Our results indicate that stink bug management efforts should focus earlier in the growing season and given the long period of migration, barriers are a more sustainable way of slowing movement into the orchard than the current sole reliance on chemical control.

Contact toxicity and proximate effect of fipronil on insect pest and predatory ant community structure in cocoa agro-ecosystem

Although usage persists in some countries, fipronil is banned or restricted in many others. Prior to its ban on cocoa in Ghana, concerns about its effect on non-target insects and secondary outbreak of Anomis leona were conflicting. This study, which predates the ban, assessed the toxicity and the short-term effect of fipronil on specific insect community structure in the cocoa agro-ecosystem alongside bifenthrin and a non-insecticide control. Although the insecticides induced a high mortality (90-100%) on the target (mirid: Sahlbergella singularis, stink bug: Bathycoelia thalassina and coreid bug: Pseudotheraptus devastans) and non-target (ants: Oecophylla longinoda, Crematogaster africana, Pheidole megacephala and Camponotus consobrinus) insects, the knockdown to fipronil was very low compared to bifenthrin. On the field, fipronil was more detrimental to the ants. Insecticide-treated plots recorded relatively lower post-treatment pest diversity compared to the control, except the last sampling month while ant abundance, richness and diversity were lowest on the fipronil-treated plots at the end of the study period. This study demonstrates that although fipronil was effective against pests and did not result in acute secondary pest outbreak, it was harmful to the ants. This effect could potentially be replicated on these ant species in other cropping systems where the insecticide is used, adversely affecting ecosystem service delivery. Hence, research on its impact on non-target organisms in other cropping systems is needed to regulate and monitor its use.

Harvest Time Residues of Imidacloprid and Thiamethoxam in Black Gram

Imidacloprid and thiamethoxam insecticides have been important tools for controlling pests in black gram. The use of these pesticides on various crops has increased rapidly resulting the produce containing toxic residues from the application of these insecticides and in some cases the concentrations are above maximum residue limit. The prudent usage of synthetic insecticides resulted in secondary pest-outbreaks, resistance development, food, and ecosystem adulteration and so on which pose serious threat to human beings. However, food safety issues related to pesticide residues are important to consider with a food crop such as black gram which causes no harm to consumers and are permissible in domestic and international trade. Therefore, the objective of this study was to analyse harvest time residues of imidacloprid and thiamethoxam in black gram. The study was conducted during the summer season 2021 at Research Farm, Tirhut College of Agriculture, Dholi (Muzaffarpur)–Bihar. The crop (cultivar SML 613) was sown on February, 27, 2021. Insecticides were applied at 30 days after sowing which was followed by two successive sprays at 15 days intervals following the recommended dose of 25 g a.i. ha-1 for both the insecticides. Sample aliquots were analysed using HPLC (High Pressure Liquid Chromatography) equipped with Photo Diode–Array Detector (PDA). The sample taken at harvest with a pre–harvest interval (PHI) of 28 days did not reveal the residues of imidacloprid and thiamethoxam in black gram seeds at Limit of Quantification (LOQ) of 0.05 mg kg-1.

Coccoidea infesting goldenberry, Physalis peruviana L. with ecological and control studies of the cotton mealybug, Phenacoccus solenopsis tinsley (Hemiptera, Coccomorpha, Pseudocccidae) from Egypt

The promising untraditional crop, Goldenberry, Physalis peruviana L. rapidly cultivated in many countries as a demand of fruit as in fresh markets; medicinal purposes; developing processing industry and rapid growing of exportation. Unfortunately, the plant recognized highly infesting by many Coccoidea species in Qalyubiya Governorate, Egypt thus experiments conducted to survey, population fluctuations and control of the most found prominent species. During the survey study period a total of four Coccoidea species following four genera belonging to two families of Supper family Coccoidea were recorded three of them were recorded for the first time infesting Physalis peruviana L as well as a total of six predators and two parasitoids recorded associated with the collected species. Data obtained indicated that, the most dominant Coccoidea species was the cotton mealybug, Phenacoccus solenopsis causing a severe infestation reducing the quantity and quality of the goldenberry crop therefore the study on this pest covers a population fluctuations and number of generations as well as its associated natural enemies during two successive growing seasons of 2019-2020 and 2020-2021. The results obtained clarified that P. solenopsis Tinsley have three peaks of abundance in both seasons in the selected goldenberry orchards with a very low effective of the recorded parasitoid, Dicrodiplosis manihoti Harris. The correlation of the selective abiotic factors (maximum & minimum temperature and relative humidity) and biotic factors (natural enemies) with the population fluctuation of the cotton mealybug were studied. A control study conducted to evaluate the highest and safest alternative pesticide to reduce the pest especially with lake of sufficient parasitoid found during the period of study. This study could be a great help to understand the endemicity of the species and the best way to control without several problems such as, pesticide residual, pest resistance, secondary pest outbreaks.

Foliar Residual Toxicity of Insecticides to Brassica Pests and Their Natural Enemies.

Overuse of pesticides can result in the development of resistance, secondary pest outbreaks, and pest resurgence due to a reduction in natural enemies. The present study compares the residual toxicity of lambda-cyhalothrin, a relatively nonselective insecticide, with abamectin, indoxacarb, and spinosad, compounds which have been reported to be less harmful to arthropod natural enemies. Two key cosmopolitan pests of crucifer crops, (Plutella xylostella) and (Myzus persicae), and two of their respective hymenopteran parasitoids, (Cotesia vestalis) and (Aphidius colemani) were used as representative pests and natural enemies. The pyrethroid lambda-cyhalothrin was found to be the most persistent toxicant against both pest and both parasitoid species tested, while the lactones abamectin and spinosad were the least persistent toxicants. A leaf wax stripping technique was used to compare the contact toxicity of insecticide residues against adult C. vestalis and A. colemani in the epicuticular wax layer. For each compound, removal of epicuticular wax reduced the 24 h residual toxicity (LC50) of fresh deposits (day 0) by about an order of magnitude against C. vestalis. A second residual toxicity experiment showed that removal of epicuticular wax significantly reduced the residual toxicity of each compound against A. colemani at 0, 7, and 14 d after application, with little or no detectable residual activity for the oxadiazine indoxacarb or abamectin/spinosad respectively after 14 d. The present data supports the view that in addition to the intrinsic toxicity of insecticides to natural enemies, differences in their persistence as foliar residues should also be considered in IPM systems.

Spatial distribution of 17-year periodical cicada (Hemiptera: Cicadidae) exuviae and oviposition injury in Mid-Atlantic, USA Apple orchards and implications for management

Tree fruit orchards in some Mid-Atlantic states are within the geographic range of 17-year periodical cicada Brood X, Magicicada septendecim (L.) and M. cassini (Fisher) (Hemiptera: Cicadidae), and can be badly affected by injury from its oviposition in branches. Several applications of broad-spectrum insecticides, such as pyrethroids, are needed to mitigate this injury, but can incite secondary pest outbreaks by impacting natural enemy populations. The spatial distribution of cicada exuviae and oviposition injury in orchards have not been examined in relation to edge effects or the effect of different adjoining habitats, from which cicadas can move into orchards. Addressing these knowledge gaps may reveal the potential for spatially precise insecticide applications targeting cicadas, thereby mitigating the effects of spraying entire orchard blocks. In 2021, the distribution of Brood X cicada exuviae (a proxy for oviposition during its emergence 17-years previously) and oviposition injury was measured using tree transects in commercial apple orchards in Virginia and West Virginia, USA. All orchards had woods and non-woods habitats along opposite borders, and depending on their age, were or were not exposed to cicadas previously. Orchard edges facing and not facing woodlands were vulnerable to the effects from cicada. Overall, there was a tendency for somewhat higher numbers of exuviae and oviposition sites in orchard border rows facing woods, however both variables were recorded in considerable numbers in the orchard interior on edges facing and not facing woods. Results are discussed in relation to their implications for cicada management in fruit orchards.

Comparisons of economic thresholds for Asian citrus psyllid management suggest a revised approach to reduce management costs and improve yield

Huanglongbing (HLB) or citrus greening disease is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama. Vector control is considered a basic component of HLB management even under high disease incidence scenarios. While vector management heavily relies on the application of synthetic chemical sprays, overuse of insecticides raises several concerns including insecticide resistance, environmental impacts, and secondary pest outbreaks. The present study aims to compare the effects of three different economic thresholds (ET-0.2, 0.5, 1.0) and one calendar-based application schedule on the incidence of D. citri and beneficial species in plots of commercially grown citrus, as well as end-of-season yield and overall management costs. The results suggest that reducing spray frequency from eight to as few as three sprays per year had little effect on counts of pest and beneficial insects in the field. The numbers of D. citri and that of a secondary weevil pest were similar between plots treated with the calendar-based spray plots and plots managed with the ET-1.0. Furthermore, spider numbers were higher in the ET-1.0 plots, while ant numbers were lower compared with calendar sprayed plots. Management input costs were lower under economic thresholds (ET-0.5–ET-1.0) than with monthly calendar-based sprays, while yield losses were only slightly greater in the lower threshold of 0.2 mean psyllids per tap than with calendar sprays. Overall, management savings of more than 100% made up for this difference. Together, these results suggest that implementing a spray program of rotated chemistries based on an economic threshold of 0.5–1.0 adult psyllids per stem tap could provide both economic and ecological benefits. We discuss the implications of such an approach in the context of a young citrus tree protection program and the greater goals of sustainable citrus production under HLB.

Detectability of Hibiscus Mealybug, Nipaecoccus viridis (Hemiptera: Pseudoccocidae), DNA in the Mealybug Destroyer, Cryptolaemus montrouzieri (Coleoptera: Coccinellidae), and Survey of Its Predators in Florida Citrus Groves.

The Hibiscus mealybug, Nipaecoccus viridis (Newstead), has recently established in Florida citrus and become a pest of concern given secondary pest outbreaks associated with management of citrus greening disease. Chemical controls used to manage other citrus arthropod pests are not as effective against N. viridis due to its waxy secretions, clumping behavior, and induced cellular changes to host plant tissue which increase microhabitats. Populations of this mealybug pest are regulated by natural enemies in its native region, but it remains unclear if resident natural enemies in Florida citrus could similarly suppress N. viridis populations. This investigation: 1) established species-specific primers for N. viridis based on the mitochondrial gene Cytochrome-oxidase 1 (COI), 2) determined duration of N. viridis DNA detectability in a known predator, the mealybug destroyer (Cryptolaemus montrouzieri Mulsant), by using identified primers in molecular gut content analysis, and 3) screened field-collected predators for the presence of N. viridis DNA. The detection rate of N. viridis DNA was >50% at 36 h after adult C. montrouzieri feeding but DNA was no longer detectable by 72 h after feeding. Field-collected predators were largely comprised of spiders, lacewings, and C. montrouzieri. Spiders, beetles (primarily C. montrouzieri), and juvenile lacewings were the most abundant predators of N. viridis, with 17.8, 43.5, and 58.3 of field-collected samples testing positive for N. viridis DNA, respectively. Our results indicate that Florida citrus groves are hosts to abundant predators of N. viridis and encourage the incorporation of conservation or augmentative biological control for management of this pest.

Biopesticides: A healthy alternative of hazardous chemical pesticides, current development and status in China

To provide the safe and healthy food to the increasing world population in China and all over the world, the development of modern research based scientific system of organic farming is a dire need of time. Fertilizers, high yielding crop varieties and use of chemicals are key tools to ensure plentiful supply of high yielding agriculture products in China. To cope with these issues, quick and easy use of synthetic chemicals is creating several problems such as, severely health hazardous chemicals on food, environmental pollution and residual effects in land and water resources. In addition, to overcome pesticides resistance in insects, pest resurgence, secondary pest outbreak, the biologically safe and environment friendly pesticides are utmost needed. So, in current system biopesticides are good alternatives of chemical agro-inputs which are less toxic to health, ecofriendly, target specific, biodegradable, suitable for integrated pest management tool, non-phytotoxic and are easily implemented in organic farming. Biopesticides production in China is increasing rapidly by the interest of government and China's plan of zero growth of pesticides consumption to 2025. This is the key plan of biopesticides production and development to replace health hazardous chemical pesticides in China and world together. Hence, this article reviews the present status of health friendly biopesticides development and formulation for future prospects in China as healthy alternative of hazardous synthetic chemicals.

Outbreak and Insecticide Susceptibility of Pod Feeding-larvae on Cocoa in Ghana

Cocoa is an important foreign exchange earner and a major source of income for several households in Ghana. In 2018, a larval outbreak on cocoa pods was reported in Ghana. Although the origin is unknown, it was perceived to be a secondary pest outbreak. In this study, a survey was conducted in the outbreak areas to identify and determine the occurrence of the pest and its susceptibility to a commonly used insecticide. Field and laboratory studies were conducted to identify the pest, determine the level of infestation, insecticide susceptibility, and field management. The outbreak was mainly caused by larvae of Anomis leona (~96% infestation of cocoa trees in some communities) with extensive feeding damage (chewing channels/tunnels) on the pericarp of pods. Field populations of A. leona larvae from districts in the Central region subjected to bifenthrin were susceptible at the recommended field rate (0.0245%) for mirids after 48 h of exposure under laboratory conditions. The insecticide induced a median lethal concentration (LC50) of ≤0.0061% and ≤0.0018% on A. leona larvae from Jukwa and Twifo Praso in the Central region at 24 and 48 h of exposure, respectively. Field application of bifenthrin was able to suppress infestation. The findings show that Anomis larvae were responsible for the outbreak, inducing extensive damage on pods. Bifenthrin was toxic to the larvae and could be used to manage them on the field. The outbreak indicates the need to develop an integrated management and monitoring strategy for cocoa pests to minimize future outbreaks.

Insect pest management in vegetable crops through trap cropping: Review

The study was carried out at CCS Haryana Agricultural University, Hisar during 2019 as the widespread use ofinsecticides to control crop pests has created various problems such as residues in the food chain, phytotoxicity,pesticide resistance, pest resurgence, bioaccumulation and secondary pest outbreak, in addition to causing harmfuleffect on the environment and non-targeted beneficial organisms. However, trap cropping is one such type of specialcompanion planting strategy that is traditionally used for insect pest management through vegetative diversificationused to attract insect pests away from the main crops during a critical time period by providing them an optionalpreferred choice. Trap cropping also has a tremendous potential to attract and conserve natural enemies in croppingsystems. The effect of attracting natural enemies may be an advantage compared to the other/conventional meansof pest control. Trap cropping can be integrated with other Integrated Pest Management (IPM) tactics. But trapcropping, like many other cultural tactics, remains under-exploited. Research on trap cropping has been very limited,and deserves more consideration to sustain agro-ecosystems throughout the world. In this review we have providedinformation based on trap cropping modalities and an updated list of trap cropping system in vegetable crops thatshould be proven as helpful in future trap cropping endeavors.

Non-target effect of pesticides in rice environment

Agriculture has always been affected by intractable pests. Conventional agriculture still relies on the use of several pesticides to control various pests to ensure the yield of the crop and to feed a constantly growing population. To reduce the pest menace, the fatuous behavior of people as well as a natural proclivity towards the use of pesticides in a non-judicious manner, has caused several ecological backlashes such as secondary pest outbreak, pest resurgence and non-target organism's exploitation. Effects of pesticides on non-target organisms area worldwide concern and contention are the basis for most legislation regarding usage of specific pesticides. Pesticides, besides their effect on pests, would also affect several beneficial non-targets. The effect of pesticides could be lethal and may prove catastrophic or sublethal and stimulate the growth and development of non targeted biota's. Hence, this review approaches well-analyzed hindsight regarding the effect of pesticides on the natural enemies as well as other non-target organisms present in the rice agroecosystem.

Control Failures Following Insecticide Applications in Commercial Agriculture: How Often Do They Occur? A Case Study of Lygus hesperus (Hemiptera: Miridae) Control in Cotton

Although surveys of pest populations documenting evolved insecticide resistance often suggest abundant potential for insecticide control failures, studies documenting the actual occurrence of such failures in commercial agriculture are rare. If farmers currently practice adaptive management, abandoning the use of insecticides once resistance emerges, actual control failures could be rare. Here I use data gathered by independent pest management consultants to describe a case study of the realized efficacy of commercial field applications of insecticides, examining the control of Lygus hesperus Knight on cotton. On average, insecticides reduced target pest populations to 19% of their preapplication densities. Short-term efficacy of insecticides was variable, but only one severe control failure was observed (1 of 50, 2%). The rarity of severe control failures observed in this study is in agreement with the few other studies conducted in commercial settings, but additional research is needed to assess the generality of this result. Although pesticides can cause longer-term problems, including target pest resurgences and secondary pest outbreaks, risk-averse attitudes among farmers coupled with relatively consistent short-term insecticide efficacy may be potent forces propelling farmers toward the use of insecticides.

Dispersal Mechanism Assessment forPanonychus citri(Acari: Tetranychidae) Secondary Outbreaks

AbstractSecondary population outbreaks of Panonychus citri (McGregor) (Acari: Tetranychidae) are triggered by synthetic chemical applications (dose and method), which also elicited a change in mites’ behavioral responses. This study aimed to understand the dispersal pattern of P. citri and how changes in dispersal behavior may influence secondary pest outbreaks in the field with or without chemicals. We found positive density and time-dependent dispersal within the inoculated leaflet. Dispersion from inoculated leaflets to the last leaflet depends on initial density and time. A significant difference was observed in the composite dispersal index data and preferred midrib region. The minimum dispersal was observed by P. citri in no direct contact with treated surfaces, whereas attraction was observed on treated surfaces (right). All chemicals gave different dispersal and feed disruption responses depending on the treatment application pattern. The maximum number of mites dispersed and avoid surfaces treated with abamectin and vegetable oil, respectively. Vegetable and EnSpray 99 had a positive impact on toxicity, repellency, and irritancy. The fecundity rate of P. citri boosted with a high dose and direct exposure. Panonychus citri colonization as a single individual or gregarious distribution resulted in a rapid fecundity rate, which may explain why citrus orchards were severely damaged and how suddenly a whole citrus plantation can be highly infested. This study concluded that change in treatment application patterns leads to a change in the behavioral responses in P. citri.

Cultural Control of Drosophila suzukii in Small Fruit-Current and Pending Tactics in the U.S.

Simple SummaryIntegrated Pest Management (IPM) is a science-based decision-making process that uses a variety of management approaches to increase farm profitability while protecting human health and the environment, with pesticides used only as a last resort. An important alternative to pesticides, cultural controls modify production practices and/or the crop environment to reduce pest populations and damage. This review presents the current state of knowledge and implementation of cultural controls to manage the invasive vinegar fly, spotted-wing drosophila, in U.S. small fruit crops. Spotted-wing drosophila causes direct damage by laying its eggs into ripening fruit. Because it reproduces quickly, uses a variety of cultivated and wild fruits, and is highly mobile, spotted-wing drosophila is difficult to manage. Developing effective and economic cultural controls to manage spotted-wing drosophila will help improve IPM programs.Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), a vinegar fly of Asian origin, has emerged as a devastating pest of small and stone fruits throughout the United States. Tolerance for larvae is extremely low in fresh market fruit, and management is primarily achieved through repeated applications of broad-spectrum insecticides. These applications are neither economically nor environmentally sustainable, and can limit markets due to insecticide residue restrictions, cause outbreaks of secondary pests, and select for insecticide resistance. Sustainable integrated pest management programs include cultural control tactics and various nonchemical approaches for reducing pest populations that may be useful for managing D. suzukii. This review describes the current state of knowledge and implementation for different cultural controls including preventative tactics such as crop selection and exclusion as well as strategies to reduce habitat favorability (pruning; mulching; irrigation), alter resource availability (harvest frequency; sanitation), and lower suitability of fruit postharvest (cooling; irradiation). Because climate, horticultural practices, crop, and market underlie the efficacy, feasibility, and affordability of cultural control tactics, the potential of these tactics for D. suzukii management is discussed across different production systems.

Selection for resistance to pyrethroids in the predator Orius laevigatus.

Insecticide resistance in the natural enemies of pest species is a very desirable trait. It allows better integration of biological control with the synthetic and natural compounds applied to manage certain pests, especially secondary pest outbreaks. Insecticide resistance in predatory insects has been documented for lady beetles and lacewings, but intriguingly no cases of field-evolved resistance have been noted in any heteropteran predator. In this work, we first explored the variation in susceptibility to pyrethroids in wild and commercial populations of Orius laevigatus (Fieber). Second, we exploited this genetic variation to artificially select a strain of O. laevigatus resistant to pyrethroids. We found significant variation [median lethal dose (LC50 ) 1.6-77.0 mg L-1 ] in susceptibility to pyrethroids in wild populations of the heteropteran predator O. laevigatus, with a baseline LC50 value of 14.6 mg L-1 . We successfully selected a strain of O. laevigatus highly resistant to pyrethroids (LC50 = 1059.9 mg L-1 ). In addition, such resistance was expressed in every instar, particularly in the last nymphal stages, increasing the resilience of the whole population present in the crop facing pyrethroid application. The level of resistance achieved may be sufficient to allow survival of adults and nymphs of O. laevigatus exposed to the maximum field rate of several pyrethroids and natural pyrethrins, widely used to control a number of pests in organic and integrated pest management crops. Therefore, this strain resistant to pyrethrins and pyrethroids would improve the resilience of biocontrol protocols, which is an urgent requirement for wider adoption of biological control. © 2021 Society of Chemical Industry.

Evaluation of Various Pest Management Modules Against Rice Yellow Stemborer, Scirphopaga incertulas (Walker) (Crambidae: Lepidoptera)

Background: Globally, rice yellow stem borer alone causes yield losses of 10 m t accounting for 50 per cent of all insecticides usage in the rice field farmers depend upon a plenty of insecticide applications, even though a lot of insecticide applications are not effectual (Sarwar et al., 2005). The over- reliance on use of chemicals to manage this pest had lead to numerous undesirable consequences like disrupting natural enemy complexes, secondary pest outbreaks, pest resurgence, development of insecticide resistance and environmental pollution. Keeping in view the deleterious effects of chemical pesticides, there is a need to evaluate alternate methods or integrated methods to manage the rice stem borer effectively without any menace to the ecological niche. Hence, a research trial was conducted to evaluate the efficacy of various pest management modules against rice stem borer in comparison to farmers practice and sole chemical control, besides in concern to yield and cost economics. Methods: The field efficacy of various pest management modules viz., non-chemical based, non-chemical + biorational methods, chemical-based, IPM module and farmers practice against rice yellow stem borer were evaluated during the wet season and dry seasons of 2016 and 2017. The experimental was laid in a net area of 10 m x 20 m each plot laid in Randomized Block Design which comprised of five treatments (modules) with four replications. The incidence of rice yellow stem borer (YSB) in various modules in terms of percent dead hearts (% DH) during tillering stage and percent white ears (%WE) during maturing stage were recorded. Result: It was evident from the pooled mean data that among various modules, the least per cent dead hearts (2.68 and 2.56% DH ) and white ears (2.79 and 2.31% WE) were registered in IPM based module followed by farmers practice (2.31 and 2.32% dead hearts and 3.92 and 4.77% white ears) and chemical-l based module (2.90 and 4.24% dead hearts and 5.59 and 5.18% white ears) as against highest incidence in non- chemical (13.78 and 13.7% dead hearts; 18.24 and 17.94% white ears) and non- chemical + bio rational (11.40 and 9.88% dead hearts; 13.09 and 11.25% white ears ) based modules during the wet season and dry season, respectively.

Repellency of Ferulago angulata (Schlecht.) Boiss essential oil on two major stored-product insect pests without effect on wheat germination

There has been an increasing demand among agricultural researchers and producers for bio-insecticides due to the threats of the related chemicals leading to human health problems, environmental contamination, pest resistance, and secondary pest outbreaks. In this regard, the repellent effects of the essential oil extracted from Ferulago angulata (Schlecht.) Boiss as a well-known medicinal plant were measured against the red flour beetle (Tribolium castaneum (Herbst)) and lesser grain borer (Rhyzopertha dominica (F.)) using the three different techniques of filter paper, leaky glass, and olfactometry. The experiments were conducted at the concentrations of 30, 52, 93, 165, and 300 ppm under controllable conditions. The maximum Percent Repellency (PR) rates of the essential oil at the concentration of 300 ppm were found to be 59.01, 54.12, and 43.21% for T. castaneum and 48.84, 50.52, and 42.73% for R. dominica based on the mentioned methods, respectively. By enhancing the essential oil concentrations and exposure times, the PR rates increased. Furthermore, the essential oil effects of F. angulata on wheat germination were evaluated and no decreases in the germination of the treated wheat seeds were found at the tested concentrations. According to the results of the present study, the essential oil of F. angulata could be used for reducing T. castaneum and R. dominica populations.