Integrated Pest Management Decision Research Articles

Integrated Pest Management Decision Support System (IPM-DSS) a tool to support management of tree diseases in Kenya

Tree diseases have been noted as one of the major causes of abnormalities and malformations on perennial plants. Tree disease research in Kenya has resulted in a list of diseases identified to cause significant losses on forest plantations. The need for management of such diseases have been on the increase. The Decision Support System (DSS) was envisioned to help stakeholders make decisions to manage tree diseases on farm and in tree plantations. Information was collected across Kenya on diseases affecting seed, seedlings, plantations, natural forests and post-harvest products in sawmills. The data was entered into excel sheets and organized for database administration on MySQL software. Over 20 major fungal species were identified and their biology, distribution and management determined. This information was further fed into a query system to allow different groups of stakeholders to access the information for diagnosis and control of tree diseases. Results showed that major tree diseases in Kenya were caused by fungi belonging to the families; Botryosphaeriaceae, Nectriaceae, and Amphisphaeriaceae. The data and information availed through this query system is being used in trend analysis for proactive control and management of tree diseases in Kenya. It will also be used for farmer advisory services through closest match selection of symptom appearance based on the tree species. The query system is an innovation that will also be used for Citizen Science Data Capture to aid Kenya Forestry Research Institute in detecting emerging diseases in real-time for phytosanitary measures. The identification of commonly occurring pathogens in commercial forestry species in the country has led to research towards their control and tree improvement for resistance to tree diseases. Future plantation establishment should be based on resistant species and high-quality germplasm for maximum survival and improved yields. Key words: Advisory services, Botryosphaeriaceae, citizen science, Decision Support System, Integrated Pest Management, tree diseases.

Using targeted sequencing and TaqMan approaches to detect acaricide (bifenthrin, bifenazate, and etoxazole) resistance associated SNPs in Tetranychus urticae collected from peppermint fields and hop yards.

Tetranychus urticae (Koch) is an economically important pest of many agricultural commodities world-wide. Multiple acaricides, including bifenazate, bifenthrin, and extoxazole, are currently registered to control T. urticae. However, populations of T. urticae in many different growing regions have developed acaricide resistance through multiple mechanisms. Within T. urticae, single nucleotide polymorphisms (SNPs) have been documented in different genes which are associated with acaricide resistance phenotypes. The detection of these mutations through TaqMan qPCR has been suggested as a practical, quick, and reliable tool to inform agricultural producers of acaricide resistance phenotypes present within their fields and have potential utility for making appropriate acaricide application and integrated pest management decisions. Within this investigation we examined the use of a TaqMan qPCR-based approach to determine genotypes which have been previously associated with acaricide resistance in field-collected populations of T. urticae from peppermint fields and hop yards in the Pacific Northwest of the United States and confirmed the results with a multiplex targeted sequencing. The results suggest that a TaqMan qPCR approach accurately genotypes T. urticae populations for SNPs that have been linked to Bifenazate, Bifenthrin, and Etoxazole resistance. The results also demonstrated that different populations of mites in Washington and Idaho displayed varying frequencies of the examined SNPs. While we were able to detect the SNPs associated with the examined acaricides, the mutation G126S was not an appropriate or accurate indicator for bifenazate resistance.

Wind Tunnel and Field Evaluation of Trapping Efficiency of Semiochemical Baited Camera-Traps for Capturing Codling Moth (Lepidoptera: Tortricidae).

Sex pheromone baited monitoring traps are a critical tool for integrated pest management decisions against many insects, particularly codling moths (Cydia pomonella L.). The addition of cameras for remote monitoring has the potential to enhance the usefulness of these important tools. However, changes in trap design could potentially alter plume structure and trapping efficiency of these new traps. Here we look at several trap configurations designed to optimize the capture of codling moths in traps equipped with cameras. We found that, in both wind tunnel and field trials, camera equipped triangle traps and camera equipped rectangle traps (both V1 and V2) caught codling moths equivalent to a standard 'delta' style trap. While catch was unaffected, altering our rectangular trap opening from 4 to 8 cm (V1 and V2, respectively) decreased frequency of moths contacting the front of trap and increased the frequency of moths flying directly into the trap. We show that these novel camera equipped semiochemical-baited traps catch equivalent to the industry standard white delta trap.

Biology and Management of Small Hive Beetles (Coleoptera: Nitidulidae): A Pest of European Honey Bee (Hymenoptera: Apidae) Colonies

AbstractSmall hive beetle (Aethina tumida Murray) control has become an issue of increasing importance for North American apiculturists throughout the past two decades. Aethina tumida was discovered in Florida in 1989, presumably transported from its native habitat of sub-Saharan Africa through the shipment of European honey bee (Apis mellifera L) queens. Estimates of damage from A. tumida were as high as $3 million annually in the United States by the year 2004, and A. tumida was found in nearly every state by 2008. When adult beetles emerge from pupation in soil surrounding the hive, they are attracted to A. mellifera hives through a variety of pheromones and volatile organic compounds from bees and hive products. Aethina tumida larvae and adults consume hive products and bee brood, generating fermenting waste (or slime), which can eventually lead to hive abandonment in cases of severe infestation. Pest management efforts for A. tumida have focused on trapping adults, applying lime, diatomaceous earth, pyrethroid soil drenches, and entomopathogenic nematodes to the soil surrounding A. mellifera hives. Understanding the biology and life history of A. tumida, along with current control methods, can aid apiculturists in making informed integrated pest management decisions. Additionally, understanding critical knowledge gaps in the current research is an important step in identifying promising future management tactics in the ongoing efforts to manage this invasive pest.

Influences of Stored Product Insect Movements on Integrated Pest Management Decisions.

Insect movement inside and outside grain bulks and processed products influences pest management decisions. Movement allows insects to find essential food resources, shelters (refuges), warmer and/or humid locations, mating and egg-laying sites, even when they are rare in fields, buildings, mills, warehouses, and inside grain masses. This review discussed the advantages and disadvantages of stored product insect movements, and the influence of insect mobility on some integrated pest management practices. Insect movement (1) results in clumped insect spatial distributions and thus makes large sample sizes necessary for monitoring; (2) makes trapping more efficient, but is influenced by many factors; (3) allows control methods to be effective, but requires pest management programs to be area-wide; (4) makes eradication of quarantine pests difficult and commodities are quickly re-infested; and (5) results in a diverse genetic pool and speeds the development of resistance to pesticides. Any element of an IPM approach should use the knowledge of insect movement. Reasons for the difficult interpretation of cryptic movement behaviours of insects were provided and future research areas were suggested.

Dispersion and Optimization of Sequential Sampling Plans for Coffee Berry Borer (Coleoptera: Curculionidae) Infestations in Hawaii.

Coffee berry borer, Hypothenemus hampei (Ferrari, Coleoptera: Curculionidae) is a serious pest of coffee in most coffee-growing areas of the world. This beetle was first detected in Big Island of Hawaii in 2010 and has since spread to other islands. Being an invasive pest that causes serious economic damage, efforts are in progress in Hawaii to develop an integrated approach to manage this pest. In this study, we sampled commercial coffee orchards from representative coffee-growing regions in the Big Island, Hawaii, to understand dispersion of the pest in the field and develop a reliable sampling plan based on the dispersion characteristics. Analysis of data collected from 12 commercial fields over three growing seasons suggests an aggregated pattern of dispersion of the pest in the field. Two fixed-precision sequential sampling plans based on berry cluster and branch as sample units were modeled and validated using Resampling for Validation of Sampling Plans software. The models suggest that infestation density can be estimated reliably for integrated pest management (IPM) practices with minimal sampling effort by sampling berry clusters or branches using sequential sampling plans. Sequential sampling plan based on berry cluster requires detection of fewer infested berries compared to branch sampling for a reliable estimation of mean density of infested berries and IPM decision making.

Decision Making in Integrated Pest Management and Bayesian Network

Timely availability of expert support to the farmers for appropriate decision-making on 'whether and what pest management option is required' is imperative for effective Integrated Pest Management (IPM). For several decades Economic Threshold Level (ETL) has been the basis for decision-making but in modern IPM emphasis is given on agro-ecological situation wherein IPM decisions are based on large range of pest relevant information such as crop health, natural enemies, weather etc. beside pest incidence scientifically obtained through farmers' field scouting. But large farming community in India can rather obtain the tentative information of this kind, consisting uncertainties. Bayesian Network (BN), anartificial intelligence approach could help in developing technique/model to deal with tentative pest relevant information which can be used in field scouting based IPM Decision Support Systems (DSSs) to automate the process of advising appropriate pest management option to the farmers on the basis of tentative agro-ecological situation of their fields.

Maximizing Information Yield From Pheromone-Baited Monitoring Traps: Estimating Plume Reach, Trapping Radius, and Absolute Density of Cydia pomonella (Lepidoptera: Tortricidae) in Michigan Apple.

Novel methods of data analysis were used to interpret codling moth (Cydia pomonella) catch data from central-trap, multiple-release experiments using a standard codlemone-baited monitoring trap in commercial apple orchards not under mating disruption. The main objectives were to determine consistency and reliability for measures of: 1) the trapping radius, composed of the trap’s behaviorally effective plume reach and the maximum dispersive distance of a responder population; and 2) the proportion of the population present in the trapping area that is caught. Two moth release designs were used: 1) moth releases at regular intervals in the four cardinal directions, and 2) evenly distributed moth releases across entire approximately 18-ha orchard blocks using both high and low codling moth populations. For both release designs, at high populations, the mean proportion catch was 0.01, and for the even release of low populations, that value was approximately 0.02. Mean maximum dispersive distance for released codling moth males was approximately 260 m. Behaviorally effective plume reach for the standard codling moth trap was < 5 m, and total trapping area for a single trap was approximately 21 ha. These estimates were consistent across three growing seasons and are supported by extraordinarily high replication for this type of field experiment. Knowing the trapping area and mean proportion caught, catch number per single monitoring trap can be translated into absolute pest density using the equation: males per trapping area = catch per trapping area/proportion caught. Thus, catches of 1, 3, 10, and 30 codling moth males per trap translate to approximately 5, 14, 48, and 143 males/ha, respectively, and reflect equal densities of females, because the codling moth sex ratio is 1:1. Combined with life-table data on codling moth fecundity and mortality, along with data on crop yield per trapping area, this fundamental knowledge of how to interpret catch numbers will enable pest managers to make considerably more precise projections of damage and therefore more precise and reliable decisions on whether insecticide applications are justified. The principles and methods established here for estimating absolute codling moth density may be broadly applicable to pests generally and thereby could set a new standard for integrated pest management decisions based on trapping.

Environmental and biological drivers of flight initiation in a sporadic pest, Rutherglen bug, Nysius vinitor Bergroth (Hemiptera: Orsillidae)

Flight initiation is fundamental to insect dispersal. Insights into the meteorological and environmental drivers of flight initiation, and their relative importance, can therefore help determine the conditions under which mass dispersal events may occur. In relation to insect pestmanagement, the ability to anticipate such events would allow us to predict mass colonisation of crops and better manage outbreaks of an insect pest. This study insects aims to better predict flight initiation of Rutherglen bug, Nysius vinitor, and thus crop outbreaks originating from over-winter weed hosts. We examined the influence of temperature in combination with sex and the availability of food and water, under controlled environment conditions inside a flight chamber. Most of the variation in flight initiation was explained by temperature. We found that warm temperatures are required for flight initiation: the lower flight threshold was determined as 21 degrees C, the optimum temperature for flight as 25 degrees C and the upper flight threshold as 28 degrees C, fitting a quadratic distribution. However, additional data shows that such thresholds are not limiting: when N. vinitor is under extreme heat stress (35-40 degrees C) for a short period, they have a very high propensity to take-off. The rate of flight initiation was fastest within the first 5 h in both males and females for all tested temperatures. A lack of food and water resulted in a faster take-off rate of males, but had no effect on female flight initiation. Application of our analysis to temperature data in New South Wales (NSW) and Queensland (Qld), Australia, indicates that flight initiation in N. vinitor is likely to be highly seasonal, with very little flight activity expected in winter in eastern Australia. We found a longer suitable flight period and a greater number of suitable flight days per month in Qld compared to NSW. Such estimates could be used to inform regional pest arrival forecasts, integrated pest management decisions and the development of dispersal simulation models for this pest.

Assessment of a more conservative stink bug economic threshold for managing stink bugs in Brazilian soybean production

The objective of this study was to assess the stink bug economic threshold for soybean integrated pest management decisions. For this purpose, a replicated experiment was implement in a commercial soybean crop located in Arapongas, Parana State, Brazil, during two crop seasons: 2010/2011 and 2011/12. Treatments consisted of different stink bug densities triggering the application of insecticides, ¼ of the economic threshold (ET) (= 0.5 stink bugs m−1) and ET (= 2 stink bugs m−1), and without applying an insecticide (control). The stink bugs were quantified weekly and all specimens were identified to the species level. At harvest, yield and quality of the seeds were also measured. In all crops, Euschistus heros was the most abundant species. The highest yield and percentage of viable seeds were found in the 'BMX Power RR′ cultivar (indeterminate growth cultivar), indicating a better seed quality. At the end of the experiment, there was no observed difference in yield between different stink bug management thresholds, indicating the effectiveness of the control when adopting ET. This study demonstrates that decreasing the economic threshold increased the number of required insecticide applications, but did not increase yield or bean quality neither the net income when an economic analysis was performed.

Intercrop movement of convergent lady beetle, Hippodamia convergens (Coleoptera: Coccinellidae), between adjacent cotton and alfalfa.

A 2-year study was conducted to characterize the intercrop movement of convergent lady beetle, Hippodamia convergens Guerin-Meneville (Coleoptera: Coccinellidae) between adjacent cotton and alfalfa. A dual protein-marking method was used to assess the intercrop movement of the lady beetles in each crop. In turns field collected lady beetles in each crop were assayed by protein specific ELISA to quantify the movement of beetles between the crops. Results indicated that a high percentage of convergent lady beetles caught in cotton (46% in 2008; 56% in 2009) and alfalfa (46% in 2008; 71% in 2009) contained a protein mark, thus indicating that convergent lady beetle movement was largely bidirectional between the adjacent crops. Although at a much lower proportion, lady beetles also showed unidirectional movement from cotton to alfalfa (5% in 2008 and 6% in 2009) and from alfalfa to cotton (9% in 2008 and 14% in 2009). The season-long bidirectional movement exhibited by the beetles was significantly higher in alfalfa than cotton during both years of the study. The total influx of lady beetles (bidirectional and unidirectional combined) was significantly higher in alfalfa compared with that in cotton for both years. While convergent lady beetles moved between adjacent cotton and alfalfa, they were more attracted to alfalfa when cotton was not flowering and/or when alfalfa offered more opportunities for prey. This study offers much needed information on intercrop movement of the convergent lady beetle that should facilitate integrated pest management decisions in cotton utilizing conservation biological control.

Within-plant distribution of Aulacorthum solani (Hemiptera: Aphididae), on various greenhouse plants with implications for control.

Foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), has recently undergone a status change from an occasional pest to a serious pest in greenhouses of North America and the United Kingdom. Little nonanecdotal information exists on the ecology of this insect in greenhouse crops. To help improve integrated pest management decisions for A. solani, the within-plant distribution of this pest was explored on a variety of common greenhouse plants in both the vegetative and flowering stage. This aphid generally was found on lower leaves of vegetative plants, but was found higher in the canopy on reproductive plants (on flowers, flower buds, or upper leaves). Aphid numbers were not consistently positively correlated with total leaf surface areas within plant strata across plant species. Thus, the observed differences in preferred feeding sites on vegetative versus flowering plants are possibly a response to differences in nutritional quality of the various host-plant tissues. Despite being anecdotally described as a "stem-feeding aphid," A. solani was rarely found feeding on stems at the population densities established in our tests, with the exception of racemes of scarlet sage (Salvia splendans). Although some previous reports suggested that A. solani prefers to feed on new growth of plants, our results indicate that mature leaves are preferred over growing tips and young leaves. The implications of the within-plant feeding preferences of A. solani populations with respect to both biological and chemical control are discussed.

Indifference Analysis: A Practical Method to Assess Uncertainty in IPM Decision Making

Since the publication of the integrated control concept ( Stern et al. 1959 ), integrated pest management (IPM) has been based upon the principle of rational decision making with knowledge of plant-pest interactions and economic tradeoffs. In addition, although the determination of economic-injury levels and other decision benchmarks have been extraordinarily helpful with the application of IPM principles, they often are fixed, when, in fact, the situation-specific circumstances require a more dynamic approach. Moreover, in situations for which preventive control measures are preferred or required, there has been little guidance for decision makers on how to quantify payoffs to their control options. This paper introduces an approach referred to as indifference analysis, a simple and straightforward practitioner approach to support decision making in IPM programs when outcomes are unknown. The concept is based upon a basic 2 × 2 payoff matrix of prospective financial outcomes for pest management decisions taken with uncertain outcomes. Two case studies are presented to illustrate the use of indifference analysis. For each case, an indifference point is determined that provides transparency regarding the relative financial risk of various management options, leading to insights for selecting tactics under uncertainty. This approach may enlighten decision makers in choosing their IPM practices when outcomes are unknown and uncertain.

Within-Plant Distribution of &lt;I&gt;Bemisia tabaci&lt;/I&gt; (Homoptera: Aleyrodidae) Adults and Immatures on Greenhouse-Grown Winter Cucumber Plants

Within-plant distribution of adults, pupae, nymphs, and eggs of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) on leaves of greenhouse-grown winter cucumber, Cucumis sativum L., plants were studied in field plots for integrated pest management decision making. Distribution of specific life stages depended on the leaf positions. The leaves with most abundance and low or lowest variation of whiteflies were leaves 8-12 for adults, 8-11 for pupae, 6-12 for nymphs, and 6-9 for eggs. In light of the criterion in selecting within-plant sample sites with pest abundance and low variation, these leaves were considered as the most convenient for sampling specific life stages of B. tabaci. Single a and b values for each life stage of the whitefly were calculated by Taylor's power law and were used to estimate minimum sample sizes at a precision of 0.25 (SE/mean). The minimum sample size decreased with increasing density of adults on leaves 8-12, of nymphs on leaves 7 and 8, and of eggs on leaf 6, but slightly increased with increasing density of pupae on leaves 8-11, of nymphs on leaves 6 and 9-12, and of eggs on leaves 7-9.

Within-Plant Distribution of Bemisia tabaci (Homoptera: Aleyrodidae) Adults and Immatures on Greenhouse-Grown Winter Cucumber Plants

Within-plant distribution of adults, pupae, nymphs, and eggs of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) on leaves of greenhouse-grown winter cucumber, Cucumis sativum L., plants were studied in field plots for integrated pest management decision making. Distribution of specific life stages depended on the leaf positions. The leaves with most abundance and low or lowest variation of whiteflies were leaves 8–12 for adults, 8–11 for pupae, 6–12 for nymphs, and 6–9 for eggs. In light of the criterion in selecting within-plant sample sites with pest abundance and low variation, these leaves were considered as the most convenient for sampling specific life stages of B. tabaci. Single a and b values for each life stage of the whitefly were calculated by Taylor’s power law and were used to estimate minimum sample sizes at a precision of 0.25 (SE/mean). The minimum sample size decreased with increasing density of adults on leaves 8–12, of nymphs on leaves 7 and 8, and of eggs on leaf 6, but slightly increased with increasing density of pupae on leaves 8–11, of nymphs on leaves 6 and 9–12, and of eggs on leaves 7–9.

Integrated Pest Management of Insects, Plant Pathogens, and Weeds in Dryland Cropping Systems of the Great Plains

In this article, we trace the development of the concepts and practices of Integrated Pest Management (IPM). Tactics used in IPM of insect pests, plant pathogens, and weeds are discussed, with particular emphasis on application to dryland cropping systems of the Great Plains. Recommendations are made for guiding the development of IPM in such systems. Introduction Insect pests, plant pathogens, and weeds pose a considerable threat to the dryland cropping systems of the Great Plains. The concepts and practices of Integrated Pest Management (IPM) provide an approach to managing these pests. The objectives of this paper are to review and synthesize existing information about IPM and to discuss the application of IPM specifically in the dryland cropping systems of the Great Plains. Literature Summary Many descriptions of IPM have been provided in the literature. The description used here is: “IPM is the judicious use and integration of various pest control tactics, in the context of the associated environment of the pests, in ways that complement and facilitate biological control and other ecological processes that reduce pest impact, to meet economic and environmental goals. IPM addresses the basic causes of pest problems in a holistic manner.” Table 1 lists categories and sub-categories of IPM tactics. Decisions regarding what tactics to use and when and how to use them are a critical aspect of IPM, The concept of the economic injury level (EIL) was developed as a decision tool for managing insect pests in the 1950s and has become a major component of IPM. There are, however, limits to its usefulness, particularly in dryland cropping systems. Study Description Published IPM practices specific to the dryland cropping systems of the Great Plains were reviewed and discussed, with particular emphasis on the use of the EIL and the tactics of pest resistant cultivars, crop rotations, and planting date. In addition, management systems were reviewed for wheat streak mosaic virus, wheat stem sawfly, and Russian wheat aphid. Applied Questions What are the IPM tactics that are most appropriate for IPM in dryland cropping systems of the great plains? The tactics to be emphasized in dryland systems are those that can be designed into the cropping system to reduce the likelihood of pest problems developing. Examples are: cultivars resistant to the pest, crop rotations, certain types of biological control, and planting date adjustment. Tactics such as pesticides, that are applied once a pest problem is active, have limited usefulness because of the expense of gathering information about the current status of pests and the cost of applying the tactic. In low value, dryland cropping systems, the potential increase in economic return from the use of these tactics typically does not justify the cost. Is the EIL concept useful in IPM in the dryland cropping systems of the great plains? Yes. However, its usefulness is limited by the relatively low value of the crops grown in dryland systems and the expense associated with acquiring and interpreting the information required for use of the EIL in IPM decisions. Another important limitation to the usefulness of the EIL is the expense of applying the tactics (mostly pesticides) that are available for use against an active pest problem. Recommendations To best meet the needs for IPM in the dryland cropping systems of the Great Plains, management tactics must be built into cropping systems design. This will require a systems approach with teams of individuals from many disciplines working together. Adoption of such systems will be enhanced if the teams include expertise in research and extension and if producers are closely involved from the earliest stages. Table 1. IPM tactics. Pesticides Host plant resistance Biological control Importation and release Conservation Augmentation Cultural practices Rotations lnterplantings Cover cmps Planting density Pest-k planting materials Planting date Harvesting date Tillage Sanitation Field size Adjacent land uses Soil fertility management lmgation management

Sampling Insect Populations for the Purpose of IPM Decision Making

Decision making is a key aspect of current integrated pest management (IPM) programs and will continue to play an important role as IPM programs mature (71, 106). In an IPM context, decision making relies on protocols for deciding on the need for some management action based on an assessment of the state of a pest population (and ideally its natural enemies). These protocols, which we refer to as control decision rules, consist of at least two components and may include a third: (a) a procedure for assessing the density of the pest population, (b) an economic threshold (63)';�and (c) a phenological forecast (e.g. 49), which is often necessary to determine the appropriate time to assess popUlation densities. Assessment of pest density usually requires obtaining actual counts of the pests, and therefore, sampling is important. Because sampling is time consuming and expensive, one must know how to gather enough information about pest abundance to be able to make correct decisions without incurring excessive costs. Decision making in IPM is important for two reasons. First, decision­ making protocols can be used to reduce pesticide use. Ideally, IPM relies on benign tactics such as biological control, plant resistance, and cultural prac­ tices to maintain fluctuating pest populations below economic injury levels.

Generalization and Application of a Degree-Day Model Predicting Pecan Nut Casebearer (Lepidoptera: Pyralidae) Activity1

The generalization of a degree-day model which predicted biological events for Acrobasis nuxvolla Nuenzig was undertaken by using a frost-free day conversion factor based on other experimentation. The accuracy of the model was determined by using reports from the literature which showed the model to predict events better than calendar days. Real-time implementation of the model for field use was developed and analyzed. Results indicated the model improved capabilities to make integrated pest management decisions on pecan.