Presence Of Pests Research Articles

Biological control of Tetranychus evansi Baker & Pritchard and Tetranychus urticae Koch by Phytoseiulus longipes Evans in tomato greenhouses in Spain [Acari: Tetranychidae, Phytoseiidae

The two-spotted spider mite Tetranychus urticae and the tomato red spider mite Tetranychus evansi are known to cause severe damage in tomato crops. Preliminary laboratory studies showed that a phytoseiid predatory mite from Argentina, Phytoseiulus longipes, could be a potential candidate for the control of those two pests. The present paper aims to assess the effectiveness of this predator for controlling both pests under tomato experimental greenhouse conditions. Six treatments were considered: T. urticae without predators, T. evansi without predators, a high and a low predator–prey ratios (1–5 and 1–25 predator–prey, respectively) used with both prey. Mites were counted twice a week during 35 days after the predators were released. Without predators, plant damage was quickly noticed. P. longipes was able to maintain T. urticae and T. evansi populations under a threshold of 25 mites/leaflet at a high predator–prey ratio. However, at the low predator–prey ratio, plants showed damages in presence of both pests. The predatory mite population considered could constitute a real improvement for the biological control of T. urticae and T. evansi in European tomato greenhouses. Perspectives for the use of P. longipes as a biocontrol agent and the additional work required to make this a reality are discussed.

Are Building-Level Characteristics Associated with Indoor Allergens in the Household?

Building-level characteristics are structural factors largely beyond the control of those who live in them. We explored whether building-level characteristics and indoor allergens in the household are related. We examined the relationship between building-level characteristics and indoor allergens: dust mite, cat, cockroach, and mouse. Building-level characteristics measured were presence of pests (seeing cockroaches and rodents), building type (public housing, buildings zoned commercially and residentially, and building size), and building condition (building age and violations). Allergen cutpoints were used for categorical analyses and defined as follows: dust mite: >0.25 μg/g; cat: >1 μg/g; cockroach: >1 U/g; mouse: >1.6 μg/g. In fully adjusted linear analyses, neither dust mite nor cat allergen were statistically significantly associated with any building-level characteristics. Cockroach allergen was associated with the presence of cockroaches (2.07; 95% CI, 1.23, 3.49) and living in public housing (2.14; 95% CI, 1.07, 4.31). Mouse allergen was associated with the presence of rodents (1.70; 95% CI, 1.29, 2.23), and building size: living in a low-rise (<8 floors; 0.60; 95% CI, 0.42, 0.87) or high-rise (8 + floors; 0.50; 95% CI, 0.29, 0.88; compared with house/duplex). In fully adjusted logistic analyses, cat allergen was statistically significantly associated with living in a high-rise (6.29; 95% CI, 1.51, 26.21; compared with a house/duplex). Mouse allergen was associated with living in public housing (6.20; 95% CI, 1.01, 37.95) and building size: living in a low-rise (0.16; 95% CI, 0.05, 0.52) or high-rise (0.06; 95% CI, 0.01, 0.50; compared with a house/duplex). Issues concerning building size and public housing may be particularly critical factors in reducing asthma morbidity. We suggest that future research explore the possible improvement of these factors through changes to building code and violations adherence, design standards, and incentives for landlords.

Scale invariant feature approach for insect monitoring

One of the main problems in greenhouse crop production is the presence of pests. In order to address this problem, the implementation of a Integrated Pest Management (IPM) system involving the detection and classification of insects (pests) is essential for intensive production systems. Traditionally, this has been done by placing hunting traps in fields or greenhouses and later manually counting and identifying the insects found. This is a very time-consuming and expensive process. To facilitate this process, it is possible to use machine vision techniques. This work describes an application of the machine vision system LOSS V2 algorithm, an expanded version of the LOSS algorithm discussed in a previous work by the same authors. This expanded version demonstrated improved potential and was used to detect and identify the following pest species: Diabrotica (Coleoptera: Chrysomelidae), Lacewings ( Lacewings spp.), Aphids ( Aphis gossypii Genn.), Glassy ( Empoasca spp.), Thrips ( Thrips tabaci L.), and Whitefly ( Bemisia tabaci Genn.). The algorithm identifies pest presence in the crop and makes it possible for the greenhouse manager to take the appropriate preventive or corrective measures. The LOSS V2 involves the application of the LOSS algorithm for initial pest identification, followed by the application of the image processing technique known as scale invariant feature transform (SIFT). This allows for more accurate pest detection because it is possible to discriminate and identify different types of insects. Therefore, when compared to manual pest counting, the newly developed LOSS V2 algorithm showed more precision in identifying different pest varieties, and also, a much higher determination coefficient, R 2 = 0.99.

Arthropod monitoring in an automated pasta warehouse

Pest monitoring was carried out in an automated pasta warehouse. It is managed with a logistic process and can contain more than 30,000 pallets. Good pest monitoring is difficult in this environment particularly because of the height (more than 20 m). Several sticky traps were placed on the floor under the shelves to monitor the presence of arthropods. Monitoring was done twice, once in March and once in November, each time for two weeks. Results showed the presence of stored-product pests, but also the occurrence of other arthropods. Keywords : Pest monitoring, Stored-product pests, Automatic warehouse, Arthropods, Insects.

Another Look at Pesticide Productivity and Pest Damage

Using the Lichtenberg‐Zilberman‐Fox‐Weersink damage specification, we develop a short‐run, supply‐response framework based on rational producer behavior in the presence of damage agents. We show how representation can be used to measure and decompose the economic damage associated with the presence of pests, how to measure the shadow prices of damage‐control agents, how to measure the manner in which pesticide application biases variable input use, and how pesticide application affects the relative returns to quasi‐fixed factors of production. An econometric version of the model is estimated using a panel data set on Greek olive producers. Both our theoretical and our empirical results suggest that the most traditional measure of pest damage understates actual economic losses and revenue losses due to pests.

Postharvest management of insects in horticultural products by conventional and organic means, primarily for quarantine purposes

Purpose of review: The presence of arthropod pests in or on horticultural commodities has caused major disruptions in the storage, processing and shipment of these products. Management of these pests has posed a problem to humans for thousands of years. Current technology has led to the development of numerous means (chemical, mechanical or procedural) to control these pests. For the most part, postharvest pest control is focused on trade and exports. The accidental introduction of a pest into a place where it is not known to be present has resulted in the establishment of quarantine restrictions and export treatment requirements. This review focuses on the most current state of postharvest and quarantine treatments in development and currently in use on horticultural products. The current implementation and acceptance of these treatments is also addressed. Findings: Conventional postharvest pest control measures include treatments with chemical fumigants and topical pesticides. Concerns over environmental pollution and human health have obstructed the use of conventional chemicals and fumigants and further development of new chemicals for postharvest treatments. Irradiation is considered a conventional treatment, however, it does not use chemicals nor does it result in detectible residues in the commodity. Improvements in engineering commercial irradiators such as restricting source exposure, and the development of more powerful X-ray converters of electron beams, as well as refinement of generic treatments for groups of pests, had led to the expansion of this treatment to achieve quarantine goals. Directions for future research: Organic compliant postharvest treatments have received much attention and are the area of the most research. These treatments can include topical treatments with organic, natural pesticides and biologically derived fumigants, temperature extremes, modified atmospheres, and other novel physical treatments. The status of postharvest treatments for the control of arthropod pests both approved and in development is discussed.

Evaluation of biological aspects of the predacious mite, Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) due to prey changes using selected arthropods

ABSTRACT Supplying mite predators with alternate feeding stratagems are important in determining their survival and these could play a key role in their use for biocontrol. This paper describes the food habits of predatory mite Neoseiulus cucumeris (Oudemans) in the presence or absence of target insect and acarine pests. The study used well known pests, the stored food mite Tyrophagus putrescentiae (Schrank), the red spider mite Tetranychus urticae Koch, and the western flower thrips Frankliniella occidentalis (Pergande), as prey for the predatory mite. Survival of N. cucumeris was observed in relation to the prey diets offered, prey consumption, fecundity, development time, and adult longevity as influenced by changes in prey were recorded. Significant differences were observed for the types of prey diet used, Ty. putrescentiae was the most suitable prey closely followed by Te. urticae; then F. occidentalis diet. Predation response observed after feeding trials began at a prey density of 15 individuals per predator; N. cucumeris adults displayed higher consumption rates (7.0 and 6.4 nymphs/24 h) for Ty. putrescentiae and Te. urticae, respectively, than for F. occidentalis larvae (4.0/24 h). The duration of the developmental stages of the predatory mites reared on Ty. putrescentiae and Te. urticae were 7.6 and 7.7 days, respectively, compared to 8.5 days when reared on thrips. Total adult female survival periods were higher (30.2 and 28.0 days) when predators were fed these mites than when fed thrips (23.0 days). Survival periods were 27.4, 25.0, and 20.4 days, respectively, for the male predatory mite. Average fecundities of N. cucumeris fed Ty. putrescentiae and Te. urticae were 3.8 and 3.4 eggs after 24 h, respectively, compared to 2.2 eggs when fed thrips. Respective oviposition periods were 20.4, 18.0, and 13.4 days. After transfer to a new prey host, adult N. cucumeris of which the parental stock had been fed F. occidentalis, showed preference for Ty. putrescentiae and Te. urticae. Predatory mites for whom the parent generation had been reared on Ty. putrescentiae and Te. urticae also accepted F. occidentalis as substitute prey but inadequate predation was apparent, as indicated by reduced egg production, growth period, and survival. Although relatively short, the periods measured were sufficient to reveal differences linked to the initial and previous diets. The predatory mite N. cucumeris is a promising biological control agent for thrips, spider mite, and mold mite because it can feed and survive on alternative nutritional sources when prey is absent or scarce.

Intensive versus low-input cropping systems: What is the optimal partitioning of agricultural area in order to reduce pesticide use while maintaining productivity?

Pesticide use should be reduced for sustainable agriculture. Low-input cropping systems, centered on hardy varieties that maintain their yield in the presence of pests, allow pesticide use to be reduced. Since yield potential is generally lower for hardy varieties than for high-yielding varieties, a balance must be found between production and pesticide reduction. In order to compute the optimal partitioning of agricultural area between intensive and low-input cropping systems, we present a model that allows yield and gross margins to be computed at the landscape scale, as a function of the proportion of the area under intensive and low-input systems. The model shows that two cases must be distinguished, depending on inoculum production by each of the coexisting systems. If the low-input system produces less inoculum (e.g. because resistant varieties are used), coexistence can be optimal, whereas if the low-input system produces more inoculum (e.g. because tolerant varieties are used), it is best to devote the whole area to a single system. The model gives the gross margin for each cropping system as a function of the proportion of low-input systems – and so predicts the proportion to which the farmers’ choices will lead – and illustrates the use of different (simplified) policies that would ensure that the optimum proportion is reached.

Current control methods for diamondback moth and other brassica insect pests and the prospects for improved management with lepidopteran-resistant Bt vegetable brassicas in Asia and Africa

The diamondback moth (DBM), Plutella xylostella (L.), remains a major pest of brassica crops worldwide. DBM has been estimated globally to cost US$ 1 billion in direct losses and control costs. Chemical control of this pest remains difficult due to the rapid development of resistance to insecticides and to their effect on natural enemies. These problems are especially severe in South Asia and Africa where lack of knowledge, limited access to newer and safer insecticides, and a favourable climate result in DBM remaining a serious year-round pest which substantially increases the cost and uncertainty of crop production. Despite these problems, application of synthetic insecticides remains overwhelmingly the most common control strategy. Biologically-based efforts to control DBM in Africa and Asia have focused strongly on parasitoid introductions. However, despite the identification and deployment of promising parasitoids in many regions, these efforts have had limited impact, often because farmers continue early-season spraying of broad-spectrum insecticides that are lethal to parasitoids and thus exacerbate DBM outbreaks. A significant driver for this pattern of insecticide use is the presence of aphids and other pests whose appearance initiates inappropriate spraying. Despite often extensive training of producers in farmer field schools, many growers seem loath to discard calendar or prophylactic spraying of insecticides. The introduction of an IPM technology that could replace the use of broad-spectrum insecticides for DBM and other key Lepidoptera is crucial if the benefits of parasitoid introduction are to be fully realised. The deployment of DBM-resistant brassicas expressing proteins from Bacillus thuringiensis could help to break this cycle of insecticide misuse and crop loss, but their deployment should be part of an integrated pest management (IPM) package, which recognises the constraints of farmers while addressing the requirement to control other Lepidoptera, aphids and other secondary pests.

Qualidade de sementes de milho armazenadas em diferentes embalagens

O armazenamento é parte decisiva para a produção de sementes de alta qualidade. Com o objetivo de avaliar a qualidade física, fisiológica e sanitária de sementes de três variedades de milho armazenadas durante seis meses, em embalagens plásticas e em sacos de algodão, foram realizadas determinações da perda de peso, da quantificação de danos por insetos e do teste de germinação e sanidade. No armazenamento em embalagens plásticas, observou-se redução na germinação, porém o dano por insetos foi menor. O armazenamento em saco de algodão proporcionou redução na qualidade das sementes, pela presença de insetos-praga e pela alta incidência de fungos do gênero Fusarium, Penicillium e Aspergillus, exceto para a variedade Pururuca Branco. O armazenamento em embalagens plásticas possibilitou a manutenção da qualidade das sementes, tendo uma menor incidência de insetos e de fungos em comparação com sacos de algodão. As variedades Caiano e Pururuca Branco apresentaram comportamento diferenciado em relação às embalagens utilizadas.

Machine vision algorithm for whiteflies (Bemisia tabaci Genn.) scouting under greenhouse environment

AbstractOne of the main problems in greenhouse crop production is the presence of pests. Detection and classification of insects are priorities in integrated pest management (IPM). This document describes a machine vision system able to detect whiteflies (Bemisia tabaci Genn.) in a greenhouse by sensing their presence using hunting traps. The extracted features corresponding to the eccentricity and area of the whiteflies projections allow to establish differences among pests and other insects on both the trap surfaces and dust generated artefacts. Because of whiteflies geometrical characteristics, it was possible to design an efficient (related to manual counting) machine vision algorithm to scout and count units of this pest within a greenhouse environment. These algorithm results show high correlation indexes for both, sticky screens (R2 = 0.97) and plant leaf situations (R2 = 1.0). The machine vision algorithm reduces the scouting time and the associated human error for IPM‐related activities.

Factors affecting the incidence of pathogenic micro-organisms in fresh-cut produce

of review: This review focuses on the main factors influencing the incidence of pathogenic micro-organisms in fresh-cut pro- duce. Findings: The increase in the per capita consumption of fresh-cut produce is expected to continue during the forthcoming years, there- fore it is necessary to strengthen microbial safety issues related to fresh-cut produce. Different factors affecting the presence of patho- genic micro-organisms in fresh-cut produce during processing have been identified: the raw produce coming from field and process water quality; the hygiene and health of food handlers; the sanitation and cleanliness of facilities; processing equipment and utensils; and the presence of pests in processing plants. Raw produce quality is one of the most important factors that can affect the arrival of pathogenic micro-organisms on fresh-cut fruits and vegetables. Limitations/implications: The high cost associated with implementing Good Agricultural Practices (GAPs), Good Manufacturing Practices (GMPs) and Hazard Analysis and Critical Control Points (HACCP) as food safety programs. Directions for future research: Efforts should be made to develop feasible procedures for small- and medium-sized industries that ensure high microbiological safety and quality standards, through HACCP plans, for each fresh-cut produce. It is also necessary to explore new treatments that improve the safety and quality of fresh-cut produce in order to prevent the incidence, survival and growth of pathogenic micro-organisms, as well as to prolong the microbiological shelf-life.

Pathogen‐tested material of grapevine varieties and rootstocks

Pathogen‐tested material of grapevine varieties and rootstocks

Developing a generic sampling system for monitoring the key arthropod pests of table grapes, Vitis vinifera L.

We describe a system developed for monitoring arthropod pests of table grapes in the Hex River Valley, South Africa. The system has wide applicability for monitoring pests at grape-producing localities in the country. Six Vitis vinifera cv. Barlinka and six V. vinifera cv. Dauphine vineyards were used as sampling sites. In each vineyard, 100 vines were inspected bi-weekly, to record damage or the presence of arthropod pests on the cordon, one bunch and one leaf per vine. Sampling precision and operating characteristic (OC) curves were estimated for each of the pests. Using previously determined economic thresholds together with the OC curves, action thresholds were determined for Tetranychus urticae Koch (Prostigmata: Tetranychidae) (11–29% leaf infestation), Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) (2% cordon infestation), Epichoristodes acerbella (Walker) (Lepidoptera: Tortricidae) and Phlyctinus callosus Boh. (Coleoptera: Curculionidae) (1% bunch damage). This novel system can be used for monitoring arthropod pest population levels in all types of South African vineyards, providing a basis for the development of integrated pest management (IPM) systems in these vineyards.

Housing characteristics, home environmental factors and respiratory health in 14,729 Chinese children

Background Very few studies have assessed the relative impact of housing characteristics and home environmental factors on asthma and asthma-related symptoms in Chinese children who have lower rates of asthma. To our knowledge few studies have assessed respiratory symptoms and allergies in this context. Methods To assess the effects of housing characteristics, pet keeping, home decorations and other indoor environmental factors on respiratory health of Chinese children. We studied a population of 14,729 children (1–13 years old) from 12 districts in Liaoning province, Northeast China. Information on respiratory health, housing characteristics, and environmental pollutions were obtained by a standard questionnaire from the American Thoracic Society. Results Housing conditions, house adjacent to traffic or not, house with or without pollution source nearby, pet keeping, presence of pests and mold/water damage in the home, home decorations and exposure to environmental tobacco smoke (ETS) were associated with doctor-diagnosed asthma and asthma-related symptoms both in boys and girls. The vulnerability towards exposure to housing conditions and environmental factors differed between males and females. Among boys, the risk of respiratory morbidity appeared to be reduced in households with larger surface areas and more rooms; use of a ventilation device was strongly protective against persistent phlegm (OR = 0.68; 95%CI: 0.48, 0.96). Asthma-related symptoms were more associated with different pets among girls than among boys. The presence of a cat in the household was associated with doctor-diagnosed asthma (OR = 1.89; 95% CI, 1.11–3.20), current wheeze (OR = 2.64; 95% CI, 1.52–4.59), persistent cough (OR = 1.84; 95% CI, 1.18–2.87) and persistent phlegm (OR = 2.17; 95% CI, 1.21–3.87) only among girls. Conclusion Living within the vicinity of a source of pollution, traffic, pet keeping, home decorations, pests, mold and ETS are important determinants of children's respiratory health in China.

Biological control of thrips and whiteflies by a shared predator: Two pests are better than one

We studied the capacity of one species of predator to control two major pests of greenhouse crops, Western flower thrips ( Frankliniella occidentalis (Pergande)) and the greenhouse whitefly ( Trialeurodes vaporariorum (Westwood)). In such a one-predator–two-prey system, indirect interactions can occur between the two pest species, such as apparent competition and apparent mutualism. Whereas apparent competition is desired because it brings pest levels down, apparent mutualism is not, because it does the opposite. Because apparent competition and apparent mutualism occurs at different time scales, it is important to investigate the effects of a shared natural enemy on biological control on a time scale relevant for crop growth. We evaluated the control efficacy of the predatory mites Amblyseius swirskii (Athias-Henriot) and Euseius ovalis (Evans) in cucumber crops in greenhouse compartments with only thrips, only whiteflies or both herbivorous insects together. Each of the two predators controlled thrips, but A. swirskii reduced thrips densities the most. There was no effect of the presence of whiteflies on thrips densities. Whitefly control by each of the two predators in absence of thrips was not sufficient, yet better with E. ovalis. However, whitefly densities in presence of thrips were reduced dramatically, especially by A. swirskii. The densities of predators were up to 15 times higher in presence of both pests than in the single-pest treatments. Laboratory experiments with A. swirskii suggest that this is due to a higher juvenile survival and developmental rate on a mixed diet. Hence, better control may be achieved not only because of apparent competition, but also through a positive effect of mixed diets on predator population growth. This latter phenomenon deserves more attention in experimental and theoretical work on biological control and apparent competition.

Application of Radiofrequency Power for Non-Chemical Disinfestation of Rough Rice with Full Retention of Quality Attributes

The presence of insect pests in stored grains constitutes an undesirable condition leading to product losses, lesser quality, and reduced market value. Currently, to protect grains, the rice industry relies on insecticides and fumigants but many of these products are facing elimination (deregistration) due to health and environmental concerns. An alternative non-chemical disinfestation process is therefore needed. Radiofrequency (RF) power was selected as it can be applied to induce well-controlled, lethal thermal energy levels, rapidly, efficiently, and throughout the whole mass of grains with minimal physical and chemical changes. Natural and laboratory infested dried storage rough rice containing all life cycles of lesser grain borers (Rhyzopertha dominica) and Angoumois grain moths (Sitotroga cerealella) were used to evaluate the efficacy of RF power treatment. This study developed relationships between temperature and disinfestation effects that were used to optimize the process's disinfestation efficiency while operating at power and thermal load levels well tolerated by the commodity. Low-thermal load RF processing at 55C to 60C bulk rice temperatures for short times (5 min) resulted in >99% control of all biological stages of Sitotroga cerealella (grain moth). When higher thermal loads were applied using 50C for Sitotroga cerealella with a 2-h tempering or 60C for Rhyzopertha dominica with 1-h tempering, the treatment provided 100% control as indicated by the absence of emerging adults over a 120-d observation period. Under these processing conditions, no moisture losses or changes in milling quality were observed. An analysis of the potential of RF power for commercial disinfestation of grains is also included.

Exasticolus fuscicornis em lagartas de Spodoptera frugiperda

O objetivo deste trabalho foi monitorar a presença de pragas e seus inimigos naturais em diferentes regiões produtoras de milho. Foram coletadas 7.415 lagartas em plantas de milho, em municípios dos estados de Minas Gerais, Mato Grosso do Sul e Goiás. Foi observada associação do parasitóide Exasticolus fuscicornis Cameron (Hymenoptera: Braconidae) com o hospedeiro, lagarta de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), em 1,54% das lagartas coletadas. O ciclo de vida do parasitóide foi de 23,31 dias. A longevidade de machos e fêmeas foi de 15 e 16,5 dias, respectivamente. A razão sexual foi de 0,36.

Colecta de frutales tropicales en El Salvador

The objective of this study was to collect, characterize and establish fruit collections of: Pouteria sapota (zapote), Manilkara zapota (níspero), Psidium sp. (guava), Spondias sp. (jocote), and Mammea americana (mamey apple). Exploration and collecting tours in several zones with a high potential for the cultivation of these fruits were undertaken. Collection site and characterization of the germplasm information was obtained. Weigth, length, diameter, germination percentage, number of seeds, flavor and color of pulp, form of the fruit, color of shell, presence of pests and diseases, and bromatological analysis were also obtained. The data were analyzed using descriptive statistics for minimum, maximum and average. Collections of fruit trees were established in the Centers of Technology in San Andrés, Izalco and Morazán. Zapote Magaña produced fruits with the highest weight, longitude and diameter, texture of quite fibrous pulp. Zapote valiente produced fruits with a high protein of (2.65%) content and fat (0.77%). Zapote Rivera produced fruits with the higher carbohydrate content (32,15%). Miami guava the higher crude fiber content (3,72%). The main plagues and diseases for the jocote were trips, fruit flies and anthracnoses. A collection of jocote of these types was established: azucaron, verano, pitarrillo, chapin, invierno, iguana and tronador at the Technological Innovation Center in San Andrés, La Libertad.

Sampling of consignments for visual phytosanitary inspection

Sampling of consignments for visual phytosanitary inspection