Biological abilities of storage pests required for the successful penetration of food packages or seeds: Presentation

Storage pests cause enormous damage to stored seed commodities and packaged food. Most of the work published on pest risk assessment concentrates mainly on the effects of “pest –package” or “pest-seed” interactions: i.e. if some species is able (or not able) to penetrate in a sound kernel or package. Based on such “YES-NO outcomes”, the particular stored product pest species is then categorized to either as a “primary” or “secondary” seed feeder; or “penetrator” or “invader” of packages. However, less research attention is paid to the functional explanations of the observed interaction-outcomes. This work therefore deals with comparison of morphological adaptation in various species storage insects with regards to their penetration abilities. For this analysis our original data as well as data from literature were used. As the most important morphological (pre-) adaptations, modulating penetrative/invasive success of storage insect pests, have been recognized: (i) shape and hardness of mandibles, (ii) size and strength of mandibular muscles, (iii) morphology of tarsi enabling climbing and/or firm stance on smooth surfaces. In addition to the morphological adaptations the specific genetically pre-programmed behavioural patterns and abilities may also play a significant role. It will be demonstrated that the above morphological abilities must be taken into account while establishing standard methods of testing of various packages in terms of their sensitivity to penetration/invasion by various species s of storage pests.Storage pests cause enormous damage to stored seed commodities and packaged food. Most of the work published on pest risk assessment concentrates mainly on the effects of “pest –package” or “pest-seed” interactions: i.e. if some species is able (or not able) to penetrate in a sound kernel or package. Based on such “YES-NO outcomes”, the particular stored product pest species is then categorized to either as a “primary” or “secondary” seed feeder; or “penetrator” or “invader” of packages. However, less research attention is paid to the functional explanations of the observed interaction-outcomes. This work therefore deals with comparison of morphological adaptation in various species storage insects with regards to their penetration abilities. For this analysis our original data as well as data from literature were used. As the most important morphological (pre-) adaptations, modulating penetrative/invasive success of storage insect pests, have been recognized: (i) shape and hardness of mandibles, (ii) size and strength of mandibular muscles, (iii) morphology of tarsi enabling climbing and/or firm stance on smooth surfaces. In addition to the morphological adaptations the specific genetically pre-programmed behavioural patterns and abilities may also play a significant role. It will be demonstrated that the above morphological abilities must be taken into account while establishing standard methods of testing of various packages in terms of their sensitivity to penetration/invasion by various species s of storage pests

Rodents in Crop Production Agricultural Systems—Special Issue

Rodents are among the major pests that have accompanied human society and agriculture since ancient times [...

Efficacy of Eight Anticoagulant Food Baits in House Mouse (Mus musculus): Comparison of Choice and No-Choice Laboratory Testing Approaches

House mouse (Mus musculus) is a cosmopolitan pest in agricultural facilities, commodity stores and rural and urban environments. It is regularly controlled by anticoagulant-based baits. Since the number of registered active ingredients is limited, the producers are trying to develop new formulations with increased tamper-resistance, attractiveness and palatability. Reliable and economical methods for laboratory screening/testing are needed. Therefore, this work compared simple no-choice with more economically demanding choice feeding tests for laboratory evaluation of efficacy of rodenticide anticoagulant-based preparations in wild populations of house mouse. We analyzed mice survival and bait intake of the various rodenticide commercial preparations differing in a toxic active substance (warfarin, bromadiolone, brodifacoum, difethialone) and nontoxic food lure components. In most cases, we found insignificant differences in survival of house mice treated with eight test baits within the no-choice and choice feeding tests. We rejected the tested hypothesis that there would be significant differences in all tested preparations for two different testing approaches

Comparison of mandible morphology of two stored product bostrichid beetles, Rhyzopertha dominica and Prostephanus truncatus: Poster

Insect mandibles are most frequently encountered fragments in processed foods. Thanks to their sclerotised and darkly pigmented nature, they usually remain intact in foods and are relatively easily detectable. Moreover, because of their complexity and variety of shapes, stored product beetle mandibles may be useful in species determination. The present work deals with a comparative morphology of two stored product bostrichid beetles, Rhyzopertha dominica and Prostephanus truncatus. The mandibles were studied using by light and scanning electron microscopy and their morphological details, overall appearance and size are provided.Insect mandibles are most frequently encountered fragments in processed foods. Thanks to their sclerotised and darkly pigmented nature, they usually remain intact in foods and are relatively easily detectable. Moreover, because of their complexity and variety of shapes, stored product beetle mandibles may be useful in species determination. The present work deals with a comparative morphology of two stored product bostrichid beetles, Rhyzopertha dominica and Prostephanus truncatus. The mandibles were studied using by light and scanning electron microscopy and their morphological details, overall appearance and size are provided

First Case of Dual Size Asymmetry in an Identical Arthropod Organ: Different Asymmetries of the Combative (Sexual) and Cutting (Non-Sexual) Parts of Mandibles in the Horned Stored-Product Beetle <i>Gnatocerus cornutus</i> (Fabricius, 1798)

Although it is known that separate insect body structures may be asymmetrical within one species, the different functional asymmetries within a single organ as a result of differential selective regimes have not been described. Based on microscopic measurements and SEM photography, we examined the size, shape and asymmetry of the mandibular structures of males and females of the sexually dimorphic broad-horned flour beetle, Gnatocerus cornutus (Tenebrionidae, Coleoptera). It was found that sexual dimorphism only manifests in certain outgrowth parts (horns) of male mandibles, while the remaining cutting parts of the mandibles hold identical morphologies for both sexes. A more interesting finding&#8212;since this is the first published case of dual functionally selected asymmetry in an identical arthropod organ&#8212;was that the cutting part of the male mandible exhibited directional asymmetry, whereas the outgrowth horn part of the mandible showed a high degree of symmetry. Moreover, there was no relationship between the size and asymmetry of horns. The results indicate different regulatory mechanisms of sexually selected combative horns and the food-functional, more conservative (constrained by hard food and adult long life) cutting parts of mandibles

Evaluation of Phosphine Resistance in Populations of Sitophilus oryzae, Oryzaephilus surinamensis and Rhyzopertha dominica in the Czech Republic

Phosphine is globally the most widely adopted fumigant for the control of storage pests. Recently, an increase in the frequency of stored-product pest resistance has been observed with significant geographical and interspecific variations. In this context, there are available data for the occurrence of resistant populations from America, Asia, Africa, and Australia, but there are few data in the case of Europe. Therefore, the aim of this work was to evaluate phosphine efficacy in important beetle pests of stored products, i.e., Sitophilus oryzae (L.), Oryzaephilus surinamensis (L.), and Rhyzopertha dominica (F.) sampled from the Czech Republic, using a rapid diagnostic test that is based on the speed to knockdown after exposure. Apart from the standard laboratory populations, which were used as the controls, we tested 56 field populations of these three species, collected in Czech farm grain stores. The survey revealed that 57.1% of the tested field populations were classified as phosphine-susceptible, based on the knockdown method used. However, profound variations among species and populations were recorded. The species with the highest percentage of resistant populations was R. dominica (71.4% of the populations; resistance coefficient 0.5&ndash;4.1), followed by S. oryzae (57.1% of the populations; resistance coefficient 0.8&ndash;6.9), and O. surinamensis (9.5% of the populations; resistance coefficient 0.5&ndash;2.9). Regarding the intra-population variability in response to phosphine (slope of the knockdown time regression), the laboratory and slightly resistant populations of all species were homogenous, whereas the most resistant populations were strongly heterogeneous. Our data show that the occurrence of resistance in the Czech Republic is relatively widespread and covers a wide range of species, necessitating the need for the adoption of an action plan for resistance mitigation

Synthetic and Natural Insecticides: Gas, Liquid, Gel and Solid Formulations for Stored-Product and Food-Industry Pest Control

The selective application of insecticides is one of the cornerstones of integrated pest management (IPM) and management strategies for pest resistance to insecticides. The present work provides a comprehensive overview of the traditional and new methods for the application of gas, liquid, gel, and solid physical insecticide formulations to control stored-product and food industry urban pests from the taxa Acarina, Blattodea, Coleoptera, Diptera, Hymenoptera, Lepidoptera, Psocoptera, and Zygentoma. Various definitions and concepts historically and currently used for various pesticide application formulations and methods are also described. This review demonstrates that new technological advances have sparked renewed research interest in the optimization of conventional methods such as insecticide aerosols, sprays, fumigants, and inert gases. Insect growth regulators/disruptors (IGRs/IGDs) are increasingly employed in baits, aerosols, residual treatments, and as spray-residual protectants for long-term stored-grain protection. Insecticide-impregnated hypoxic multilayer bags have been proven to be one of the most promising low-cost and safe methods for hermetic grain storage in developing countries. Insecticide-impregnated netting and food baits were originally developed for the control of urban/medical pests and have been recognized as an innovative technology for the protection of stored commodities. New biodegradable acaricide gel coatings and nets have been suggested for the protection of ham meat. Tablets and satchels represent a new approach for the application of botanicals. Many emerging technologies can be found in the form of impregnated protective packaging (insect growth regulators/disruptors (IGRs/IGDs), natural repellents), pheromone-based attracticides, electrostatic dust or sprays, nanoparticles, edible artificial sweeteners, hydrogels, inert baits with synthetic attractants, biodegradable encapsulations of active ingredients, and cyanogenic protective grain coatings. Smart pest control technologies based on RNA-based gene silencing compounds incorporated into food baits stand at the forefront of current strategic research. Inert gases and dust (diatomaceous earth) are positive examples of alternatives to synthetic pesticide products, for which methods of application and their integration with other methods have been proposed and implemented in practice. Although many promising laboratory studies have been conducted on the biological activity of natural botanical insecticides, published studies demonstrating their effective industrial field usage in grain stores and food production facilities are scarce. This review shows that the current problems associated with the application of some natural botanical insecticides (e.g., sorption, stability, field efficacy, and smell) to some extent echo problems that were frequently encountered and addressed almost 100 years ago during the transition from ancient to modern classical chemical pest control methods

Minimal Thermal Requirements for Development and Activity of Stored Product and Food Industry Pests (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera and Blattodea): A Review

Low temperatures play an important role in arthropods because they affect both the individual and population development of all physiological and behavioural activities. Manipulation with low temperatures is a primary nonchemical pest control method. For stored product and food industry practitioners, a knowledge of pest thermal requirements, in particular threshold temperatures at which development and other activities of a particular pest species cease, is of crucial importance. This review presents summary data regarding the lower temperature thresholds of 121 species of stored product and food industry pests from six arthropod taxa (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera, and Blattodea). In particular, this review collected and summarized information regarding the lower development thresholds, lower population thresholds, lower acoustic or respiratory thresholds, lower walking and flying thresholds and lower trap capture thresholds for flying and walking arthropods. The average lower development threshold (LDT) differed among orders: the lowest was reported for Acari (6.8 &#176;C) and Diptera (8.1 &#176;C), followed by Lepidoptera (11.3 &#176;C) and Psocoptera (13.8 &#176;C), and the highest was reported for Coleoptera (14 &#176;C) and Blattodea (15 &#176;C). An exclusion-function was established showing the percentage of pest species (n = 112) that were developmentally suppressed (excluded) due to temperatures reaching the LDT in the range of decreasing temperatures from 25 &#176;C to 0 &#176;C. We scaled various temperature thresholds from the lowest to highest temperature as follows: the walking threshold, the trap capture threshold for walking insects, the lower development threshold, lower population threshold, lower flying threshold and the lower trap capture threshold for flying pests. Important pest species were identified for which information regarding the lower temperature threshold is missing, or for which the information is too variable and should be refined in future research

Bluefume (HCN) and EDN® as fumigation alternatives to methy bromide for control of primary stored product pests: Presentation

The presented paper provides preliminary results on the fumigation potential of two preparations: Bluefume (HCN - hydrogen cyanide) and EDN®. (Ethane-dinitrile). Their biological efficacy was tested on Granary weevil (Sitophilus granarius; Curculionidae; Coleoptera) as a primary stored product pest in the Czech Republic. In fumigation chamber, we tested temporal survival of various S. granarius strains following exposure of a dose of 9 g.m-3 HCN (Bluefume). We compared differential sensitivity of one laboratory (i.e. sensitive) CRI-strain and 9 field strains collected from the Czech stores and mills. The HCN Ct products required to kill the tested S. granarius strains ranged from CTp= 30.5 g.m-3.h-1 to CTp= 51.7 g.m3.h-1. The efficacy of EDN (30 g.m-3) on various developmental stages S. granarius was tested in a fumigation chamber. No live individual of S. granarius belonging to any life stage was recorded following 18 hours of EDN exposure.The presented paper provides preliminary results on the fumigation potential of two preparations: Bluefume (HCN - hydrogen cyanide) and EDN®. (Ethane-dinitrile). Their biological efficacy was tested on Granary weevil (Sitophilus granarius; Curculionidae; Coleoptera) as a primary stored product pest in the Czech Republic. In fumigation chamber, we tested temporal survival of various S. granarius strains following exposure of a dose of 9 g.m-3 HCN (Bluefume). We compared differential sensitivity of one laboratory (i.e. sensitive) CRI-strain and 9 field strains collected from the Czech stores and mills. The HCN Ct products required to kill the tested S. granarius strains ranged from CTp= 30.5 g.m-3.h-1 to CTp= 51.7 g.m3.h-1. The efficacy of EDN (30 g.m-3) on various developmental stages S. granarius was tested in a fumigation chamber. No live individual of S. granarius belonging to any life stage was recorded following 18 hours of EDN exposure