Red wood ants (the Formica rufa group) are important predators which affect animal communities in their territory. Therefore, they are useful in forest protection. On the other hand, they also prey ...on beneficial organisms. We have asked whether Formica rufa L. affects the abundance of the parasitic flies Ernestia rudis (Fallén). Ten anthills situated in about 40-year- old pine plantations were used for the study. The presence of E. rudis cocoons was assessed in eight soil samples excavated in the surrounding of each nest at a distance of 2–17 m. Our results show a considerably lower abundance of E. rudis only to 4.5 m from the nests. The occurrence of Formica rufa ants therefore had no significant effect on the beneficial E. rudis population in plantation forests, where ants populations are low.
Plants synthesize a multitude of compounds that contribute to adaptation to their ecological niches. Such compounds serve as attractants of other living organisms beneficial to the plants or as ...defense against other biotic as well as abiotic agents. Selection for increased fitness, a never-ending process, has resulted in each plant lineage synthesizing a distinct set of specialized metabolites appropriate for its environment. The total number of specialized metabolites found in the plant kingdom far exceeds the capacity of any one plant genome to encode the necessary enzymes, and just as a plant lineage acquires the ability to make new specialized compounds during evolution, it also loses the ability to make others. Although the ability of plants to make novel, specialized metabolites continues to evolve, there are also many examples in which different plants have independently evolved the ability to make compounds already present in other plant lineages or to make different compounds that fulfill the same role-both are examples of convergent evolution. Here, we discuss many examples of convergent evolution in specialized metabolism. There are many genetic and biochemical mechanisms that can give rise to convergent evolution, and we conclude that, overall, convergent evolution in plant specialized metabolism is surprisingly common.
Plants have sophisticated defense systems to protect their tissues against the attack of herbivorous organisms. Many of these defenses are orchestrated by the oxylipin jasmonate. A growing body of ...evidence indicates that the expression of jasmonate-induced responses is tightly regulated by the ecological context of the plant. Ecological information is provided by molecular signals that indicate the nature of the attacker, the value of the attacked organs, phytochrome status and thereby proximity of competing plants, association with beneficial organisms and history of plant interactions with pathogens and herbivores. This review discusses recent advances in this field and highlights the need to map the activities of informational modulators to specific control points within our emerging model of jasmonate signaling.
The use of entomopathogenic fungi represents one of the most important non-chemical alternatives for pest control in crop production. In addition to their pathogenicity to arthropods, they have many ...other important effects that favor their use in biological control. They live in plants as endophytes and have an inhibitory effect on plant pathogens. They inhabit the rhizosphere of many plants in natural and agricultural ecosystems and have a stimulatory effect on their growth and development. These recently acquired ecological functions are not yet fully understood, but point to the broader potential of using entomopathogenic endophytic fungi in crop production, not only as biopesticides but also as mycofungicides and growth stimulants (biostimulants). To achieve the full potential of entomopathogenic endophytic fungi in daily agricultural practice, practical application should be considered in the development of commercial products and the application techniques of entomopathogenic endophytic fungi that allow successful colonization of plants should be considered.
Genomic stability and maintenance of the correct chromosome number are assumed to be essential for normal development in eukaryotes. Aneuploidy is usually associated with severe abnormalities and ...decrease of cell fitness, but some organisms appear to rely on aneuploidy for rapid adaptation to changing environments. This phenomenon is mostly described in pathogenic fungi and cancer cells. However, recent genome studies highlight the importance of Leishmania as a new model for studies on aneuploidy. Several reports revealed extensive variation in chromosome copy number, indicating that aneuploidy is a constitutive feature of this protozoan parasite genus. Aneuploidy appears to be beneficial in organisms that are primarily asexual, unicellular, and that undergo sporadic epidemic expansions, including common pathogens as well as cancer.
Gambusia affinis and G. holbrooki, introduced worldwide from eastern North America, are collectively the most abundant, widespread freshwater fish in the world, which is not surprising because they ...tolerate, and sometimes thrive under, an exceptional range of environmental conditions and have high reproductive potential. Some know them as mosquitofish because of a legendary ability to control mosquitoes, and diseases they carry, while others doubt this ability or argue that indigenous fish are equally or more effective. However, rigorous evidence to support these views remains scant, so the legend persists. Some know them as plague minnow because of negative impacts on many native animal species, and abundant evidence exists to support this view. Despite such polarized attitudes toward them, their high abundance and wide distribution, and a large scientific literature devoted to them, many important aspects of their biology remain poorly known.
Demographic approaches give a better understanding of the side effects of pesticides on beneficial organisms. In this study the effect of sublethal (LC10 and LC30) concentrations of thiamethoxam on ...the demographic parameters of Hippodamia variegata were assessed and the data analyzed using the age-stage, two-sex life table procedure. Results showed that thiamethoxam didn't have any significant effects on the developmental time of third instars, adult longevity and fecundity. However, the developmental time of fourth instars, pupae, the total preoviposition period (TPOP) and the adult preoviposition period (APOP) were affected significantly. Three main population parameters (r, λ and R0) were affected by the sublethal treatments. The intrinsic rate of increase (r) was 0.18 day−1 in the control but in LC10 and LC30 thiamethoxam treated insects this parameter declined to 0.15 and 0.13 day−1, respectively. The finite rate of increase (λ) in controls was about 1.20 whilst it was 1.16 for LC10 and 1.14 day−1 for LC30 treated insects. The net reproductive rate (R0) in control, LC10 and LC30 treated insects were 232.5, 114.6 and 68.5 offspring/individual, respectively. Therefore, the results achieved in this study showed that thiamethoxam at sublethal concentrations have potential to affect the predatory lady bird adversely. Thus more care should be taken when this insecticide is used in IPM programmes.
Display omitted
•Sublethal concentrations of thiamethoxam affect three parameters including r, λ and R0.•Sublethal concentrations of thiamethoxam affect development time of the larvae and pupae.•Sublethal concentrations of the insecticide does not affect the insect fecundity.•Sublethal concentrations of thiamethoxam affect TPOP and APOP.
Global agriculture is heavily dependent on sustainable plant protection. Worldwide, the concept of integrated pest management (IPM) is being followed. IPM utilizes a range of strategies, with ...chemical synthetic pesticides being employed only as a last resort. However, in agricultural practice, farmers continue to rely primarily on this option. To further reduce this dependence, new strategies are being sought to strengthen the use of biological control within the IPM approach including the identification of novel non-synthetic natural compounds. Here, we discuss and report on the state of the art in biological control research in areas such as biocontrol agents and application of ecological principles. These practices can help to establish sustainable plant protection systems, with the greatest impact achieved when they are used in appropriate combinations. We highlight the conditions that currently prevent or hinder the increased use of biocontrol measures. On the background of agroecological experiences, we discuss why additional advancements in plant protection practices are imperative to more effectively break the life cycles of pests, diseases and weeds. We emphasize the significance of a judicious application of chemical control technologies, adapted to local conditions. Additionally, we highlight the key role and expertise of operators in implementing these practices and their knowledge thereof.
Banker Plant Method in Biological Control Huang, Ningxing; Enkegaard, Annie; Osborne, Lance S ...
Critical reviews in plant sciences,
05/2011, Letnik:
30, Številka:
3
Journal Article
Recenzirano
In the banker plant method, long-lasting rearing units for beneficials are created in the crop by distributing plants infested with herbivores or carrying other food items, such as pollen. The method ...has been widely investigated over many years and used to aid establishment, development and dispersal of beneficial organisms employed in biological control. In this review, we refine the definition of the banker plant method based on previous concepts and studies and offer the term “banker plant system” to describe the unit that is purposefully added to or established in a crop for control of pests in greenhouses or open field. The three basic elements of a banker plant system (banker plant, food source, beneficials) are discussed and illustrated with examples, and the diversity of banker plant systems (classified by target pest) used or investigated is documented. The benefits of using banker plant systems, such as low cost, increased freshness of beneficials, possibility for preventive control and for integration within IPM frameworks, make the method an interesting plant protection option with potential to enhance adoption of biological control in pest management programs.
Neonicotinoid insecticides are widely used for control of insect pests around the world and are especially pervasive in agricultural pest management. There is a growing body of evidence indicating ...that the broad-scale and prophylactic uses of neonicotinoids pose serious risks of harm to beneficial organisms and their ecological function. This provides the impetus for exploring alternatives to neonicotinoid insecticides for controlling insect pests. We draw from examples of alternative pest control options in Italian maize production and Canadian forestry to illustrate the principles of applying alternatives to neonicotinoids under an integrated pest management (IPM) strategy. An IPM approach considers all relevant and available information to make informed management decisions, providing pest control options based on actual need. We explore the benefits and challenges of several options for management of three insect pests in maize crops and an invasive insect pest in forests, including diversifying crop rotations, altering the timing of planting, tillage and irrigation, using less sensitive crops in infested areas, applying biological control agents, and turning to alternative reduced risk insecticides. Continued research into alternatives is warranted, but equally pressing is the need for information transfer and training for farmers and pest managers and the need for policies and regulations to encourage the adoption of IPM strategies and their alternative pest control options.
PDF
