Sort:
Show:
Page Size:
Topic review
Updated time: 02 Dec 2020
Submitted by: Valeria Blanda
Definition: Interactions between tick-borne pathogenic hemoparasites and different host effector mechanisms of T- and/or B cell-mediated adaptive immunity, involved in the late and long-lasting protective immune response.
Unfold
Others
Updated time: 05 Nov 2020
Submitted by: Mohammad Akhoundi
Abstract: The bed bugs (Cimex lectularius and C. hemipterus) have undergone a significant resurgence worldwide since the 1990s. Herein, we discuss on the main evolutionary events, from fossil evidence, dating from 11,000 years ago, until the present that has led to the current worldwide expansion of Cimicid species. We present the hypotheses on the possible dispersion pathways of bed bugs in light of the major historical and evolutionary events. A detailed classification of the Cimicidae family and finally, an illustrative map displaying the current distribution of known Cimex species in each geographical ecozone of Asia, Europe, Africa, the Americas, and Australia are presented.
Unfold
Topic review
Updated time: 05 Nov 2020
Submitted by: Michał Filipiak
Definition: For all bee species, the pollen quality determines the overall quality of the larval food, influences the development of individuals and shapes their populations. However, not all plants produce pollen that fully satisfies the nutritional requirements of bees. Lack of understanding of the nutritional requirements of wild bees may lead to unintended negative effects of conservation efforts. Ecological stoichiometry provides an approach to better understand the nutritional constraints on growing and developing organisms and their colonies and populations. It makes reference to elements that, if scarce in the environment, prevent the construction of biologically important organic molecules. The least understood aspect of the nutritional requirements of bees concerns stoichiometric balancing and the need for adequate ratios of nutritional elements in consumed food. This text providestheoretical foundation for the project aiming at determining the likely limitations imposed on wild bees by the lack of nutritionally balanced pollen. The following hypotheses may be tested: 1. Pollen stoichiometry vary among plant species and populations but will differ more widely among species than within different populations of the same species.2. The stoichiometry of bees will vary substantially among bee species and between sexes within a species, which suggests the existence of different nutritional demands. Therefore, it is expected that the stoichiometric mismatches experienced by bees will vary in a species-specific and sex-specific manner.3. For a given bee species, specific pollen species allow the overcoming of stoichiometric mismatches and will balance the diet. Accordingly, it is expected expect that flora diversity and, thus, pollen diversity matches the stoichiometric niches of bees. I predict that the occurrence of specific key host plant species that produce stoichiometrically desirable pollen allows bees to stoichiometrically balance their diets. The project may ask if and how floral diversity, particularly the accessibility of nutritionally desirable key species, may influence bee populations. The obtained data will allow the parameterization of a conceptual model of nutritional limitations (to be developed in the future), which will enable to predict how floral community influences wild bee populations via supply and demand of nutrients.
Unfold
Topic review
Updated time: 23 Dec 2020
Submitted by: Melissa A. Johnson
Definition: Coffee berry borer (CBB) is the most serious insect pest of coffee worldwide, causing more than US$500M in damages annually. Reduction in the yield and quality of coffee results from the adult female CBB boring into the coffee fruit and building galleries for reproduction, followed by larval feeding on the bean itself.
Unfold
Topic review
Updated time: 09 Nov 2020
Submitted by: Maurizio Brivio
Definition: Parasitoid wasps inject eggs into the host insect along with several factors that modulate the immune response, in addition these molecular structures and compounds, present at the surface of the gamete, contribute to the evasive and depressive strategies of the parasitoid by facilitating the development of eggs and larvae within the host body.
Unfold
Topic review
Updated time: 16 Nov 2020
Submitted by: Peter Hristov
Definition: Various factors have been considered to be contributing to honey bee losses, and recent investigations have established some of the most important ones, in particular, pests and diseases, bee management, including bee keeping practices and breeding, the change in climatic conditions, agricultural practices, and the use of pesticides. The global picture highlights the ectoparasitic mite Varroa destructor as a major factor in colony loss. Last but not least, microsporidian parasites, mainly Nosema ceranae, also contribute to the problem. Thus, it is obvious that there are many factors affecting honey bee colony losses globally. Increased monitoring and scientific research should throw new light on the factors involved in recent honey bee colony losses.
Unfold
Topic review
Updated time: 28 Oct 2020
Submitted by: Nelson Mpumi
Definition: The propagation and regeneration of Brassica species has been successful using seeds and different explants like petioles, cotyledons, stems and shoot tips. Shoot regeneration and rooting of Brassica species are successfully obtained from cotyledons and hypocotyl explants. The biological cycle length of Brassica species may either differ slightly or may not differ from one species to another. For instance, the seeds of Brassica oleracea take five days to germinate after sowing at 20–25 °C while the seeds of Brassica campestries take about three to five days to germinate after sowing at 20–25 °C. The most common insect pests of economic importance to Brassica oleracea in African smallholder farmers include Plutella xylostella, Helula undalis, Pieris brassicae, Brevycoryne brassicae, Trichoplusia ni and Myzus persicae. Those insect pests infest cabbages at different stages of growth, causing huge damage and resulting into huge yield losses. The African smallholder farmers use cultural and synthetic pesticides to control those insect pests and minimize infestations. The cultural practices are environmental friendly but are ineffective to control the insect pests. Due to ineffectiveness of cultural practices, African smallholder famers use broad-spectrum synthetic pesticides to effectively control the Brassica species insect pests. The improper and misuse of synthetic pesticides result into insect pests resistance towards the insecticides applied, environmental pollution and human health threats. Insect pests such as Plutella xylostella, Hellula undalis, Brevicoryne brassicae and Myzus persicae have developed resistance to a wide range of pesticides used such as cypermethrin, parathion, decamethrin, quinalphos and lamda-cyhalothrin. Therefore, that calls for search of the alternative products which can effectively be used to control those insect pests in the field.
Unfold
Topic review
Updated time: 22 Feb 2021
Submitted by: David Headrick
Definition: The Federal National Organic Program (NOP) guidelines for insect pest management can be viewed as constraining to certified organic growers due to the disallowance of certain tactics such as synthetic insecticides and transgenically derived pest resistant crops. The types of insect pest management tactics that are promoted by the NOP require in-depth entomological knowledge for successful management such as pheromone disruption, augmentation and conservation biological control. There are significant gaps in the Federal NOP guideline recommendations, such as insect identification and population monitoring, that if included could aid in grower adoption of practices that inform better decision making and efficacy. This review promotes the idea that these issues can be overcome by utilizing experiential learning programs to educate growers and paid professionals like those who are a part of the California system of state licensed Pest Control Advisors (PCA) and having those paid advisors provide much needed individualized, hands-on grower guidance. If the PCA or paid professional is regarded as a valued partner in the educational and extension process of addressing pest management issues, they can be an effective advocate, educator, mentor and assessor for the growers; ultimately reaching more growers to ensure effective adoption and use of a variety of management tactics. This model has the capacity to achieve the NOP's philosophical goal of a production system managed to respond to site-specific conditions by integrating cultural, biological and mechanical practices for effective pest management.
Unfold
Topic review
Updated time: 30 Oct 2020
Submitted by: Anamika Sharma
Definition: Biological control agents and semiochemicals have become essential parts of the integrated pest management of insect pests over the last several years, as the incorporation of semiochemicals with natural enemies and entomopathogenic microbials has been gaining significance. Semiochemicals can enable the successful dispersal of entomopathogenic microbials. Using semiochemicals to disseminate microbial pathogens is still at the initial stage. For dispersal of entomopathogenic fungus semiochemicals have been successfully used in field conditions, however same can not be said about the other microbials such as specially for bacterial and viral entomopathogens.
Unfold
Topic review
Updated time: 30 Oct 2020
Submitted by: Michał Filipiak
Definition: Dead wood is rich in sugars and can serve as an energy source when digested, but it lacks other nutrients, preventing the growth, development, and maturation of saproxylophages.Prokaryotic N fixation partially mitigates the limitations on saproxylophages by the scarcity of N, often the most limiting nutrient, what does not mitigate co-limitation by other physiologically essential nutrients.Fungal transport can shape nutrient dynamics early in wood decay, rearranging extremely scarce nutritional composition of dead wood environment during its initial stage of decomposition and assisting saproxylophage growth and development.This nutritional enrichment of dead wood creates a nutritional niche for xylophages that allows them to grow, develop, and reach maturity. Therefore, xylophagous insects (considered as “wood-eaters”) are unable to gather the necessary amounts of nutritional elements from pure dead wood to grow and mature, but instead must utilize fungal tissues.
Unfold