Topic Review
Insect Pests of Brassica oleracea
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.
  • 1216
  • 28 Oct 2020
Topic Review
Bed Bugs
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.
  • 1174
  • 05 Nov 2020
Topic Review Video
Bee Nutritional Demands
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 provides theoretical 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.
  • 640
  • 05 Nov 2020
Topic Review
Semiochemicals and Entomopathogenic Microbials
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. 
  • 618
  • 30 Oct 2020
Topic Review
Entompathogen Wasps
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.
  • 601
  • 09 Nov 2020
Topic Review
Wood-Eating Insects and Wood Eaters
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.
  • 589
  • 30 Oct 2020
Topic Review
Coffee Berry Borer (Hypothenemus hampei)
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.
  • 547
  • 23 Dec 2020
Topic Review
Cytochrome c oxidase in Insects
Flight dispersal represents a key aspect of the evolutionary and ecological success of insects, allowing escape from predators, mating, and colonization of new niches. The huge energy demand posed by flight activity is essentially met by oxidative phosphorylation (OXPHOS) in flight muscle mitochondria. In insects, mitochondrial ATP supply and oxidant production are regulated by several factors, including the energy demand exerted by changes in adenylate balance. Indeed, adenylate directly regulates OXPHOS by targeting both chemiosmotic ATP production and the activities of specific mitochondrial enzymes. In several organisms, cytochrome c oxidase (COX) is regulated at transcriptional, post-translational, and allosteric levels, impacting mitochondrial energy metabolism, and redox balance.
  • 241
  • 10 Jun 2021
Topic Review
Adaptive Immune-Response to Tick-Borne Hemoparasites
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. 
  • 204
  • 02 Dec 2020
Topic Review
Insect Lectin-Mediated Immune Responses
Lectins are carbohydrate-binding proteins that recognize and selectively bind to specific sugar structures. Interaction of lectin with sugars on cell surface can activate multiple cellular responses, including the immune response. Many insect lectins have been identified or predicted but without in-depth analysis.
  • 176
  • 05 Jul 2021
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