Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

Blood-red colour as a prey choice cue for mosquito specialist predators

Abstract: Specialist predators are innately and distinctively proficient at targeting specific prey types. This is enabled by behavioural, perceptual and cognitive mechanisms that can only be understood using carefully designed experiments. Evarcha culicivora is an East African jumping spider that feeds on vertebrate blood acquired indirectly by actively targeting blood-carrying female mosquitoes as preferred prey. Here we asked whether these spiders use the colour red to identify this prey....

A randomized, double-blind placebo-control study assessing the protective efficacy of an odour-based ‘push–pull’ malaria vector control strategy in reducing human-vector contact

Abstract: Novel malaria vector control strategies targeting the odour-orientation of mosquitoes during host-seeking, such as ‘attract-and-kill’ or ‘push-and-pull’, have been suggested as complementary tools to indoor residual spraying and long-lasting insecticidal nets. These would be particularly beneficial if they can target vectors in the peri-domestic space where people are unprotected by traditional interventions. A randomized double-blind placebo-control study was implemented i...

Evaluation of the solar-powered Silver Bullet 2.1 (Lumin 8) light trap for sampling malaria vectors in western Kenya

Abstract: Background Centers for Disease Control and Prevention (CDC) light traps are widely used for sampling mosquitoes. However, this trap, manufactured in the USA, poses challenges for use in sub-Saharan Africa due to procurement costs and shipping time. Traps that are equally efficient than the CDC light trap, but which are amenable for use in remote African settings and made in Africa, are desirable to improve local vector surveillance. This study evaluated a novel solar-powered light ...

Microsporidia MB in the primary malaria vector Anopheles gambiae sensu stricto is avirulent and undergoes maternal and horizontal transmission

Abstract: Background The demonstration that the recently discovered Anopheles symbiont Microsporidia MB blocks malaria transmission in Anopheles arabiensis and undergoes vertical and horizontal transmission suggests that it is a promising candidate for the development of a symbiont-based malaria transmission-blocking strategy. The infection prevalence and characteristics of Microsporidia MB in Anopheles gambiae sensu stricto (s.s.), another primary vector species of malaria in Kenya, were in...

A review of edible saturniidae (Lepidoptera) caterpillars in Africa

Abstract: Background Edible saturniids constitute an important component of traditional diets in sub-Saharan Africa. They are also a source of livelihood for many rural communities both as food and as a source of income. Main body This review compiles information on the diversity, distribution, decimating factors, nutrition and conservation concerns of edible saturniids. A compilation of nutritional profiles, amino-acids, mineral and fat content of saturniids is presented. Details of edible ...

The potential contribution and challenges of edible grasshopper (Ruspolia differens) to food and nutrition security in Uganda- a literature review

Abstract: Insects are being considered a sustainable protein food source for the future to forestall the impending world protein shortage, exacerbated by population growth and climate change. The edible grasshopper Ruspolia differens, a high protein insect traditionally consumed in East Africa- particularly in Central Uganda presents an opportunity for local solutions to food and nutritional security. This literature review consolidates research information, mainly derived from peer reviewed...

Patterns of Aedes aegypti abundance, survival, human-blood feeding and relationship with dengue risk, Kenya

Abstract: Dengue virus (DENV) transmission risk is influenced by the bionomic traits of the key vector, Aedes aegypti. We investigated patterns of abundance, survival, and human blood-feeding of Ae. aegypti populations in two environments in Kenya: peri-urban Rabai (coastal Region, dengue-endemic) and rural Kerio Valley (Rift Valley Region, no reported dengue outbreak). In both environments, Ae. aegypti survival (estimated by parity), was inversely correlated with vector abundance, and this ...

Root exudate chemical cues of an invasive plant modulate oviposition behavior and survivorship of a malaria mosquito vector

Abstract: Gravid female Anopheles gambiae mosquitoes identify suitable oviposition sites through a repertoire of cues, but the influence of allelochemicals, especially root phytochemicals in modulating this behavior and impacting subsequent progeny bionomics remains unexplored. We addressed these questions in the malaria vector Anopheles gambiae and its invasive host plant Parthenium hysterophorus. Using chemical analysis combined with laboratory behavioral assays, we demonstrate that a blen...

Mosquitoes Larvicidal Activity of Ocimum kilimandscharicum Oil Formulation under Laboratory and Field-Simulated Conditions

Abstract: Mosquitoes are vectors of many severe diseases, including malaria, yellow as well as dengue fever, and lymphatic filariasis. The use of synthetic chemical insecticides for mosquito control has been associated with resistance development and detrimental human, and ecological effects. For a safer alternative, the emulsified Ocimum kilimandscharicum oil formulation was evaluated for its larvicidal activity. The oil was analyzed by GC and GC/MS. The formulations were evaluated against ...

Attraction of the Mosquitoes Aedes aegypti and Aedes albopictus (Diptera: Culicidae) to a 3-Part Phytochemical Blend in a Mesocosm

Abstract: Aedes aegypti (L.) and Aedes albopictus (Skuse) mosquitoes of both sexes were attracted to a 3-part volatile synthetic phytochemical blend but differed according to their component ratios, 7:3:2 or 1:1:1, and their initial concentrations. These arbovirus vectors were presented with the blends as baits in paired baited and blank CFG traps in a large greenhouse mesocosm. Ae. aegypti attraction was highest at a 7:3:2 blend ratio, but at a concentration half that found most effective f...

Editorial: Novel Insights Into Female Post-Mating Physiology in Insects

Abstract: Mating deeply affects female physiology and behavior. The major factors responsible for such post-mating changes that were identified so far comprise the act of mating itself, the ejaculate transferred by the male during copulation, and the female microbiome. The genes regulating post-mating responses have been only partially characterized, and mostly in model organisms. In most insects, the molecules transferred in the male ejaculate are still completely unknown, as are the biosyn...

Invasion risk by fruit trees mealybug Rastrococcus invadens (Williams) (Homoptera: Pseudococcidae) under climate warming

Abstract: The mango mealybug Rastrococcus invadens (Williams) (Homoptera: Pseudococcidae) is a destructive and important insect pest of fruit trees in Africa and Asia, especially the mango. Females and nymphs feed on plant leaves and fruits and produce honeydew that causes sooty mold, leading to yield reduction. Although it is an important pest, the distribution of R. invadens under different climate change scenarios has not been established. In this study, we predicted the suitable habitat ...

Ontogenetic responses of physiological fitness in Spodoptera frugiperda (Lepidoptera: Noctuidae) in response to repeated cold exposure

Abstract: In this era of global climate change, intrinsic rapid and evolutionary responses of invasive agricultural pests to thermal variability are of concern given the potential implications on their biogeography and dire consequences on human food security. For insects, chill coma recovery time (CCRT) and critical thermal minima (CTmin ), the point at which neuromuscu-lar coordination is lost following cold exposure, remain good indices for cold tolerance. Using laboratory-reared Spodopte...

Biogeography of cereal stemborers and theirnatural enemies: forecasting pestmanagement efficacy under changing climate

Abstract: Background: Climate warming presents physiological challenges to insects, manifesting as loss of key life-historyfitness traitsand survival. For interacting host–parasitoid species, physiological responses to heat stress may vary, thereby potentiallyuncoupling trophic ecological relationships. Here, we assessed heat tolerance traits and sensitivity to prevailing and futuremaximum temperatures for the cereal stemborer pests,Chilo partellus,Busseola fuscaandSesamia calamistisand th...

The Entomopathogenic Fungi Metarhizium anisopliae and Beauveria bassiana for Management of the Melon Fly Zeugodacus cucurbitae: Pathogenicity, Horizontal Transmission, and Compatability with

Abstract: In the laboratory, the pathogenicity of thirteen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and two isolates of Beauveria bassiana (Balsamo) Vuillemin against the melon fly Zeugodacus cucurbitae (Coquillett) were assessed by exposing adults to 0.3 g of dry conidia (~3 × 109 conidia) of each isolate for 5 min and monitoring mortality for up to 5 days. Compatibility with a male pheromone, cuelure, (4-(p-acetoxyphenyl)-2-butanone), was determined by testing conidial ge...


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