Larvicidal Activity of Selected Plant Extracts Against the Screwworm Fly Chrysomya Albiceps

Myiasis is a kind of parasitic disease originating from the invasion of tissues of domestic animals by dipteran larvae. Chrysomya albicebs is a type of screwworm fly spread in the tropical areas and known to cause myiasis among live human and animals leading to health problems and high economic losses to dairy producers. Management and control of this pest is needed to overcome these losses. Nowadays, natural botanical products have been increasingly investigated as controlling agents against insects of medical and veterinary importance. This research was designed to evaluate the larvicidal effect of the total extracts of three plants, Ficus palmate, Juniperus procera and Nerium oleander against screwworm fly Chrysomya albiceps. The plants leaves were extracted with organic solvents mixture methanol : chloroform (1:1) and were tested against the second larval instar of C. albiceps using feeding and dipping methods. The extracts caused larval mortalities in the order of F. palmate> N. oleander > J. procer with IC50 values of 15.97, 33.73 and 37.24, respectively using feeding method and in the order N. oleander > F. palmate > J. procera with IC50 values of 43.12, 47.41 and 73.39, respectively using dipping method. It is concluded that the F. palmate followed by N. oleander and J. procera are candidates to use in controlling the larvae of myiasis-caused fly C. albiceps.

the effect of temperatures and humidity rates on the mean weight loss from developement

The effect of some environmental factors in the loss rate for high weights virgins are full to the screwworm fly of the ancient world and included temperatures 15,20,25,30,35,40 study showed that the rate of loss in weight virgins advanced to full participants at a temperature of 15 C while notgets evolution

Physiological and molecular correlates of the screwworm fly attraction to wound and animal odors

The screwworm fly, Cochliomyia hominivorax (Coquerel), was successfully eradicated from the United States by the sterile insect technique (SIT). However, recent detection of these flies in the Florida Keys, and increased risk of introductions to the other areas warrant novel tools for management of the flies. Surveillance, a key component of screwworm control programs, utilizes traps baited with rotting liver or a blend of synthetic chemicals such as swormlure-4. In this work, we evaluated the olfactory physiology of the screwworm fly and compared it with the non-obligate ectoparasitic secondary screwworm flies, C. macellaria, that invade necrotic wound and feed on dead tissue. These two species occur in geographically overlapping regions. C. macellaria, along with other blowflies such as the exotic C. megacephala, greatly outnumber C. hominivorax in the existing monitoring traps. Olfactory responses to swormlure-4 constituents between sex and mating status (mated vs unmated) in both species were recorded and compared. Overall, responses measured by the antennograms offered insights into the comparative olfactory physiology of the two fly species. We also present detailed analyses of the antennal transcriptome by RNA-Sequencing that reveal significant differences between male and female screwworm flies. The differential expression patterns were confirmed by quantitative PCR. Taken together, this integrated study provides insights into the physiological and molecular correlates of the screwworm’s attraction to wounds, and identifies molecular targets that will aid in the development of odorant-based fly management strategies.

Lysenko and the Screwworm Fly—When Politics Interferes with Science and Public Health

In the One Health scenario, a deep understanding of the dynamics potentially threatening the development and implementation of useful pest and vector management tools is of key importance. The New World screwworm fly, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), is characterized by a wide host range. It acts as an important agent of myiasis in humans and warm-blooded animals in the Neotropics, and has been eliminated from a wide region through genetic methods. Of note, Serebrovsky had already proposed in 1940 the principles of autocidal control by the translocation of segments between two chromosomes, but his work was negated by Lysenko, based on the negation of Mendelian genetics. This entomological case study emphasizes the danger of politics interfering with science, a still contemporary hot issue. The negation of global warming or current pandemics are further examples of this noxious influence.

Genomic analyses of a livestock pest, the New World screwworm, find potential targets for genetic control programs

The New World Screwworm fly, Cochliomyia hominivorax, is a major pest of livestock in South America and Caribbean. However, few genomic resources have been available for this species. A genome of 534 Mb was assembled from long read PacBio DNA sequencing of DNA from a highly inbred strain. Analysis of molecular evolution identified 40 genes that are likely under positive selection. Developmental RNA-seq analysis identified specific genes associated with each stage. We identify and analyze the expression of genes that are likely important for host-seeking behavior (chemosensory), development of larvae in open wounds in warm-blooded animals (heat shock protein, immune response) and for building transgenic strains for genetic control programs including gene drive (sex determination, germline). This study will underpin future experiments aimed at understanding the parasitic lifestyle of the screwworm fly and greatly facilitate future development of strains for efficient systems for genetic control of screwworm.