|Taylor, David - Dave|
|Peterson Ii, Richard|
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/1997
Publication Date: N/A
Citation: N/A Interpretive Summary: Parasitic wasps of the genus Muscidifurax are among the most promising candidates for the biological control of flies associated with confined livestock. Although a great deal of work has been done to evaluate and optimize the use of these wasps for fly control, virtually nothing is known of the origin or relationships between the species in this genus. This information is important because previous work indicated that these wasps originated in the Eastern Hemisphere and were introduced to the Western Hemisphere along with house flies and stable flies during the early colonization of the Americas. Based upon this belief, explorations for improved biotypes of these wasps have concentrated on the Eastern Hemisphere. Our data indicate that these wasps originated in the Western Hemisphere and that the species are genetically more divergent than previously believed. These findings provide a base of data upon which we can work to genetically improve existing stocks of these wasps and search for new, more effective strains to improve biological control of filth flies in the confined livestock environment.
Technical Abstract: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analyses were used to characterize an amplicon of approximately 625 base pairs in four of the five nominate species of Muscidifurax Girault and Sanders, pupal parasitoids of muscoid flies. A single polymorphic nucleotide site was observed among two samples of M. raptor Girault and Sanders. No sequence variation was observed among three samples of M. raptorellus Kogan and Legner. The sequence of M. uniraptor Kogan and Legner was identical to that of M. raptorellus. Nucleotide divergence among the Muscidifurax spp. ranged from 0.14 to 0.18 substitutions per nucleotide. Muscidifurax zaraptor Kogan and Legner exhibited multiple haplotypes, two of which were characterized by sequencing and four others by PCR-RFLP. The sequenced haplotypes differed by 0.08 nucleotide substitutions per site. Restriction site analysis indicated that nucleotide divergence ranged from 0.03 to 0.10 among all si haplotypes. Analysis of isofemale lines indicated that the observed variation in M. zaraptor was due to multiple haplotypes within individuals rather than differentiation among individuals. These results bring to question the specific status of M. uniraptor and indicate that the genus is native to the Western Hemisphere and not introduced with their primary host, Musca domestica L., as previously proposed. Heteroplasmy and translocation of a portion of the mitochondrial genome to the nuclear genome are discussed as possible causes for the variation observed in M. zaraptor.