A Phylogeny of Genera Spirobolomyia and Blaesoxipha (Diptera: Sarcophagidae)
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A Phylogeny of Genera Spirobolomyia and Blaesoxipha (Diptera: Sarcophagidae) A thesis submitted to the Graduate School Of the University of Cincinnati In partial fulfillment of the requirements for the degree of Master of Science In the Department of Biological Sciences of the McMicken College of Arts and Sciences By Stephanie J. Gierek B.S., University of Cincinnati May 2014 Committee chair: Ronald W. DeBry, Ph.D. Abstract Blaesoxipha and Spirobolomyia are two genera from the large family Sarcophagidae, more commonly known as flesh flies. These two genera are parasitoids to a wide variety of other arthropods. When Spirobolomyia was first described by Townsend in 1917, it was a new genus with only one species. In 1965, Downes synonymized Spirobolomyia with Blaesoxipha, giving it subgeneric status, and included 3 new species. In 1996, Pape added another species and removed Spirobolomyia from Blaesoxipha returning it to genus status. In this study, I infer a phylogeny using the cytochrome oxidase I (COI) and NADH dehydrogenase (ND4) genes from the fly’s mitochondrial DNA (mtDNA) in hopes of determining if Spirobolomyia should remain a genus or be reduced to subgeneric status under Blaesoxipha. The phylogeny infers strong support for monophly of Spirobolomyia. However due to no support from the Maximum Likelihood analysis but support from the Bayesian Inference, of the monophyly of Blaesoxipha, more data is needed to determine the placement of Spirobolomyia. ii iii Acknowledgements First, I would like to thank my ever-patient husband. When we agreed I would start this journey four years ago, I promised him it would only take two years. Now here we are, four years later. And even though it took me twice as long, he as was always supportive. Whenever I doubted whether I could do this, he was always there to remind me I could do it. Josh, this is not only my victory but yours too. We did this together because without your support and constant confidence boots, I would have never made it this far. I would also like to thank Dr. Ron DeBry. Little did he know when he talked me into this journey, he would have to put up with me and my life happenings for four long years. Had it not been for him I would never have thought graduate school was an option. Ron, thank you for pushing me to do this. And although it took longer than we both anticipated, I am thankful you had the faith in me to finish. I want to say a special a thanks to Dr. Evan Wong. Without his vote of confidence, I would have never become a part of the lab. He taught me everything I needed to know when it came to lab, even the quirky little tricks it would sometime take to make something work. Evan, I was always fascinated by iv your drive to accomplish more. I know you will accomplish great things as Dr2 Evan Wong. I would also like to thank Dr. Greg Dahlem and Dr. Eric Tepe. I truly appreciate you taking the time from your busy schedules to be a part of my committee. Also, thank you for putting up with me and my last-minute neediness. I would like to give a quick thank you to my new PI, Dr. Latha Satish. You welcomed me into your lab and have given me amazing support while trying to finish up my thesis. v Table of Contents Abstract……………………………………………………………………………………………………………… ii Acknowledgements…………………………………………………………………….….……….………… iv Table of Contents………………………………………………………………………….…………………. vi List of Tables and Figures…………………………………………………………………….…………. vii Introduction……………………………………………………………………………………………...……… 1 Materials & Methods…………………………….………………………………………………….………. 4 Results……………………………………………………………………………………….……….……………… 7 Discussion………………………………………………………………………….……………….…...……… 11 Conclusion ………………………………………………………………………………………………………. 13 Tables…………………………………………………………………………………………………………………14 References…………………………………………….………………………………………………………….20 vi Tables and Figures Figure 1. The Bayesian phylogeny of Blaesoxipha and Spirobolomyia inferred using mtDNA genes COI and ND4 ……………………………….………………………………….10 Table 1. Specimen Identification: Genus, subgenus, species and voucher ……….14 Table 2. List of primers used in this study…………………………………………………………19 vii Introduction Blaesoxipha and Spirobolomyia are two genera from the large family Sarcophagidae, more commonly known as flesh flies. These two genera are parasitoids to a wide variety of other arthropods. Blaesoxipha primarily parasitizes grasshoppers and beetles, while Spirobolomyia preys on millipedes. Since these genera were described, entomologist have disagreed over whether these two groups are congeners or whether they should be recognized as two separate genera. Blaesoxipha was established by Loew in 1861. He discovered a female Blaesoxipha attempting to deposit her larva on a grasshopper using a long sword-like ovipositor. The sword- like ovipositor lead to the name Blaesoxipha, blaisos meaning “Bandy-legged, bent” and xiphos meaning “sword, saber” (Pape 1994). Blaesoxipha is one of the more species-rich taxa in the family of Sarcophagidae. It has 242 described species currently organized into ten subgenera (Pape 1994). The largest of the ten subgenera is Blaesoxipha sensu stricto. It encompasses 75 species, all of which have an old-world distribution except for two species, Blaesoxipha (Blaesoxipha) atlantis and Blaesoxipha (Blaesoxipha) opifera, which have a New World distribution. The Subgenus Acanthodotheca is nearly as large, with 71 described species attributed to it. The species in Acanthodotheca are primarily beetle parasitoids. It has an exclusive New World distribution. The subgenera Abapa (eight species) and Aldrichisca (three species) are restricted to the Antilles. Subgenera Acridiophaga (containing 11 species) and Servaisia (32 species) are Neotropic, Nearctic and Palearctic in distribution. Tephromyia is the only subgenus that is found only in the Palearctic region. It contains 21 species. Subgenera 1 Gigantotheca (17 species) and Kellymyia (three species) are both distributed among the New World. The subgenus Speciosia contains only one species. Blaesoxipha speciosa, originally designated Fletcherimyia speciosa by Downes (1947), was placed in a subgenus alone by Roeback in 1954 (Pape 1994). A vast majority of Blaesoxipha are parasitoids of grasshoppers and darkling beetles. However, there are species that are parasitoids to a large range of other insect taxa (Pape 1994). Blaesoxipha are ovoviviparous; meaning they incubate their eggs within a uterus or pouch. The eggs hatch within the uterus or pouch and first instar larvae are expelled through the larvapositor (Allen and Pape 1994). Blaesoxipha deposit or insert their larva into another insect species. Blaesoxipha have been observed depositing larva on to a host in two ways. Females will stalk their prey from a stationary position above their prey. They will then dart out and deposit a single larva either directly on the prey or even directly within the prey via the genital-anal orifice (Leonide 1964), the buccal cavity (Salvin 1958), or directly into the haemocoele through the cuticle or between the soft segments of the cuticle (Middlekauf 1958; Leonide 1967). Other species of Blaesoxipha will bend the abdomen forward and position their larvapositor between their legs and expel the larva forcefully onto the host. Larvae will quickly penetrate the host (Leonide and Leonide 1986). Larvae will remain inside the host haemocoele for 4-10 days. The host will usually survive while larvae develop within their haemocoele, and if large enough, may survive the exiting of the larva (Greathead 1963). After leaving the host, larvae burrow into the soil to pupate for 1-4 weeks (Crouzel and Slavin 1961). Spirobolomyia was originally described as a genus by Townsend (1917). Spirobolomyia has only five known species (Pape, 1994). Three of the five species of Spirobolomyia were 2 described before Townsend described the genus. All three were first identified as a part of the genus Sarcophaga. Spirobolomyia basalis was originally described by Walker in 1853 and designated Sarcophaga basalis. Sarcophaga pallipes, by original designation, was synonymized with Spirobolomyia basalis by Downes in 1965. When Aldrich (1916) described Sarcophaga pallipes, he was unable to determine the species as the holotype is female, making it difficult to identify to species with any certainty (Pape 1990). In 1916, Aldrich described a species he named Sarcophaga deceptiva in which he described to be similar Sarcophaga singularis with only minor differences. This species later was discovered to be Spirobolomyia basalis. Spirobolomyia flavipalpis was originally identified as Sarcophaga flavipalpis by Aldrich in 1916. Hall (1927) and Roback (1954) described two species (Sarcophaga flavipalpus and Sarcophaga flavipes) that were discovered to be Spirobolomyia flavipalpis. Hall (1927) discovered a species he named Sarcophaga cingularis that was also later identified to be Spirobolomyia singularis. Hall (1927) also described a species he named Sarcophaga ohioensis. These four species were included in Spirobolomyia by Downes in 1965 when he placed Spirobolomyia as a subgenus of Blaesoxipha. In 1990, Pape described the fifth species of Spirobolomyia, Spirobolomyia latissima. All five species have a Nearctic distribution with Spirobolomyia ohioensis and Spirobolomyia latissimi expanding to the Neotropic region. Spirobolomyia lay their larvae on dead and/or injured millipedes. Beyond the identification and knowledge of its parasitic behavior, there is little knowledge of the natural history of this genus. Spirobolomyia