Andrew Jansen defended Master’s thesis
Today graduate student Andrew Jansen defended his Master’s thesis entitled “A Phylogenetic Revision of Minyomerus Horn, 1876 and Piscatopus Sleeper, 1960 (Curculionidae: Entiminae: Tanymecini: Tanymecina)”.
Previously majoring in entomology, Andrew graduated with a B.Sc. from the University of Florida. Andrew came to ASU and joined the Franz Lab in 2012. For his Master’s thesis project he conducted a revision on the weevil genus Minyomerus (Curculionidae: Entiminae), members of which are primarily found throughout the U.S. Southwest. His revision added 10 new species to that genus, bringing the total species number to 17 species, thereby more than doubling the previously known diversity.
Andrew will continue to pursue a Ph.D. degree at ASU, starting in the Fall of 2014. A lot more weevils will get discovered!
Congratulations to Andrew Jansen, M.Sc.! A job well done!
Andrew’s defense talk abstract below.
A phylogenetic revision of the broad-nosed weevil genera Minyomerus Horn, 1876, and PiscatopusSleeper, 1960 (Entiminae: Tanymecini) is presented. Piscatopus was considered monotypic, comprised solely of P. griseus, whereas Minyomerus formerly was comprised of seven species: M. innocuus Horn, 1876 (designated as the type species in Pierce, 1913), M. casey (Sharp, 1891), M. conicollisGreen,1920, M. constrictus (Casey, 1888), M. languidus Horn, 1876, M. laticeps (Casey, 1888), M. microps (Say, 1831). This revision includes full redescriptions of the previously described species in these genera and descriptions of ten new species: M. imberbus sp. nov., M. caponei sp. nov., M. reburrus sp. nov., M. cracens sp. nov., M. trisetosus sp. nov., M. puticulatus sp. nov., M. bulbifrons sp. nov., M. politus sp. nov., M. gravivultus sp. nov., and M. rutellirostris sp. nov. Cladistic parsomony analysis using 46 morphological characters of 22 terminal taxa (five outgroup, seventeen ingroup) was carried out in WinClada and yielded a single most-parsimonious cladogram (length = 82, consistency index = 65, retention index = 82). The results of the cladistic analysis place Piscatopus griseus within the genus Minyomerus, sister to M. rutellirostris. Therefore, Piscatopus is demoted to a junior synonym of Minyomerus and its sole member P. griseus, is moved to Minyomerus in a proposed new combination. Additionally, the species M. innocuus Horn, 1876 is demoted to a junior synonym of M. microps (Say, 1831), and M. microps is elevated to the rank of type species for the genus. The monophyly of Minyomerus is supported by the following unreversed synapomorphies: (1) the appressed scales are sub-circular and overlap posteriorly, (2) the nasal plate is a broad, scale-covered, chevron-shaped ridge demarcating epistoma, (3) a sulcus posteriad of nasal plate is present, (4) the scrobe is subequal in length to funicle and club combined, (5) the head is directed slightly ventrally, (6) the metatibial apex lacks setiform bristles, and instead has bristles that are shorter to subequal in length to surrounding setae and conical, (7) the mid-tarsi are slightly shorter than mid-tibiae, and (8) all tarsi lack pads of setiform setae, and instead have stout spiniform setae. Members of this genus can be found on a variety of host plants, and are likely generalist feeders. Three species in the genus re putatively considered parthenogenetic, given a lack of male specimens over a broad range of sampling events: M. languidus, M. microps, and M. trisetosus. This genus is widespread throughout western North America, and can be found in the arid and semi-arid regions of Canada, the United States of America, and Mexcio, including all of the major desert biomes, Baja California, the Great Plains, and the Colorado Plateau. The diversity in exterior and genitalic morphology, range of host plants, overlapping species distributions, and wide geographic extent suggests an early origin for this genus and a pattern of diversification that likely followed the development of the desert biomes of North America.