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Paula E Cushing
Other: Curator
Denver Museum of Nature and Science
Zoology
Denver, CO USA
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| Evidence for biological control of the Russian wheat aphid with spiders in winter wheat |
| Author(s) |
Lauren M Kerzicnik, Eric C Chapman, James D Harwood, Frank B Peairs, Paula E Cushing |
| Info |
Talk category:
Ecology |
| Abstract |
The Russian wheat aphid, Diuraphis noxia (Hemiptera: Aphididae) is a significant pest of wheat agroecosystems in the United States. Establishing appropriate predator-prey linkages is important for the conservation biological control of pests within these systems. We used gut-content analysis through PCR as a minimally disruptive technique to describe the connection between two spider species, Tetragnatha laboriosa and Pardosa sternalis, and D. noxia. A partial 1146 bp sequence from the mitochondrial cytochrome oxidase I (COI) gene was used to amplify a species-specific 227 bp fragment of D. noxia DNA. We tested the hypotheses that both T. laboriosa and P. sternalis densities and predation on D. noxia would be highest at the highest aphid infestation level in the aphid-resistant wheat cultivar plots. Over 92% of T. laboriosa were collected at the 1x or 10x D. noxia infestation levels combined, demonstrating that T. laboriosa was tracking D. noxia densities. Additionally, P. sternalis predation on D. noxia increased with increasing aphid infestation levels. Feeding trials indicated that T. laboriosa and P. sternalis molecular half-lives for D. noxia DNA were 4.0 h and 2.0 h, respectively. 32% and 48% of field-collected T. laboriosa and P. sternalis spiders screened positive for the presence of D. noxia DNA, respectively. These results suggest that both T. laboriosa and P. sternalis are essential natural enemies for reducing D. noxia densities.
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| Setal and sensory structures on the pedipalps of Solifugae |
| Author(s) |
Paula E Cushing, Patrick E Casto, Tharina L Bird, Lorenzo Prendini |
| Info |
Poster category:
Morphology |
| Abstract |
Solifuges, or camel spiders (order Solifugae) keep their pedipalps extended when moving through the environment and males use them during copulation. The pedipalps are covered with sensory setae and it is assumed that they are used for chemo- and mechanoreception. However, little work has been done to test this hypothesis. We used scanning electron microscopy (SEM) to examine the surface morphology of the pedipalps of solifuges representing the 12 families. Although similar sensory setae are found throughout the order, several unique setae are found only in particular families, suggesting that the patterns and structures of these setae may be phylogenetically informative. |
| Solifugae: exploring the systematics and biology of a little known order of arachnids |
| Author(s) |
Paula E Cushing, Tharina L Bird, Robert Wharton, Jack O Brookhart, Warren Savary, Lorenzo Prendini |
| Info |
Talk category:
Systematics |
| Abstract |
Solifugae, the sixth most diverse order of arachnids, are dominant predators in arid ecosystems on most major terrestrial landmasses. Despite their diversity, worldwide distribution, ecological importance, and fascinating morphology, behavior and life history, research on these arachnids has advanced little in 50 years. Many aspects of solifuge biology remain unknown, their taxonomy is in disarray, and an average of only five publications on the order appears annually.
In 2007, Paula Cushing (Denver Museum of Nature & Science) and Lorenzo Prendini (American Museum of Natural History) were awarded a 5-year Biodiversity Surveys and Inventories grant from the U.S. National Science Foundation to study Solifugae. The objectives of this grant were to: 1) conduct a phylogenetic analysis and revise the suprageneric classification of the order based on morphological and DNA sequence data; 2) conduct several family-level taxonomic revisions within the order, also based on morphology and DNA; 3) survey, discover and describe species in the regions of highest solifuge diversity; 4) create a collaborative network of solifuge specialists; 5) train new specialists; and 6) develop a website with an online specimen database, bibliography and information about Solifugae and solifuge researchers.
During this presentation we will provide a report on the project including: a preliminary molecular phylogeny of the order supporting the monophyly of many currently recognized families; a discussion of morphological character systems identified as phylogenetically informative for Solifugae; an update on revisions of the North American Eremobatidae and the African Solpugidae; a summary of results from projects exploring the diversity, internal and external morphology, biology, and behavior of solifuges; and an overview of the web-resources developed at www.solpugid.com.
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