ARACHNIDS ASSOCIATED WITH WET PLAYAS IN THE SOUTHERN HIGH PLAINS WITH WET PLAYAS ARACHNIDS ASSOCIATED SPECIAL PUBLICATIONS Museum of Texas Tech University Number 54 2008 ARACHNIDS ASSOCIATED WITH WET PLAYAS IN THE SOUTHERN HIGH PLAINS (LLANO ESTACADO), C okendolpher et al. U.S.A. JAMES C. COKENDOLPHER, SHANNON M. TORRENCE, JAMES T. ANDERSON, W. DAVID SISSOM, NADINE DUPÉRRÉ, JAMES D. RAY & LOREN M. SMITH SPECIAL PUBLICATIONS Museum of Texas Tech University Number 54 Arachnids Associated with Wet Playas in the Southern High Plains (Llano Estacado), U.S.A. JAMES C. COKENDOLPHER , SHANNON M. TORREN C E , JAMES T. ANDERSON , W. DAVID SISSOM , NADINE DUPÉRRÉ , JAMES D. RAY , AND LOREN M. SMI T H Texas Tech University, Oklahoma State University, B&W Pantex, Texas Parks and Wildlife Department, West Texas A&M University, West Virginia University Layout and Design: Lisa Bradley Cover Design: James C. Cokendolpher et al. Copyright 2008, Museum of Texas Tech University All rights reserved. No portion of this book may be reproduced in any form or by any means, including electronic storage and retrieval systems, except by explicit, prior written permission of the publisher. This book was set in Times New Roman and printed on acid-free paper that meets the guidelines for permanence and durability of the Committee on Production Guidelines for Book Longevity of the Council on Library Resources. Printed: 10 April 2008 Library of Congress Cataloging-in-Publication Data Special Publications of the Museum of Texas Tech University, Number 54 Series Editor: Robert J. Baker Arachnids Associated with Wet Playas in the Southern High Plains (Llano Estacado), U.S.A. James C. Cokendolpher, Shannon M. Torrence, James T. Anderson, W. David Sissom, Nadine Dupérré, James D. Ray, and Loren M. Smith ISSN 0169-0237 ISBN 1-929330-16-2 ISBN13 978-1-929330-16-4 Museum of Texas Tech University Lubbock, TX 79409-3191 USA (806)742-2442 Front cover: Cover photograph of a playa at sunset by Jo-Szu (Ross) Tsai. Besides being a beautiful and inspiring sight, this picture symbolically represents the sunset of playas in general unless conservation efforts are effective. AR A CHNIDS ASSOCI A TED WITH WET PL A Y A S IN THE SOUTHERN HIGH PL A INS (LL A NO EST A C A DO ), U.S.A. JAMES C. COKENDOLPHER , SHANNON M. TORREN C E , JAMES T. ANDERSON , W. DAVID SISSOM , NADINE DUPÉRRÉ , JAMES D. RAY , AND LOREN M. SMI T H ABSTR A CT We documented the occurrence of arachnids (orders Araneae, Ixodida, Opiliones, Prostigmata, Sarcoptiformes, Solifugae) associated with wet playas in the Southern High Plains of Texas, U.S.A. Overall, we found species associated with playas, aquatic and inundated vegetation, emergent vegetation, playa edges, and those occurring only in surrounding grassland habitats. Four state, 41 Southern High Plains, and 63 first county records are documented. At least five species are thought to be undescribed and many others could not be identified with certainty. We found four families of water mites with aquatic stages as predators and parasites as well as one chigger species that has spadefoot toads as a host. Some of the water mites require an invertebrate host to disperse to other playas. Most species found in playa edges and emergent aquatic vegetation can also be found in upland grassland habitats. Therefore, many arachnid species collected within playas are likely grassland species present in dry playas prior to inundation by rains or individuals using playa vegetation as a retreat from harsh conditions of drought or bare soil created from agricultural activities. Given the importance of playas as a possible refuge for arachnids and the primary habitat for some water mite species, conserving the ecological function of playas is important to maintaining the diversity within the arachnids in the Llano Estacado. Key words: distribution, ecology, fauna, grassland, taxonomy, wetlands RESUMEN Documentamos la ocurrencia de arácnidos (órdenes: Araneae, Ixodida, Opiliones, Prostigmata, Sarcoptiformes, Solifugae) asociados a playas mojadas en las Planícies altas del Sur de Tejas, E.E.U.U. En total, se encontró especies asociada a playas, en la vegetación acuática e inundada, vegetación emergente, los bordes de playa, y están restringidas a habitats de praderas. Se documentan quatro nuevos registros para el esta- dos de Tejas, 41 en los Planícies altas del Sur, y 63 nuevos registros para condados. Se incluyó al menos cinco especies no descritas y otros registros no han sido identificados con certeza. Registramos cuatro familias de ácaros acuáticos con etapas diferenciadas como depredadores y parásitos, así como una especie de nigua fue encontrada parasi- tando en sapos. Algunos de los ácaros acuáticos requieren a otros invertebrados para dispersarse a otras playas. La mayoría de las especies fueron encontradas en bordes de playa, vegetación acuática, y en habitats de pradera. Por lo tanto, muchos arácnidos colectados dentro de playas en praderas altas probablemente estuvieron presentes en playas secas antes de la inundación de las lluvias, o están usando la vegetación de la playa como refugio de condiciones ásperas de la sequía o del suelo utilizado en actividades 1 2 SP ECI A L PUBLIC A TIONS , MUSEUM OF TEX A S TECH UNIVERSITY agrícolas. Dada la importancia de playas como un posible refugio para arácnidos y el habitat primario de algunas especies de ácaros acuáticos, es importante la conservación ecológica de playas para mantener la diversidad endémica de estos invertebrados. Palabras claves: distribución, ecología, fauna, pradera, taxonomía, tierras húme- das INTRODUCTION Playas in the Great Plains, U.S.A., are shallow As recharge wetlands, playas only receive water depressional recharge wetlands, with each playa exist- from precipitation and runoff from the immediate area ing in its own catchment (Smith 2003). Conservatively, (Bolen et al. 1989) (Photo. 2). Precipitation in this there are about 25,000 individual playas occurring semi-arid region begins primarily as thunderstorms in the Southern Great Plains (Osterkamp and Wood in spring, occurs more sporadically through summer, 1987; Sabin and Holliday 1995; see Figs. 1-3 in Cok- and increases again in autumn. Playa hydroperiods endolpher et al. 2007). In the Southern High Plains, or (how long a playa holds water) primarily depend on Llano Estacado, they are the most numerous wetland precipitation timing, amounts, and intensity (Photo. type (Photo. 1; all photographs occur in the center 3). Because each individual playa is the terminus of its of this document). The Southern High Plains is the catchment basin, playas accumulate sediment eroded largest plateau (Fig. 1) in North America (Sabin and from surrounding watersheds during precipitation and Holliday 1995) and is one of the most intensively irrigation events (Luo et al. 1999). Intensive cultivation cultivated regions in the Western Hemisphere (Bolen of surrounding watersheds, and resultant eroded sedi- et al. 1989). Note that the Southern High Plains is a ments, has decreased the average hydric soil defined plateau within the Southern Great Plains, the terms are volume of playas in cropland by more than 100% (Luo not synonymous. et al. 1997). This decreased holding volume causes shorter hydroperiods (Luo et al. 1997; Gray and Smith The number of playas in the Southern High Plains 2005) affecting the entire ecological structure of playas is about 22,000 (Guthery and Bryant 1982). There are (Smith and Haukos 2002). 33 counties in two states in the Southern High Plains (Smith 2003, minimum counts follow county names): Playas exist as the primary aquatic habitats within Texas: Andrews with 298 playas, Armstrong 676, Bai- this intensive agricultural landscape, and therefore are ley 598, Briscoe 787, Carson 535, Castro 621, Cochran the focal points of biodiversity for the entire region 395, Crosby 925, Dawson 702, Deaf Smith 451, Donley (Haukos and Smith 1994). Numerous surveys and 114, Floyd 1,783, Gaines 65, Garza 283, Gray 752, Hale studies have been conducted on the flora and fauna of 1,383, Hockley 1,171, Howard 185, Lamb 1,280, Lub- playas, as well as how cultivation of the watershed has bock 934, Lynn 842, Oldham 75, Parmer 455, Potter influenced those biotic groups (see review in Smith 69, Randall 564, Swisher 210, Terry 532, Wheeler 10, 2003). In addition to use by nonmigratory wildlife, Yoakum 38. New Mexico: Curry 524 playas, Lea 1,175, playas provide important habitat for migrating and Quay 228, Roosevelt 535. In northern Texas (north of wintering waterfowl and shorebirds (e.g., Bolen et al. Canadian River), there are an additional eight counties 1989; Davis and Smith 1998), and are also used by (Dallam with 220 playas, Hansford 345, Hartley 123, breeding waterfowl and shorebirds (Ray et al. 2003; Hemphill 9, Hutchinson 167, Lipscomb 18, Moore 195, Conway et al. 2005a, 2005b). Ochiltree 590) that also have playas and form with the other counties the High Plains Ecoregion of Texas. In Few studies have examined playa invertebrates, this paper, only the playas in the Southern High Plains many of which serve as food for wildlife species (An- are considered, but distributional records are also listed derson and Smith 1998, 2000). There is a paucity of in- for the High Plains (also called the Panhandle Plains) formation, especially lower than the family taxonomic of Texas. COKENDOL P HER ET A L .—PL A Y A AR A CHNIDS 3 Figure 1. Map showing location of the Southern High Plains, or Llano Estacado, in the Great Plains. [Modified from Smith (2003), courtesy of University of Texas Press, Austin]. level (e.g., Merickel and Wangburg 1981; Hall et al. cies are absent from this region of Texas or specimens 1999; Hall et al. 2004), and even fewer have examined are seldom collected/reported. We suggest the latter. playa arachnids. Cokendolpher et al. (2007) recently de- Previous collectors have under-sampled this region scribed a new species of linyphiid spider in playas, and of Texas because much of it is very flat and formerly this article reports other new species.