DOCSLIB.ORG

Complex Display Behaviour During the Intraspecific Interactions of Myrmecomorphic Jumping Spiders (Araneae, Salticidae)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Complex Display Behaviour During the Intraspecific Interactions of Myrmecomorphic Jumping Spiders (Araneae, Salticidae) Complex display behaviour during the intraspecific interactions of myrmecomorphic jumping spiders (Araneae, Salticidae) Running head: Comparative study of two species of Myrmarachne. XIMENA J. NELSON1* & ROBERT R. JACKSON1 1School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand *Current address: Centre for the Integrative Study of Animal Behaviour, Macquarie University, Sydney, NSW 2109, Australia. Phone: 61-2-98509232. Fax: 61-2-98509231. Email: [email protected] 1 Abstract Jumping spiders (Salticidae) are known for their elaborate vision-based display behaviour, and a sizeable minority of the species in this large family resemble ants. The display repertoire of two ant-like salticid species from the Philippines is investigated. Myrmarachne assimilis is a specialist ant mimic, closely matching the appearance of the weaver ant Oecophylla smaragdina. Myrmarachne bakeri is a generalist mimic, which, although ant-like, is not a close match to any sympatric ant species. Myrmarachne are sexually dimorphic, with males having enlarged chelicerae. The copulatory posture of Myrmarachne is unique among salticids, apparently as an adjustment for the male’s elongated chelicerae. Details concerning the intraspecific behaviour of Myrmarachne appear to be adjustments to living in environments populated by numerous other animals with similar appearance (ants). However, the specialist and the generalist that were investigated have display repertoires that are broadly similar to each other and to those of more typical salticids. Generally, the display behaviour of Myrmarachne appears not to have necessitated dramatic deviation from typical salticid display and mating strategies. Keywords: Arachnida, Batesian mimicry, communication, conditional mating strategy, jumping spider, mating behaviour, Salticidae, signals. Correspondence: Ximena Nelson, Centre for the Integrative Study of Animal Behaviour, Macquarie University, Sydney, NSW 2109, Australia. Phone: 61-2-98509232. Fax: 61-2-98509231. Email: [email protected] 2 Introduction Animal display behaviour (i.e. the use of signals that have been evolutionarily modified in a manner that enhances their capacity to convey information; Smith 1977) raises questions not only about strategic design, or function, but also about tactical design (Ord et al. 2002; Hebets and Papaj 2005), where ‘tactical design’ refers to ways in which signal structure facilitates information transfer. Tactical design, in turn, raises questions about how ‘receiver psychology’ (Guilford and Dawkins 1991; Fleishman 1992; Hauglund et al. 2006) and prevailing habitat conditions (Endler 1992; Persons et al. 1999; Leal and Fleishman 2004) might affect signal transmission. Here a special habitat condition is considered that might especially matter to a subset of Batesian mimics that rely on vision-based signals for intraspecific communication. Batesian mimics gain protection from potential predators by resembling unpalatable or dangerous model organisms, misinforming predators by providing signals normally associated with the model (Wickler 1968; Edmunds 1974). For a Batesian mimic that relies on vision for intraspecific communication, part of its habitat is the population of similar-looking model organisms, but little is known about how the mimic’s own resemblance to these other organisms might challenge the mimic’s discrimination abilities when there is a need to interact with potential mates and conspecific rivals. The problem of reliable discrimination between conspecific mimics and models might be greater for a specialist than for a generalist Batesian mimic (see Edmunds 2000, 2006), with the terms ‘specialist’ and ‘generalist’ specifying whether or not the mimic closely resembles any one particular model species. The present paper is a step toward investigating this hypothesis by examining a pair of closely related mimic species from a system in which the models are ants and the mimics are ant-like jumping spiders (Salticidae) that rely strongly on vision-based communication. Most spiders have eyes lacking the structural complexity required for acute vision (Homann 1971; Land 1985), but salticids have a pair of distinctively large forward-facing anterior-medial eyes that support exceptional spatial acuity (Land 1969a,b; Williams and McIntyre 1980; Blest et al. 1990, Harland and Jackson 2004). Not surprisingly, the most elaborate vision-based display behaviour known for spiders (Foelix 1996), and among the most elaborate ever described for any animal group, is found in this family (Jackson 1982a; Jackson and Pollard 1997). 3 Myrmecomorphic species (i.e. species that are ant-like in appearance) are a sizeable minority in the family Salticidae, with the genus Myrmarachne being especially notable (Wanless 1978). With more than 200 described species (Proszynski 2006; Platnick 2007), all of which are myrmecomorphic, Myrmarachne is the largest salticid genus and there is extensive evidence that myrmecomorphy in Myrmarachne functions as Batesian mimicry (Edmunds 1974; Jackson and Willey 1995). Ants are dangerous and unpalatable prey-size organisms (Blum 1981; Hölldobler and Wilson 1990) and a variety of would-be predators of salticids, including other salticids and mantises, avoid making predatory attacks on, or coming close to, ants (Nelson et al. 2006). Experimental studies have also shown that salticids and mantises that are averse to attacking ants are averse to attacking Myrmarachne (Harland and Jackson 2001; Nelson et al. 2004; also see Cutler 1991; Edmunds 1993). The resemblance of Myrmarachne species to ants comes from having slender legs, a narrow, elongated body constricted at the abdomen and cephalothorax to create the illusion of a three- segmented body, and an erratic, ant-like manner of moving (Cushing 1997; Edmunds 2006). The front legs, held raised and waving, or else tapping the substrate, resemble ant antennae. Contrary to its family namesake, Myrmarachne rarely jumps, doing so only when severely threatened. All Myrmarachne species are sexually dimorphic (Wanless 1978), with males having greatly enlarged chelicerae that increase their total body length by 50-70%. However, oversized chelicerae remain compatible with ant mimicry because predators appear to mistake the Myrmarachne males, with their long chelicerae, for ant workers that are carrying objects in their mandibles (Nelson and Jackson 2006). Understandably, research on Myrmarachne has been dominated by interest in the benefit these salticids gain from deceiving would-be predators. Despite the extensive literature on the intraspecific communication of salticids, little attention has been paid to myrmecomorphic species. The early literature characterized salticid display behaviour as stereotypic and reflex-like (Crane 1949; Drees 1952), but later work has largely supplanted this portrayal with an emphasis on how salticid intraspecific interactions tend to be highly variable and complex (Jackson 1982a; Jackson and Pollard 1997). The early literature also emphasized the role of vision almost to the exclusion of other sensory modalities, but there are now numerous studies illustrating that salticids make extensive use of acoustic, percussion, silk-borne, tactile and chemical signalling during intraspecific 4 interactions (Edwards 1981; Gwynne and Dadour 1985; Jackson 1987; Pollard et al. 1987; Maddison and Stratton 1988; Noordam 2002; Elias et al. 2003, 2005). ‘Courtship’ may be defined as intersexual communicatory behaviour that forms the normal preliminaries to mating (Jackson 1982a). Crane’s (1949) conclusion that visual stimuli are both necessary and sufficient for releasing salticid courtship may have been compatible with commonsense expectations about adaptive tradeoffs in small animals, yet there is no clear evidence that the exceptional eyesight of salticids has adversely affected the ability of salticids to rely on other sensory modalities, with the prevalence of courtship versatility (Jackson and Pollard 1997) being an especially striking illustration of how exceptional eyesight does not preclude using other sensory modalities in disparate communication routines. First documented in detail (Jackson 1977) for a North American species, Phidippus johnsoni (Peckham and Peckham 1883), courtship versatility is a conditional mating strategy in which males use three distinct tactics conditional on the female’s location and state of maturity. Males use vision-based displays when they encounter mature females outside nests (type 1 courtship), they use silk-borne signals when they encounter adult females inside nests (type 2 courtship), and they make a second chamber fastened to subadult females’ nests where they wait until the subadult female matures (cohabitation: see Jackson 1986a). Vision may be necessary and sufficient for eliciting the type 1 courtship of most, but not all salticids (see Elias et al. 2005). However, salticids readily communicate with type 2 courtship and mate inside their nests in total darkness. Comments in the early literature might suggest that courtship versatility is also prevalent in myrmecomorphic salticids. For example, there are reports of Myrmarachne plataleoides (OP- Cambridge 1869), M. foenisex Simon 1909 and M. legon Wanless 1978 mating in nests, and of the males of the first two of these species cohabiting with subadult females (Mathew 1940; Collart 1941; Edmunds 1978). However, detailed documentation of the display behaviour of only one Myrmarachne
Load more

Recommended publications
  • A Novel Trade-Off for Batesian Mimics Running Title
    Out of the frying pan and into the fire: A novel trade-off for Batesian mimics Running title: Salticids that mimic ants and get eaten by ant specialists Ximena J. Nelson*†, Daiqin Li§ and Robert R. Jackson† *Department of Psychology, Animal Behaviour Laboratory, Macquarie University, Sydney, NSW 2109, Australia Email: [email protected] Phone: 61-2-98509232 Fax: 61-2-98509231 §Department of Biological Sciences, National University of Singapore, Singapore †School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand Key words: Ants, Batesian mimicry, myrmecophagy, predation, spiders, trade-off Abstract A mimicry system was investigated in which the models were ants (Formicidae) and both the mimics and the predators were jumping spiders (Salticidae). By using motionless lures in simultaneous-presentation prey-choice tests, how the predators respond specifically to the static appearance of ants and ant mimics was determined. These findings suggest a rarely considered adaptive trade-off for Batesian mimics of ants. Mimicry may be advantageous when it deceives ant-averse potential predators, but disadvantageous in encounters with ant- eating specialists. Nine myrmecophagic (ant-eating) species (from Africa, Asia, Australia and North America) and one araneophagic (spider-eating) species (Portia fimbriata from Queensland) were tested with ants (5 species), with myrmecomorphic (ant-like) salticids (6 species of Myrmarachne) and with non-ant-like prey (dipterans and ordinary salticids). The araneophagic salticid chose an ordinary salticid and chose flies significantly more often than ants. P. fimbriata also chose the ordinary salticid and chose flies significantly more often than myrmecomorphic salticids. However, there was no significant difference in how P.
    [Show full text]
  • Arachnids (Excluding Acarina and Pseudoscorpionida) of the Wichita Mountains Wildlife Refuge, Oklahoma
    OCCASIONAL PAPERS THE MUSEUM TEXAS TECH UNIVERSITY NUMBER 67 5 SEPTEMBER 1980 ARACHNIDS (EXCLUDING ACARINA AND PSEUDOSCORPIONIDA) OF THE WICHITA MOUNTAINS WILDLIFE REFUGE, OKLAHOMA JAMES C. COKENDOLPHER AND FRANK D. BRYCE The Wichita Mountains are located in eastern Greer, southern Kiowa, and northwestern Comanche counties in Oklahoma. Since their formation more than 300 million years ago, these rugged mountains have been fragmented and weathered, until today the highest peak (Mount Pinchot) stands only 756 meters above sea level (Tyler, 1977). The mountains are composed predominantly of granite and gabbro. Forests of oak, elm, and walnut border most waterways, while at elevations from 153 to 427 meters prair­ ies are the predominant vegetation type. A more detailed sum­ mary of the climatic and biotic features of the Wichitas has been presented by Blair and Hubbell (1938). A large tract of land in the eastern range of the Wichita Moun­ tains (now northeastern Comanche County) was set aside as the Wichita National Forest by President McKinley during 1901. In 1905, President Theodore Roosevelt created a game preserve on those lands managed by the Forest Service. Since 1935, this pre­ serve has been known as the Wichita Mountains Wildlife Refuge. Numerous papers on Oklahoma spiders have been published (Bailey and Chada, 1968; Bailey et al., 1968; Banks et al, 1932; Branson, 1958, 1959, 1966, 1968; Branson and Drew, 1972; Gro- thaus, 1968; Harrel, 1962, 1965; Horner, 1975; Rogers and Horner, 1977), but only a single, comprehensive work (Banks et al., 1932) exists covering all arachnid orders in the state. Further additions and annotations to the arachnid fauna of Oklahoma can be found 2 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY in recent revisionary studies.
    [Show full text]
  • Sexual Selection Research on Spiders: Progress and Biases
    Biol. Rev. (2005), 80, pp. 363–385. f Cambridge Philosophical Society 363 doi:10.1017/S1464793104006700 Printed in the United Kingdom Sexual selection research on spiders: progress and biases Bernhard A. Huber* Zoological Research Institute and Museum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany (Received 7 June 2004; revised 25 November 2004; accepted 29 November 2004) ABSTRACT The renaissance of interest in sexual selection during the last decades has fuelled an extraordinary increase of scientific papers on the subject in spiders. Research has focused both on the process of sexual selection itself, for example on the signals and various modalities involved, and on the patterns, that is the outcome of mate choice and competition depending on certain parameters. Sexual selection has most clearly been demonstrated in cases involving visual and acoustical signals but most spiders are myopic and mute, relying rather on vibrations, chemical and tactile stimuli. This review argues that research has been biased towards modalities that are relatively easily accessible to the human observer. Circumstantial and comparative evidence indicates that sexual selection working via substrate-borne vibrations and tactile as well as chemical stimuli may be common and widespread in spiders. Pattern-oriented research has focused on several phenomena for which spiders offer excellent model objects, like sexual size dimorphism, nuptial feeding, sexual cannibalism, and sperm competition. The accumulating evidence argues for a highly complex set of explanations for seemingly uniform patterns like size dimorphism and sexual cannibalism. Sexual selection appears involved as well as natural selection and mechanisms that are adaptive in other contexts only. Sperm competition has resulted in a plethora of morpho- logical and behavioural adaptations, and simplistic models like those linking reproductive morphology with behaviour and sperm priority patterns in a straightforward way are being replaced by complex models involving an array of parameters.
    [Show full text]
  • 2017 AAS Abstracts
    2017 AAS Abstracts The American Arachnological Society 41st Annual Meeting July 24-28, 2017 Quéretaro, Juriquilla Fernando Álvarez Padilla Meeting Abstracts ( * denotes participation in student competition) Abstracts of keynote speakers are listed first in order of presentation, followed by other abstracts in alphabetical order by first author. Underlined indicates presenting author, *indicates presentation in student competition. Only students with an * are in the competition. MAPPING THE VARIATION IN SPIDER BODY COLOURATION FROM AN INSECT PERSPECTIVE Ajuria-Ibarra, H. 1 Tapia-McClung, H. 2 & D. Rao 1 1. INBIOTECA, Universidad Veracruzana, Xalapa, Veracruz, México. 2. Laboratorio Nacional de Informática Avanzada, A.C., Xalapa, Veracruz, México. Colour variation is frequently observed in orb web spiders. Such variation can impact fitness by affecting the way spiders are perceived by relevant observers such as prey (i.e. by resembling flower signals as visual lures) and predators (i.e. by disrupting search image formation). Verrucosa arenata is an orb-weaving spider that presents colour variation in a conspicuous triangular pattern on the dorsal part of the abdomen. This pattern has predominantly white or yellow colouration, but also reflects light in the UV part of the spectrum. We quantified colour variation in V. arenata from images obtained using a full spectrum digital camera. We obtained cone catch quanta and calculated chromatic and achromatic contrasts for the visual systems of Drosophila melanogaster and Apis mellifera. Cluster analyses of the colours of the triangular patch resulted in the formation of six and three statistically different groups in the colour space of D. melanogaster and A. mellifera, respectively. Thus, no continuous colour variation was found.
    [Show full text]
  • SPIDERS of WASHINGTON COUNTY, MISSISSIPPI Orrey P. Young Southern Field Crop Insect Management Laboratory USDA-ARS, P.O. Box
    Young, O . P., T. C . Lockley and G . B . Edwards . 1989 . Spiders of Washington County, Mississippi . J . Arachnol ., 17 :27-41 . SPIDERS OF WASHINGTON COUNTY, MISSISSIPPI Orrey P. Young Southern Field Crop Insect Management Laboratory USDA-ARS, P.O. Box 346 Stoneville, Mississippi 38776 USA Timothy C. Lockley Imported Fire Ant Station USDA-APHIS-PPQ 3505 25th Avenue Gulfport, Mississippi 39501 USA and G. B. Edwards Florida State Collection of Arthropods Division of Plant Industry Florida Dept. Agric. & Cons . Serv. P.O. Box 1269 Gainesville, Florida 32602 USA ABSTRACT Over a seven-year period, approximately 35,000 spiders representing 26 families, 133 genera, and 234 species were captured in Washington County, Mississippi, by pitfall, sweepnet, vacuum, bag, and hand. Specimens were collected in 10 different habitat types and in four vegetational strata . Old-field habitats yielded the most species (152) and residential lawns the fewest (14) . Considering all habitats sampled, the ground layer produced 111 species, the herbaceous strata 133, the shrub layer 49, and the tree strata 30 species . The sweepnet method of capture obtained 128 species, pitfall 95, hand 61, vacuum 53, and bagging 19 species. The largest number of species were obtained in spring and early summer (maximum of 125 in May), with the fewest in mid-winter (Jan . = 24) . Twenty-one species were considered abundant, 51 common, 67 uncommon, and 95 rare . Additions to the state list of Dorris (1972) number 102 species, for a new state total of 364 species . A comparison with the North American fauna and with other surveys indicates that Washington County is underrepresented both in cursorial forms active on the soil surface and web-spinning forms typical of undisturbed habitats .
    [Show full text]
  • CA-Dec12-Doc.6.2.A
    CA-Dec12-Doc.6.2.a - Final PRODUCT TYPE 18 – INSECTICIDES, ACARICIDES AND PRODUCTS TO CONTROL OTHER ARTHROPODS and PRODUCT TYPE 19 – REPELLENTS AND ATTRACTANTS (only concerning arthropods) Guidance to replace part of Appendices to chapter 7 (page 187 to 200) from TNsG on Product Evaluation Reader ................................................................................................................................... 5 1 GENERAL INTRODUCTION .............................................................................................. 5 1.1 Aim ........................................................................................................................... 5 1.2 Global structure of the assessment .......................................................................... 5 1.3 Dossier requirements ............................................................................................... 5 1.3.1 Test design ....................................................................................................... 6 1.3.2 Test examples ................................................................................................... 7 1.3.3 Laboratory versus (semi) field trials ................................................................... 7 1.3.4 The importance of controls on efficacy studies .................................................. 7 1.3.5 Specific data to support label claims ................................................................. 8 1.3.6 Examples of specific label claims with respect to target
    [Show full text]
  • Does Argentine Ant Invasion Conserve Colouring Variation of Myrmecomorphic Jumping Spider?
    Open Journal of Animal Sciences, 2014, 4, 144-151 Published Online June 2014 in SciRes. http://www.scirp.org/journal/ojas http://dx.doi.org/10.4236/ojas.2014.43019 Argentine Ant Affects Ant-Mimetic Arthropods: Does Argentine Ant Invasion Conserve Colouring Variation of Myrmecomorphic Jumping Spider? Yoshifumi Touyama1, Fuminori Ito2 1Niho, Minami-ku, Hiroshima City, Japan 2Laboratory of Entomology, Faculty of Agriculture, Kagawa University, Ikenobe, Japan Email: [email protected] Received 23 April 2014; revised 3 June 2014; accepted 22 June 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Argentine ant invasion changed colour-polymorphic composition of ant-mimetic jumping spider Myrmarachne in southwestern Japan. In Argentine ant-free sites, most of Myrmarachne exhibited all-blackish colouration. In Argentine ant-infested sites, on the other hand, blackish morph de- creased, and bicoloured (i.e. partly bright-coloured) morphs increased in dominance. Invasive Argentine ant drives away native blackish ants. Disappearance of blackish model ants supposedly led to malfunction of Batesian mimicry of Myrmarachne. Keywords Batesian Mimicry, Biological Invasion, Linepithema humile, Myrmecomorphy, Myrmarachne, Polymorphism 1. Introduction It has attracted attention of biologists that many arthropods morphologically and/or behaviorally resemble ants [1]-[4]. Resemblance of non-ant arthropods to aggressive and/or unpalatable ants is called myrmecomorphy (ant-mimicry). Especially, spider myrmecomorphy has been described through many literatures [5]-[9]. Myr- mecomorphy is considered to be an example of Batesian mimicry gaining protection from predators.
    [Show full text]
  • Prey of the Jumping Spider Phidippus Johnsoni (Araneae : Salticidae)
    Jackson, R. R . 1977 . Prey of the jumping spider Phidippus johnsoni (Araneae : Salticidae) . J. Arachnol. 5 :145-149 . PREY OF THE JUMPING SPIDER PHIDIPPUS JOHNSONI (ARANEAE : SALTICIDAE) Robert R. Jackson I Zoology Departmen t University of Californi a Berkeley, California 9472 0 ABSTRACT Field data indicate that P. johnsoni is an euryphagous predator, whose diet includes organisms (aphids, ants, opilionids) sometimes considered distasteful to spiders . Other spiders are preyed upon , including conspecifics. Prey size tends to be one quarter to three quarters the size of the predator . INTRODUCTION Since spiders are probably a dominant group of predators of insects (Bristowe, 1941 ; Riechert, 1974; Turnbull, 1973), there is considerable interest in their feeding ecology . Spiders have usually been considered to be euryphagous predators with a stabilizing , rather than regulative, effect on insect populations (Riechert, 1974) . However, informa- tion concerning the prey taken by particular spider species, in the field, is limited . Field studies by Edgar (1969, 1970), Robinson and Robinson (1970) and Turnbull (1960) are especially noteworthy . During the course of a study of the reproductive biology of Phidippus johnsoni (Peckham and Peckham) (Jackson, 1976), occasionally individuals of this species were found in the field holding prey in their chelicerae . Each prey discovered in this way i s listed in Table 1 . In addition, Ken Evans and Charles Griswold, who were familiar wit h this species, recorded observations of P. johnsoni with prey. (Their data are included in Table 1 .) These data came from a variety of habitats in western North America, most o f which have been described elsewhere (Jackson, 1976) .
    [Show full text]
  • Visual Perception in Jumping Spiders (Araneae,Salticidae)
    Visual Perception in Jumping Spiders (Araneae,Salticidae) A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy in Biology at the University of Canterbury by Yinnon Dolev University of Canterbury 2016 Table of Contents Abstract.............................................................................................................................................................................. i Acknowledgments .......................................................................................................................................................... iii Preface ............................................................................................................................................................................. vi Chapter 1: Introduction ................................................................................................................................................... 1 Chapter 2: Innate pattern recognition and categorisation in a jumping Spider ........................................................... 9 Abstract ....................................................................................................................................................................... 10 Introduction ................................................................................................................................................................ 11 Methods .....................................................................................................................................................................
    [Show full text]
  • Ants and Their Relation to Aphids Charles Richardson Jones Iowa State College
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1927 Ants and their relation to aphids Charles Richardson Jones Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Entomology Commons Recommended Citation Jones, Charles Richardson, "Ants and their relation to aphids" (1927). Retrospective Theses and Dissertations. 14778. https://lib.dr.iastate.edu/rtd/14778 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps.
    [Show full text]
  • Somerset's Ecological Network
    Somerset’s Ecological Network Mapping the components of the ecological network in Somerset 2015 Report This report was produced by Michele Bowe, Eleanor Higginson, Jake Chant and Michelle Osbourn of Somerset Wildlife Trust, and Larry Burrows of Somerset County Council, with the support of Dr Kevin Watts of Forest Research. The BEETLE least-cost network model used to produce Somerset’s Ecological Network was developed by Forest Research (Watts et al, 2010). GIS data and mapping was produced with the support of Somerset Environmental Records Centre and First Ecology Somerset Wildlife Trust 34 Wellington Road Taunton TA1 5AW 01823 652 400 Email: [email protected] somersetwildlife.org Front Cover: Broadleaved woodland ecological network in East Mendip Contents 1. Introduction .................................................................................................................... 1 2. Policy and Legislative Background to Ecological Networks ............................................ 3 Introduction ............................................................................................................... 3 Government White Paper on the Natural Environment .............................................. 3 National Planning Policy Framework ......................................................................... 3 The Habitats and Birds Directives ............................................................................. 4 The Conservation of Habitats and Species Regulations 2010 ..................................
    [Show full text]
  • The Jumping Spiders (Araneae: Salticidae) of the Virginia Peninsula1
    Vol. 98, No. 5, November & December 1987 235 THE JUMPING SPIDERS (ARANEAE: SALTICIDAE) OF THE VIRGINIA PENINSULA 1 2 C.L. Stietenroth, N.V. Horner ABSTRACT: Thirty species representing 1 8 genera of Salticidae are recorded from the Virginia Peninsula. Habitat and natural history information for each species is presented. Some salticids on the peninsula occupy diverse habitats while other species appear to confine themselves to more restricted environments. The most abundant salticid was Hentzia palmarum. Metaphi- dippus galathea and Platycryptus undatus were most widely distributed species. Salticids reported in Virginia for the first time are Phidippus princeps, P. otiosus, Thiodina sylvana, Sitticus fasciger and Zygoballus sexpunctatus. A few studies concerning the spider fauna of Virginia have been published. The earliest record of occurrence was by John Banister between 1678 and 1692 (Ewan and Ewan, 1970). More recently, McCaffrey and Hornsburgh published three studies concerning spiders in apple orchards in central Virginia. Their assessment of spider populations in an unsprayed orchard was published in 1 1 977 followed ( 978) by laboratory feeding studies performed to evaluate potential effects of predaceous spiders on insect residents of apple orchards. Later (1980), a comparison was made between the spider populations in abandoned and commercial orchards; 68 species were identified. Dowd and Kok (1981), and McPherson el al. (1982) considered spider and other arthropod predation on the curculionid beetle, Rhynocyllus sp., in a in 1 soybean cropping system Virginia. Holsinger ( 982) reported on the spider cave-fauna in Burnsville Cove. The efficiency of limb-beating for capturing various spider families in apple orchards is discussed by McCaffrey and Parrella(1984).
    [Show full text]