DOCSLIB.ORG

Sex- and Season-Dependent Behaviour in a Flightless Insect, the Auckland Tree Weta (Hemideina Thoracica)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Sex- and Season-Dependent Behaviour in a Flightless Insect, the Auckland Tree Weta (Hemideina Thoracica) AvailableWehi et al.: on-line Seasonal at: http://www.newzealandecology.org/nzje/ behaviour patterns in weta 75 Sex- and season-dependent behaviour in a flightless insect, the Auckland tree weta (Hemideina thoracica) Priscilla M Wehi1,4*, Murray Jorgensen2 and Mary Morgan-Richards3 1Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand 2Department of Statistics, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand 3Institute of Natural Resources, Massey University, Private Bag 11222, Palmerston North, New Zealand 4Present address: CSAFE, University of Otago, P O Box 56, Dunedin, New Zealand *Author for correspondence (Email: [email protected]) Published online: 17 December 2012 Abstract: In a polygynous mating system, males frequently compete by locating and defending sites with resources essential to female survival and reproduction. We investigated seasonal changes in site occupancy in a sexually dimorphic, harem-forming insect, the Auckland tree weta (Hemideina thoracica). First we established artificial cavities as diurnal refuge cavities and potential harem guarding sites. We then examined cavity occupancy changes, and, based on our knowledge of prior occupants, determined sex-specific patterns of arrival, departure, and aggregation at a population level throughout the year. Both season and the sex of prior occupants influenced weta occupancy patterns. Most observations were of single females. However, both males and females moved into cavities previously occupied by a weta of the opposite sex more often than expected by chance alone. Females avoided cavities where other females were present, except during summer when most harems formed. In early summer, male and female tree weta previously living apart began co-habiting. Generally there was little relationship between the number and sex of the weta inside cavities and female departure rates from cavities. Males who were sharing with other males departed cavities more frequently than single males, as might be expected in a polygynous species with male–male combat. Males were less likely to depart if they were sharing a cavity with a harem of more than two females during the summer–autumn period. Analysis of departure rates from artificial cavities indicates males are more mobile than females only in winter and spring. Based on our arrival and departure data, and high occupancy of artificial cavities, we suggest that female weta at this site are mobile and may search for mates during the summer. The data are consistent with a polygynandrous mating system as inferred for other tree weta species (Hemideina spp.). Keywords: aggregation; harem; mating system; Orthoptera; polygyny Introduction Resource variation can lead to plasticity in mating systems so that, for example, mating system can vary within a species Searching for mates can be costly (Gwynne 1987; Acharya if resource availability varies spatially or temporally (Emlen 1995), but nonetheless is a requirement for most sexually & Oring 1977; Gwynne 1991). Seasonal effects can result reproducing organisms (Kokko & Wong 2007). Search effort in if resources vary throughout the year. Thus, for example, if one sex is dependent on search effort in the other (Hammerstein density is high, polygynous mating systems that have large & Parker 1987), but because males may benefit more from numbers of sneakers (or satellites), as well as residents, can multiple mating than females (Bateman 1948) males are favour mobile males (Reichard et al. 2004). Differences in generally predicted to mate-search more than females when aggregation and occupancy patterns between the sexes can multiple mating is common and sperm competition occurs thus occur both spatially and temporally as a consequence (Kokko & Wong 2007). However, males may attempt to of both sex-specific searching patterns and mating system monopolise resources, including females, if doing so increases (Lehmann & Perrin 2003). Nonetheless, data that report reproductive success. seasonal changes in sex-specific searching and aggregation In a polygynous mating system, males compete directly behaviour are predominantly from well-studied, large diurnal for access to females through male–male combat (cf. Darwin species. Data are still lacking for many taxa, and particularly 1874) or indirectly by locating and defending sites with for many insects. resources essential to female survival and reproduction (Emlen In many Orthopterans, males call, using stridulatory & Oring 1977; Shuster & Wade 2003; Kelly 2006a). If male ridges on their limbs or wings, and females search for mates, guarding of a limited resource (such as females, or refuge with females benefiting from male nuptial gifts such as cavities) increases reproductive success, then males might be spermatophores. However, sexually dimorphic New Zealand sedentary, and if females gain by enhancing their encounter tree weta (Hemideina spp., Anostostomatidae) have small rate with potential mates, they might be more mobile than spermatophores compared with other Orthoptera (Gwynne otherwise expected. The ability of individuals to monopolise 1995; Stringer 2001), and both males and females have matings will in turn influence the intensity of sexual selection stridulatory ridges. In six of the seven tree weta species, (Trivers 1972), particularly in polygynous species where mating males have enlarged mandibles used in male–male combat effort, and the opportunity for sexual selection for males, is (McIntyre 2001), and females form aggregations, or harems, high (Bateman 1948; Trivers 1985). in cavities used as day-time refugia (Field & Sandlant 2001). New Zealand Journal of Ecology (2013) 37(1): 75-83 © New Zealand Ecological Society. 76 New Zealand Journal of Ecology, Vol. 37, No. 1, 2013 These characteristics suggest that tree weta movement patterns tree saplings less than 2 m high. Predation pressure from associated with mating may not be typical of Orthopterans as introduced mammals and native owls was low (Morgan et al. a whole. If male guarding of a limited resource (e.g. females) 2009; PMW unpubl. data). Human disturbance was generally increases reproductive success, then males might be sedentary, low at night, when tree weta are active. Daytime disturbance, and if females gain by enhancing their encounter rate with however, was greater, with paths through the forest fragment potential mates, they might be more mobile than otherwise well used by members of the public. expected. However, there are few data on the formation or duration of aggregations, and of female harems that males Observations of movement patterns appear to defend (Field & Jarman 2001; Kelly 2006b). Recent research has highlighted potential negative effects of Tree weta are large-bodied (adults generally 3–6 g), tagging of study animals (e.g. Davis & Ovaska 2001; Boiteau flightless and nocturnal Orthopterans that seek refuge in tree et al. 2009; Barron et al. 2010; Saraux et al. 2011).Two trials cavities diurnally (Gibbs 1998). Eggs hatch in spring, and a to determine whether tagging might be a useful tool for this minimum of eight instars is required to reach adulthood in these study raised questions about the effects of tagging on tree weta hemimetabolous insects. Adults are long lived (adult lifespan movement. A majority of tree weta (93.4%; total n = 30) did not 9 months to 3 years; Leisnham et al. 2003). Because tree weta return to cavities after pronotum tagging with either bee tags or are nocturnal and their behaviour is difficult to observe directly, paper tags, and were not seen again either in these cavities or artificial cavities have proven useful to study tree weta ecology elsewhere, despite data suggesting that Hemideina thoracica and behaviour (e.g. Trewick & Morgan-Richards 1995). and H. crassidens individuals most likely have high site fidelity Hypotheses about the genus have developed in large part from (Spurr & Berben 2004; PMW unpubl. data). Given this result, work on Hemideina crassidens Blanchard 1851 (e.g. Moller and the results from a previous tagging study (Ordish 1992), 1985; Kelly 2006a, b) and Hemideina maori Pictet & Saussure we minimised disruption by recording data from unmarked 1891 (e.g. Jamieson et al. 2000; Leisnham & Jamieson 2002; individuals; individual tracking is not essential to understand Leisnham et al. 2003). In contrast, little is known of Auckland occupancy and movement patterns at the population level. tree weta (Hemideina thoracica White 1846) ecology despite its extensive distribution throughout much of the North Island, Refuge design and monitoring New Zealand. Field studies of Hemideina crassidens indicate Forty artificial refuges, consisting of two cavities each, were that females apparently prefer unoccupied cavities, males constructed from aged Podocarpus totara (tōtara) timbers defend females not cavities, and males are more transient and attached to 20 randomly selected, mature Dacrycarpus than females (Kelly 2006c). Nonetheless, most of these field dacrydioides trees (Fig. 1). Refuges were attached vertically studies were undertaken in weta populations where more refuge at 2.5 m and their direction randomised on each tree. Refuge cavities were empty than were occupied, in young forest (less design was generally similar to that suggested in Trewick & than 30 years old), and with observations undertaken during Morgan-Richards (2000) and Spurr & Berben (2004), but on a the late summer and autumn only. We investigated occupancy patterns
Load more

Recommended publications
  • Shifting Ranges of Two Tree Weta Species (Hemideina Spp.)
    Journal of Biogeography (J. Biogeogr.) (2014) 41, 524–535 ORIGINAL Shifting ranges of two tree weta species ARTICLE (Hemideina spp.): competitive exclusion and changing climate Mariana Bulgarella*, Steven A. Trewick, Niki A. Minards, Melissa J. Jacobson and Mary Morgan-Richards Ecology Group, IAE, Massey University, ABSTRACT Palmerston North, 4442, New Zealand Aim Species’ responses to climate change are likely to depend on their ability to overcome abiotic constraints as well as on the suite of species with which they interact. Responses to past climate change leave genetic signatures of range expansions and shifts, allowing inferences to be made about species’ distribu- tions in the past, which can improve our ability to predict the future. We tested a hypothesis of ongoing range shifting associated with climate change and involving interactions of two species inferred to exclude each other via competition. Location New Zealand. Methods The distributions of two tree weta species (Hemideina crassidens and H. thoracica) were mapped using locality records. We inferred the likely mod- ern distribution of each species in the absence of congeneric competitors with the software Maxent. Range interaction between the two species on an eleva- tional gradient was quantified by transect sampling. Patterns of genetic diver- sity were investigated using mitochondrial DNA, and hypotheses of range shifts were tested with population genetic metrics. Results The realized ranges of H. thoracica and H. crassidens were narrower than their potential ranges, probably due to competitive interactions. Upper and lower elevational limits on Mount Taranaki over 15 years revealed expan- sion up the mountain for H. thoracica and a matching contraction of the low elevation limits of the range of H.
    [Show full text]
  • Flawke's Bay Twits $ At\; Is T *:';;Q*E Kit *: Hawkt:Bad \, Nth U Line Uniat! of Species, Habitats Grid Natural Lectures
    , , ,,,..*. *'.~,*, . , ** **~ I*~ tv, *..',.- 4'1 I, ' it**.*, , , *. * 44 ,,! ~**~ $1. \ -* * .,,;. f, *- , **, 3* .* ,J re* *. ^ ,~ I * ,* ,, ^ "*'. 441 , ,*.A, * ~*\,*t* J The open braids of the Totaekuri River Flawke's Bay twits $ at\; is t *:';;q*e Kit *: hawkt:bad \, nth u line uniat! of species, habitats Grid natural lectures. Hawke's Bay is a special part of New Zealand with a It, :ae from one threat can be exacerbated by the effects of variety of species, habitats and natural features, other threats acting together, i. e. habitat fragmentation Before humans settled here, almost the entire lowlands combined with invasive species. and hill country of the region would have been covered Despite extensive modification, Hawke's Bay contains a in dense forests, rich in birdlife. Clearance of vegetation great diversity of landscapes, habitats, plants, animals, cover started with early Maori and continued with and areas of high natural and historic value. There the arrival of Fakeba leaving a legacy of almost total are areas in Flawke's Bay which support a diverse and modification of the natural ecosystems. significant range of indigenous species and ecosystems including the Kaweka Ranges, Lake Walkaremoana, Forest dearance, wedand drainage, engineering of Pekapel<a Wetland, Whal{a}d Lagoon, AhuririEstuary, waterways and redamation of coastal margins has Blowhard Bush, Cape Kidnappers Sanctuary and been necessary for the development of our cities and Boundary Stream. Many of these sites are in very good the region. We are able to live safely and prosper in a condition. Several endemic species which at. e nationally beautiful part of the world but development has had a considerable impact on indigenous biodiversity.
    [Show full text]
  • Weta Sometimes 5 Cicada Mouthparts? Earwig 3 Pairs Stick Insect 1 Pair with Fangs and Now Name One Poison Characteristic Each Wings? of the Other 6 Bugs Usually
    Insects To be used with the Tangihua lions lodge program What is an insect All insects ? This insect have these has these Characteristics characteristics 6 legs What do you think? 8 legs More! Just circle the answer Wings Body parts? Or 2 No wings 3 A long thin body Legs? or 6 well developed legs 8 and long feelers More! I am a Eyes? Beetle 6 simple ones Fly 8 simple ones Moth Usually 2 but Giant Weta sometimes 5 Cicada Mouthparts? Earwig 3 pairs Stick insect 1 pair with fangs and Now name one poison characteristic each Wings? of the other 6 bugs Usually Draw a line showing who relates to what What habitats do you find insects in Weta To be used with the Tangihua lions lodge program Animals With out red blood or back bone Red blooded Invertebrates vertebrates Cephalopods Crustaceans Arthropod Plant animals Birds Fish Whales and Reptiles Land Cnidarians dolphins mammals Insects spider Wētā are arthropods and belong to the insect group because they have: 6 legs, 2 antennae, and a 3-part body Weta 5 types Tree Weta Ground Weta Giant Weta Tusked Weta Cave Weta Weta ? two compound eyes for close-up sight have these and three little eyes called ocelli to sense light and dark Antenna short tail-pieces called cerci to detect Femur vibrations Hind leg females have a long ovipositor at the- back to deposit eggs into the soil Front leg an ear on each front leg knee joint Ear palps alongside the jaws for tasting Ovipositor and smelling (like our tongue and nose) Spiracles spikey back legs that kick into the air Palps for defence and make a rasping sound as they come back down.
    [Show full text]
  • Managing Weta Damage to Vines Through an Understanding of Their Food, Habitat Preferences, and the Policy Environment
    Lincoln University Digital Thesis Copyright Statement The digital copy of this thesis is protected by the Copyright Act 1994 (New Zealand). This thesis may be consulted by you, provided you comply with the provisions of the Act and the following conditions of use: you will use the copy only for the purposes of research or private study you will recognise the author's right to be identified as the author of the thesis and due acknowledgement will be made to the author where appropriate you will obtain the author's permission before publishing any material from the thesis. Managing weta damage to vines through an understanding of their food, habitat preferences, and the policy environment A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Applied Science at Lincoln University by Michael John Smith Lincoln University 2014 Abstract of a thesis submitted in partial fulfilment of the requirements for the Degree of Master of Applied Science. Abstract Managing weta damage to vines through an understanding of their food, habitat preferences, and the policy environment by Michael John Smith Insects cause major crop losses in New Zealand horticulture production, through either direct plant damage or by vectoring disease Pugh (2013). As a result, they are one of the greatest risks to NZ producing high quality horticulture crops (Gurnsey et al. 2005). The main method employed to reduce pest damage in NZ horticulture crops is the application of synthetic pesticides (Gurnsey et al. 2005). However, there are a number of negative consequences associated with pesticide use, including non–target animal death (Casida & Quistad 1998) and customer dissatisfaction.
    [Show full text]
  • The Development and Investigation of an Audio Lure for Improved Possum (Trichosurus Vulpecula) Monitoring and Control in New Zealand
    Lincoln University Digital Thesis Copyright Statement The digital copy of this thesis is protected by the Copyright Act 1994 (New Zealand). This thesis may be consulted by you, provided you comply with the provisions of the Act and the following conditions of use: you will use the copy only for the purposes of research or private study you will recognise the author's right to be identified as the author of the thesis and due acknowledgement will be made to the author where appropriate you will obtain the author's permission before publishing any material from the thesis. The Possum Pied Piper: the development and investigation of an audio lure for improved possum (Trichosurus vulpecula) monitoring and control in New Zealand A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University by Matthew J. Kavermann Lincoln University 2013 ii iii Declaration Some aspects of this thesis have been published or accepted for publication (copies of the published and submitted papers are attached at the back of the thesis) or presented at conferences. Publications Kavermann M, Ross J, Paterson A, Eason, C. (in press) Progressing the possum pied piper project. Proceedings of the 25th Vertebrate Pest Conference, Monterey Ca 2012. Dilks P, Shapiro L, Greene T, Kavermann M, Eason CT, Murphy EC (2011). Field evaluation of para- aminopropiophenone (PAPP) for controlling stoats (Mustela erminea) in New Zealand. New Zealand Journal of Zoology 38(2): 143-150 Conference presentations Kavermann M, Ross J, Paterson A, Harper, G. 2012 Assessing the sensitivity of interference based monitoring devices to possum presence.
    [Show full text]
  • Phylogeny of Ensifera (Hexapoda: Orthoptera) Using Three Ribosomal Loci, with Implications for the Evolution of Acoustic Communication
    Molecular Phylogenetics and Evolution 38 (2006) 510–530 www.elsevier.com/locate/ympev Phylogeny of Ensifera (Hexapoda: Orthoptera) using three ribosomal loci, with implications for the evolution of acoustic communication M.C. Jost a,*, K.L. Shaw b a Department of Organismic and Evolutionary Biology, Harvard University, USA b Department of Biology, University of Maryland, College Park, MD, USA Received 9 May 2005; revised 27 September 2005; accepted 4 October 2005 Available online 16 November 2005 Abstract Representatives of the Orthopteran suborder Ensifera (crickets, katydids, and related insects) are well known for acoustic signals pro- duced in the contexts of courtship and mate recognition. We present a phylogenetic estimate of Ensifera for a sample of 51 taxonomically diverse exemplars, using sequences from 18S, 28S, and 16S rRNA. The results support a monophyletic Ensifera, monophyly of most ensiferan families, and the superfamily Gryllacridoidea which would include Stenopelmatidae, Anostostomatidae, Gryllacrididae, and Lezina. Schizodactylidae was recovered as the sister lineage to Grylloidea, and both Rhaphidophoridae and Tettigoniidae were found to be more closely related to Grylloidea than has been suggested by prior studies. The ambidextrously stridulating haglid Cyphoderris was found to be basal (or sister) to a clade that contains both Grylloidea and Tettigoniidae. Tree comparison tests with the concatenated molecular data found our phylogeny to be significantly better at explaining our data than three recent phylogenetic hypotheses based on morphological characters. A high degree of conflict exists between the molecular and morphological data, possibly indicating that much homoplasy is present in Ensifera, particularly in acoustic structures. In contrast to prior evolutionary hypotheses based on most parsi- monious ancestral state reconstructions, we propose that tegminal stridulation and tibial tympana are ancestral to Ensifera and were lost multiple times, especially within the Gryllidae.
    [Show full text]
  • ARTHROPODA Subphylum Hexapoda Protura, Springtails, Diplura, and Insects
    NINE Phylum ARTHROPODA SUBPHYLUM HEXAPODA Protura, springtails, Diplura, and insects ROD P. MACFARLANE, PETER A. MADDISON, IAN G. ANDREW, JOCELYN A. BERRY, PETER M. JOHNS, ROBERT J. B. HOARE, MARIE-CLAUDE LARIVIÈRE, PENELOPE GREENSLADE, ROSA C. HENDERSON, COURTenaY N. SMITHERS, RicarDO L. PALMA, JOHN B. WARD, ROBERT L. C. PILGRIM, DaVID R. TOWNS, IAN McLELLAN, DAVID A. J. TEULON, TERRY R. HITCHINGS, VICTOR F. EASTOP, NICHOLAS A. MARTIN, MURRAY J. FLETCHER, MARLON A. W. STUFKENS, PAMELA J. DALE, Daniel BURCKHARDT, THOMAS R. BUCKLEY, STEVEN A. TREWICK defining feature of the Hexapoda, as the name suggests, is six legs. Also, the body comprises a head, thorax, and abdomen. The number A of abdominal segments varies, however; there are only six in the Collembola (springtails), 9–12 in the Protura, and 10 in the Diplura, whereas in all other hexapods there are strictly 11. Insects are now regarded as comprising only those hexapods with 11 abdominal segments. Whereas crustaceans are the dominant group of arthropods in the sea, hexapods prevail on land, in numbers and biomass. Altogether, the Hexapoda constitutes the most diverse group of animals – the estimated number of described species worldwide is just over 900,000, with the beetles (order Coleoptera) comprising more than a third of these. Today, the Hexapoda is considered to contain four classes – the Insecta, and the Protura, Collembola, and Diplura. The latter three classes were formerly allied with the insect orders Archaeognatha (jumping bristletails) and Thysanura (silverfish) as the insect subclass Apterygota (‘wingless’). The Apterygota is now regarded as an artificial assemblage (Bitsch & Bitsch 2000).
    [Show full text]
  • Mark-Recapture Study of Mountain Stone Weta Hemideina Maori (Orthoptera: Anostostomatidae) on Rock Tor ‘Islands’
    JAMIESON, FORBES, McKNIGHT: SURVIVAL AND MOVEMENT OF WETA 209 SHORT COMMUNICATION Mark-recapture study of mountain stone weta Hemideina maori (Orthoptera: Anostostomatidae) on rock tor ‘islands’ Ian G. Jamieson, Mark R. Forbes1 and E. Brooke McKnight Department of Zoology, University of Otago, PO Box 56, Dunedin, New Zealand (E-mail:[email protected]) 1Department of Biology, 2240 Herzberg Laboratories, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada KlS 5B6 __________________________________________________________________________________________________________________________________ Absract: Mountain stone weta (Hemideina maori) on the Rock and Pillar Range in the South Island, New Zealand, are found primarily in cavities under flat rocks on isolated outcrops or ‘tors’. We marked 66 adult weta on one tor and 30 adults on an adjacent tor and recorded their location during the summer and for the following three years to obtain baseline data on survival, longevity, dispersal, and movement within tors. It was not uncommon for adult weta to live for two to three years. Most marked weta were resighted at least once, usually under the same rock. Few weta moved further than the rock adjacent to where they were first captured and only one dispersed to a neighbouring tor. On one tor, a relatively stable group of 6–8 females and 2 males was resighted during most of the summer period under one large rock. An analysis of our mark-recapture methodology and results indicates that H. maori may be an appropriate species for investigating population structure in a metapopulation context as well as local mate competition. __________________________________________________________________________________________________________________________________ Key words: survival; longevity; dispersal; Stenopelmatidae; New Zealand.
    [Show full text]
  • Hemideina Crassidens
    UNIVERSITÉ DU QUÉBEC À MONTRÉAL LE MAINTIEN DE STRATÉGIES ALTERNATIVES CHEZ LE WELLINGTON TREE WETA (HEM/DE/NA CRASSIDENS): TESTER LES PRÉDICTIONS DE L'HYPOTHÈSE DE POLYMORPHISME GÉNÉTIQUE MÉMOIRE PRÉSENTÉ COMME EXIGENCE PARTIELLE DE LA MAÎTRISE EN BIOLOGIE PAR SARAHNASON JANVIER 2019 UNIVERSITÉ DU QUÉBEC À MONTRÉAL Service des bibliothèques Avertissement La diffusion de ce mémoire se fait dans le respect des droits de son auteur, qui a signé le formulaire Autorisation de reproduire et de diffuser un travail de recherche de cycles supérieurs (SDU-522 - Rév.07-2011). Cette autorisation stipule que «conformément à l'article 11 du Règlement no 8 des études de cycles supérieurs, [l'auteur] concède à l'Université du Québec à Montréal une licence non exclusiye d'utilisation et de publication de la totalité ou d'une partie importante de [son] travail de recherche pour des fins pédagogiques et non commerciales. Plus précisément, [l'auteur] autorise l'Université du Québec à Montréal à reproduire, diffuser, prêter, distribuer ou vendre des copies de [son] travail de recherche à des fins non commerciales sur quelque support que ce soit, y compris l'Internet. Cette licence et cette autorisation n'entraînent pas une renonciation de [la] part [de l'auteur] à [ses] droits moraux ni à [ses] droits de propriété intellectuelle. Sauf entente contraire, [l'auteur] conserve la liberté de diffuser et de commercialiser ou non ce travail dont [il] possède un exemplaire.» UNIVERSITÉ DU QUÉBEC À MONTRÉAL THE MAINTENANCE OF ALTERNATIVE STRATEGIES IN WELLINGTON TREE WETA (HEMIDEINA CRASSJDENS): TESTING THE PREDICTIONS OF THE GENETIC POLYMORPHISM HYPOTHESIS MÉMOIRE PRESENTED IN FULFILLMENT OF MASTER'S IN BIOLOGY BY SARAHNASON JANUARY, 2019 REMERCIEMENTS 1 would like to thank my supervisor Dr.
    [Show full text]
  • Male Tree Weta Are Attracted to Cuticular Scent Cues but Do Not Discriminate According to Sex Or Among Two Closely Related Species
    Received: 26 April 2017 | Revised: 7 June 2017 | Accepted: 3 July 2017 DOI: 10.1111/eth.12652 RESEARCH PAPER Male tree weta are attracted to cuticular scent cues but do not discriminate according to sex or among two closely related species Priscilla M. Wehi1,2 | Adrian Monks2 | Mary Morgan-Richards1 1Institute of Agriculture & Environment, Massey University, Palmerston North, Abstract New Zealand Recognition of conspecifics is an essential precursor of successful mating. Where 2 Landcare Research, Dunedin, New Zealand related species coexist, species discrimination might be important, but because related Correspondence species are similar, species signal recognition may actually be low. Chemical cues such Priscilla M. Wehi, Landcare Research, Private as cuticular hydrocarbons (CHCs) are frequently used by insects to identify suitable Bag 1930 Dunedin, 9054 New Zealand. Email: [email protected] sexual partners. We predicted that New Zealand tree weta (Hemideina spp.), a genus Funding information of nocturnal ensiferan Orthoptera that live both allopatrically and sympatrically, use This work was supported by New Zealand chemical signals from either frass or CHCs to find mates. In a series of six laboratory Foundation for Research, Science and Technology contract number UOWX0501, trials using both H. thoracica and H. crassidens, we found that male tree weta, but not and Postdoctoral fellowship MAUX0905; female tree weta, occupied cavities primed with female cuticular cues more often than Rutherford Discovery Fellowship 14- LCR- 001 to PMW; and Massey University MURF cavities without. However, males did not discriminate between chemical cues of male funding “What limits a weta?” to MMR. and female conspecifics, or between conspecifics and heterospecifics.
    [Show full text]
  • Spineless Spineless Rachael Kemp and Jonathan E
    Spineless Status and trends of the world’s invertebrates Edited by Ben Collen, Monika Böhm, Rachael Kemp and Jonathan E. M. Baillie Spineless Spineless Status and trends of the world’s invertebrates of the world’s Status and trends Spineless Status and trends of the world’s invertebrates Edited by Ben Collen, Monika Böhm, Rachael Kemp and Jonathan E. M. Baillie Disclaimer The designation of the geographic entities in this report, and the presentation of the material, do not imply the expressions of any opinion on the part of ZSL, IUCN or Wildscreen concerning the legal status of any country, territory, area, or its authorities, or concerning the delimitation of its frontiers or boundaries. Citation Collen B, Böhm M, Kemp R & Baillie JEM (2012) Spineless: status and trends of the world’s invertebrates. Zoological Society of London, United Kingdom ISBN 978-0-900881-68-8 Spineless: status and trends of the world’s invertebrates (paperback) 978-0-900881-70-1 Spineless: status and trends of the world’s invertebrates (online version) Editors Ben Collen, Monika Böhm, Rachael Kemp and Jonathan E. M. Baillie Zoological Society of London Founded in 1826, the Zoological Society of London (ZSL) is an international scientifi c, conservation and educational charity: our key role is the conservation of animals and their habitats. www.zsl.org International Union for Conservation of Nature International Union for Conservation of Nature (IUCN) helps the world fi nd pragmatic solutions to our most pressing environment and development challenges. www.iucn.org Wildscreen Wildscreen is a UK-based charity, whose mission is to use the power of wildlife imagery to inspire the global community to discover, value and protect the natural world.
    [Show full text]
  • The Early Evolution of Biting–Chewing Performance in Hexapoda
    Chapter 6 The Early Evolution of Biting–Chewing Performance in Hexapoda Alexander Blanke Abstract Insects show a plethora of different mandible shapes. It was advocated that these mandible shapes are mainly a function of different feeding habits. This hypothesis was tested on a larger sampling of non-holometabolan biting–chewing insects with additional tests to understand the interplay of mandible function, feeding guild, and phylogeny. The results show that at the studied systematic level, variation in mandible biting–chewing effectivity is regulated to a large extent by phylogenetic history and the configuration of the mandible joints rather than the food preference of a given taxon. Additionally, lineages with multiple mandibular joints such as primary wingless hexapods show a wider functional space occupation of mandibular effectivity than dicondylic insects (¼ silverfish + winged insects) at significantly different evolutionary rates. The evolution and occupation of a compa- rably narrow functional performance space of dicondylic insects is surprising given the low effectivity values of this food uptake solution. Possible reasons for this relative evolutionary “stasis” are discussed. 6.1 Introduction Insecta sensu lato (¼ Hexapoda) display a high diversity of mouthpart shapes within the early evolved lineages which started to radiate approximately 479 million years ago (Misof et al. 2014). These shape changes were described qualitatively and were often stated to relate mainly to the type of food consumed (Yuasa 1920; Isely 1944; Evans and Forsythe 1985; Chapman and de Boer 1995). To the knowledge of the author, this and related statements regarding mouthpart mechanics being shaped by functional demands have never been tested in a quantitative framework.
    [Show full text]