Taxonomic Revision of the Ant Genus Linepithema [Hymenoptera

162 Pages·2007·2.21 MB·English

by  Alexander L. Wild

University of California Press
(University of California, Office of the President)
Year  Paper vol 
Taxonomic Revision of the Ant Genus
Linepithema (Hymenoptera: Formicidae)
Alexander L. Wild
University of Arizona
ThispaperispostedattheeScholarshipRepository,UniversityofCalifornia.
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Copyright(cid:13)c2007bytheauthor.
Taxonomic Revision of the Ant Genus
Linepithema (Hymenoptera: Formicidae)
Abstract
The primarily Neotropical dolichoderine ant genus Linepithema is revised
at the species level for the first time. Morphological and biogeographic data
support the recognition of 19 species. The following taxonomic scheme is pro-
posed: L. angulatum (Emery) stat. nov. [= pordescens (Wheeler) syn. nov.],
L. dispertitum (Forel), L. flavescens (Wheeler & Mann) stat. nov., L. fuscum
Mayr, L. gallardoi (Br`ethes) [=breviscapa (Santschi) syn. nov. = impotens
(Santschi) syn. nov.], L. humile (Mayr) [=arrogans (Chopard) = riograndense
(Borgmeier)], L. iniquum (Mayr) [= bicolor (Forel) syn. nov. = dominicense
(Wheeler) syn. nov. = fuscescens (Wheeler) syn. nov. = melleum (Wheeler)
syn. nov. = nigellum (Emery) syn. nov. = succineum (Forel) syn. nov.],
L. keiteli (Forel) [= subfaciatum (Wheeler & Mann) syn. nov.], L. leucomelas
(Emery) [= aspidocoptum (Kempf) syn. nov.], L. micans (Forel) stat. nov.
[= platense (Forel) syn. nov. = scotti (Santschi) syn. nov.], L. oblongum
(Santschi), L. piliferum (Mayr). Seven species are described as new: L. anath-
ema sp. nov., L. aztecoides sp. nov., L. cerradense sp. nov., L. cryptobioticum
sp. nov., L. neotropicum sp. nov., L. pulex sp. nov., and L. tsachila sp. nov..
Seventeen species are sorted into one of four groups associated with the species
L. fuscum, L. humile, L. iniquum, or L. neotropicum, and two species are left
unassigned. New generic diagnoses are provided for worker, male, and queen
castes, and Shattuck’s (1992a) generic descriptions of the worker, male, and
queen castes are modified slightly to take into account expanded knowledge of
characterstatevariation. Workerand,whereknown,maleandqueencastesare
described. Diagnoses, illustrations, and keys are supplied for worker and male
castes. Discussions ofvariation, comparisons to similar species, and nomenclat-
ural issues are given for each species, as well as synopses of life history traits
such as queen number, colony structure, geographic distribution, nest site and
habitat records, and associations with parasitoid Pseudacteon flies (Diptera:
Phoridae).

Taxonomic Revision of the
Ant Genus Linepithema
(Hymenoptera: Formicidae)
Alexander L. Wild

Taxonomic Revision of the
Ant Genus Linepithema
(Hymenoptera: Formicidae)
Alexander L. Wild
University of California Press
Berkeley • Los Angeles • London
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University of California Publications in Entomology, Volume 126
Editorial Board: Bradford A. Hawkins, John Heraty, Lynn S. Kimsey, Serguei V. Triapitsyn, Penny Gullan,
Philip S. Ward, Kipling Willy
University of California Press
Berkeley and Los Angeles, California
University of California Press, Ltd.
London, England
© 2007 by The Regents of the University of California
Printed in the United States of America
Library of Congress Cataloging-in-Publication Data
Wild, Alexander L., 1973-
Taxonomic revision of the ant genus Linepithema (Hymenoptera:Formicidae) / Alexander L. Wild.
p. cm. -- (University of California publications in entomology ; v. 126)
Includes bibliographical references.
ISBN 978-0-520-09858-9 (pbk. : alk. paper)
1. Linepithema--Classifi cation. I. Title.
QL568.F7W628 2007
595.79ʼ6--dc22
2007000110
The paper used in this publication meets the minimum requirements of
ANSI/NISO Z39.48-1992 (R 1997) (Permanence of Paper).{∞}
CONTENTS

Acknowledgements, vi
Abstract, vii

Introduction ………………………………………………………………………… 1
Materials and Methods ……………………………………………………………… 5
Taxonomic Results ………………………………………………………………… 13
Generic diagnoses of Linepithema worker, queen, and male castes, 13
Table 1: Diagnoses of species groups, 16
Taxonomic synopsis of Linepithema species, 17
Key to the species of Linepithema based on workers, 19
Key to the species of Linepithema based on males, 24
Species synopses, 27
L. anathema sp. nov., 27
L. angulatum stat. nov., 29
L. aztecoides sp. nov., 34
L. cerradense sp. nov., 37
L. cryptobioticum sp. nov., 41
L. dispertitum, 43
L. flavescens stat. nov., 49
L. fuscum, 51
L. gallardoi, 55
L. humile, 61
L. iniquum, 67
L. keiteli, 76
L. leucomelas, 81
L. micans stat. nov., 85
L. neotropicum sp. nov., 91
L. oblongum, 97
L. piliferum, 101
L. pulex sp. nov., 105
L. tsachila sp. nov., 109
Literature Cited …………………………………………………………………… 114
Figures …………………………………………………………………………… 120
v
vi University of California Publications in Entomology

ACKNOWLEDGEMENTS

Phil Ward, Jack Longino, Roy Snelling, Penny Gullan, Beto Brandão, Barry Bolton,
and Jo-anne Holley made valuable comments on the manuscript. I would like to thank
Bolivar R. Garcete-Barrett, the U. S. Peace Corps, and the Fundación Moises Bertoni
for their help in Paraguay. Juan Vieira and David Donoso (QCAZ) provided valuable
assistance in Ecuador, as did Jack Schuster in Guatemala and Kelvin Guerrero in the
Dominican Republic. Nicole Heller assisted in the field in Argentina. Fabiana Cuezzo
(IFML), Roberto Brandão (MZSP), Giovanni Onore (QCAZ), Stefan Schoedl
(NHMW), Roberto Poggi (MCSN), Bernhard Merz (MHNG), Daniel Burkhardt
(NHMB), and Barry Bolton (BMNH) made possible visits to their respective
museums. Stefan Cover, Jack Longino, Bill MacKay, Jes Pedersen, Leo Rivera,
Thibaut Delsinne, Andy Suarez, Ted Schultz, Jarbas Queiroz, Jo-anne Holley and Roy
Snelling provided me with useful material. Jo-anne Holley helped in the preparation
of figures. This work was made possible by financial support from the United States
National Science Foundation grant #0234691, by a National Science Foundation
Graduate Research Fellowship, and by grants from the University of California at
Davis: Jastro Shields, Center for Population Biology, and Center for Biosystematics.
Taxonomic Revision of the Ant Genus Linepithema vii

ABSTRACT

The primarily Neotropical dolichoderine ant genus Linepithema is revised at the
species level for the first time. Morphological and biogeographic data support the
recognition of 19 species. The following taxonomic scheme is proposed: L. angulatum
(Emery) stat. nov. [= pordescens (Wheeler) syn. nov.], L. dispertitum (Forel), L.
flavescens (Wheeler & Mann) stat. nov., L. fuscum Mayr, L. gallardoi (Brèthes) [=
breviscapa (Santschi) syn. nov. = impotens (Santschi) syn. nov.], L. humile (Mayr) [=
arrogans (Chopard) = riograndense (Borgmeier)], L. iniquum (Mayr) [= bicolor
(Forel) syn. nov. = dominicense (Wheeler) syn. nov. = fuscescens (Wheeler) syn.
nov. = melleum (Wheeler) syn. nov. = nigellum (Emery) syn. nov. = succineum
(Forel) syn. nov.], L. keiteli (Forel) [= subfaciatum (Wheeler & Mann) syn. nov.], L.
leucomelas (Emery) [= aspidocoptum (Kempf) syn. nov.], L. micans (Forel) stat. nov.
[= platense (Forel) syn. nov. = scotti (Santschi) syn. nov.], L. oblongum (Santschi), L.
piliferum (Mayr). Seven species are described as new: L. anathema sp. nov., L.
aztecoides sp. nov., L. cerradense sp. nov., L. cryptobioticum sp. nov., L.
neotropicum sp. nov., L. pulex sp. nov., and L. tsachila sp. nov.. Seventeen species
are sorted into one of four groups associated with the species L. fuscum, L. humile, L.
iniquum, or L. neotropicum, and two species are left unassigned. New generic
diagnoses are provided for worker, male, and queen castes, and Shattuck’s (1992a)
generic descriptions of the worker, male, and queen castes are modified slightly to
take into account expanded knowledge of character state variation. Worker and, where
known, male and queen castes are described. Diagnoses, illustrations, and keys are
supplied for worker and male castes. Discussions of variation, comparisons to similar
species, and nomenclatural issues are given for each species, as well as synopses of
life history traits such as queen number, colony structure, geographic distribution, nest
site and habitat records, and associations with parasitoid Pseudacteon flies (Diptera:
Phoridae).

Key words: Linepithema, taxonomy, Formicidae, systematics, monograph, natural
history.