INVESTIGATION OF AN INVASIVE ANT SPECIES

161 Pages·2012·33.93 MB·English

INVESTIGATION OF AN INVASIVE ANT SPECIES: Nylanderia fulva COLONY
EXTRACTION, MANAGEMENT, DIET PREFERENCE, FECUNDITY, AND
MECHANICAL VECTOR POTENTIAL

A Dissertation
by
DANNY LEE MCDONALD

Submitted to the Office of Graduate Studies of
Texas A&M University
in partial fulfillment of the requirements for the degree of

DOCTOR OF PHILOSOPHY

Approved by:
Chair of Committee, Roger E. Gold
Committee Members, Bastiaan M. Drees
Jerry L. Cook
Robert N. Coulson
Leon H. Russell
Head of Department, David W. Ragsdale

December 2012
Major Subject: Entomology
Copyright 2012 Danny Lee McDonald
ABSTRACT

Invasive species often threaten biodiversity and environmental processes in their
introduced range by extirpating native species due to competition for resources.
Nylanderia fulva (formerly N. (=Paratrechina) sp. nr. pubens) is an ecologically
dominant and economically important invasive species in the United States. This
dissertation addresses aspects of the biology, behavior, management, and collection
techniques for N. fulva. Specifically, topics investigated include a modified drip
technique for extracting ants from their substrate, the effectiveness of a broadcast ant
bait as a stand-alone treatment, the foraging preference and peak activity of workers, the
reproductive potential of queens, and the ability of this species to translocate pathogenic
microorganisms. The primary goal of these works was to better understand the
biological idiosyncrasies of this species that may ultimately lead to the mitigation N.
fulva populations.
A modified drip technique was developed to quickly and efficiently extract N.
fulva from their nesting substrates. Ants and their associated substrates were collected in
18.9 L buckets lined with talcum powder and transported to the laboratory. Substrates
were weighted down and a cardboard tower was provided for the immigration of ants as
they were forced out of substrates with a slow influx of water.
Three applications of Advance® Carpenter Ant Bait (ACAB) were applied to a N.
fulva population in East Columbia, TX. A series of GIS interpolated maps depict
achieved management and subsequent rebound of N. fulva populations. As great as 77%
ii
population reduction was achieved by 1 week post treatment, but N. fulva populations
rebounded within 3-4 weeks. As a stand-alone treatment, this bait did not provide
adequate ant management in treatment plots.
Diet preference experiments were performed using artificial diets and food lures.
These results of these trials indicated that N. fulva preferred the most carbohydrate rich
diet offered through all seasons and that mint apple jelly or hot dog slices were the
favored food lures. Diel foraging behavior was observed when temperatures were
between 9.95 and 37.26°C. Peak foraging activity occurred at 28.24 ± 3.12°C.
A laboratory investigation of N. fulva suggested that as the number of queens
increased, individual queen fecundity increased. This phenomenon is a novel
observation among ants and suggests an alternative mechanism for intracolony
dominance. Hexagyne colony fecundity of 0.25 ± 0.12 eggs/queen/hr was the maximum
fecundity observed.
Results of laboratory experiments showed that N. fulva were capable of
transferring E. coli up to 4.5 m in 6 hrs after acquisition from a contaminated source.
Pyrosequencing of ectomicrobial assemblages revealed a suite of 518 bacteria and 135
fungi species associated with N. fulva, many of which are known pathogens of plants
and animals, including humans. These results suggested that N. fulva should be regarded
as both a medically and agriculturally important species.
iii
DEDICATION

I would like to dedicate these works to my family, whose unwavering support
and love have always been a source of my strength. Thank you for instilling within me a
sense of work ethic, morality, and faith in God. Mother, your everlasting love and
encouragement I carry with me always. I owe my skepticism of the implausible and
sense of curiosity to your example. Dad, I hope that I display even a fraction of the
selflessness that you show towards your children. Your altruistic behavior is a marvel
among the ants. Glen, your unquenchable thirst for knowledge is a wonderful example,
and I am happy to carry on that torch. Ray, your passion for your family and admirable
career choice as a protector of the innocent are truly inspirational. Thank you for being
my guardian, supporter, confidant, and comic relief. Grandma and Granddad, your
constant approval and encouragement have always meant the world to me. My love,
Michelle, I look forward to a lifetime of adventures with you.
Proverbs 6:6-8
Go to the ant, O sluggard;
Observe her ways and be wise,
It has no commander,
No overseer or ruler,
Yet it stores its provisions in summer,
And gathers its food at harvest.

“The Creation, whether you believe it was placed on this planet by a single act of God or
accept the scientific evidence that it evolved autonomously during billions of years, is
the greatest heritage, other than the reasoning mind itself, ever provided to humanity.”
“Science and religion are the two most powerful forces of society. Together they can
save the Creation.”
~ Edward O. Wilson from The Creation: An Appeal to Save Life on Earth.
iv
ACKNOWLEDGEMENTS

I would like to express my sincere appreciation to all those who have helped
facilitate these experiments. I am truly grateful for the good will and generosity of all
benefactors involved. This project has been a blessing and validation that I have found
my true calling in life. My career of investigating invasive ant species ecology will
ensure that I never feel like I have to work a day in my life.
My gratitude is extended toward my committee chair, Dr. Roger Gold, for
providing me with the opportunity to write this chapter of my life. I feel very fortunate
to have been a part of your program. Dr. Bart Drees, I consider your mentorship among
the greatest experiences of my dissertation process. Thank you for always being there to
answer questions, listen to my ideas, and encourage independent thought. Dr. Jerry
Cook, I appreciate all of your guidance and support throughout the course of my
research. I look forward to working with you in the future. Dr. Robert Coulson and Dr.
Leon Russell, many thanks for all of the knowledge you bestowed upon me in your
courses.
Dr. Robert Puckett, your advice, edits, and patience have been irreplaceable
throughout the past 4 years. I respect you as a friend, teacher, and mentor. Dr. Jeff
Brady, the vector potential chapter would not have been as successful without your
plentiful knowledge and support. I look forward to working with you on many future
projects. Dr. Steve Cook, thank you for your expertise and advice regarding the diet of
ants. Your artificial ant diets were paramount in strengthening my experiment. Tom
v
Rasberry, Corrie Bowen, Dr. Paul Nester, and Dr. Alejandro Calixto, thank you for
enduring the heat, humidity, and mosquitoes of East Columbia, Texas. Dr. Bob Davis
(BASF), thank you for providing products for ant management experiments. Your
continued support of my research toward invasive ant species management is greatly
appreciated.
I would also like to thank the faculty and staff in the department of entomology,
for making my time at Texas A&M University a great experience. Special thanks goes
out to the Center for Urban and Structural Entomology lab: Laura Nelson, Brett Neff,
Grant Hale, and Janis Reed for the various behind the scenes coordination of logistics
and processing samples. Thanks also to my fellow graduate students for your support
and motivation. Justin Fiene, I especially appreciate all of the philosophical
conversations wherein we exchanged ideas and solved the problems of the world.
To the community of East Columbia, Texas (especially Flem and Cheryl Rogers
and Guy and Gene Paul) I am forever in your debt for the generosity bestowed upon a
weary graduate student.
I wish to thank those who provided the scholarships I received throughout my
time in graduate school. The financial help I was given provided me the opportunity to
focus on my research and class work.

vi
TABLE OF CONTENTS

Page
ABSTRACT ................................................................................................................... ii
DEDICATION ............................................................................................................... iv
ACKNOWLEDGEMENTS ........................................................................................... v
TABLE OF CONTENTS .............................................................................................. vii
LIST OF FIGURES ........................................................................................................ ix
LIST OF TABLES ......................................................................................................... xi
CHAPTER
I INTRODUCTION AND LITERATURE REVIEW .............................. 1
Invasive Ant Species .................................................................. 1
Taxonomy and Origins of Nylandera sp. ................................... 4
Biology and Behavior of N. fulva ............................................... 7
Pest Status of N. fulva ............................................................... 11
Management of N. fulva ............................................................ 12

II A MODIFIED DRIP TECHNIQUE FOR EXTRACTING
Nylanderia fulva (HYMENOPTERA: FORMICIDAE) FROM
SUBSTRATES ...................................................................................... 16

Introduction ............................................................................... 16
Materials and Methods .............................................................. 17
Results and Conclusions ............................................................ 26
III EFFECTS OF ADVANCE® CARPENTER ANT BAIT ON
Nylanderia fulva (HYMENOPTERA: FORMICIDAE)
POPULATION DENSITY IN EAST COLUMBIA, TEXAS .............. 28

Introduction ............................................................................... 28
Materials and Methods .............................................................. 34
Results ....................................................................................... 40
Conclusions ............................................................................... 45
vii
CHAPTER Page

IV DIEL AND SEASONAL FORAGING PREFERENCE OF
Nylanderia fulva (HYMENOPTERA: FORMICIDAE) IN
TEXAS .................................................................................................. 50

Introduction ............................................................................... 50
Materials and Methods .............................................................. 55
Results ....................................................................................... 58
Conclusions ............................................................................... 72

V FECUNDITY OF Nylanderia fulva UNDER LABORATORY
CONDITIONS (HYMENOPTERA: FORMICIDAE) ........................... 79

Introduction ............................................................................... 79
Materials and Methods .............................................................. 83
Results ....................................................................................... 85
Conclusions ............................................................................... 89

VI MECHANICAL VECTOR POTENTIAL AND MICROBIOTA
ASSEMBLAGES OF Nylanderia fulva (HYMENOPTERA:
FORMICIDAE) ..................................................................................... 93

Introduction ............................................................................... 93
Materials and Methods .............................................................. 98
Results ...................................................................................... 103
Conclusions .............................................................................. 108

VII CONCLUSIONS .................................................................................. 114

REFERENCES ............................................................................................................. 117

APPENDIX A ................................................................................................................ 133

APPENDIX B ................................................................................................................ 147
viii
LIST OF FIGURES

FIGURE Page
1 An 18.9 L bucket dusted with talcum powder to prevent ants from
escaping ................................................................................................... 19

2 A shelf and spacers for the tower with a ruler for a scale reference ....... 20

3 A cardboard tower constructed by stacking 6 shelves on top of each
other, bottoms down ................................................................................ 21

4 A weight placed on top of the substrate to prevent floatation, which
can be used by ants as a raft, and to provide a foundation upon
which the tower rested ............................................................................. 22

5 A bridge constructed from a 28 cm piece of stiff wire mesh with 6
mm openings ........................................................................................... 23

6 The final construction consisting of a bucket with substrate and
ants, a weight, bridge, and cardboard tower. ........................................... 24

7 A drip rate of 1-2 drops per second was used to allow ants to move
brood and queens into the cardboard tower............................................. 25

8 The 23 N. fulva infested Texas counties ................................................. 29

9 Survey of N. fulva population extent from 2008-2011 ............................ 36

10 Food lure transects and treatment areas in East Columbia, TX .............. 38

11 Analysis of differences between treatments of Advance® Carpenter
Ant Bait and control plots in East Columbia, Brazoria Co., Texas
in 2009 ..................................................................................................... 41

12 GIS interpolation of N. fulva population density in treated and
untreated plots in East Columbia, Brazoria Co., Texas in 2009 ............. 42

13 GIS interpolation of N. fulva population density in treated and
untreated plots in East Columbia, Brazoria Co., Texas in 2009 ............. 44

ix
FIGURE Page

14 GIS interpolation of N. fulva population density in treated and
untreated plots in East Columbia, Brazoria Co., Texas in 2009 ............. 45

15 Food lure preference of N. fulva across all seasons and cover types ...... 60

16 Food lure preference of N. fulva across all seasons in the sun ................ 62

17 Food lure preference of N. fulva across all seasons in the shade ............ 63

18 Diet preference of N. fulva across all seasons and cover types ............... 67

19 Diet preference of N. fulva across all seasons in the sun ........................ 68

20 Diet preference of N. fulva across all seasons in the shade ..................... 69

21 Foraging temperature tolerance of N. fulva on hot dog food lures.......... 70

22 Peak foraging time of N. fulva across all seasons ................................... 71

23 Queen number effects on individual fecundity ....................................... 86

24 The frequency of observations within different ranges of fecundity ...... 87

25 Effects of the number of queens per colony on total number of
eggs produced .......................................................................................... 88

26 Effect of queen weight on number of eggs/queen/hr .............................. 89

27 An illustration showing the various components of experimental
arenas ....................................................................................................... 99

28 A comparison of dish #4 treatments (a) and controls (b) ....................... 104

29 Bacterial species found on N. fulva ........................................................ 106

30 Fungal species found on N. fulva ........................................................... 107
x