The$popula*on,level$consequences$of$na*ve$and$invasive$herbivores$for$na*ve$
cac*$in$Florida$Kristen(E.(Sauby,(Mary(C.(Christman(and(
Robert(D.(Holt(Department(of(Biology,((University(of(Florida(
Ecological(Society(of(America(Fort(Lauderdale,(Florida(
August(8,(2016(
IntroducKon(
• What(is(the(impact(of(an(invasive(insect(to(its(naKve(host(plants?(– Host(plant(vital(rates(
– negaKve(effects(on(vital(rates(do(not(necessarily(translate(into(a(negaKve(effect(on(populaKon(size(or(trends(
– thus(it(is(difficult(to(infer(the(consequences(of(species(interacKons(to(plant(populaKon(dynamics(
IntroducKon(
• What(is(the(impact(of(an(invasive(insect(to(its(naKve(host(plants?(– Host(plant(vital(rates(
– negaKve(effects(on(vital(rates(do(not(necessarily(translate(into(a(negaKve(effect(on(populaKon(size(or(trends(
– thus(it(is(difficult(to(infer(the(consequences(of(species(interacKons(to(plant(populaKon(dynamics(
QuesKons(
• What(is(the(impact(of(an(invasive(insect(to(naKve(host(plant(vital(rates?(
• What(is(the(impact(of(an(invasive(insect(to(naKve(host(plant(populaKon(dynamics((i.e.,(asymptoKc(populaKon(growth(rate)?(
Florida$Opun%a'and$Their$Specialist$Insect$Herbivores'
Florida$Opun%a'and$Their$Specialist$Insect$Herbivores'
The$invasive$cactus$moth,$Cactoblas%s'cactorum,'
“blas*ng”$its$host$species,$Opun%a'stricta,'in$Florida'
The$Path$to$the$North$American$Introduc*on$of$C.'cactorum$
1925(
Successful$Biological$Control$in$Australia$
Before…$ AFer.$
Photos(from(Osmond(et&al.&2008&(Journal(of(Experimental(Botany)(
1957(
Early(1930s(
1925(
The$Path$to$the$North$American$Introduc*on$of$C.'cactorum$
Source:(USDA(APHIS,(h_p://www.aphis.usda.gov/plant_health/plant_pest_info/cactoblasKs/spread.shtml,((((((((accessed(21(March(2009(
Most(recent(detecKons:(Jefferson,(Lafourche,(and(Terrebonne(Parishes,(Louisiana((2009)(
Distribu*on$of$the$Invasive$Cactus$Moth$in$the$Southeastern$United$States$
South$Carolina,$2004$
Louisiana,$2009$
First$detec*on,$Florida$Keys,$1989$
2000$2003$ 2002$
Sampling(at(the(Guana(Tolomato(Matanzas(NaKonal(Estuarine(Research(Reserve((GTMNERR)(
Torreya SP
Mexico Beach
Big Lagoon SP
St. Andrew's SP
Nokuse Plantation
Henderson Beach SP
MARINELAND
SAINT AUGUSTINE
0 400 800 1,200 1,600200Kilometers
0 5 10 15 202.5Kilometers
400 0 400200 Meters
660 0 660330 Meters 0.6 0 0.60.3 Kilometers
ST. JOHNSCOUNTY
FLAGLERCOUNTY
0 0.3 0.6 0.9 1.20.15Kilometers
0 0.5 10.25 Kilometers
0 350 700175 Meters
(a)
(b)
Plot(Surveys(Across(7(Habitat(Patches((• 447(1fmeter2(plots(
• Each(plot(was(surveyed(twice(a(year(from(May(2013(–(August(2015(• Measured(plant(size(and(reproducKve(output(Spring/Summer(• Recorded(insect/presence(absence,(recruitment(in(Spring/Summer(and(Fall/Winter(• Number(of(individuals(surveyed(at(start(:(886((Spring/Summer(2013)(• Number(of(individuals(surveyed(in(total:(1369((483(recruits)(
Torreya SP
Mexico Beach
Big Lagoon SP
St. Andrew's SP
Nokuse Plantation
Henderson Beach SP
MARINELAND
SAINT AUGUSTINE
0 400 800 1,200 1,600200Kilometers
0 5 10 15 202.5Kilometers
400 0 400200 Meters
660 0 660330 Meters 0.6 0 0.60.3 Kilometers
ST. JOHNSCOUNTY
FLAGLERCOUNTY
0 0.3 0.6 0.9 1.20.15Kilometers
0 0.5 10.25 Kilometers
0 350 700175 Meters
(a)
(b)
Hypotheses(
• The(invasive(moth(will(negaKvely(affect(vital(rates(and(the(asymptoKc(populaKon(growth(rate,(λ,(of(Opun-a&stricta(
• The(naKve(moth(will(have(no(effect(on(vital(rates(and(λ(
Objec*ves$
• Examine(relaKonship(between(moth(presence(and(vital(rates(– Growth(– Sexual(ReproducKon(– Survival(
• Construct(and(analyze(matrix(populaKon(model(to(determine(effect(of(moth(presence(on(asymptoKc(populaKon(growth(rate,(λ(– ElasKcity(analysis(
Rela*ve$Growth$Rate$
RGR = 365×(!"#$!!! − !"#$!)/(!×!"#$!)
d(=(days(between(survey(at(Kme&t&and(Kme(t+1&
Growth$
Linear(mixed(model(in(SAS/STAT(version(13.2((
0
10
20
30
0 1 2 3 4 5
ln(Sizet)
Annu
al R
elat
ive G
row
th R
ate
Invasive Moth Present During Study? Yes No
• Overall,(negaKve(relaKonship(between(size(and(RGR(• Significant((small)(posiKve(effect(of(the(invasive(moth(
0
10
20
30
0 1 2 3 4 5
ln(Sizet)
Annu
al R
elat
ive G
row
th R
ate
Native Moth Present During Study? Yes No
Growth$
Linear(mixed(model(in(SAS/STAT(version(13.2((
• Significant((small)(posiKve(effect(of(the(naKve(moth(
0
10
20
30
0 1 2 3 4 5
ln(Sizet)
Annu
al R
elat
ive G
row
th R
ate
Native Moth Present During Study? Yes No
Growth$
Linear(mixed(model(in(SAS/STAT(version(13.2((
• Significant((small)(posiKve(effect(of(the(naKve(moth(
Sexual$Reproduc*on$
• No(effect(on(fruit(presence(• PosiKvely(associated(with(higher(fruit(count(
(• Found(on(only(one(plant(with(fruit(
0
1
2
3
4
No Yes
Invasive Moth PresentDuring Study?
ln(N
umbe
r of F
low
ers
and
Frui
t)
Invasive$Moth$
Na*ve$Moth$
Zerofinflated(Poisson(model((SAS/STAT(version(13.2)((
Survival$
Study(length(=(1000(days((2012f12f02(to(2015f08f29)(Cox(proporKonal(hazards(regression((SAS/STAT(version(13.2)((
Follow Up Time (Days)0 100 200 300 400 500 600 700 800 900 1000
Surv
ival P
roba
bilit
y0.
00.
20.
40.
60.
81.
0
Invasive Moth Absent
InvasiveMothPresent
Higher(for(plants(infested(by(the(invasive(moth(during(the(study(
Posi*ve$Rela*onship$Between$Survival$and$Invasive$Moth$Presence$During$the$Study$
Due(to(the(invasive(moth’s(a_racKon(to(larger(plants?(
0
1
2
3
4
5
No Yes
Invasive Moth Presentat Time t?
ln(Size t)
Posi*ve$Rela*onship$Between$Survival$and$Invasive$Moth$Presence$During$the$Study$
Due(to(the(invasive(moth’s(a_racKon(to(larger(plants?(
0
1
2
3
4
5
Island 1 Island 2 Island 3 Island 4 Island 5 CoastalGrassland
BeachDunes
Habitat Patch
ln(S
izet)
Invasive Moth Present at Time t? No Yes
0
1
2
3
4
5
No Yes
Invasive Moth Presentat Time t?
ln(Size t)
Follow Up Time (Days)0 100 200 300 400 500 600 700 800 900 1000
Surv
ival P
roba
bilit
y0.
00.
20.
40.
60.
81.
0
Native Moth Absent
NativeMothPresent
Survival$
Study(length(=(1000(days((2012f12f02(to(2015f08f29)(Cox(proporKonal(hazards(regression((SAS/STAT(version(13.2)((
No(effect(of(naKve(moth(presence(during(the(study(
What(are(the(consequences(of(invasive(moth(infestaKon(for(the(asymptoKc(
populaKon(growth(rate,(λ?(
• Construct(Matrix(PopulaKon(Models(
• Determine(which(vital(rates(are(most(important(to(the(populaKon(growth(rate(– With(elasKcity(analyses(
Juvenile((1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
4(segments(
3(segments(
5(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Recruitment$Seed(Seedling(
Stasis$
Note:(• TransiKons(are(based(on(data(except(• seed$recruitment$rate:(based(on(previous(studies(• Number$of$seeds$produced$per$plant:((
• Average(#(of(seeds(per(fruit((observed(from(40(fruit)(x(observed(number(of(fruit(
• Time(step(is(1(year(• Data(represents(transiKons(from(2013(to(2014(
Seed(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
4(segments(
3(segments(
5(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Growth$(1$year)$
Seedling(Juvenile((1(segment)(
Seedling( Seed(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
4(segments(
3(segments(
5(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Juvenile((1(segment)(
Stasis$
Seedling( Seed(Juvenile(
(1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
2(segments(
4(segments(
3(segments(
5(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Sexual$Reproduc*on$
Growth$
Growth$
1(segment(
Stasis$
Stage(7((10+(
segments)(
Seedling( Seed(Juvenile(
(1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
4(segments(
3(segments(
5(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Clonal$Reproduc*on$+$$Retrogression$
Growth$Stasis$
Growth$
2(segments(
Seedling( Seed(Juvenile(
(1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
4(segments(
5(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Clonal$Reproduc*on$+$$Retrogression$
Growth$
Growth$
Stasis$
Clonal$Reproduc*on$+$$Retrogression$
3(segments(
Seedling( Seed(Juvenile(
(1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
3(segments(
5(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Stasis$
Growth$
Clonal$Reproduc*on$+$$Retrogression$
Clonal$Reproduc*on$+$$Retrogression$
Retrogression$
4(segments(
Seedling( Seed(Juvenile(
(1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
4(segments(
3(segments(
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Retrogression$
Stasis$
Growth$Clonal$Reproduc*on$+$$
Retrogression$
Retrogression$
5(segments(
Seedling( Seed(Juvenile(
(1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
4(segments(
3(segments(
5(segments(
Stage(7((10+(
segments)(
Stasis$
Growth$Clonal$Reproduc*on$+$$Retrogression$
Retrogression$
Sexual$Reproduc*on$
Stage(6((6f9(
segments)(
Seedling( Seed(Juvenile(
(1(segment)(
Life$Cycle$Diagram$for$Opun%a'stricta'
1(segment(
2(segments(
4(segments(
3(segments(
5(segments(
Stage(6((6f9(
segments)(
Stasis$
Clonal$Reproduc*o
n$
Clonal$Reproduc*on$
Retrogression$
Retrogression$
Sexual$Reproduc*on$
Stage(7((10+(
segments)(
Seedling( Seed(Juvenile(
(1(segment)(
Important$Transi*ons$According$to$Elas*city$Analysis'
1(segment(
2(segments(
4(segments(
3(segments(
5(segments(
0.14$
Note:(• All(2013f2014(transiKon(data(• StarKng(values(• 1000(seeds(• 100(individuals(all(other(stages(
0.15$
0.06$
Stage(7((10+(
segments)(
Stage(6((6f9(
segments)(
Popula*on$Dynamics$Based$on$2013,2014$Transi*on$Data$
Model$ λ$ Number$of$Unique$Individuals$
EnKre(Dataset( 0.988( 778(
Divide(dataset(based(on(invasive(moth(presence(
With(Invasive(Moth( 0.982( 664(
Without(Invasive(Moth( 1.45( 114(
Divide(dataset(based(on(invasive(moth(presence(
With(NaKve(Moth( 1.098( 397(
Without(NaKve(Moth( 1.001( 381(
• For(dataset(without(invasive(moth(• no(seedling(recruitment(observed;(set(to(0.001(• Seedling(to(juvenile(set(to(1(
Plots(with(cacK(sampled(in(clusters(
Yellow:(CacK(absent$Green:(CacK(present(
Popula*on$Dynamics$Based$on$2013,2014$Transi*on$Data$
Model$ λ$ Number$of$Unique$Individuals$
EnKre(Dataset( 0.988( 778(
Divide(dataset(based(on(invasive(moth(presence(
With(Invasive(Moth( 0.982( 664(
Without(Invasive(Moth( 1.45( 114(
Divide(dataset(based(on(invasive(moth(presence(
With(NaKve(Moth( 1.098( 397(
Without(NaKve(Moth( 1.001( 381(
• For(dataset(without(invasive(moth(• no(seedling(recruitment(observed;(set(to(0.001(• Seedling(to(juvenile(set(to(1(
Popula*on$Dynamics$Based$on$2013,2014$Transi*on$Data$
Model$ λ$ Number$of$Unique$Individuals$
EnKre(Dataset( 0.988( 778(
Divide(dataset(based(on(invasive(moth(presence(
With(Invasive(Moth( 0.982( 664(
Without(Invasive(Moth( 1.45( 114(
Divide(dataset(based(on(invasive(moth(presence(
With(NaKve(Moth( 1.098( 397(
Without(NaKve(Moth( 1.001( 381(
• For(dataset(without(invasive(moth(• no(seedling(recruitment(observed;(set(to(0.001(• Seedling(to(juvenile(set(to(1(
Conclusions$
• Impact(of(invasive(but(not(naKve(moth(to(cactus(vital(rates(
• PopulaKon(models(suggest(that(the(invasive(may(negaKvely(impact(the(populaKon(growth(rate(– Also(suggests(no(effect(of(naKve(moth(
Future(Work(
• Run(simulaKons(with(2013f2014(and(2014f2015(transiKon(data(to(incorporate(– Demographic(stochasKcity(
– SpaKal(variaKon((among(the(7(habitat(patches)(
• Sufficient(data(for(Life(Table(Response(Experiments?(
• Increase(sample(size(of(large(plants?(
Acknowledgments$• University$of$Florida$
• James(Nifong(• Polly(Harding(
• GTMNERR$• KaKe(Petrinec(• Ma_(Welsh(
(
Funding$• Carrie(Lynn(Yoder(Scholarship(for(Plant(Ecology(and(
ConservaKon(Research(in(Florida(• Florida(NaKve(Plant(Society(• Botanical(Society(of(America(• QuanKtaKve(SpaKal(Ecology,(EvoluKon,(and(Environment(
(QSE3)(IGERT(• Garden(Club(of(America(and(Center(for(Plant(ConservaKon(• Cactus(and(Succulent(Society(of(America(• Graduate(Student(Council,(University(of(Florida(• Department(of(Biology,(University(of(Florida(