on and Daniel Rubinoff - University of Hawaii · Title: Microsoft PowerPoint -...
1
Outbreaks of the Hawaiian geometrid cate Outbreaks of the Hawaiian geometrid cate defoliation of defoliation of koa koa forests ( forests (Acaci Acaci William P. Haines William P. Haines and Daniel and Daniel Rubinoff Rubinoff University of Hawaii, Plant and Environmental Protection Sciences, 3050 MaileWay, Gilmore 310, Honolulu, HI 96822. [email protected] College of Tropical Agriculture and Human Resources UNIVERSITYOF HAWAI‘IAT MĀNOA However,thetriggersoftheseoutbreaksareunknown.In2003and2004, koa forests on East Maui were severely defoliated by S. paludicola. Defoliation was first noted in Kipahulu Valley within Haleakala National Park,andsubsequentlyinMakawaoForestReserve,togethercomprising about 16 km 2 (Fig. 2). We took this opportunity to explore possible limiting factors of S. paludicola. Because outbreaks of other tropical insectshavebeenlinkedtoclimaticfactorssuchasdrought(Mattsonand Haack 1987, Van Bael et al. 2004), we obtained local rainfall and temperature data for the past 90 years, and looked for relationships betweenthesedataandtheoccurrenceofoutbreaksinMakawaoForest, ofwhichfivehavebeenreportedinthepast90years. RESULTS We found no clear evidence that rainfall or temperature influence S. paludic Plotsofmonthlydata(Fig.4)showednoobviousrelationshipbetweenthe oc outbreakandeitherrainfallortemperature. Althoughrainfallwason averag 12monthspriorto outbreaks comparedtononoutbreakyears(Fig.5), Ma tests did not show this to be significant. Logistic regression found that variables, rainfall came closest to explaining outbreaks, but again, it was (Table 1). All analyses unambiguously failed to find a significant relation temperatureandtheoccurrenceofoutbreaks. Figure 1: Vast defoliation of koaforest in KipahuluValley in late 2003. Photo by Bill Haus. Inset: Adult Scotorythra paludicola moth Figure 2: Defoliation of koaforest on east Maui as of February 2004. Defoliation was first noted in KipahuluValley in mid-2003, and later reported further north, in Makawao Forest Reserve. METHODS Analyses of historic climate data and occurrence of outbreaks: Weusedrainfallandtemperaturedatafrom1919-2006fromEastMauiweather stations managed by the National Climatic Data Center (NCDC 2008). For monthlyrainfall,weuseddatafromfoursites:HaleakalaRanch432,Olinda#1 332, Ukulele 333, and Waikamoi 449 (Fig. 2). For temperature, only three weatherstationsonEastMauihaddataavailablefrom1919to2006:HanaAP 354/355, Kailua 446, and Kula Hospital 267 (Fig. 2). We used daily maximum temperature, since this was the most highly correlated temperature variable among the three stations. To correct for differences between stations and seasons, data were converted to deviations from the long term monthly averagesforeachstation.Overallmeanmonthlydeviationswerethencalculated acrossallstations. Outbrea years, in press). W and exa scale, w as pred observe temper noted. T month overlap model, the tw p>0.10. rainfall Observ We col Kipahul during selected quantifi notbe laborato estimat 1.00-1.4 on koa preserv 20mm Figure 3: Caterpillars of S. paludicola from a typical sample. INTRODUCTION AND BACKGROUND Thegeometrid Scotorythra paludicola (Butler)isendemictotheHawaiian Islands,belongingtoamonophyleticlineagecontainingabout60species. Caterpillarsof S. paludicola specializeonleavesofthehardwoodtreekoa (Acacia koa Gray), a widespread and dominant tree in native Hawaiian mesicforest.KoawoodisoneofthemostvaluablewoodsinHawaiiand theworld. Occasionally, S. paludicola experiences huge population explosions, of whichtherehavebeenatleast12sincethelate1800s(Hainesetal. in press), making this the most notable irruptive native insect in Hawaii. Regardingoneoftheearliestrecordedoutbreaks,Perkins(1913)wrote: “…the starving caterpillars formed writhing masses on the ground beneath the tall koa trees. The dropping of excrement from the trees on the dead leaves beneath made a rattling noise as of a hailstorm.” Figure 4: Deviations from mean mon and temperature for three years pre five recorded historical outbreaks of Solid circles denote when outbreaks observed. There were no obvious extrem patterns in either rainfall or te prior to the outbreaks. erpillar erpillar Scotorythra Scotorythra paludicola paludicola Butler and Butler and ia ia koa koa): a historical perspective ): a historical perspective cola outbreaks. ccurrence ofan ge lowerduring ann WhitneyU- of the climate non-significant nship between REFERENCES Haines, W. P. , M. L. Heddle, P. Welton, and D. Rubinoff. in press. A recent outbreak of the Hawaiian koamoth, Scotorythra paludicola (Lepidoptera: Geometridae), and a review of outbreaks between 1892 and 2003. Pacific Sci. Mattson, W. J. and R. A. Haack. 1987. The role of drought in outbreaks of plant eating insects. BioScience37. National Climatic Data Center (NCDC). 2008. Web Climate Services, version 2.1. http://www.ncdc.noaa.gov/oa/climate/stationlocator.html Accessed 30 April 2008. Perkins, R. C. L. 1913. Introductory essay on the fauna. in D. Sharp, ed. Fauna Hawaiiensis. University Press. Stein, J. D. 1981. Notes and Exhibitions, March 1978: Scotorythra paludicola. Proc. Haw. Ent. Soc. 23: 315-316. Van Bael, S., Aiello, A., Valderrama, A., Medianero, E., Samaniego, M. and S. J. Wright. 2004. General herbivore outbreak of following an El Niño related drought in a lowland Panamanian forest. J. Trop. Ecol. 20. ACKNOWLEDGEMENTS WeespeciallythankM.HeddleandP.Welton,whoareco-authorsonthepaperwheretheseanalysesareinpress.We alsothankstaffoftheNationalParkService,G.ShishidooftheHawai‘iDepartmentofLandandNaturalResources,M. Caterino of the Santa Barbara Natural History Museum for assistance in the field. C. Shimoda of the University of Hawai‘iassistedwithrearinglarvae.A.TaylorandC.Daehlerprovidedinvaluablefeedbackontheanalyses.Ourwork in Haleakala National Park was conducted under NPS permit HALE-2003-SCI-0010. Funding was provided by the NationalParkService,theNationalScienceFoundation,andtheU.S.DepartmentofAgriculture. RESULTS (continued) Outbreaking populations of S. paludicola are more or less synchronous: aks inMakawaoForestReservewerereportedfivetimesinthepast90 n Jan1926,Jan1946,Sep1971,Jan1977,andFeb2004(Hainesetal. in We plottedrainfallandtemperaturefor3yearsprecedingeachoutbreak, amined theseplotsforcommonpatternsamongoutbreaks.Onanannual we performedlogisticregressionanalyses(Minitab14)withclimatedata dictors and a binary response (“outbreak observed” or “no outbreak ed”). For each outbreak (N=5), we calculated means of rainfall and rature fora12-monthperiodprecedingthemonththattheoutbreakwas To representconditionsduringnon-outbreakperiods(N=81),weused12- averages based on calendar years from 1919-2006, omitting years that pped with the 12 months preceding outbreaks. We started with a full whichincludedrainfall,temperature,andaninteractiontermbetween wo. We progressively removed non-significant predictors at the level . Wealsoperformedseparatenon-parametricMann-WhitneyU-testson andtemperaturebetweentheseoutbreakandnon-outbreakperiods. vations of S. paludicola during 2003-2004 outbreak: llected S. paludicola adults and caterpillars at three sites. We visited lu Valley twice, Healani once, and Makawao Forest Reserve five times 2004. Larvae were collected by shaking branches from haphazardly d trees onto a white, 1 m 2 , “beating sheet”. Search effort was not ied orkeptconstantamongcollectingtrips,sodensitiesoflarvaecould comparedovertimeorbetweensites.Larvaewerebroughtbacktothe ory andsortedintosixsizeclassesbasedonheadcapsulewidthsasan te oflarvalage(1:0.20-0.30mm,2:0.45-0.60mm,3:0.70-1.00mm,4: 40 mm,5:1.40-1.80mm,6:>1.80mm).Larvaewererearedindividually phyllodes at 23°C. Development was monitored and parasitoids were ved andidentified. Life cycle duration of S. paludicola is approximately2-3 months: Of the 47 larvae that were collected in the first instar, 16 completed development to adulthood in the laboratory. The mean development time from first instar to adulthood underlaboratoryconditionswas42days(±0.84SE,N=16).Meanlarvaldevelopmenttime (fromfirstinstartopupation)underlaboratoryconditionswas29.1days(±0.51SE,N=8). Becauselaboratoryconditionsweremostlikelywarmerthanconditionsexperiencedinthe field,weassumethattheseareunderestimates.However,eveniffielddevelopmenttime istwicewhatweobservedinthelaboratory,weestimateagenerationtimeoflessthan90 days.ThisisconsistentwithpriorobservationsofStein(1981),whofoundthatadultmoths begantoemerge en masse abouttwomonthsafterlarvaewerefirstnotedinthefield. Parasitoids of S. paludicola : Most(80%)ofthe296larvaethatwerecollectedduringthis study died due to pathogens or unknown causes, making it impossible to calculate meaningful parasitism rates. However, three species of non-native parasitoid wasps were reared from larvae: the braconids Meteorus laphygmae (Fig. 7) and Cotesia marginiventris, and the ichneumonid Hyposoter exiguae. Oneichneumonidhyperparasitoid, Gelis sp.,wasrearedaswell.Manypupalcasesof M. laphygmae and H. exiguae werealsoobservedattachedtokoabranches atallfieldsites.Nonativeparasitoidswerereared,although this may be an artifact of small sample size due to high mortalityinlaboratoryrearedlarvae. Figure 3: Meteoruslaphygmae, the parasitoid most commonly reared and observed in the field. Table 1: Results of multiple logistic regression: Neither rainfall nor temperature was statistically significant. Figure 5: Comparisons of (A) rainfall and (B) maximum temperature during 12 month periods preceding outbreaks and in non-outbreak years, and results of Mann Whitney U-tests. nthly rainfall eceding the f S. paludicola. were mities or emperature Figure 6: Size classes of S. paludicola larvae collected at three week intervals from Makawao Forest Reserve. At a given time, larvae were mostly of a similar age. This was true at all localities sampled. IMPLICATIONS Although our analyses failed to find a significant predictive effect of rainfall, our retrospective approach was constrained by several problems, including imprecise weather data, a small sample of outbreaks, and the likelihood that some outbreaks went unreported in the literature. Future studies should include quantitative monitoringofcaterpillarandparasitoidpopulationsduringoutbreaksandnon-outbreak periods,combinedwithmonitoringoflocalclimate,includingrainfall,temperature,and wind. Because S. paludicola belongs to an adaptive radiation that includes both outbreakingandnon-outbreakingspecies,includingotherspeciesthatfeedonkoa,a comparativeapproachmightalsobeinformative.
Transcript of on and Daniel Rubinoff - University of Hawaii · Title: Microsoft PowerPoint -...
Ou
tbre
ak
s of th
e H
aw
aiia
n g
eo
me
trid ca
terp
illar
Ou
tbre
ak
s of th
e H
aw
aiia
n g
eo
me
trid ca
terp
illar
de
folia
tion
of
de
folia
tion
of k
oa
ko
afo
rests (
fore
sts (Aca
cia
Aca
cia
Willia
m P. H
ain
es
Willia
m P. H
ain
es
an
d D
an
iel
an
d D
an
iel R
ub
ino
ffR
ub
ino
ffU
nive
rsity of H
awaii, P
lant an
d E
nviro
nm
en
tal Pro
tectio
n
Scien
ces, 3
05
0 M
aileW
ay, Gilm
ore
31
0, H
on
olu
lu, H
I 96
82
2.
wh
ain
es@
ha
wa
ii.ed
u
Co
lleg
e o
f Trop
ical A
gricu
lture
an
d H
um
an
Re
sou
rces
UN
IVE
RSIT
YO
FH
AW
AI‘I
AT
MĀ
NO
A
Ho
we
ver,
the
trigge
rso
fth
ese
ou
tbre
aks
are
un
kno
wn
.In
20
03
an
d2
00
4,
koa
fore
stso
nEa
stM
au
iw
ere
seve
rely
de
folia
ted
by
S.
pa
lud
icola
.
De
folia
tion
wa
sfirst
no
ted
inK
ipa
hu
luV
alle
yw
ithin
Ha
lea
kala
Natio
na
l
Pa
rk,a
nd
sub
seq
ue
ntly
inM
aka
wa
oFo
rest
Re
serve
,to
geth
er
com
prisin
g
ab
ou
t1
6km
2(Fig.
2).
We
too
kth
iso
pp
ortu
nity
toexp
lore
po
ssible
limitin
gfa
ctors
of
S.
pa
lud
icola
.B
eca
use
ou
tbre
aks
of
oth
er
trop
ical
inse
ctsh
aveb
ee
nlin
ked
toclim
atic
facto
rssu
cha
sd
rou
ght
(Ma
ttson
an
d
Ha
ack
19
87
,V
an
Ba
el
et
al.
20
04
),w
eo
bta
ine
dlo
cal
rain
fall
an
d
tem
pe
ratu
red
ata
for
the
pa
st9
0ye
ars,
an
dlo
oke
dfo
rre
latio
nsh
ips
be
twe
en
the
sed
ata
an
dth
eo
ccurre
nce
of
ou
tbre
aks
inM
aka
wa
oFo
rest,
of
wh
ichfive
have
be
en
rep
orte
din
the
pa
st9
0ye
ars.
RE
SU
LTS
We
fou
nd
no
clea
re
vid
en
ceth
at
rain
fall
or
tem
pe
ratu
rein
flue
nce
S.
pa
lud
icola
Plo
tso
fm
on
thly
da
ta(Fig.
4)
sho
we
dn
oo
bvio
us
relatio
nsh
ipb
etw
ee
nth
eo
ccurre
nce
ou
tbre
ak
an
de
ithe
rra
infa
llo
rte
mp
era
ture
.A
ltho
ugh
rain
fall
wa
so
nave
rage
12
mo
nth
sp
rior
too
utb
rea
ksco
mp
are
dto
no
no
utb
rea
kye
ars
(Fig.5
),M
an
n
tests
did
no
tsh
ow
this
tob
esign
ifican
t.Lo
gisticre
gre
ssion
fou
nd
tha
to
f
varia
ble
s,ra
infa
llca
me
close
stto
expla
inin
go
utb
rea
ks,b
ut
aga
in,
itw
as
no
n
(Tab
le1
).A
lla
na
lyses
un
am
bigu
ou
slyfa
iled
tofin
da
significan
tre
latio
nsh
ip
tem
pe
ratu
rea
nd
the
occu
rren
ceo
fo
utb
rea
ks.
Fig
ure
1: V
ast d
efo
liatio
n o
f koa
fore
st in K
ipa
hu
luV
alle
y in la
te 2
00
3. P
ho
to b
y Bill
Ha
us. In
set: A
du
lt Sco
tory
thra
pa
lud
icola
mo
th
Fig
ure
2:
De
folia
tion
of
koa
fore
st on
ea
st Ma
ui a
s of
Feb
rua
ry 20
04
.
De
folia
tion
wa
s
first no
ted
in
Kip
ah
ulu
Va
lley
in m
id-2
00
3,
an
d la
ter
rep
orte
d
furth
er n
orth
,
in M
aka
wa
o
Fore
st Re
serve
.
ME
TH
OD
SA
na
lyse
so
fh
istoric
clima
ted
ata
an
do
ccurre
nce
of
ou
tbre
ak
s:W
eu
sed
rain
fall
an
dte
mp
era
ture
da
tafro
m1
91
9-2
00
6fro
mE
ast
Ma
ui
we
ath
er
statio
ns
ma
na
ge
db
yth
eN
atio
na
lC
lima
ticD
ata
Ce
nte
r(N
CD
C2
00
8).
For
mo
nth
lyra
infa
ll,w
eu
sed
da
tafro
mfo
ur
sites:
Ha
lea
kala
Ra
nch
43
2,
Olin
da
#1
33
2,
Uku
lele
33
3,
an
dW
aika
mo
i4
49
(Fig.2
).Fo
rte
mp
era
ture
,o
nly
thre
e
we
ath
er
statio
ns
on
East
Ma
ui
ha
dd
ata
availa
ble
from
19
19
to2
00
6:
Ha
na
AP
35
4/3
55
,K
ailu
a4
46
,a
nd
Ku
laH
osp
ital
26
7(Fig.
2).
We
use
dd
aily
ma
ximu
m
tem
pe
ratu
re,
since
this
wa
sth
em
ost
high
lyco
rrela
ted
tem
pe
ratu
reva
riab
le
am
on
gth
eth
ree
statio
ns.
Toco
rrect
for
diffe
ren
ces
be
twe
en
statio
ns
an
d
sea
son
s,d
ata
we
reco
nve
rted
tod
evia
tion
sfro
mth
elo
ng
term
mo
nth
ly
avera
ges
for
ea
chsta
tion
.O
vera
llme
an
mo
nth
lyd
evia
tion
sw
ere
the
nca
lcula
ted
acro
ssa
llstatio
ns.
Ou
tbre
aks
yea
rs,in
pre
ss).W
e
an
dexa
min
ed
scale
,w
e
as
pre
dicto
rs
ob
serve
d”)
tem
pe
ratu
re
no
ted
.To
mo
nth
ove
rlap
pe
d
mo
de
l,
the
two
p>
0.1
0.
rain
fall
Ob
serv
atio
ns
We
colle
cted
Kip
ah
ulu
du
ring
sele
cted
qu
an
tified
no
tb
e
lab
ora
tory
estim
ate
1.0
0-1
.40
on
koa
pre
serve
d2
0m
m
Fig
ure
3: C
ate
rpilla
rs of S
. pa
lud
icola
from
a typ
ical sa
mp
le.
INT
RO
DU
CT
ION
AN
DB
AC
KG
RO
UN
DT
he
geo
me
tridSco
tory
thra
pa
lud
icola
(Bu
tler)
ise
nd
em
icto
the
Ha
wa
iian
Islan
ds,
be
lon
ging
toa
mo
no
ph
yletic
line
age
con
tain
ing
ab
ou
t6
0sp
ecie
s.
Ca
terp
illars
of
S.
pa
lud
icola
spe
cialize
on
leave
so
fth
eh
ard
wo
od
tree
koa
(Aca
ciako
aG
ray),a
wid
esp
rea
da
nd
do
min
an
ttre
ein
na
tiveH
aw
aiia
n
me
sicfo
rest.
Ko
aw
oo
dis
on
eo
fth
em
ost
valu
ab
lew
oo
ds
inH
aw
aiia
nd
the
wo
rld.
Occa
sion
ally,
S.
pa
lud
icola
expe
rien
ces
hu
gep
op
ula
tion
explo
sion
s,o
f
wh
ichth
ere
have
be
en
at
lea
st1
2sin
ceth
ela
te1
80
0s
(Ha
ine
se
ta
l.in
pre
ss),m
akin
gth
isth
em
ost
no
tab
leirru
ptive
na
tivein
sect
inH
aw
aii.
Re
gard
ing
on
eo
fth
ee
arlie
stre
cord
ed
ou
tbre
aks,
Pe
rkins
(19
13
)w
rote
:
“…th
esta
rvin
gca
terp
illars
form
ed
writh
ing
ma
sses
on
the
gro
un
d
be
ne
ath
the
tall
ko
atre
es.
Th
ed
rop
pin
go
fe
xcre
me
nt
from
the
tree
so
n
the
de
ad
lea
ve
sb
en
ea
thm
ad
ea
rattlin
gn
oise
as
of
ah
ailsto
rm.”
Fig
ure
4: D
evia
tion
s from
me
an
mo
nth
ly rain
fall
an
d te
mp
era
ture
for th
ree
yea
rs pre
ced
ing th
e
five re
cord
ed
histo
rical o
utb
rea
ks of
Solid
circles d
en
ote
wh
en
ou
tbre
aks w
ere
ob
serve
d.
Th
ere
we
re n
o o
bv
iou
s ex
trem
ities o
r
pa
ttern
s in e
ithe
r rain
fall o
r tem
pe
ratu
re
prio
r to th
e o
utb
rea
ks.
Ou
tbre
ak
s of th
e H
aw
aiia
n g
eo
me
trid ca
terp
illar
Ou
tbre
ak
s of th
e H
aw
aiia
n g
eo
me
trid ca
terp
illar S
coto
ryth
raS
coto
ryth
rap
alu
dico
lap
alu
dico
laB
utle
r an
d
Bu
tler a
nd
Aca
cia
Aca
cia k
oa
ko
a): a
histo
rical p
ersp
ectiv
e): a
histo
rical p
ersp
ectiv
e
pa
lud
icola
ou
tbre
ak
s.
occu
rren
ceo
fa
n
avera
gelo
we
rd
urin
gM
an
nW
hitn
ey
U-
of
the
clima
te
no
n-sign
ifican
t
rela
tion
ship
be
twe
en
RE
FE
RE
NC
ES
Ha
ine
s, W. P. , M
. L. He
dd
le, P. W
elto
n, a
nd
D. R
ub
ino
ff. in p
ress. A
rece
nt o
utb
rea
k of th
e H
aw
aiia
n ko
am
oth
,
Sco
tory
thra
pa
lud
icola
(Lep
ido
pte
ra: G
eo
me
trida
e), a
nd
a re
view
of o
utb
rea
ks be
twe
en
18
92
an
d 2
00
3. P
acific Sci.
Ma
ttson
, W. J. a
nd
R. A
. Ha
ack. 1
98
7. T
he
role
of d
rou
ght in
ou
tbre
aks o
f pla
nt e
atin
g inse
cts. Bio
Scien
ce3
7.
Na
tion
al C
lima
tic Da
ta C
en
ter (N
CD
C). 2
00
8. W
eb
Clim
ate
Service
s, versio
n 2
.1.
http
://ww
w.n
cdc.n
oa
a.g
ov/o
a/clim
ate
/statio
nlo
cato
r.htm
l Acce
ssed
30
Ap
ril 20
08
.
Pe
rkins, R
. C. L. 1
91
3. In
trod
ucto
ry essay o
n th
e fa
un
a. in
D. Sh
arp
, ed
. Fau
na
Ha
wa
iien
sis. Un
iversity P
ress.
Stein
, J. D. 1
98
1. N
ote
s an
d E
xhib
ition
s, Ma
rch 1
97
8: S
coto
ryth
rap
alu
dico
la. P
roc. H
aw
. En
t. Soc. 2
3: 3
15
-31
6.
Va
n B
ae
l, S., Aie
llo, A
., Va
lde
rram
a, A
., Me
dia
ne
ro, E
., Sam
an
iego
, M. a
nd
S. J. Wrigh
t. 20
04
. Ge
ne
ral h
erb
ivore
ou
tbre
ak o
f follo
win
g an
El N
iño
rela
ted
dro
ugh
t in a
low
lan
d P
an
am
an
ian
fore
st. J. Trop
. Eco
l. 20
.
AC
KN
OW
LED
GE
ME
NT
SW
ee
spe
cially
tha
nk
M.
He
dd
lea
nd
P.W
elto
n,
wh
oa
reco
-au
tho
rso
nth
ep
ap
er
wh
ere
the
sea
na
lyses
are
inp
ress.
We
also
tha
nk
staff
of
the
Na
tion
al
Pa
rkS
ervice
,G
.S
hish
ido
of
the
Ha
wa
i‘iD
ep
artm
en
to
fLa
nd
an
dN
atu
ral
Re
sou
rces,
M.
Ca
terin
oo
fth
eSa
nta
Ba
rba
raN
atu
ral
Histo
ryM
use
um
for
assista
nce
inth
efie
ld.
C.
Sh
imo
da
of
the
Un
ive
rsityo
f
Ha
wa
i‘ia
ssisted
with
rea
ring
larva
e.
A.
Taylor
an
dC
.D
ae
hle
rp
rovid
ed
inva
lua
ble
fee
db
ack
on
the
an
alyse
s.O
ur
wo
rk
inH
ale
aka
laN
atio
na
lP
ark
wa
sco
nd
ucte
du
nd
er
NP
Sp
erm
itH
ALE
-20
03
-SCI-0
01
0.
Fun
din
gw
as
pro
vide
db
yth
e
Na
tion
alP
ark
Service
,th
eN
atio
na
lScie
nce
Fou
nd
atio
n,
an
dth
eU
.S.D
ep
artm
en
to
fA
gricultu
re.
RE
SU
LTS
(con
tinu
ed
)
Ou
tbre
ak
ing
po
pu
latio
ns
of
S.
pa
lud
icola
are
mo
reo
rle
sssy
nch
ron
ou
s:O
utb
rea
ksin
Ma
kaw
ao
Fore
stR
ese
rvew
ere
rep
orte
dfiv
etim
es
inth
ep
ast
90
inJa
n1
92
6,
Jan
19
46
,Se
p1
97
1,
Jan
19
77
,a
nd
Feb
20
04
(Ha
ine
se
ta
l.in
We
plo
tted
rain
fall
an
dte
mp
era
ture
for
3ye
ars
pre
ced
ing
ea
cho
utb
rea
k,
exam
ine
dth
ese
plo
tsfo
rco
mm
on
pa
ttern
sa
mo
ng
ou
tbre
aks.
On
an
an
nu
al
we
pe
rform
ed
logistic
regre
ssion
an
alyse
s(M
inita
b1
4)
with
clima
ted
ata
pre
dicto
rsa
nd
ab
ina
ryre
spo
nse
(“ou
tbre
ak
ob
serve
d”
or
“no
ou
tbre
ak
ob
serve
d”).
For
ea
cho
utb
rea
k(N
=5
),w
eca
lcula
ted
me
an
so
fra
infa
lla
nd
tem
pe
ratu
refo
ra
12
-mo
nth
pe
riod
pre
ced
ing
the
mo
nth
tha
tth
eo
utb
rea
kw
as
Tore
pre
sen
tco
nd
ition
sd
urin
gn
on
-ou
tbre
ak
pe
riod
s(N
=8
1),
we
use
d1
2-
avera
ges
ba
sed
on
cale
nd
ar
yea
rsfro
m1
91
9-2
00
6,
om
itting
yea
rsth
at
ove
rlap
pe
dw
ithth
e1
2m
on
ths
pre
ced
ing
ou
tbre
aks.
We
starte
dw
itha
full
wh
ichin
clud
ed
rain
fall,
tem
pe
ratu
re,
an
da
nin
tera
ction
term
be
twe
en
two
.W
ep
rogre
ssively
rem
ove
dn
on
-significa
nt
pre
dicto
rsa
tth
ele
vel
.W
ea
lsop
erfo
rme
dse
pa
rate
no
n-p
ara
me
tricM
an
n-W
hitn
ey
U-te
stso
n
an
dte
mp
era
ture
be
twe
en
the
seo
utb
rea
ka
nd
no
n-o
utb
rea
kp
erio
ds.
Ob
serv
atio
ns
of
S.
pa
lud
icola
du
ring
20
03
-20
04
ou
tbre
ak
:co
llecte
dS
.p
alu
dico
laa
du
ltsa
nd
cate
rpilla
rsa
tth
ree
sites.
We
visited
Kip
ah
ulu
Va
lley
twice
,H
ea
lan
io
nce
,a
nd
Ma
kaw
ao
Fore
stR
ese
rvefive
time
s
20
04
.La
rvae
we
reco
llecte
db
ysh
akin
gb
ran
che
sfro
mh
ap
ha
zard
ly
sele
cted
tree
so
nto
aw
hite
,1
m2,
“be
atin
gsh
ee
t”.Se
arch
effo
rtw
as
no
t
qu
an
tified
or
kep
tco
nsta
nt
am
on
gco
llectin
gtrip
s,so
de
nsitie
so
fla
rvae
cou
ld
com
pa
red
ove
rtim
eo
rb
etw
ee
nsite
s.La
rvae
we
reb
rou
ght
ba
ckto
the
lab
ora
tory
an
dso
rted
into
sixsize
classe
sb
ase
do
nh
ea
dca
psu
lew
idth
sa
sa
n
estim
ate
of
larva
la
ge
(1:
0.2
0-0
.30
mm
,2
:0
.45
-0.6
0m
m,
3:
0.7
0-1
.00
mm
,4
:
40
mm
,5
:1
.40
-1.8
0m
m,
6:
>1
.80
mm
).La
rvae
we
rere
are
din
divid
ua
lly
koa
ph
yllod
es
at
23°C
.D
eve
lop
me
nt
wa
sm
on
itore
da
nd
pa
rasito
ids
we
re
pre
serve
da
nd
ide
ntifie
d.
Lifecy
cled
ura
tion
of
S.
pa
lud
icola
isa
pp
rox
ima
tely
2-3
mo
nth
s:
Of
the
47
larva
eth
at
we
reco
llecte
din
the
firstin
star,
16
com
ple
ted
de
velo
pm
en
tto
ad
ulth
oo
din
the
lab
orato
ry.T
he
me
an
de
velo
pm
en
ttim
efro
mfirst
insta
rto
ad
ulth
oo
d
un
de
rla
bo
rato
ryco
nd
ition
sw
as
42
days
(±0
.84
SE,
N=
16
).M
ea
nla
rval
de
velo
pm
en
ttim
e
(from
firstin
star
top
up
atio
n)
un
de
rla
bo
rato
ryco
nd
ition
sw
as
29
.1d
ays(±
0.5
1SE
,N
=8
).B
eca
use
lab
orato
ryco
nd
ition
sw
ere
mo
stlike
lyw
arm
er
tha
nco
nd
ition
sexp
erie
nce
din
the
field
,w
ea
ssum
eth
at
the
sea
reu
nd
ere
stima
tes.
Ho
we
ver,
eve
nif
field
de
velo
pm
en
ttim
e
istw
icew
ha
tw
eo
bse
rved
inth
ela
bo
ratory,
we
estim
ate
age
ne
ratio
ntim
eo
fle
ssth
an
90
days.
Th
isis
con
sisten
tw
ithp
rior
ob
serva
tion
so
fSte
in(1
98
1),
wh
ofo
un
dth
at
ad
ult
mo
ths
be
gan
toe
me
rgee
nm
asse
ab
ou
ttw
om
on
ths
afte
rla
rvae
we
refirst
no
ted
inth
efie
ld.
Pa
rasito
ids
of
S.
pa
lud
icola
:
Mo
st(8
0%
)o
fth
e2
96
larva
eth
at
we
reco
llecte
dd
urin
gth
is
stud
yd
ied
du
eto
pa
tho
gen
so
ru
nkn
ow
nca
use
s,m
akin
git
imp
ossib
leto
calcu
late
me
an
ingfu
lp
ara
sitismra
tes.
Ho
we
ver,
thre
esp
ecie
so
fn
on
-na
tive
pa
rasito
idw
asp
sw
ere
rea
red
from
larv
ae
:th
eb
raco
nid
sM
ete
oru
sla
ph
yg
ma
e
(Fig
.7
)a
nd
Co
tesia
ma
rgin
ive
ntris,
an
dth
eich
ne
um
on
id
Hy
po
sote
re
xig
ua
e.
On
eich
ne
um
on
idh
ype
rpa
rasito
id,
Ge
lis
sp.,
wa
sre
are
da
sw
ell.
Ma
ny
pu
pa
lca
ses
of
M.
lap
hy
gm
ae
an
dH
.exig
ua
ew
ere
also
ob
serve
da
ttach
ed
toko
ab
ran
che
sa
ta
llfie
ldsite
s.N
on
ative
pa
rasito
ids
we
rere
are
d,
alth
ou
gh
this
may
be
an
artifa
cto
fsm
allsa
mp
lesize
du
eto
high
mo
rtality
inla
bo
rato
ryre
are
dla
rvae
.F
igu
re 3
:M
ete
oru
sla
ph
ygma
e,
the
pa
rasito
id m
ost co
mm
on
ly
rea
red
an
d o
bse
rved
in th
e fie
ld.
Tab
le 1
: Re
sults o
f mu
ltiple
logistic re
gressio
n:
Ne
ithe
r rain
fall n
or te
mp
era
ture
wa
s statistica
lly sig
nifica
nt.
Fig
ure
5: C
om
pa
rison
s of (A
) rain
fall a
nd
(B)
ma
ximu
m te
mp
era
ture
du
ring 1
2 m
on
th p
erio
ds
pre
ced
ing o
utb
rea
ks an
d in
no
n-o
utb
rea
k yea
rs,
an
d re
sults o
f Ma
nn
Wh
itne
y U-te
sts.
: De
viatio
ns fro
m m
ea
n m
on
thly ra
infa
ll
an
d te
mp
era
ture
for th
ree
yea
rs pre
ced
ing th
e
five re
cord
ed
histo
rical o
utb
rea
ks of S
. pa
lud
icola
.
Solid
circles d
en
ote
wh
en
ou
tbre
aks w
ere
Th
ere
we
re n
o o
bv
iou
s ex
trem
ities o
r
pa
ttern
s in e
ithe
r rain
fall o
r tem
pe
ratu
re
Fig
ure
6:
Size
classe
s of S
.
pa
lud
icola
larva
e
colle
cted
at th
ree
we
ek in
terva
ls
from
Ma
kaw
ao
Fore
st Re
serve
. At
a give
n tim
e,
larva
e w
ere
mo
stly of a
simila
r
age
. Th
is wa
s true
at a
ll loca
lities
sam
ple
d.
I MP
LICA
TIO
NS
Alth
ou
gho
ur
an
alyse
sfa
iled
tofin
da
significan
tp
red
ictivee
ffect
of
rain
fall,
ou
r
retro
spe
ctivea
pp
roa
chw
as
con
strain
ed
by
seve
ral
pro
ble
ms,
inclu
din
gim
pre
cise
we
ath
er
da
ta,
asm
all
samp
leo
fo
utb
rea
ks,a
nd
the
likelih
oo
dth
at
som
eo
utb
rea
ksw
en
tu
nre
po
rted
inth
elite
ratu
re.
Futu
restu
die
ssh
ou
ldin
clud
eq
uan
titative
mo
nito
ring
of
cate
rpilla
ra
nd
pa
rasito
idp
op
ulatio
ns
du
ring
ou
tbre
aks
an
dn
on
-ou
tbre
ak
pe
riod
s,co
mb
ine
dw
ithm
on
itorin
go
flo
calclim
ate
,in
clud
ing
rain
fall,
tem
pe
ratu
re,
an
d
win
d.
Be
cau
seS.
pa
lud
icola
be
lon
gs
toa
na
dap
tivera
dia
tion
tha
tin
clud
es
bo
th
ou
tbre
akin
ga
nd
no
n-o
utb
rea
king
spe
cies,
inclu
din
go
the
rsp
ecie
sth
at
fee
do
nko
a,
aco
mp
ara
tivea
pp
roa
chm
ight
also
be
info
rma
tive.
