COOPERATIVE NATIONAL PARK RESOURCES STUDIES UNIT UNIVERSITY OF HAWAII AT MANOA

Department of Botany Honolulu, Hawaii 9 6 8 2 2

( 8 0 8 ) 9 4 8- 8 2 1 8

Clifford W. Smith, Unit Director Associate Professor of Botany

Technical Report 29 MITES (CHELICERATA: ACARI) PARASITIC ON BIRDS

IN HAWAII VOLCANOES NATIONAL PARK Technical Report 30

DISTRIBUTION OF MOSQUITOES (DIPTERA: CULICIDAE) ON THE EAST FLANK OF MAUNA LOA VOLCANO, HAWAI'I

M. Lee Goff

February 1 9 8 0

UNIVERSITY OF HAWAII AT MANOA

NATIONAL PARK SERVICE Contract No. CX 8000 7 0009 Contribution N o s . CPSU/UH 0 2 2 / 7

and CPSU/UH 0 2 2 / 8

V

RECOMMENDATIONS

Mosquito popu la t i ons i n Hawaii Volcanoes Nat ional Park a r e

d i r e c t l y r e l a t e d t o t h e numJer of breeding s i t e s a v a i l a b l e .

Whi le i t would be i m p r a c t i c a l tbi even cons ide r t r ea tmen t of t h e

dominant n a t u r a l breeding s i t e s ( t r e e - h o l e s , e t c . ) , i t i s pos-

s i b l e t o reduce t h e number o f a r t i f i c i a l breeding s i t e s a v a i l -

a b l e . The fol lowing measures should be taken:

1. Reduce t h e number of open c o n t a i n e r s which pre-

s e n t l y a c t a s breeding a r e a s i n t h e f o r e s t s of t h e

Park ( e . g . , r a i n b a r r e l s , water t r oughs , d i s ca rded

b o t t l e s and c a n s ) .

2. Proper ly s c r e e n a l l water s t o r a g e a r e a s (wa te r

t anks ) t o p reven t e n t r y of mosquitoes.

3 . Make Park Se rv i ce personne l aware of t h i s problem

s o when they come upon s tand ing wate r , i t can

e i t h e r be e l imina t ed o r repor ted t o t he resource

manager f o r proper a c t i o n .

Vi

4 . During c o n s t r u c t i o n a c t i v i t y b r e e d i n g si tes a r e

f r e q u e n t l y c r e a t e d . One of t h e c o n t r a c t u a l o b l i -

g a t i o n s s h o u l d be t h a t a l l s t a n d i n g water be e l i -

mina ted . The c o n s t r u c t i o n a rea s h o u l d be mon i to red

by t h e r e s o u r c e manager f o r compl i ance .

T r e a t m e n t i n v o l v i n g t o x i c a g e n t s i s n o t recommended a t t h i s time

and it is d o u b t f u l t h a t p o p u l a t i o n s o f m o s q u i t o e s w i l l reach

l e v e l s a t w h i c h s u c h t r e a t m e n t w i l l be i n d i c a t e d .

vii

TABLE OF CONTENTS

. .

A B S T R A C T . . . . . . . . . . . . . . . . . . . . . . . . . . i v

RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . V

L I S T OF TABLES. . . . . . . . . . . . . . . . . . . . . . . V i i i

L I S T O F F I G U R E S . . . . . . . . . . . . . . . . . . . . . . V i i i

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . 15

MATERIALS AND METHODS . . . . . . . . . . . . . . . . . . . 1 5

R E S U L T S . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7

L a r v a e and Pupae. . . . . . . . . . . . . . . . . . . . 1 7

E g g s . . . . . . . . . . . . . . . . . . . . . . . . . . 1 9

A d u l t s . . . . . . . . . . . . . . . . . . . . . . . . . 1 9

D I S C U S S I O N . . . . . . . . . . . . . . . . . . . . . . . . . 2 1

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . 2 2

LITERATURE C I T E D . . . . . . . . . . . . . . . . . . . . . . 23

v i i i

L IST OF TABLES

Table

1. Col lec t ion record o f mosquito l a rvae from the samplinq s t a t i o n s alonq the two t r a n s e c t s on the e a s t f lank o f Mauna Loa volcano. . . 25

2 . Col lec t ion record of mosquito l a rvae by e l eva t ion on the e a s t f lank o f Mauna Loa volcano. . 27

3 . Total number of a d u l t Culex quinquefasciatus co l l ec ted per month from l i g h t t r a p s on the i s land of Hawai'i . . . . . . 28

L I S T OF FIGURES

Figure

1. Locations of sample s t a t i o n s on e a s t f lank of Mauna Loa volcano. . . . . . . . . . 16

2 . Locations o f l i g h t t r a p s operated by Vector Control Branch, Hawaii S t a t e Department o f Health . . . . . . . . . . 20

15

I N T R O D U C T I O N

There have been four spec ies of blood-feeding mosquitoes introduced i n t o t h e Hawaiian Is lands . Two of these , Aedes aegypti (Linnaeus, 1 7 6 2 ) and - A. a lbop ic tus (Skuse, 1 8 9 5 ) , a r e day- bi te rs ; the o ther two, A. vexans nocturnus (Theobald, 1 9 0 3 ) and Culex guinquefasc ia tus Say, 1823 , a r e n igh t- b i t e r s . Four add i t iona l predatory spec ies have been introduced f o r b io log ica l con t ro l (Hardy 1 9 6 0 ) ; Toxorhynchites amboinensis (Dolescha l l ) ;

b rev i a1 u s Theobald; T . inornatus (Walker); and - T. theobaldi fiya- O f these f o u r p reda to r s , o n l y T. amboinensis appears t o have become well e s t ab l i shed ( S t e f f a n 1 9 6 8 ) .

- Culex p i n ue fasc ia tus has been implicated i n the t rans- m i s s i o n of f ik-nucherer i a bancrof t i ) , dog hear tworm ( D i r o f i l a r i a i m m i t i s ) , avian malar ia , and fowl pox and may poss ib ly be i m m a t e d i n t ransmission of severa l v i r a l agents including Japanese B-type e n c e p h a l i t i s (Hardy 1 9 6 0 ) . Aedes albo- p i c t u ? is a vector of dengue f e v e r , dog heartworm, a n - p s e B-type e n c e p h a l i t i s (Hardy 1 9 6 0 ) and is l i s t e d a s a minor vector o f avian malar ia (Plasmodium s p . ) by Boyd ( 1 9 4 9 ) . Aedes a e g e is the major vector o f yellow fever a s well a s transmittimg dengue and avian malar ia (Boyd 1 9 4 9 ; Hardy 1 9 6 0 ) . - Aedes vexans nocturnus i s a vector for dog heartworm, fowl pox (exper i - m e n t a m , and various encephalides (Joyce 6 Nakagawa 1 9 6 3 ) . The Vector p o t e n t i a l s l i s t e d above have resu l t ed i n a su rve i l l ance o f these spec ies i n a reas around human h a b i t a t i o n by the Vector Control Branch, Hawaii S t a t e Department of Health. Their d i s t r i - bution i n unpopulated a reas of Hawai'i i s l a r g e l y unknown, w i t h the exception of work by Warner ( 1 9 6 8 ) concerning - C . Yuinque- f a s c i a t u s on the i s land of Kaua' i .

Five spec ies o f mosquitoes a r e known from the i s land of Hawai'i. Of the four blood-feeding spec ies , th ree a r e c u r r e n t l y reported : A. a lbop ic tus , A. -ti, and C . gu inquefasc ia tus . However, no specimens of-A. aeqypti were-recovered during the c u r r e n t s t u d y . The four th srjecies, A . vexans nocturnus, f i r s t reported i n the Hawaiian Islands- i n 1 9 6 2 , h a s n o t ye t been recovered on Hawai' i. The predatory Toxorhynchites amboinensis has been reported from Hawai'i b u t was not recorded during the present s tudy;

MATERIALS AND METHODS t

Twenty-one sample s t a t i o n s were e s t ab l i shed ( F i g . 1) ranging from sea l e v e l to 6 0 0 0 f e e t ( 2 0 0 0 m ) . They a r e p a r t of two t ran- s e c t s along an e l e v a t i o n a l g rad ien t . One t r a n s e c t i n r a i n f o r e s t environments (sample s t a t i o n s 1 - 1 0 ) runs from H i l o t o the Krlauea

16

H A W A I I

FIGURE 1. Loca t ions of sample s t a t i o n s on east f l a n k of flauna Loa volcano. Numbers refer t o Table 2 .

1 7

. C

Fores t R e s e r v e ; t h e o t h e r i n d r y s e a s o n a l f o r e s t ( s a m p l e s t a t i o n s 1 1- 2 1 ) r u n s f rom Ka lapana t o t h e t o p o f t h e Mauna Loa S t r i p Road. Sampl ing was d o n e a t mon th ly i n t e r v a l s from November 1977 t h r o u g h March 1979.

A r t i f i c i a l o v i p o s i t i o n s i t e s c o n s i s t i n g of t h r e e e a c h o f c o c o n u t s , # 1 0 metal c a n s , and S ty ro foam c o n t a i n e r s were p r o v i d e d a t e a c h s t a t i o n . C o n t a i n e r s were checked f o r e g g s , l a r v a e , and pupae e a c h month, and t h e c o n t e n t s o f o n e o f e a c h t y p e c o n t a i n e r removed f o r e x a m i n a t i o n i n t h e l a b o r a t o r y . P o t e n t i a l n a t u r a l o v i p o s i t i o n s i t e s ( g r o u n d p o o l s , hZpu 'u s t u m p s , t r e e - h o l e s , l e a f a x i l s , e c t . ) were l o c a t e d a t e a c h s t a t i o n and checked mon th ly f o r l a r v a l a c t i v i t y .

M o n i t o r i n g o f a d u l t p o p u l a t i o n s o f Culex g u i n q u e f asc i a t u s f o r t h e i s l a n d o f Hawai ' i is c a r r i e d o u t on a c o n t i n u i n g b a s i s by t h e Vector C o n t r o l Branch , Hawaii S t a t e Depa r tmen t o f H e a l t h , u s i n g a s e r i e s o f 30 l i g h t t r ap s o p e r a t e d 24 h o u r s p e r d a y . Coun t s from t h e s e t r a p s were made a v a i l a b l e f o r t h i s s t u d y . S u p p l e m e n t a l t r a p p i n g a t each o f t h e 2 1 s t a t i o n s was d o n e on a mon th ly b a s i s from November 1977 t o March 1 9 7 8 , u s i n g s t a n d a r d N e w J e r s e y Mosqui to L i g h t Traps , b o t h u n b a i t e d and w i t h a COO a t t r a c t a n t . Due t o poo r r e s u l t s and l o s s o f t r a p s , t h i s s ampl ing method was d i s c o n t i n u e d i n Apr i l 1978 . B i t i n g - c o l l e c t i o n s d e r e made on a m o n t h l y b a s i s f o r b o t h C. g u i n q u e f a s c i a t u s and A2des a l b o p i c t u s . A d d i t i o n a l b i t i n g c o T l e c t i o n s f o r C . u inque- f a s c i a t u s were made by v o l u n t e e r s d u r i n g J u l y and Eecem9ber 1978 and F e b r u a r y 1979 .

RESULTS

L a r v a e and Pupae

L a r v a e and pupae of Cu lex g u i n q u e f a s c i a t u s were r e c o v e r e d from a r t i f i c i a l o v i p o s i t i o n s i t e s a t s t a t i o n s f rom sea l e v e l t o 5000 f e e t ( 1 6 5 0 m ) ( T a b l e s 1 & 2 ) . B reed ing p o p u l a t i o n s were p r e s e n t a t S t a t i o n 1 ( s ea l e v e l ) , S t a t i o n 7 a t 3500 Eeet (1200 m ) , and S t a t i o n 1 8 a t 4 0 0 0 f e e t ( 1 3 5 0 m ) d u r i n g t h e e n z i r e s t u d y p e r i o d .

S t a t i o n 9 a t 4500 f e e t ( 1500 m ) , l o c a t e d on Keauhou R a i c h , had a b r e e d i n g p o p u l a t i o n p r e s e n t d u r i n g a l l months f o r w i i c h d a t a was a v a i l a b l e . Dur ing t h e months f rom F e b r u a r y t h r o u g h May and J u l y 1 9 7 8 , t h e a r t i f i c i a l o v i p o s i t i o n s i t e s a t t h i s l o c a t i o n were d e s t r o y e d by a c t i v i t i e s o f c a t t l e and p i g s . Sampl ing o f n a t u r a l o v i p o s i t i o n s i t e s a t S t a t i o n 9 r e v e a l e d l a r v a e p r e s e n c i n a t r e e - h o l e d u r i n g March, A p r i l , and J u l y . Thus , l a r v a e were n o t o b s e r v e d a t S t a t i o n 9 f o r o n l y two sample p e r i o d s , F e b r u a r y and May.

18

S t a t i o n s 5 and 1 5 a t 2700 f e e t ( 9 0 0 m ) showed l a r v a l a c t i v - i t y , b u t n o t on a c o n t i n u o u s bas i s . The r e l a t i v e l y c o n s t a n t s t r o n g winds , r e l a t i v e l y low r a i n f a l l , and f e w n a t u r a l o v i p o s i - t i o n s i tes a v a i l a b l e a t S t a t i o n 1 5 t e n d t o l i m i t mosqu i to a c t i v - i t y . La rvae were c o l l e c t e d h e r e d u r i n g t h e months o f J a n u a r y t h r o u g h March, c o r r e s p o n d i n g w i t h t h e a n n u a l p e r i o d of i n c r e a s e d r a i n f a l l (December t h r o u g h A p r i l ) . V e g e t a t i o n a t S t a t i o n 1 5 c o n s i s t e d p r i m a r i l y o f g r a s s e s , s c a t t e r e d s h r u b s , and t r e e s ( ' C h i l a and k o a ) . Lava s u b s t r a t e a t t h i s s t a t i o n was t o o p o r o u s t o m a i n t a i n ground p o o l s s u f f i c i e n t f o r l a r v a l deve lopmen t . Ground p o o l s were o b s e r v e d a t tiiis s t a t i o n o n l y d u r i n g t h e p e r i o d December 1978 t h r o u g h F e b r u a r y 1979 , when t h e r e was u n u s u a l l y heavy r a i n f a l l r e s u l t i n g i n f l o o d i n g o v e r a ma jo r p o r t i o n of t h e i s l a n d . P o t e n t i a l n a t u r a l o v i p o s i t i o n s i t e s c o u l d n o t be l o c a t e d a t S t a t i o n 15 .

A s i t u a t i o n s imilar t o t h a t a t S t a t i o n 1 5 was e n c o u n t e r e d w i t h r e g a r d t o r a i n f a l l , v e g e t a t i o n , and n a t u r a l o v i p o s i t i o n s i tes a t S t a t i o n 1 4 (600 m ) . Here C. g u i n q u e f a s c i a t u s l a r v a e were t a k e n o n l y i n F e b r u a r y and March-1978.

S t a t i o n 5 was l o c a t e d i n a r a i n f o r e s t w i t h a n abundance of p o t e n t i a l n a t u r a l o v i p o s i t i o n s i t e s , i n c l u d i n g ground p o o l s , h z p u ' u s t u m p s , and t r e e - h o l e s . However, C . g u i n q u e f a s c i a t u s l a r v a e were r e c o v e r e d from t h i s s t a t i o n o n l y T u r i n g September and Oc tobe r 1978 .

Culex g u i n q u e f a s c i a t u s l a r v a e were r e c o v e r e d on a n i r r e g u l a r basis- a r t i f i c i a l o v i p o s i t i o n s i t e s a t s t a t i o n s from 4 5 0 f e e t t o 1800 f e e t ( 1 5 0 m-500 m ) , b u t were o b s e r v e d r e g u l a r l y i n n a t u r a l o v i p o s i t i o n s i tes a t a l l s t a t i o n s e x c e p t S t a t i o n 1 4 , a s p r e v i o u s l y n o t e d .

A l though C . g u i n q u e f a s c i a t u s l a r v a e were r e c o r d e d o n l y o n c e i n t h e a r t i f i c i a l o v i p o s i t l o n s i t e s p r o v i d e d a t S t a t i o n 1 0 a t 5000 f e e t (1650 m ) , o t h e r r e c o r d s a r e a v a i l a b l e from h i g h e r e l e v a t i o n s on t h e i s l a n d o f Hawai ' i . Swezey and Will iams ( 1 9 3 2 ) r e p o r t e d egg r a f t s from a r a i n b a r r e l a t 5500 f e e t (1850 m ) on M t . H u a l a l a i and l a r v a e i n a p o o l a t 6 0 0 0 f e e t ( 2 0 0 0 m ) a t N a u h i , Mauna Kea. Komatsu ( 1 9 6 6 ) r e p o r t e d b o t h egg r a f t s and l a r v a e from c o n c r e t e p o o l s a t t h e PEhakuloa NFnG Farm a t 6 0 0 0 f e e t ( 2 0 0 0 m ) . While t hese r e c o r d s d o n o t i n d i c a t e a permanent breed- i n g p o p u l a t i o n o f C. g u i n q u e f a s c i a t u s , r e s u l t s o f l a r v a l s a m p l e s i n t h e c u r r e n t s t u r y l n d i c a t e a permanent p o p u l a t i o n a t 4500 f e e t (1500 m ) .

L a r v a e and pupae o f Aedes a l b o p i c t u s were r e c o v e r e d from a r t i f i c i a l o v i p o s i t i o n s l t es and i n " n a t u r a l " o v i p o s i t i o n s i t e s , p r i m a r i l y d i s c a r d e d c a n s , t i r e s , and human r e f u s e , up t o 9 0 0 f e e t ( 3 0 0 m ) f o r a l l months o f t h e s t u d y . Recovery o f A . a l b o p i c t u s l a r v a e a t S t a t i o n 4 a t 1800 f e e t ( 6 0 0 m ) and S t a F i o n 5 a t 2 7 0 0 f e e t ( 9 0 0 m ) was a s s o c i a t e d w i t h a reas o f human a c t i v i t y ( con- s t r u c t i o n e q u i p m e n t ) . La rvae were p r e s e n t a t t hese e l e v a t i o n s o n l y f o r t h e p e r i o d o f t h e a c t i v i t y and were n o t r e c o v e r e d from

L .

1 9

a r t i f i c i a l o v i p o s i t i o n s i t e s d u r i n g sampl ing e i t h e r p r i o r t o o r f o l l o w i n g s u c h a c t i v i i t y . No A . a l b o p i c t u s l a r v a e were r e c o v e r e d a t s t a t i o n s above 2 7 0 0 f e e t ( 9 5 0 m ) .

Eggs

Egg r a f t s w e r e- c o l l e c t e d from 5 0- g a l l o n w a t e r drums l o c a t e d a t S t a t i o n 18 (Kipuka K i ) from November 1977 t h r o u g h October 1978 , a t which p o i n t t h e drums were removed by t h e N a t i o n a l P a r k S e r v i c e . - C u l e x g u i n q u e f a s c i a t u s was t h e o n l y m o s q u i t o s p e c i e s o v i p o s i t i n g a t t h i s s t a t i o n . During t h i s p e r i o d 46 egg r a f t s were removed from t h e drums. A mean o f 1 7 1 e g g s / r a f t was c a l- c u l a t e d w i t h a r a n g e o f 9 1 t o 273 e g g s / r a f t . No a n n u a l v a r i a t i o n i n numbers o f e g g s p e r r a f t was o b s e r v e d and mon th ly mean v a l u e s ranged from 1 4 6 t o 1 9 3 e g g s / r a f t .

Four C. g u i n q u e f a s c i a t u s egg r a f t s werg removed from a r t i - f i c i a l o v y p o s i t i o n s i t e s a t S t a t i o n 1 5 (Kipuka Ngng) i n J a n u a r y 1978. A mean o f 177 e g g s / r a f t was c a l c u l a t e d f o r t h i s c o l l e c t i o n w i t h a r a n g e o f 130 t o 213 e g g s / r a f t .

Egg r a f t s were c o l l e c t e d from g round p o o l s n e a r sea l e v e l from November 1 9 7 7 t h r o u g h Oc tobe r 1978 . During t h i s p e r i o d 5 2 egg r a f t s were c o l l e c t e d . A mean o f 179 e g g s / r a f t was c a l c u l a t e d f o r t h i s c o l l e c t i o n w i t h a r a n g e o f 1 2 0 t o 260 e g g s / r a f t .

Thus t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n numbers o f e g g s p e r r a f t w i t h e l e v a t i o n from sea l e v e l t o 4 0 0 0 f e e t (1350 m) i n t h e p r e s e n t s t u d y ( t = 1 . 6 7 ; d f = 96; P > 0 . 0 5 ) . No egg r a f t s were r e c o v e r e d a t s t a t i o n s above 4 0 0 0 f e e t i n t h e c u r r e n t s t u d y .

Eggs o f Aedes a l b o p i c t u s were n o t sampled d u r i n g t h e p r e s e n t s t u d y .

A d u l t s

R e s u l t s o f l i g h t t r a p s o p e r a t e d by t h e V e c t o r C o n t r o l Branch , Hawaii S t a t e Depar tment o f H e a l t h , a t l o c a l i t i e s i n d i - c a t e d i n F i g u r e 2 , a r e g i v e n i n T a b l e 3 . T h e s e t r a p s were p r i - m a r i l y o p e r a t e d i n a reas o f human a c t i v i t y and a t e l e v a t i o n s below 2700 f e e t (900 m ) . These r e s u l t s show a p o p u l a t i o n of - Culex p i a s c i a t u s p r e s e n t i n a l l l o c a l i t i e s sampled on a y e a r round s , a l t h o u g h more numerous from A p r i l t h r o u g h September . t r a p s .

As e x p e c t e d , species o f - Aedes were n o t t a k e n i n l i g h t

I n t h i s s t u d y , s t a n d a r d N e w J e r s e y Mosqui to L i g h t T r a p s were used a l o n g t h e Mauna Loa t r a n s e c t s ( F i g . 1) and sampled month ly from November 1 9 7 7 t h r o u g h A p r i l 1978 . R e s u l t s from t h e s e t r a p s were n e g a t i v e when used e i t h e r w i t h a C 0 2 a t t r a c t a n t o r w i t h o u t an a t t r a c t a n t .

Culex g u i n q u e f a s c i a t u s a d u l t s were f r e q u e n t l y o b s e r v e d a t l o w e r e l e v a t i o n s t a t i o n s , and e g g s , l a r v a e , and pupae were

20

FIGURE 2. Loca t ions of l i g h t t r a p s ope ra t ed by Vector Cont ro l Branch, Hawaii S t a t e Department of Heal th . Numbers r e f e r t o Table 2 .

2 1

sampled. Both male and female C. q u i n q u e f a s c i a t u s were o b s e r v e d r e g u l a r l y a t S t a t i o n 1 8 (Kipuka K i , 1350 m ) i n t h e v i c i n i t y o f o v i p o s i t i o n s i t e s .

B i t i n g c o l l e c t i o n s a t a l l s t a t i o n s d u r i n g t h i s same p e r i o d were n e g a t i v e f o r C. g u i n q u e f a s c i a t u s . B i t i n g c o l l e c t i o n s o f A. a l b o i c t u s were m<de i n e a r l y morning and w i t h p o s i t i v e y e s e a t i o n s up t o 9 0 0 f e e t ( 3 0 0 m ) . B i t e s r anged from 1 5 t o 30 i n a 10-minute p e r i o d w i t h no s i g n i f i c a n t v a r i a t i o n ob- s e r v e d f o r t h e s t u d y p e r i o d a l t h o u g h h i g h e r numbers tended t o o c c u r i n t h e warmer summer months .

A d u l t f e m a l e s o f A. a l b o p i c t u s were o b s e r v e d b i t i n g i n December 1277 and J a n u z r y T978 a t S t a t i o n 18 (Kipuka K i ) and one female a t Kilauea F o r e s t Rese rve i n A p r i l 1978 .

D I S C U S S I O N

Based on s t u d i e s c o n d u c t e d on K a u a ' i , Warner ( 1 9 6 8 ) i n d i - c a t e d t h a t d i s t r i b u t i o n of -L11.-r Culex g u i n q u e f a s c i a t u s i s r e s t r i c t e d t o e l e v a t i o n s below 2100 f e e t ( 7 0 0 m ) . R e s u l t s o f t h e c u r r e n t s t u d y on Hawail i p r e s e n t a c o n s i d e r a b l y d i f f e r e n t p i c t u r e . C o l l e c t i o n s o f e g g s , l a r v a e , a n d pupae i n d i c a t e b r e e d i n g popula- t i o n s of C. g u i n q u e f a s c i a t u s p r e s e n t f o r t h e e n t i r e y e a r a t e l e v a t i o n s up t o 4500 f e e t (1500 m ) . A d u l t s o f C . u inque- f a sc i a tu s were o b s e r v e d mon th ly a t S t a t i o n 1 8 (Kipuk; K i ) g w i t h a n e l e v a t i o n o f 4 0 0 0 f e e t (1350 m ) . D i s t r i b u t i o n o f C. u inque- f a s c i a t u s was, however , un i fo rm t h r o u g h o u t i t s a l t i f u d i n z l r a n g e but v a r i e d c o r r e s p o n d i n g t o d e g r e e o f v o l c a n i c a c t i v i t y i n t h e s t u d y area o n t h e e a s t f l a n k o f Mauna Loa v o l c a n o . S t a t i o n s i n t h e p r e s e n t s t u d y below 3300 f e e t ( 1 1 0 0 m ) were l o c a t e d i n a r e a s w i t h a r e l a t i v e l y un i fo rm v e g e t a t i o n c o v e r and w i t h many a v a i l - able o v i p o s i t i o n s i tes. Above t h i s e l e v a t i o n , i r r e g u l a r i t i e s i n p a t t e r n s o f l a v a f l o w s from r e c e n t e r u p t i o n s have r e s u l t e d i n t h e f o r m a t i o n o f k r p u k a s ( p o c k e t s o f u n d i s t u r b e d v e g e t a t i o n - s u r - rounded by r e l a t i v e l y bar ren l a v a f l o w s ) . W i t h i n t h e k i p u k a , t h e r e a re o v i p o s i t i o n s i t e s f o r m o s q u i t o e s and v e g e t a t i o n p ro- v i d i n g b o t h food and r o o s t i n g s i t e s f o r b i r d and mammal h o s t s . P r e d i c t a b l y , C. s u i n q u e f a s c i a t u s a c t i v i t y o b s e r v e d i n t h i s s t u d y was c o n c e n t r a T e d i n t h e s e k i p u k a s .

T h i s phenomenon i s well i l l u s t r a t e d by t h e l a r v a l col-lec- t i o n s a t S t a t i o n s 1 8 and 1 8 a . S t a t i o n 1 8 was l o c a t e d i n Kipuka K i a t a n e l e v a t i o n o f 4 0 0 0 f e e t (1350 m ) . V e g e t a t i o n c o v e r con- s i s t e d o f koa and ' E h i ' a t r e e s w i t h a n u n d e r s t o r y o f pzkiawe and g r a s s e s . C . g u i n q u e f a s c i a t u s were r e c o r d e d from t h i s s t a t i o n i n e x p e r i m e n t x l o v i p o s i t i o n s i tes a s wel l a s n a t u r a l s i t e s , i n c l u d - i n g ha'pu'u stumps, t r e e - h o l e s , and ground p o o l s . The ma jo r b r e e d i n g s i t e s a t t h i s s t a t i o n were t r e e - h o l e s . S t a t i o n 1 8 a was l o c a t e d on exposed l a v a w i t h g r a s s e s and low koa t r e e s some 150 f e e t ( 5 0 m ) o u t s i d e o f Kipuka K i . A s shown i n T a b l e 1, no l a r v a e were r e c o v e r e d from a r t i f i c i a l o v i p o s i t i o n s i t e s p r o v i d e d . A d d i t i o n a l l y , no n a t u r a l b r e e d i n g s i t e s c o u l d be l o c a t e d i n t h e

22

immediate v i c i n i t y o f S t a t i o n 18a and the re was minimal indica- t i o n s of any hos t a c t i v i t y although 150 f e e t ( 5 0 m ) d i s t a n t a t S t a t i o n 18 t h e r e was a s t a b l e breeding population of - C. guinyue- f a s c i a t u s and considerable hos t concentrat ion.

A s imi la r s i t u a t i o n was observed fo r o ther klpukas i n t h e s t u d y a rea . Dis t r ibu t ion of C. gu inquefasc ia tus a t e l evg t ions above 3300 f e e t ( 1 1 0 0 m ) coincidTd w i t h the presence of kipukas caused by volcanic a c t i v i t y . T h i s d i s t r i b u t i o n , combined w i t h the increased b i rd and mammal a c t i v i t i e s associated w i t h the kipuka, would appear t o increase the vector p o t e n t i a l o f even a small population o f - C. quinquefasciatus .

Taylor and Maffi ( 1 9 7 8 ) i nd ica te t h a t ground pools , d i t c h e s , and l a r g e a r t i f i c i a l con ta ine r s were the p r i n c i p a l breeding s i t e s f o r C. gu inquefasc ia tus i n the South P a c i f i c . I n c o n t r a s t , the main-natural breeding s i t e s fo r C . su inquefasc ia tus a t S t a t i o n 18 were t ree- holes . T h i s was obserTed a l s o a t o ther s t a t i o n s . Lack of permanent ground pools due t o the porous na ture of the lava s u b s t r a t e precludes t h i s a s a breeding s i t e a t most of the s t a- t i o n s above 3300 f e e t ( 1 1 0 0 m ) . Standing water i n t ree- holes and hZpu'u stumps a t s t a t i o n s loca ted i n kipukas is abundant and se rves here a s the main na tu ra l breeding s i t e s . Additional

and water troughs placed i n the kipukas by the National Park Service.

breeding of guinguefasciatus was observed i n l a r g e o i l drums

Aedes albo l c t u s on the e a s t f lank of Mauna Loa volcano was prima- w i t h human a c t i v i t i e s and r e s t r i c t e d t o e l eva t ions below 9 0 0 f e e t ( 3 0 0 m). Although the re were th ree females observed b i t i n g a t e l e v a t i o n s o f 4 0 0 0 f e e t (1350 m ) and 5000 f e e t (1650 m ) , no permanent populat ions appeared t o ex i s t and these inc iden t s were i n a reas associa ted w i t h human a c t i v i t y .

T h u s , p a t t e r n s of d i s t r i b u t i o n fo r C . gu inquefasc ia tus given by Warner ( 1 9 6 8 ) for Kaua'i do not appeaF on Hawai'i. The cur- r e n t s t u d y suggests t h a t the "mosquito- free sanctuary" above 1 8 0 0 f e e t ( 6 0 0 m ) fo r Hawaiian b i r d s does not e x i s t on the e a s t f lank o$ Mauna Loa. I n f a c t , due t o the concentrat ing mechanism of the kipuka a t e l e v a t i o n s above 3300 f e e t ( 1 1 0 0 m ) , the b i r d s and mosquitoes l i v e i n c lose a s soc ia t ion providing an idea l s i t u a t i o n fo r transmission o f avian malar ia and other such d i s e a s e s among t h e endemic and introduced b i rds .

ACKNOWLEDGMENTS

I am g r a t e f u l t o many ind iv idua l s for t h e i r a s s i s t a n c e i n t h i s p ro jec t . Thanks a r e extended t o Dr. C . van Riper 111, S . van Riper, M. Quick, and the members o f the Earthwatch teams f o r t h e i r a s s i s t a n c e . I am g r a t e f u l t o Dr. W . A. S t e f f a n , B i shop Museum, f o r a review of the manuscript , and t o Betty Cunningham f o r a s s i s t a n c e i n prepara t ion of the manuscript. L i g h t t r a p co l- l e c t i o n d a t a f o r the i s land of Hawai'i was provided through the

23

c o u r t e s y Of t h e Vector Cont ro l B ranch , Hawaii S t a t e D e p a r t m e n t of H e a l t h . S t u d i e s upon wh ich t h i s paper i s b a s e d were s u p p o r t e d by C o o p e r a t i v e N a t i o n a l P a r k R e s o u r c e s S t u d i e s U n i t C o n t r a c t CX 8000-7-0009 t o t h e U n i v e r s i t y o f Hawaii.

LITERATURE C I T E D

Boyd, M. F. ( E d . ) . 1949 . M a l a r i o l o g y . Vols . I and 11. W. B. S a u n d e r s Co., P h i l a d e l p h i a . Pp. x x i + 1- 1487.

Hardy , D. E. 1960 . I n s e c t s of Hawaii. Vo l . 1 0 . Dip te ra : Nematocera - B r a c h y c e r a . U n i v e r s i t y o f Hawaii P r e s s , H o n o l u l u . Pp. ix + 1-368.

J o y c e , C . R . , and P. Y . Nakagawa. 1963 . Aedes vexan_ n o c t u r n i s ( T h e o b a l d ) i n Hawaii. P r o c . H a w . E n t G SOC. 18 : 273-280.

Komatsu, G. 1966 . Notes and e x h i b i t i o n s . Proc. H a w . En tomol . SOC. 19 : 150 .

S t e f f a n , W . A. 1968 . Hawa i i an T o x o r h y n c h i t e s (D ip te ra : C u l i - c i d a e ) . P r o c . H a w . En tomol . SOC. 20: 141- 155.

Swezey, 0. H . , a nd F. X . Williams. 1932 . Some o b s e r v a t i o n s o n f o r e s t i n s e c t s a t t h e Nauhi N u r s e r y and v i c i n i t y on Hawaii. P r o c . Haw. En tomol . SOC. 8 : 179- 195.

T a y l o r , B . , and M. M a f f i . 1978 . A r e v i e w o f t h e m o s q u i t o f a u n a of t h e Solomon I s l a n d s ( D i p t e r a : C u l i c i d a e ) . P a c i f i c I n s e c t s 1 9 : 165- 248.

Warner , R. E. 1968 . The r o l e o f i n t r o d u c e d d i s e a s e s i n t h e e x t i n c t i o n o f t h e endemic Hawa i i an a v i f a u n a . Condor 70 : 101- 120.

TABLE 1. Collect ion record of msqUito larvae frm the sampling s t a t i o n s along the two transects on the east flank of m~na h a volcano (A = _ _ _ . ~edes albopictus larvae; C = Culex quinquefasciatus larvae; * = m i p o s i t i o n sites disturbed, m data; 1 =. Sta t ion not y e t established).

E l ev . 1977 1978 1979 Sta t ion (n;) Location Nov. Gec. Jan. Feb. Mar. Apr. May June Ju ly Aug. Sep. Oct. Nov. Cec. Jan.

1

2

3

4

5

6

7

a 9

10

11

1 2

13

14

0

150

300

600

900

1050

1200

1350

1500

1650

0

300

600

600

~~. ~

Hilo A i r p r t AC AC C C C C C C C AC C C C

Hilo Zoo 1 1 A A A A A A A

Lower Killani A A A A A AC A A AC AC AC A

AC AC A

A C C C

-- -- -- --

--

-- -- -- -- -- -- -- -- -- A

A

C

Upper KGlani

Lower Volcano

Upper Volcano

A v i a n Disease Lab. C C C C C C C C C C C AC

Lower Keauhou

-- -- -- -- -- -- -- --

-- I -- -- -- -- -- -- -- -- -- --

--

-- C -- C -- -- -- -- I -- -- -- --

C * C C C C * * -- -- Uppr Keauhou C C C

-- -- -- -- -- -- -- -- - -- - C K k ? u e a Forest €&serve --

Kal apana 1 1 A A A AC A A A A A A A

Keaouhana Forest 1 1 A A A A A A A A A A A

C C

2 6 I

I

I I

c

c

I I

c

c

I

I I

I I

V

V

V

I I

la ,

4 9 2

1.4 M

0 0 cn

ul r - i

I

I

I

I

I I

V

c

c

I

I

I

I I

I 1

I I

I

2 8 rrJ rl

Y 0 M

0 In 0 rl

Q rl

I

I I

I

I I

I I

I I

c

c

I

I

I I

I

I I

I I

I I

V h LI a U .rl rl

3 9 a

a rl 1.d M

0 0 cu rl

P rl

c

V

V

V

V

V

I

V

V

V

V

V

V

V

V

.rl M

9 2

1.4 M

0 Ln m r - l

05 rl

I I

I

I

I

I

I

I

I

I

I

I I

I

I

I I

I 1

h

a

rl

.rl M rrJ Y

1.4 M

% Y

3 4

0 In m r l

a co rl

I

I I

I

I I

I I

I

I

I I

I I

I

I I

I I

I I

I I

I I

h

3 1 s!

v

a .rl L1 U m

0 0 Ln r-i

m 4

I

I I

I I

I

I I

I

I

I

I

I I

I

I

I

I

I I

3 0 G-l

3 * 0

d

2 0 Ln w rl

0 (u

I I

I I

I I

I

I I

I I

c

c

I I

I

I I

I I

I I

I

I I

7l s! a .?-I L1 U m w 0

8 E-c

0 0 0 cu

rl (u

' l ? ~ L E 2- Collection record of mosquito larvae by elevation on the east flank of Mauna ma volcano ( A = Aedes albopictus larvae; C = C U k X - quinquefasciatus larvae; * = Oviposition sites disturbed, no data; - = No larvae present),

Elev , 1977 1978 1979 (m) Nov Dec Jan Ekb Mar Apr May Jun J u l Aug Sep Oct Nov Dec Jan

0 AC

-- 150

300 A

600

900

1050

1200 C

1350 C

1500 C

1650

2000

-

-

-

--

AC

-- A

A

AC

C

C

C

* -

-

AC

A

A

* * -

*C

C

*C

I

*

Ac

A

A

* * --

*C

* * I

*

Ac

AC

AC

C

A

-

C

C

C

C

--

Ac

A

AC

AC

*C

-

C

C

C

I

-

AC

A

AC

AC

*C

-

C

C

C

I

--

AC

A

A

*A

C

-

AC

C

C

I

--

AC

AC

A

A

A

-

C

*C

C

--

-

WLE 3. mtal nunher of adult Culex quinquefasciatus collected per mnth fran light traps on the island of Hawai'i (* = trap mlfunction),

I 1977 1978 1979 May June J u l y Aug. Sep. Oct. Nov. Dec. Jan. I

&P Number Wality I Nov. Dec. Jan. Feb. Mar. Apr.

1

2

3

4

5

6

7

8

9

10

11

12

13

1 4

15

16

Kapiol ani

Kea' au

WaTakea

H i l o Wharf

Old Airport

P i ' ihonua

Keaukaha

KaGana

Municipal Golf Course

Kdlaniana' ole

Hakalau

LaupZhoehoe

Pah?ja

M t . V i ew

'0 ' Ckala

Kea' a u

1 9

104

11

9

13

8

8

5

86

23

14

22

0

4

72

95

30

181

10

4

10

3

11

11

46

17

7

41

6

10

45

343

55

97

4

25

7

0

17

12

33

27

27

67

4

15

31

263

15 11 33

35 241 751*

1 7* 14

8 3 1*

1 2 1*

6 2 3

2 6* 22

3 11 18

9 1 9 152

82 76 193

O* 10 29

2 4 4

0 5 63

3 7 37

16 15 21

67 523 121

104

980

25

5

0

16

70

42

34 8

42

13

7

98*

24

11

52

54

20 5

52

7

0

6

103

1 2

409

43

25*

2

31

25

21

7

184 80

373 1941

15 27

33 13

2 3

9 0

21 113

27 95

461 980

360 237

13 2

1 2 0

119 257

83 82

44 34

20 57

17*

323

1 4

8

1

2*

16 * 32*

507

25

3

4

65

15

48

53

16

361

18

30

0

13

92

7*

531

26

1

31

117

57

476

74

23

147

24

14

1

13

13

1*

91

51

1*

24

6*

18

86

24

32 11*

184 36

8 3*

14 2"

1 3

8 3

76 21

* o

167 22

51 44*

0 4*

42 17*

0 14

a 11

21 23*

38 7

1977 1978 1979 Number bcal i t y Nov. Dec, Jan. Feb, Mar. Apr. May June J u l y Aug. Sep. Oct. Nov. Dee . Jan. b P

17

18

19

20

21

22

23

24

25

26

27

28

29

30

21 a-

Total

J. Sera in

Hilo Airport

Okamoto S t o r e

Ghala

Waimea Airport

Kawaihae Harbor

Kohala Bspital

Ke-*le Airport

Kailua School

Kona Health Center

Kona County Garage

Pepe' ekeo

U, H, H i l o

C. Granat

for Island

73 15 56 3

1 4 1 70 74 6

21 34 28 3

0 3 0 0

2 0 0 0

0 0 0 1

1 0 0 0

2 1 1 1

1 0 4 2

0 0 0 0

3 1 6 5

1 2 6 5

82 64 36 6

0 0 0 0

24 55 57 11

~~

5* 42 170 36 91 234 117 11* Of 84 63*

362 1040 1617 649 428" 2428 272 456 461 399 79

44 249 247 105 51 237 92 182 144 189 35

1 2 4 0 0 0 0 0 4 7 7 2

5 2 2 0 0 1 0 0 0 3 0

0 0 0 0 0 0 0 0 0 1 0

0 0 0 0 0 0 0 0 0 2 0

1 2 1 0 0 26 o* 0 0 6 2

1 10 47 98 176 75 52 1 2 25 17

0 3 8 15 27 10 3 0 2 2 2

3 8 22 35 26 14 11 5 7 10 16

4 9 28 40 31 33 26 7 5 1 6 20

414 156* 290 433 467 402 319 105 413 716 264*

0 2 0 0 1 0 0 0 0 0 0

21 19 discontinued--------------------------------------

h) W

843 1020 952 293 1814 3015 4269 2413 3074 7381 2025 2621 1578 2111 721