11. tie odonata of the cayman islands, british west indies

11. TIE ODONATA OF THE CAYMAN ISLANDS, BRITISH WEST INDIES

R.R. Askew

On e a c n o f t h e Cayman I s l a n d s t h e r e a r e s e v e r a l l a g o o n s . These a r e of v ~ r v i n g s a l i n i t y and a r e und0ubtedi.y t h e most i m p o r t a n t breedi1-q s i t e s of d r a g o n f l i e s . T h e r e a r e a l s o a c c u m u l a t i o n s of s t a n d i n g f r e s h - w a t e r b u t t h e s e a r e g e n e r a l l y s m a l l and m0sti.y t e m p o r a r y , F r a s e r

( 1 9 4 3 ) p r o v i d e s a s y n o p s i s of t h e t y p e s of d r a g o n f l y b r e e d i n g a r e a s f o u n d on t h e i s i a n d s ,

D r a g o n f l i e s c o n s t i t u t e a c o n s p i c u o u s and a b u n d a n t component of t n e entomofauna. P u b l i s h e d i n f o r m a t i o n on t h e Odonata of t h e i s l a n d s a p p e a r s t o be l i m i t e d , however, t o a p a p e r by F r a s e r (1943) i n which t h e r e s u l t s of t h e 1938 Oxford U n i v e r s i t y e x p e d i t i o n a r e d e s c r i b e d .

I n 1975 t h e Royal S o c i e t y

-

Cayman I s l a n d s Government e x p e d i t i o n was b a s e d f o r a b o u t f i v e weeks on L i t t l e Cayman and e i g h t and f o u r d a y s were s p e n t r e s p e c t i v e l y on Grand Cayman and Cayman Brac. The Oxford U n i v e r s i t y e x p e d i t i o n c o l l e c t e d m a i n l y on Grand Cayman o v e r a p e r i o d of 109 d a y s . Twelve s p e c i e s a r e r e c o r d e d from t h e i s l a n d s by F r a s e r

(1943) and t o t h i s number f i v e s p e c i e s can now be added ( t a b l e 1 8 ) . Grand Cayman e v i d e n t l y s u p p o r t s t h e l a r g e s t number of s p e c i e s . More were t a k e n t h e r e i n t h e few d a y s c o l l e c t i n g i n 1975 t h a n were t a k e n d u r i n g t h e much l o n g e r p e r i o d on L i t t l e Cayman. T h e r e i s l i t t l e d o u b t t h a t more s p e c i e s a w a i t d i s c o v e r y on Grand Cayman and Cayman B r a c , a l t h o u g h t h e l i s t f o r L i t t l e Cayman i s p r o b a b l y v e r y n e a r l y c o m p l e t e .

No endemic forms a r e known on t h e Cayman I s l a n d s , p e r h a p s n o t s u r p r i s i n g l y i n view of t h e i r p r o x i m i t y t o Cuba, J a m a i c a and C e n t r a l America. Many of t h e s p e c i e s r e c o r d e d a r e m i g r a t o r y w i t h l a r g e g e o g r a p h i c a l r a n g e s , and a l l a r e w i d e s p r e a d i n t h e G r e a t e r A n t i l l e s . Anax amazili ( B u r m e i s t e r )

Two s e e n hawking o v e r t h e S e s u v i u m marsh a t t h e e a s t end o f

L i t t l e Cayman, August 5 t h . The marsh i s q u i t e e x t e n s i v e , i t s e a s t e r n

Atoll Research Bulletin No. 241: 115-120, 1980.

T a b l e 18. S p e c i e s of Odonata r e c o r d e d from t h e Cayman I s l a n d s by t h e 1938 Oxford U n i v e r s i t y E x p e d i t i o n and t h e 1975 Royal Society-Cayman I s l a n d s Government E x ~ e d i t i o n .

Grand Cayman Cayman Brac L i t t l e Cayman

A N 1 SOPTERA Ae s h n i d a e

Anax a m z i l i G y n a c a n t h a n e r v o s a

L i b e l i u l i d a e

13rachymesia f u r c a t a E r y t h e m i s p l e b e j a E r y t h r o d i p l a x n a e v a E . f e r v i d a

E

.

conna t a E . umbrata

L e p t h e m i s v e s i c u l o s a M i c r a t h y r i a d i d y m O r t h e m i s f e r r u q i n e a P a n t a l a f l a v e s c e n s

?

.

^{h ymenea}

Tramea a b d o m i n a l i s T

.

c o p h ysa

ZYGOPTERA L e s t i d a e

L e s t e s s p u m a r i u s

Coenagrionidae

A n o m a l a q r i o n h a s t a t u m I s c h n u r a r a m b u r i

edge b e i n g a b o u t 500 m e t r e s from t h e e a s t c o a s t from which i t i s s e p a r a t e d by b l u f f l i m e s t o n e and s t o r m beach. S e s u v i u m grows l u x u r i a n t l y o v e r a b o u t % sq. km. of wet ground i n t e r s p e r s e d w i t h a number of s m a l l , s h a l l o w p o o l s . A l l s p e c i e s of d r a g o n f l y r e c o r d e d by u s from L i t t l e Cayman were s e e n a t t h i s p l a c e .

G y n a c a n t h a n e r v o s a (Rarnbur )

A s i n g l e f e m a l e c a p t u r e d f l y i n g i n a l i g h t e d b u i l d i n g i n Georgetown, Grand Cayman a t 1 . 0 0 a.m., August 1 2 t h .

B r a c h y m e s i a f u r c a t a (Hagen)

Seen on L i t t l e Cayman a t s e v e r a l l a g o o n s , p a r t i c u l a r l y i n t h e e a s t , between J u l y 3 0 t h and August 5 t h , and a l s o on t h e s t o r m b e a c h e s an6 o c c a s i o n a l l y i n t h e i n t e r i o r . I t spends rnuch ~ i m e p e r c i ~ i n g on t w i g s aild i s e a s i l y r e c o g n i s e d by i c s r e d d i s h abdomen and c o l o u r e d h i n d wing b a s e s

.

E r y t h e m i s p l e b e j a ( B u r m e i s t e r ) Not o b s e r v e d i n 1975.

E r y t h r o d i p l a x n a e v a (Hagen)

The most abundant s p e c i e s and found on a l l t h r e e i s l a n d s . On L i t t l e Cayman it o c c u r r e d everywhere, v e r y common n e a r t h e c o a s t a l l a g o o n s and on t h e s t o r m b e a c h e s , b u t a l s o p e n e t r a t i n g t h e i n t e r i o r and b e i n g s e e n a t t h e summit of Sparrowhawk H i l l . Throughout t h e p e r i o d of t h e e x p e d i t i o n , b l a c k i s h mature a d u l t s and y e l l o w and b l a c k immature specimens were n o t e d .

E . f e r v i d a ( E r i c h s o n )

A s i n g l e female found on u n c u l t i v a t e d ground i n Georgetown, Grand Cayman on August 1 3 t h .

E . c o n n a t a ( B u r m e i s t e r )

I n s e c t s s e e n b u t n o t c a p t u r e d by t h e 1938 e x p e d i t i o n f l y i n g o v e r Z o s t e r a beds i n s i d e t h e f r i n g i n g r e e f a t Bloody Bay, L i t t l e Cayman, a r e c o n s i d e r e d (under t h e name E r y t h e m i s m i n u s c u l a (Rarnbur) ) t o b e r e f e r r a b l e t o E . c o n n a t a ( F r a s e r 1 9 4 3 ) . E r y t h r o d i p l a x m i n u s c u l a a u c t . from t h e West I n d i e s i s E . c o n n a t a c o n n a t a ( B u r m e i s t e r ) ( B o r r o r 1 9 4 2 ) .

E . umbrata (L. )

Recorded from a l l t h r e e i s l a n d s i n b o t h 1938 and 1975. I n 1975 it was widespread b u t n o t common on L i t t l e Cayman, and appeared t o be more numerous on t h e o t h e r two i s l a n d s . On Grand Cayman it was abundant a t West Bay. Two m a t u r e f e m a l e s and one male o n l y were

t a k e n , a f e m a l e from Grand Cayman h a v i n g a l m o s t h y a l i n e wings w h i l s t a f e m a l e from Cayman Brac h a s v e r y d a r k wing p a t c h e s .

L e p t h e m i s v e s i c u l o s a (F

.

⁾

An a t t r a c t i v e g r e e n d r a g o n f l y w i t h a l o n g , s l e n d e r abdomen, p o s s i b l y c o n f i n e d t o Grand Cayman. I n 1975 i t was s e e n a t West Bay on J u l y 6 t h and a male was t a k e n on August 1 3 t h o v e r marshy ground b e s i d e t h e m i d - i s l a n d r o a d .

M i c r a t h y r i a didyma ( S e l y s ) Not o b s e r v e d i n 1975.

O r t i l e m i s f e r r u g i n e a (F , )

A l a r g e , r e d - b o d i e d d r a g o n f l y o b s e r v e d q u i t e commonly a t t h e S E S ~ Z V ~ uin marsh, R o s e t t a F1.a ts and Digga-ry P o i n t on L i t t l e Cayman, The s p e c i e s s e t t l e s f r e q u e n t l y on t w i g s .

Pan t a l a f i a v e s c e n s (F

.

^j

T h i s l a r g e , y e l l o w i s h d r a g o n f l y was common on L i t t l e Cayman

t h r o u g h o u t t h e p e r i o d of t h e e x p e d i t i o n , b u t i t was a l m o s t c o n f i n e d t o a r e a s a d j a c e n t t o t h e c o a s t a l l a g o o n s . Here numbers c o u l d be s e e n t o g e t h e r hawking, p r o b a b l y f o r m o s q u i t o e s , a t a h e i g h t of f o u r o r f i v e m e t r e s . These f l o c k s d i s p e r s e d a t s u n s e t when t h e i n s e c t s went t o r o o s t i n mangroves f r i n g i n g t h e l a g o o n s .

P. hymenea (Say)

Although t a k e n more f r e q u e n t l y t h a n t h e p r e c e d i n g s p e c i e s by t h e 1938 e x p e d i t i o n and found t h e n on L i t t l e Cayman, t h i s s p e c i e s was n o t o b s e r v e d i n 1975.

Tramea a b d o m i n a l i s (Kambur )

A s i n g l e male o n l y of t h i s l a r g e r e d d r a g o n f l y w i t h b o l d l y marked hindwing b a s e s was c a p t u r e d , a l t h o u g h s e v e r a l were s e e n , i n c l u d i n g p a i r s i n tandem, on L i t t l e Cayman a t R o s e t t a F l a t s and t h e S e s w i u m marsh. The s p e c i e s s e t t l e s o n l y r a r e l y and hawks a t a h e i g h t o f a b o u t f i v e m e t r e s .

T . c o p h y s a ( S e l y s )

No examples of t h i s s p e c i e s was n o t e d i n 1975. I t i s s a i d (Needham and W e s t f a l l 1 9 5 5 ) t o b e d i s t i n g u i s h a b l e i n f l i g h t from i t s congener above by i t s r e d d i s h v e n a t i o n and b l a c k s u b t e r m i n a l abdominal segments.

L e s t e s s p u m a r i u s ( S e l y s ) Not o b s e r v e d i n 1975.

A n o m a l a g r i o n h a s t a t u n l ( S a y )

A s t r o n g c o l o n y o f t h i s v e r y s m a l l d a m s e l f l y was f o u n d on marshy ground b e s i d e t h e m i d - i s l a n d r o a d , Grand Cayman on August 1 3 t h .

I s c h n u r a r a m u r i ( S e l y s )

S e v e r a l specimens o f t h i s d a m s e l f l y were s e e n , and a f e m a l e was t a k e n on u n c u l t i v a t e d l a n d i n Georgetown, Grand Cayman, on August 1 3 t h . The s p e c i e s was n o t found by t h e 1938 e x p e d i t i o n a l t h o u g h F r a s e r (1943) a n t i c i p a t e s i t s d i s c o v e r y on t h e i s l a n d s .

The m a t e r i a l c o l l e c t e d i n 1975 i s d e p o s i t e d i n t h e Manchester Museum and B r i t i s h Musem ( N a t u r a l H i s t o r y ) .

R e f e r e n c e s

W r r o r

,

^{D ,} ,J, 1962. A r e v i s i o n of t h e L i b e l l u l i n e qenils E r y t h r o d i p l a x (Odonata) ^, O h i o S t a t e Univ. C o n t r , i n Zool. a n d E n t . 4 , B i o l . S e r a # 286pp. Columbus, Ohio,

F r a s e r , F.C. 1943. R e p o r t on t h e Odonata c o l l e c t e d by t h e Oxford U n i v e r s i t y Cayman I s l a n d s B i o l o g i c a l E x p e d i t i o n , 1938. A n n l s . Mag. n a t . H i s t . 1 0 , 398-405.

Needham, ,J.G. and W e s t f a l l , M.,J. 1955. A m a n u a l o f t h e d r a g o n f l i e s o f North A m e r i c a ( A n i s o p t e r a ) . B e r k e l e y and Los A n g e l e s ,

Univ. C a l i f . P r e s s , G15pp.