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A N I N V E S T I G A T I 0 N I N T 0 T H E E C 0 L 0 G Y ,

B I 0 L 0 G Y, D I S T R I B U T I 0 N A N D C 0 N T R 0 L

0 F H A E M A P H Y S A L I S L 0 N G I C 0 R N I S

N E U M A. N N , 1 9 0 1 .

A thesi s presented i n par t i al fulfilme nt

of the requ ireme n t s for the degree of

Master of Ve terina& Science at

Massey Uni versi t y .

Fre deri ck Jame s Alexander Ne ilson B . V . Sc .

1 980

<J

A B S T R A C T

In 1 974 , que sti onnai res were di stribute d t o farmer s i n the

Eas t Coast and Hawke� Bay areas of the Nor th Island of

New Zealand . The t i ck Haemaphysalis longi corni s Neumann 1 90 1 was pre sent on 59% o f farms i n the East Coast-Nor thern

Hawk�s Bay are a and 7% of farms in the remainde r of t he Hawke�

Bay are a . In the former area the t i ck appeare d to have spread

rapidly be tween 1 96 4 and 1 974 .

In the East Coas t -Nor thern Hawkes Bay are a , approx imately one

third of all farme r s consi dere d that the t i ck was a

signi f i cant prob lem on their farm . In t he Cen t ral and Sou t hern

Hawk�s Bay are a the t i ck was not conside r e d a problem and

cond i t i ons were probab ly margi nal for t i ck surv ival .

The di s tribution o f the t i ck was relate d to temperature ,

rainfall and alti tude . Almo st all farms where t i cks we re

pre sent were si tua t e d at less than 300 me tres above sea leve l .

The d i s tribution o f t i ck counts of she e p were posi t i vely

skewed and i t was s hown that the data should be normalized b y

transforming t o logari thms or square roo t s . S quar e roo t s

repre sent the easi e s t me thod o f transformat ion .

A compar i son betwe e n t i ck counts of the l e f t ear , right ear ,

both e ars and the b ody , showe d that overall ear counts

cont r i bute to nearly 50% o f t he to tal t i ck count . Howeve r ,

the propor tion o f t i cks on t he ears compare d wi t h on the b ody

varied over the count ing period and e ar counts were not hi ghly

c orrelated with body counts ( highe s t c or re lat i on , r = 0 . 38 ) .

The diamide , ami tra z , showe d a higher i n i t ial e f ficacy

against H . longi c orni s compared wi th Chlorfenv i nphos , but the

lat t e r appeare d to have a longer period of re sidual acti v i t y .

i i

0

In t he Northern Hawke� Bay and East Coas t are a most (�4%) she e p

owners dip be twe en January and March and over half ( 54%) dip i n

January o r March and t h i s period does no t coincide w i th the

adu l t and larva l peaks .

Inc reasing she ep numbers from 3 per 1 000 m2 ( equi valent to 2

30 per hec tare ) to 3 per 500 m ( e quivalent to 60 per he c tare ) re sul ted in lower t i ck survival in the more heavily s tocked

are as .

An examinat ion of the water balance of t he unfe d s tage s showed

that larvae were very susce p t i b le to de s i c cation at humi di t i e s

be low 80% R . H . Adu l t s we re more re si stant to desiccation than

nymphs . Larvae and nymphs re gain water rapi dly af ter

de siccati on . The cri t i cal e quilibrium a c t i vities for the unfed

s tage s was found to be approximately 0 . 8 , 0 . 7 and 0 . 9 for

larvae , nymphs and adults re spe c tive l y .

Immersion of unfed and engorge d stage s i n water indi cated t hat

t he former survive i mmersion for � 1 8 days whi le t he latter

showed lowe r survival .

Evidence i s pre se nted to sugge st H. longi corni s can cause

deaths from anaemia i n young Re d De er .

i i i

A C K N 0 W L E D G E M E N T S

The i nvestigations reported in this the s i s were carried ou t

f rom 1 9 74 - 1 980 whi le the author was a ve terinary offi cer wi t h

t h e Mini stry of Agri cul ture and Fi sheri e s . Some experimental

work was carried out at Wallaceville Animal Re search Centre and

t he remainder on farms in the Eas t Coast and Hawk�s Bay are a .

I am grateful to t he dire c torate ( Dr G . Adlam and

Mr R . Sali sbury ) and t he regional ve terinary officer

(Mr E . H . Shortri dge ) o f the Animal Healt h Divi sion , Mini stry

of Agri culture and Fi sheries , New Ze aland , for permi ssion for

this work to be under t aken and for arrangi ng study leave .

I am i ndebted to Dr W . A . G . Charleston and Dr A . C . G . Heat h who

superv i se d the rese arch and provided valuable advi ce ,

cri t i c i sm and encouragement throughou t this study .

I wish t o express my thanks to all past and pre sent staff of

the Animal Healt h Div i sion , M . A . F . from Gi sborne , Wairoa and

Rua toria who assisted wi th fenc ing and t i c k counting . To

Messrs R . de Bors t and M . Venni ng who also assisted with t i ck

coun ting , my grate ful thanks . Mr G . B . Dav i s collated the

tick questi onnai roofrom the central and sou thern Hawk�s Bay

are a and I wish to acknowledge and thank him for this

assistance .

Farmer s i n the Gi sborne are a also ass i s t e d wi th thi s study

and I would like to t hank Mr J . Wilson and Mr W. Condor .

As well I am i ndeb t e d to Mr John Holdswo r th , Waikohu Station ,

who provided s taff and 'ac i l i t i e s , over a considerable period ,

for mustering and spraying sheep and holding sheep for t i ck

count s .

v I w i sh to thank Dr A . Heath for arranging the use of fac i li t i e s

at Wallacevi lle and for hi s collabora t i on wi t h Mr L . M . Morri son

in the statisti cal analysis of the t i ck c oun t s from the

i nse c t i c i dal experiment .

iv

V

I also appreci ate the assi stance o f the se ni or supervi sor ,

Dr Charles ton , for hi s adv i ce on the pre s e ntation of t hi s thesi s .

Fi nal ly , t o Mr s A . WiRepa , my hear tfe lt thanks for typ i ng t he

dra f t and final copy o f thi s thesi s .

F . J . A . NEILSON

De cember, 1 980

PRE F A C E

Be t we e n 1 9 70 and 1 974 th e range and pre valence o f

Haemaphysal i s longi c o rn i s appeare d t o b e i nc r e a s i n g o n farms i n

t h e Ea s t Coa s t and Nor t he r n Hawkes Bay are a . Be cause o f t h i s

appare n t i ncre ase i n t i ck numb e r s a ce nsu s was p o s t e d t o farm e r s

i n t he a r e a wi t h t he a i m o f mappi ng t i ck d i s t r i b u t i o n . The n b y

a p roce ss o f i nduc t i ve re asoning i t was hope d t o exam i ne var i ou s

fac t o r s t h a t mi ght i nf lu e nce t h i s di s tr i b u t i on. The C e n t r a l

Hawke� Bay area w a s i nc luded i n t he c e n s u s a s o nl y a f e w t i ck s

h a d b e e n r e p o r t e d f r o m t hi s are a .

Some f arme r s i n the Eas t Coa s t and Northern H . B . area c o n s i de r e d

t h a t the t i ck was e con omi cally i mportant so se l e c t e d farm

p r a c t i c e s (e . g . s t ocki ng rate , t i me o f d i p p i ng or showe ring ,

c h o i c e of i nse c t i c i de) were i nve s t i ga t e d as i t was hop e d t h i s

m i gh t prov i de i nforma t i o n o n wh i c h re comme nd a t i o ns f o r the

c o n t r o l o f the t i ck c ou l d be base d .

Wa t e r balance i s e s se n t i al for the surv ival of all animal

spe c i e s but i t is cru c i a l to t he exis t e n c e of t i cks be cause of

the ir surface to vo lume r a t i o . A s the wa t e r rela t i o ns o f e ggs

and e ngorge d s tage s o f H . longi corn i s hav e b e e n t h orough ly

i nv e s t i ga t e d (He a t h , 1 974 ) so i t was d e c i d e d to i nves t i ga t e

t h i s relat i o nship i n t h e unfed s tage s . It was hop e d that thi s

m i gh t lead t o a b e t t e r unde r s t anding o f the survi val and he n c e

t h e d i s tr i b u t ion o f t h e t i ck .

"The t i ck i s ge nerate d f rom c ouch grass . "

Ar i s to tle i n H i s t o r i a Ani mal i um , c i r ca 300 B.C.

vi .

"Af t e r trea tmen t t he r e w i l l be no sore s and the wool wi l l be more

ple n t i fu l and i n be t te r cond i t i on and the r i ci ni ( t i c ks ) w i l l no t

be troub le some" .

M . Por c i u s Cata 200 B . C .

T A B L E 0 F C 0 N T E N T S

Abst rac t

Acknowle dge m e n t s

Pre face

1 . Re v i e w o f the l i tera t ur e

1 • 1 1 . 2 1 . 3

Ge neral i n trod uc t i o n

Tax o nomy o f t i ck s

The ge nus Haemap h ysal i s

1 . 4 Taxo nomy o f d i s t r i b u t i on o f Hae maphysali s

longi c orni s

1 . 6

Morpho logy o f t i ck s

1 .5 . 1 1 .5 . 2

Gene ral

Morpho logy o f H. longi c o r ni s

Ge ne t i c s o f H . l o ngi c orni s

1 . 7 I n t roduc t i o n o f H. longi c or ni s i n t o New Ze aland

and Au s t r a l i a

1 . 8 The e s tabli shme n t , spre ad and pre se nt

Page

i i

i v

v i

1 2 4

5 1 1 1 1

1 2 1 6

1 9

di s t r i bu t i o n o f H . longi c orni s i n New Ze aland 23 1 . 9 1 . 10

1 . 1 1

1 . 1 2

Ti ck fauna o f th e Ne w Ze aland sub-regi o n

The s i gni fi cance and e conomi c i m p o r t ance o f t i cks

1 . 1 0 . 1 B i o l ogy

1 . 1 1 . 1 1 . 1 1 . 2 Ec o l ogy

1 . 1 2 . 1 1 . 1 2 . 2 1 . 1 2 . 3 1 . 1 2 . 4 1 . 1 2 .5

1 . 1 2 . 6

The s i gni fi cance o f H . l ongi c o r n i s

o f t i c ks

B i o logy o f H . longi c or n i s

Se asona l i t y o f H . l o nsi c orni s

of t i c k s

The t e mperature r e la t i o n s of t i cks

Te mpera ture re l a t i ons o f H . l o ngi c orn i s

The wa t e r re la t i on s o f t i cks

The wat e r re lat i ons o f H . lo ngi corni s

The i�f luence o f v e ge ta t i o n o n the

surv i va l , act i v i t y , d e ve lopme n t and

d i s t r i bu t i on of t i ck s

The i n f luence o f v e ge t a t i o n o n t he

survival , deve lopmen t a c t i vi t y and

d i s t r i bu t i on of H . longi co rn i s

1 . 1 3 Hosts o f H . l o ngi corni s

26 27 30

33 39

43 48 48 50

56 63

67

70

75

v i i .

1 . 1 4 The c o n trol of t i ck s

1 . 1 4 . 1 The c on tro l of H . l o ngi corni s

Exp e r i me ntal Se c t i o n

2 .

3 .

Ti c k que s t i o n naire

2 . 1 Int r o du c t i on

2 . 2 Mate r i al s and me t ho ds

2 . 3 Re su l t s

2 . 4 Di scu s s i on

Ti c k coun t i ng . Di s t r i b u t ion o f t i ck s counts o f s he e p

3 . 1 In tro d u c t i on

3 .2 Mat e r i al s and me thods

3 . 3 Re su l t s

3 . 4 Di s c u s s i on

4 . Ti ck count i ng: the re la t i onshi p be twe e n ear and body

c ou n t s o f H . longi corni s on she e p

4 . 1 4 .2 4 . 3 4 . 4

In t r o duc t ion

Mat e r ials and me thods

Re s u l t s

Di scuss i on

5 . Exam i nat i o n of ind i vi dual t i c k coun ts from she e p for

e v i d e nce of r e s i s t ance to i nfe s t a t i on

6 .

5 . 1 In tr oduc t i on

5 . 2 Mat e r i als and me t hods

5 . 3 Re sul t s

5. 4 Di s c u ss i o n

Chem i cal c o n trol o f H . longi corni s on she e p:

Compari son o f the e f f i cay o f two i n se c t i c i d e s

6. 1 6 . 2

6.3 6 . 4

In tr oduc t ion

Mate r i al s and me t ho d s

Re su l t s

Di s c u s s i o n

7 . Chemi cal c on t rol of H . long i c orni s: i nf orma t i o n from

the Ne w Ze a land She e p R e turns o n the me thod a nd t i m i ng o f

dippi ng i n the Eas t Coast Northern Hawke s Bay ar e a

7. 1 fn t r oduc t i on

7 .2 Mat e r i als and me thods

7 . 3 Re sul t s

7 . 4 Di s c u s sion

v i i i .

Page

77· 79 8 4 84 84 8 4 86 9 4

109 109 1 09 1 10 1 1 8

1 20 120 1 20 1 2 1 1 2 6

1 2 8 1 2 8 1 28 1 30

1 30

1 33

1 33 1 33 1 35 1 38

1 40

1 40 1 40 1 40 1 42

8 . The i nflue nce o f stocking r a t e on t i c k survival

8 . 1

8 . 2

8 . 3 8 . 4

Introdu c t i o n

Mat e r i a l s and m e t ho d s

Re sul t s

Di sc u ssion

9 . The water b alance of u nfed larvae, nymphs and adu l t s

1 0 .

o f H . longi corni s

9 . 1 Introdu c t i on

9 . 2 Mate r i al s and me t hods

9 . 3 Re su l t s

9 . 4 Di s c u s s i o n

T h e effe c t s o f immer s i o n i n wat er on H . long i c o rni s

1 0 . 1 In trodu c t i on

1 0 . 2 1 0 . 3 1 0 . 4

Ma t e r i als and me t ho d s

Re sul t s

Di scu s s i on

1 1 . S ummary and c onclusi ons

Appe n d i x

1 . Copy of the que st ionna i re p o s t e d to farmers i n

De cemb e r . 1 974 2 . P ho t ograph of a map of the locat i on of f arme r s in t he

Cook County who rep l i e d t o t he 1 974 que s t i onnaire

3 . Pho t ograph of a map of the locat i o n of farmer s i n t he

Page

1 43 1 43 1 43 1 43 1 44

1 46 1 46 1 4 7 1 50

1 59 1 63 1 63 1 63 1 6 4 1 67 1 70

1 73

1 76

Waikohu Coun t y who r e p l i ed to the 1 974 ques t i onnaire 1 77 4 . Pho t ogr aph o f a map o f t he l o c a t i o n of f armer s i n the

Wai apu Count y who repl i e d t o t he 1974 que s t i onnaire

5 . Pho t ograph of a map o f t he lo c a t i o n of f arm e r s in t he

1 78

Wai roa County who re p li e d to t he 1 974 ques t i o nnai re 1 79

( ;

ix •

App e nd i c e s 6 t o 30 are t i ck c o u n t s of sheep refe r r e d

t o i n Se c t i o n s 3 , 4, 5 , 6

6 .

7 . 8 . 9 .

1 0 . 1 1 . 1 2 . 1 3 . 1 4 . 1 5 . 1 6 . 1 7 . 18 . 1 9 . 20 . 2 1 . 2 2 . 23 . 2 4 .

25 . 2 6 . 2 7 .

1 8 . 2 9 . 30 . 3 1 .

32 .

3 3-

Ti c k coun t s of A0 .03 " " " "

" "

" " " " " "

" " "

" " " " " " " "

" ,,

" "

" "

" " " " " "

" " " "

" "

" " " " " " " ,,

" "

" " " " " " " "

" " " A0 . 05 " "

" " " " " " " " " so .o6 " " " "

" "

" "

" "

" Cont r o l group

" " " "

" " " " " "

" " " " " "

day " " 11

" "

" " " " "

"

" 11

"

"

'"

" "

" "

"

" " " " "

0 and day 7 "

1 3 "

27 "

0 "

1 3 "

27 "

0 0

1 3 "

2 7 "

0

"

"

1 3 "

"

2 7 " "

"

"

" " "

"

" " " " " "

" " " " " "

"

"

"

"

"

" "

"

" " " " "

"

"

" " "

"

"

" "

"

" "

,,

"

20 "

3 4 "

7 "

20 "

34 "

7 7

20 "

"

7

" " " " " 20

" "

" "

" 34 " "

" "

A naemia and deaths i n Red De e r assoc iate d w i t h heavy

i nfe s tat i on s of H. longic orni s

Bib l i o graphy

x.

Page,

1 80 1 8 1 1 8 2 1 83 1 8 4 1 85 1 86 1 8 7 1 8 8 1 89 1 90 1 9 1 192 1 93 1 94

1 95

196 1 9 7 198

1 99 200 20 1 202 203 204

205 206

207

2 1 1

T a b l e

1 . 1

1 . 2

1 . 4

1 . 5

L I S T 0 F T A B L E S

T axono m i c re l at ion sh i p s of t i cks

Wo rld di s t r i b u t i o n s of H. l o ngi c o r n i s and

H. b i spi nosa

Compar i so n of H. l ongi c orni s and H. b i sp i nosa

Approx i m a t e size range s o f H. longi corni s

F i e l d and l aborat o r y d a t a o n t he b i o logy o f

H . longi c orni s

1 . 6 Proposed r e l a t io nship b e t we e n t e mp e rate and b i o logy

of H. longi corni s

1 . 7 D i stri but i o n o f H. l o ngi corni s i n Ne w Ze a land and

A u s t r a l i a in r e l a t i o n t o cli ma t i c i nd i ce s

1 . 8 S o i l t e mpera tu re and wa t e r measureme n t s i n t he

e nvi ro nme n t of rye grass and paspalum pas t u re s

1 . 9

1 . 1 0

H o s t s of H. longi c o r ni s

Summary o f i nse c t i c i d a l t r i a l s agai ns t

xi

Page

3

9

1 0

1 5

40

5 1

55

74

76

H. longi corni s on c a t t le and she ep i n New Zealand 8 1

2 . 1 Length of t i me H. longi corni s pre s e n t on farms i n

t he Northern H. B. a nd Eas t Coas t are a

2 . 2 A l t i tude, rainfall and annual mean t e mpera t u re s for

t he Cl im ato logi cal S t a t i o n s in the are a m ap p e d for

t i ck d i s t r i b u t i o n

3.1 Chi -squar e d value s f r o m t e s t i ng goodne ss o f f i t o f

ac tual t i ck counts t o a normal d i s t ribu t i o n

Chi-squar e d value s f r o m t e s t i ng goodne ss o f f i t o f

a c tual t i ck count + 1 t ransform e d to logar i t hms t o

a normal d i s t r i bu t i o n

8 7

1 0 0

1 1 7

1 1 7

xii

Table Page

3 . 3 Chi-squar e d value s from t e s t i ng goodne ss o f f i t o f

ac t ual t i ck c ou n t s trans formed t o square r oo t s t o

a normal d i s t r i bu t i o n

4 . 1 Compar i son by ANOVAR o f le f t, r i g h t and comb i ned

ear c ou n t s and body c o u n t s o f 302 sheep o n day 0

4 . 2 Compar i so n by ANOVAR o f t o tal le f t , r i ght a n d

c o mb i ne d e ar coun t s a n d b o d y cou n t s o f t i ck s from

98 she e p o n days 0 , 7 , 13 , 20 , 2 7 and 34

Compar i so n b y ANOVAR o f comb i ne d e ar coun t s w i th

body c ou n t s o f 98 she e p o n days 0 , 7 , 1 3 , 20 , 27

and 3 4

4 . 4 Ear and body c ou n t s o f t i cks at i nd i vi dual

4 . 5

observa t i o n t i me s f o r a l l untre a t e d she e p

Correla t i on be twe e n c ombi ne d ear a n d b o d y c o u n t s

5 . 1 Cumula t i ve freque n c y d i s t r i b u t i o n o f t o t a l t i ck

c ou n t s of 302 she e p o n day 0

5 . 2 ANOVAR of t i ck c ount s o f she e p whi c h had b e e n

ass i gn e d t o one o f 3 groups o f t he bas i s o f t he

i ni t ial t i ck count

6 . 1 A NOVAR o f t o t al t i ck c o u n t s for days 0 , 7 and 1 3

f o r 3 t re a t me nt group s and a c o n t r o l group

6 . 2 A NOVAR o f t o tal t i ck c o u n t s for days 20 , 2 7 and 34

f o r 3 t r e a t m e n t group s and a c o n t r o l group

7 . 1 Mai n d i p p i ng me t ho d o n farms i n t h e Eas t Coas t and

Nor thern H.B. area

7 . 2 Mon th o f d i p pin g nomi na t e d b y She e p-owner s i n t he

Sas t C�a s t and Nort he r n H.B. are a

1 1 8

1 2 1

1 22

1 2 3

12 4

1 2 5

1 2 9

1 3 1

1 36

1 37

1 4 1

1 42

Tab l e

8 . 1

8 . 2

Nymphal count� o f she e p i n p addo c k s A , B, C and D

Adu l t count s o f sh e e p i n p addo cks A, B, C and D

9 . 1 Me an we i ght c hange s of u nfed larvae, nymphs and

adu l t s of H . longi corni s de s i c c a t ed for var yi ng

p e r i ods

1 0 . 1

10 . 2

3 3.1

33-2

Effe c t o f i mme r s i o n i n wa t e r on e ngorged s t a ge s of

H . l o ngi corni s

Effe c t o f i mme r si o n i n wa t e r on u nfed st age s o f

H . longi c ornis

H ae mato logi c a l exam i na t i o n of 4 fawns

Normal value s for c e l l u lar cons i tue n t s of Red De er

xiii

Page

144

144

1 50

1 66

208

209

xiv

L I S T 0 F F I GURES

F i gure

1 . 1 Wor l d d i s t r i b u t i on of H . l ongi c or n i s and H . b i sp i nosa 7

1 . 2 H . l ongi c or n i s from c a t t le - i nfe r t i le ma l e 1 3

1 . 3

1 . 4

1 . 5

1 . 6

1 . 7

11

11

11

Di s t ri b ut i on

L i f e c y c l e o f

11 " - s l i gh t ly engorge d female

11 " - nymph

" " - larva

of H . l on �i c orni s w i t hi n Ne w Ze aland

i x od i d t i ck s

1 . 8 Di agramma t i c a l re pr e se n t a t i on of t he seas ona l i t y of

H . l ongi c orni s

1 . 9 S e a s onal di s t r i but i on of p re c ip i t a t i on ex c e e d i ng 50 mm

1 . 10

1 . 1 1

1 . 1 2

pe r mon t h

The range o f t empe r a t u r e s a n d s a t ur a t i on de f i c i t s

f a vourab le f or survi va l and de ve l opme nt of n on­

paras i t i c s t a ge s of H. l ongi c orn i s

Cumula t i ve we i ght l oss of e ggs and e ngorge d s t age s

of H . l ongi c orni s e x p os e d t o d r y a i r at 2 5°C

Range of t e mperature a n d re la t i ve humi d i t y f ou n d t o

b e favourab l e f or t he e ggs , engor ge d lar vae and

nymphs of H . l ongi c or ni s

1 . 1 3a Pe r c e n tage of i mpr ove d land c on t a i n i ng paspalum i n

t h e pas t ure

1 3

1 4

1 4

2 4

38

44

4 6

5 2

6 5

6 6

72

1 . 1 3b Pr op or t i onat e change i n p aspalum c on t e n t 72

2 .1 Approx i ma t e are a of d is tr ib ut i on of q ue s tionnaire 8 5

2 . 2 Op i ni on s of farme r s i n t h e Eas t C oa s t and N or t he r n

H . B . as t o t he si gn i f i c a n ce o f H. l ongi c or n i s 8 7

Figur e Page

2 . 3 Di s tribut io n o f farms in Ce n tral H . B . on which

t i c k s were r e p o r t e d t o be pre se n t

2 . 4 A r e a from whi c h re p l i e s t o the que s t i o nnai re were

r e c e ive d by t he Gi sborne o f f i ce of t he M . A . F .

2 . 5 Distr i b u t i o n o f prope r t i e s on whi c h no t i ck s we re

r e p o r t e d to be pre sent

2 . 6 Di s t r i b u t i o n o f prope r t i e s on t i ck s we re pre s e n t

b u t n o t c o n s i de re d a p r o b l e m

2 . 7 Di s trib u t i on o f proper t i e s where t i cks wer e pr e se n t

a n d c ons i d e r e d a prob l e m

2 . 8 M e a n rai nfa l l and rai n f a l l for Nove mber, De c e mb e r

January and Fe bruary ( Manu tuke Cl imat ologi c a l

S t a t i o n )

2 . 9 M e a n tempe rature and t e m p e ra t ure f or June, Ju l y,

A ugu s t and S e p tember ( Manu tuke C l i ma t ol ogi c a l

S t a tion)

2 . 10

2 . 1 1

2 . 1 2

2 . 1 3

3. 1

3. 2

3-3

3. 4

3-5

3. 6

Clima tologi c a l S t a t i o n s i n .the are a in whi ch t i ck

dis t r i b u t i o n was map p e d

M e a n annual rainfall i n C e n tral and Sou the r n H.B.

Soil t ype s o f Cook, Wai k o hu , Wair o a and Wai apu

Cou n t i e s

Me a n annual rai nfall i n t he Ea s t Coast and

N o r thern H . B . are a

Fre que nc y d i s t r i bu tio n o f t i c k c o u n t s - d a y 0

" " " " " " 7

" " " " " " 1 3 � " " ,, " " " 20

" " " " " " 2 7

" " ,, " " " 34

8 8

90

9 1

92

9 3

9 8

9 9

102

1 0 5

10 6

1 1 1

1 1 2

1 1 3

1 1 4

1 1 5

1 1 6

XV

Figure

9. 1 a M e a n we i ght c hange s o f une ngorge d l arvae o f

H . l ongi corn i s d e s i c c a t e d f o r 4 hou r s the n

xvi

t rans f e r r e d t o 6 d i f f e r e n t R .H . 's 1 5 1

9 . 2a & 9 . 2 b Me an we i ght change s o f unengorged nymphs of

9.3a

9 . 3 b

9-5

9 . 6

H . longi corni s d e s i c c a t e d for 28 hours t he n

trans f e rre d t o 6 d i f f e r e n t R .H .'s

Me an we i ght change s o f unengorged ffema l e s

o f H . l o ngi c orni s d e s i c c a t e d f o r 24 ho ur s the n

tran s f e r r e d t o 6 d i f f e r e n t R .H . 's

Me an we i ght change s o f une ngorged f e m al e s of

H. lo ngi corni s d e s i c ca t e d f o r 48 ho u r s the n

tran s f e rre d t o 6 d i f f e r e n t R .H . 's

Regr e s s i o n of % c hange i n p o s t-de s i c c a t e d

b o d y we i gh t o f u n f e d H . l o ngi corni s larvae

on R .H . %

Re gr e s s i on o f % change i n p o s t-de s i c c a t e d

b o d y we i ght o f u n f e d H . longi corni s nymphs

on R .H . %

Regr e s s i o n o f % c ha nge i n p o s t -de s i c c a t e d b o d y

we i gh t of u nf e d H . l o ngi c orni s female s o n

R .H . %

,.

152

1 5 3

1 5 3

1 56

1 5 7