Ecology and Health

LaboratoryDepartment of Public

HealthUniversity of Otago

Wellington

Kapiti Expressway hearing

Mosquitoes around Waikanae

… some field data & health concerns

Dr M.McIntyre

Trapping:• CDC (USA) surveillance std• residential + peri-urban bush

remnants + nearby paddocks

• ~ 2-wk intervals Oct-Apr

Total sampling effort • 998 trap.nights• >18 000 mosquitoes

Total mosquitoes Oct.-Aprlocation 02-03 03-04

_____________________

Karori 52 47

Belmont 10 37

Waikanae 763 17 251_____________________

(Snell A. PhD thesis 2006 UOW)

0

50

100

150

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

tota

l mos

quito

es 2002-2003

2003-2004

Australian surveillance scale (Doggett et al 2001)

Category no./trap.night

Low <50

Moderate 50-100

High 101-1000

Very high >1000

Extreme 10 000

Waikanae (12 sites, 338 trap.nights)

Oct April

1 2 3 4 5 6 7 8 9 10 11 12 13 14 150

5000

2002-03

2003-04

date

tota

l mos

quito

es

1 Oct. Month 3 Apr

Max. 5728

14

18

22

26

max

. tem

p. o

CWeather Ppm airport (Data NIWA)

0

100

200

300

400

Sept Oct Nov Dec Jan Feb Mar Apr

rain

fall-

mm

02-03 03-04

4 Feb

.04

19-F

eb3-M

ar

16-M

ar

30-M

ar0

2000

4000

6000

Ae ant

Ae not

Cx pvg

tota

l - 1

2 tra

ps

Species breakdown

Introduced Aedes notoscriptus - “the striped mosquito”

Culex quinquefasciatus - ‘Southern house’ mosquito (USA)

Native

Cx pervigilans – “vigilant mosquito”

Ae antipodeus – bush mosquito, “the ‘singer”

Coquellitidia iracunda – “the angry, mosquito”

Cq tenuipalpus – rare, little known

Maorigoeldia agyropus – probably extinct in area (Snell, Derraik, McIntyre 2005)

Vector ability of some native spp tested in US lab for MAF Biosecurity (Kramer et al 2010)

A bad disease record overseas!

(Photo: Landcare Res)

Concerns

• standing water will extends breeding habitat

• planted wetlands + vegetation corridors + open water surface creates humidity corridors which facilitate adult dispersal

• exacerbation of seasonal biting nuisance

• adjacent homeowners - especially where low-lying

• irruption in favourable seasonal/weather conditions (flooding; ?drought)

• avian malaria in native birds

• future climate change & arbovirus threat

Measures• construction & planting of ponds

• ecological function

• pre-construction survey to establish baseline & best monitoring sites (seasonal timing important)

• construction period contingencies

• post-construction surveys

• development of contingencies

Warmer spring-autumn conditions will increase …

• mosquito breeding

• build up of virus – in mosquitoes (& wildlife – birds/possums)

• range & seasonal expansion of anthropophilic mosquitoes

• outdoor lifestyles / human exposures

• flooding/ drought episodes

MfE predict +2.1- 2.2oC 1990-2090

… thank-you