Transcript Effects of Climate change

The Effects of Climate Change
on Pest Problems
Moray Anderson


Technical Director,
Killgerm Group.
Climate change
Examples to be discussed:

New diseases associating with established insect
species
 West Nile Virus.

New invasive insect species
 New diseases associated with these.

Re-emergence of “old” pest species
 Microclimatic changes.
Climate change
What is predicted ?

Universal increase in temperatures
 Insect metabolism – temperature dependant
 Small changes can have significant effects


Lengthening of breeding seasons
Changes in insect distribution geographically
Bedbug life cycle.
Cimex lectularius – Eggs
Temperature
(°C)
Egg hatching
time (days)
13
49
15
34
18
21
22
12
27
5-6
Climate change
New diseases associating with
established insect species
 West Nile Virus.
Mosquito borne disease
Disease transmission – summary
Disease causing pathogen ingested with blood
Multiplies in insect gut
Develops in insect gut
Migrates into mosquito haemolymph (blood)
Transfers to salivary glands
Injected into new host
1999 West Nile Virus
2000
2001
2002
2003
2004
2005
2006
2006
2007
2008
2009
West Nile virus is a flavivirus
Conditions in US perfect for distribution of virus
a) susceptible birds
b) insect vectors present - biting birds and
other vertebrates
c) susceptible horses/humans
Increase in numbers &
distribution of
human-biting mosquitoes
in the UK
Introduction of a more
efficient mosquito
vector
WNV in the UK?
DoH – surveillance systems for people …… no evidence of WNV infection
Local bird population examined ….… positive for WNV antibodies
Mosquito surveillance
…………
all negative for WNV
Overall risk of WNV transmission in the UK categorized by DoH as ‘LOW’..
Level of risk may increase if…
Changes in human
behaviour, encouraging
greater human/vector
contact
Changes in climate
to allow survival of
efficient vector
Climate change
New invasive species
 New diseases associated with these.
Aedes albopictus
Aedes albopictus – in USA
Aedes albopictus
• Spread
through import and internal
movement of used tyres
•Importation into California on “Lucky
Bamboo”
Europe
First appearance in Albania in 1979
Since then been reported in:

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
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Belgium, Bosnia & Herzegovina
Croatia, France, Germany, Greece
Italy, Malta, Monaco, Montenegro
Netherlands, San Marino, Slovenia
Spain, Switzerland, Vatican City
Imported tyres – into UK
(According to “Used Tyre Working Group”)
1999: 20,254 tonnes (units 3,116,000)
2000: 34,921 tonnes (units 5,372,462)
2001: 37,473 tonnes (units 5,765,077)
Research: Mosquito breeding in tyre
disposal sites in the West Midlands

Mosquito breeding potential in disposed tyres in the UK
Findings



Mosquitoes breeding at all sites
Within 1m of vegetation: 60% of tyres sampled housed
mosquitoes
Within 10m of vegetation, only 3% of tyres had
mosquitoes present
Invasive species - UK
Mosquito Watch was established in
2005
Environmental health practitioners
(EHPs) in responding to pest issues
receive insects from public
Invasive species
EHPs will likely be one of the first
groups to be asked identify new
mosquito nuisance-biting species.
Need for reporting system that could be
related to invasive species.
Invasive species
During five years of the scheme, there
were


116 confirmed mosquito reports
21 reports associated with other insect
groups.
The most commonly reported mosquito
species were:
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Culiseta annulata (56 reports)
Culex pipiens (42)
Ochlerotatus detritus (7)
Aedes/Ochlerotatus sp. (7)
Coquillettidia richiardii (1)
Anopheles maculipennis s.l. (1)
UK
No sign of Aedes albopictus in UK as yet !
Raising
awareness information
sheet
London Boroughs of
Hounslow /
Richmond on Thames
Thames Water
Climate change
Re-emergence of “old” pest species
 Microclimatic changes.
Bedbugs
“Microclimate Change”
Household environment
Bedbugs
Increase in numbers in recent years

Reasons ?
 Poor hygiene in communal living
 Increase in overseas travel
 Freecycle, e-bay
 Laundry
Bedbug life cycle.
Cimex lectularius – Egg to Adult
Temperature
(°C)
Complete
cycle (weeks)
13
Not completed
15
34
18
18
22
8
27
4.5
Bedbugs
Increase in numbers in recent years

Reasons ?
Laundry
Bedbug control
WET/DRY bedding:
It is the time
time taken to reach the required core
temperature of 400C - 500C which is
vital
Wet bedding, it took about 2.5 times
longer to reach the required core
temperature.
Climate change
Conclusions

New diseases associating with established insect
species

New insect species

Re-emergence of “old” pests