Mosquitoes, ticks, biting midges 2/29/2016
DHG 1
Mosquitoes, Biting Midges,
and Ticks Madness
Mosquitoes can breed in……..A. Natural water
catchments, and man-made containers, but not in irrigated lawns
B. In man-made containers holding more than 1 pint of water
C. Natural water catchments, man-made containers, and irrigated lawn areas, but not maintained swimming-pools
A. B. C.
94%
3%3%
Brown dog ticks
A. Are intolerant to high temperatures
B. Are relatively heat tolerant
C. Prefer room temperature
A. B. C.
94%
3%3%
MosquitoesMosquitoes
Mosquitoes need water
Four life stagesegg, larva, pupa, and adult
Larval and pupal stages are aquatic
Two-winged Diptera (flies) Family Culicidae: most species females have a long proboscis for sucking blood
• Eggs
• Singly on surface or edge of water
• Eggs in rafts on surface of water
• Some sp. hatch 24-36 h• Some hatch after 1-3 y • Overwintering stage for
some species
Larvae
• 1st, 2nd, 3rd, 4th
instars
• “Wigglers”, very active, most come to surface for air
• 4-12 d, some species weeks
Mosquitoes, ticks, biting midges 2/29/2016
DHG 2
Pupae• Stage that changes from larva to adult
• “Tumblers” very active, come to surface for air
• 3-6 d
• Non-feeding stage
Adult mosquitoes emerge from aquatic stages
Adult (Male)• Emerges first
• Feeds on nectar sources for energy
• Mates within 2 -7 d and dies
Adult (Females)
• Emerge and feed on nectar
• Mates usually once
• Needs blood meal to develop eggs
• 1-5 blood meals over life of 7 - 28 d
Winter Survival Is Important:
Most overwinter in the egg stage
Some as larvae
Some as adults
Mated females rest in protected, cool locations
Warm spring days allowfemales to seek a blood meal
Mosquitoes are classified based on larval habitat• Floodwater mosquitoes - Eggs laid
in damp areas
• Permanent water
• Containers
Mosquitoes, ticks, biting midges 2/29/2016
DHG 3
Flood Water Mosquitoes
• Aedes and Psorophora• Some genera are important pest species• Bite humans, livestock, pets• Can have very large populations
in spring and early summer
• Can survive in egg stage for several years until flooded
• Can have different hatches within several days if increased water levels hatch new eggs
Floodwater (cont.) • Adult populations peak in late April, May, and June, some species hatch with late summer fall rains
• Adults die quickly during hot weather
• Flood water usually dries up too fast to support larvae in hot weather
• Females most active around sunset or in shady areas when disturbed
• Some are active during the day
Permanent Water Mosquitoes
• Anopheles, some Culex spp.
• Quiet bodies of freshwater with sunlight, surface vegetation and little wave action
• Shallow edges of ponds, some lakes backwaters of rivers slow moving streams
• Never in lakes with wave action
U.S. Mosquitos of Great Concern
• Culex tarsalis, C. quinquefasciatus(southern house mosquito)
• Note: all are permanent water mosquitoes, populations peak in summer through fall at same time virus activity peaks
• Feed on birds and mammals
• Vector WNV, WEE and SLE
Mosquitoes, ticks, biting midges 2/29/2016
DHG 4
Culex quinquefasciatus
Culex tarsalis
• Populations low in spring
• Build through the summer
• Peak July-October (varies by location)
• Many prefer birds as hosts, feed on mammals
• Vectors of viruses
• Bite more readily at night
Permanent Water Group (cont.)
Roadside ditches Wastewater treatment
Culex spp. prefer nasty, smelly water
Container Mosquitoes(you breed ‘em, you feed ‘em)
• 99% = Culex or Aedes• Larvae live in tree holes, rock pools even
leaf axils• Many associated with man made
containers• Tires, cans, buckets, birdbaths, gutters, pet
water dishes, plant container bottoms that catch water, even cans, paper cups etc.
Typical Container Mosquito Habitat Mosquito Hunting
Mosquitoes, ticks, biting midges 2/29/2016
DHG 5
Locations of mosquitosurveillance and Aedes aegyptipresence in Arizona -2015
• Source Reduction
• Eliminate mosquito breeding sites
•Oils•Suffocation – mechanical barrier•Suffocation – oil entering the siphon blocking air•Poisoning due to toxic properties of the volatiles
•Bacterial (Bti, B. sphaericus)•Chemicals (organophosphate-temephos, Abate®) •IGR (growth hormones - methoprene) •Fish, copepods, turtles
Types of Larvacides
AdulticidesExpensive and relatively ineffective <60%
ULV hand fogger and portable mist blowers•Organophoshates•Pyrethroids/pyrethrum
•ULV•Droplet size 10-46 microns
•Portable mist blowers•Large droplet size
Mosquitoes, ticks, biting midges 2/29/2016
DHG 6
Live bearers– 75 young/female
New brood/6-8 weeksOmnivorous
30-50 Gambusiaaffinis /pool
Mosquito Management
• Stop them at their source – larvacide
• Kill vectoring adults – adulticide
• Erect barriers against the ones you miss
• Advocate personal protection as the final layer of protection – repellents
• Virus
• 1O vectors
• Human hosts
• % symptomatic
• % chronic
• % fatality
• Symptoms
WEST NILE CHIKUNGUNYA
• Flavivirus
• Culex
• Incidental
• <20%
• <1%
• <1%
• fever, headache, body aches, skin rash, and swollen lymph nodes
• Alphavirus
• Aedes
• 1O host
• 72-97%
• 30–40%
• 0.03%
• headache, muscle pain, joint swelling, rash
• Virus
• 1O vectors
• Human hosts
• % symptomatic
• % chronic
• % fatality
• Symptoms
DENGUE ZIKA• Flavivirus 1-4
• Aedes
• 1o host
• Can be 50%
• Variable
• <1-50% (DF,DHF)
• Headache, eye pain, joint pain, muscle and/or bone pain, rash, nausea
• Flavivirus
• Aedes
• 1o host
• <20%
• ?
• Very low GB
• fever, rash, joint pain, and conjunctivitis (?microcephaly?)
Educational Materials
CDChttp://www.cdc.gov/features/stopmosquitoes/
USGShttp://diseasemaps.usgs.gov/dep_ga_human.html
Mosquitoes, ticks, biting midges 2/29/2016
DHG 7
Brown dog tick Rhipicephalus sanguineus
General Life Cycle of a Tick
Male
Female
Larva
Nymph
Egg
Adults
Feed
Develop
Lay eggs
Feed
Develop
molt
Feed
Develop
molt
Hatch
Ixodidae
Brown dog tick Rhipicephalus sanguineus (3000‐4000 eggs)
Brown dog ticks are “special”• Heat tolerant ticks• Low desert tick activity year‐round• Reproduce indoors or outdoors in 63‐93 days• Widespread tick distribution (69%‐83% houses with dogs)
• High tick densities in peridomestic environment• Close contact between humans, dogs and ticks
• Potential for transport of ticks across widespread area due to stray dogs
• Transmit RMSF very rapidly
Rhipicephalus sanguineus
When to Suspect Tick‐borne Illness
Acute febrile illness without apparent cause (fever, malaise, lethargy + other symptoms)
Onset during May‐September (high tick activity)
History of tick bite or exposure
Persons at risk for tick bite
History of travel to endemic areas (US and global travel)
Thrombocytopenia, elevated liver enzymes
Rash not always a feature
Mosquitoes, ticks, biting midges 2/29/2016
DHG 8
RMSF cases 2013Rocky Mountain Spotted Fever (RMSF)
• Disproportionately affects children and elderly
• Acute febrile illness with severe manifestations
• Typical symptoms include: fever, headache, nausea, vomiting, abdominal pain, and muscle pain
• A rash occurs 2‐5 days after fever, may be absent in some cases
• Low incidence, high consequence disease
• High case fatality rate
• RMSF can be a severe or even fatal illness if not treated in the first few days of symptoms
• Doxycycline is most effective if started in the first 5 days of symptoms
Rocky Mountain Spotted Fever (RMSF)
Mention of trade names does not imply endorsement by UA, CDC or other agencies.
RMSF in Arizona• Identified in tribal communities in eastern Arizona since 2003
• High infestations of brown dog ticks
• Many confirmed bites by nymphs (usually behind ears or back of neck)
When first investigated in AZ, the annual incidence of RMSF in this area was 300x that of
rest of country
RMSF in Arizona
• Now seen in many widely separated tribal lands (over 400,000 persons at risk)
• From 2002‐2013, 321 cases were identified
Case fatality rate = 7%
CDC, IHS and 2 tribes, estimate $13.2 million due to the epidemic of RMSF 2002 ‐ 2011, on two Indian reservations
RMSF in Arizona
• Dog serosurveys
• 3‐50% across six tribal lands (avg. 28.5%)
• Arizona, non‐tribal lands 5%
Mosquitoes, ticks, biting midges 2/29/2016
DHG 9
Biological Features
Ticks move among hosts during high tick activity (interrupted feeding)
Nocturnal detachment of nymphal and adult engorged ticks concentrates ticks and facilitates host contact
Increased height of questing and human biting rate with elevated temperature (Melendez et al. 1995; Parola et al. 2008)
Survives temperatures and humidities that other ticks cannot (Yoder et al. 2006a,b): 90% survival at 40°C and 33% survival at 50°C (122°F)
Biological Features
Personal Repellent Use
• DEET (N, N‐diethyl‐3‐methylbenzamide)– Use repellents containing 20‐30% DEET on exposed skin and clothing
– No greater than 15% for children
• Permethrin– Can only be used to treat clothing (0.5%)
• Other repellents registered by the EPA
Avoid Contact with Ticks
• Clothing adjustment and access prevention measures (e.g., pants in sock, double‐stick tape, wear light colored clothing to see ticks)
• Avoidance of tick habitat or tick infested areas
• Prompt tick removal reduces risk
Proper Tick Removal
DO NOT: use petroleum jelly, a hot match, nail polish, or other products to remove a tick
Prevention• Tumble clothes in a dryer on high heat for an hour
• Bathe or shower after coming indoors
• Examine gear, pets and each other
• Ask your doctor about antibiotics if bitten
• Learn the early signs of tick‐borne illness
• Routine tick check and removal
– Record date/save tick
• Control ticks around your home
Mosquitoes, ticks, biting midges 2/29/2016
DHG 10
Home Assessment‐What Are We Looking For?
Examine for suitable microhabitats aroundthe home:
• Are animals (dogs especially) present?
• Are there access points to a crawl space?
• Is vegetation present providing shade and humidity?
• Are there wood piles, other debris?
• Furniture or outdoor garbage?
Vegetation in surrounding areas increased moisture levels under houses on piers
“Shady places where dogs lie”
Rhipicephalus sanguineus InfestationRhipicephalus sanguineus Infestation
Voids in the concrete piers can contain ticks of all stages
Larvae and nymphs can quest from the surface
Rhipicephalus sanguineus InfestationRhipicephalus sanguineus Infestation Applications: Proper use of pesticides; Proper timing and dosage of application; Maximize safety
Indoors
Treatment of cracks and crevices (pyrethroids, desiccants)
Do not treat food preparation areas
Outdoors
Treatment of tick‐infested areas
Treatment of animal sleeping areas
Do not treat ground water or areas where contaminated runoff could occur
Treatment of Premises• Outdoor
– Sprays• Pyrethrins, Bifenthrin, Permethrin, Lambda‐Cyhalothrin, Carbaryl
–Granules• Carbaryl, Bifenthrin, Permethrin, Lambda‐Cyhalothrin
–Dusts• Carbaryl, Permethrin, Deltamethrin
Hose‐end sprayer for best resultsTicks detect and avoid pesticides, begin at the exterior, then work out and away from the house
Reminder: Dog Population Control
Animal control
Spay/neuter programs can stabilize the situation
Dogs get sick also
Mosquitoes, ticks, biting midges 2/29/2016
DHG 11
Topically Applied Products
• Pyrethrins
• Permethrin, Permethrin + pyriproxyfen
• Fipronil
• Fipronil + methoprene
• Fipronil + amitraz + methoprene
• Metaflumizone + amitraz
• Selamectin
Collars• Tetrachlorvinphos (Hartz Ultraguard)
• Tetrachlorvinphos + (S)‐methoprene (Hartz Ultraguard Plus)
• Propoxur (Zodiac, Breakaway Plus)
• Amitraz (Preventic)
• Amitraz + pyriproxifen (Preventic Plus)
• Deltamethrin (Adams Delta Force, Preventef‐D, Scalibor)
• Flumethrin + propoxur (Kiltix)
• Flumethrin + imidacloprid (Seresto)
Effectiveness reduced in high heat or if dog swims
Some products are highly toxic, use with caution especially when children interact with dogs
Useful Resources
• http://www.cdc.gov/rmsf/
No‐see‐ums Culicoides or Leptoconops(Ceratopogonidae)
• Summer month misery• Small <1/16th inch • Painful bites• Pass through standard window screening• Culicoides feed early dusk and night
Leptoconops during the day!• Blood‐feeding female flies• Eggs laid on moist surfaces or in water• Not human disease vectors but allergic
reactions are common
Mosquitoes, ticks, biting midges 2/29/2016
DHG 12
Mosquitoes can breed in……..A. Natural water
catchments, and man-made containers, but not in irrigated lawns
B. In man-made containers holding more than 1 pint of water
C. Natural water catchments, man-made containers, and irrigated lawn areas, but not maintained swimming-pools
A. B. C.
95%
5%0%
Brown dog ticks
A. Are intolerant to high temperatures
B. Are relatively heat tolerant
C. Prefer room temperature
A. B. C.
94%
3%3%
Common sense
Use of trade names does not imply endorsement by UA, CDC or other agencies