Bed Bugs Flashcards
Describe bed bugs
Cimex lectularius
Obligatory hematophagus ectoparasites
Adults: wingless, reddish-brown, 5mm in length
Nymphs: translucent and 1-4mm
Evolved ~100mya in Mediterranean/Middle East as parasite of bats and birds
Facts on bed bugs
Require a blood meal for moulting (5 nymphal stages)
Can survive up to 2 years without feeding
Can also undergo up to 30% in loss of water content
Very persistent pest species
Nymphs (2months) adults (2 years)
Up to 500 eggs per female (4 per day throughout lifetime)
Describe bed bug reproduction
Males pierce female abdomen with hypodermic genitalia
Known as traumatic insemination
Sperm travel via haemolymph to sperm storage areas (Seminal conceptacles)
Describe bed bugs relationships with humans
Adopted human hosts in Pleistocene (10,000BC)
Relationships strengthened as mankind began to farm (fixed settlements)
Locate hosts and each other via chemical communication i.e. kairomones and pheromones
Name the three Cimicid species that feed on humans
Leptocimex boueti (West African feeding bat parasite) Cimex hemipterous (tropics and sub-tropics) - global Cimex lectularious (temperate) - global
What are the symptoms of bed bug bites
Rashes
Allergic reactions
Emotional distress
No evidence of disease transmission
How have bed bugs been managed throughout history?
400bc earliest recorded control
1700: pest control company established in London
1730: bed bug manual published
1800s: Natural pyrethrum recommended as well as inorganic compounds (mercury chloride)
1800s: bed bug infestations common and associated with poorer people (crowding)
1900s: central heating permitted year round survival (1 in 3 housed in Europe infested)
Mid 19th century: burning sulphur (fumigant), hydrogen cyanide (zyklon B) until DDT was discovered
1947: resistance to DDT appeared, organophosphates used instead
1990s: bed bug outbreaks began to recur
2012: trials with Beauvaria, results not yet known
What are the most common treatment sites for bed bugs in the US?
Hotels (80%) Halls of residence (54%) Nursing homes (48%) Offices (38%) Schools (36%) Hospitals (31%)
What explanations are there for outbreaks recurring?
Increased travelling Lack of knowledge Lack of effective treatments Resistance in pest populations Intensification of poultry farming and birds as reservoirs for pest populations
What resistance mechanisms have been documented in bed bugs?
Detoxification, cuticular thickening and target site insensitivity
What methods are used to date to eradicate bed bugs?
Pyrethroids primary control method Mattress encasement Laundering Vacuuming Disposal Steaming
What other kinds of insecticides are used for bed bugs?
Growth regulators JH mimics Neem oil Pyrroles Desiccants Fumigants
