Bugs

Cimicidae – e.g., bed bugs
Polyctenidae – e.g., aphid-like ectoparasites of bats
Reduviidae – e.g., kissing bugs

What are the three main families of medical importance within Order Hemiptera?

Derived from Greek: "Hemi" = half, "Pteron" = wing. Refers to the forewings being partially hardened and partially membranous.

What is the origin of the name "Hemiptera"?

Piercing-sucking; feed on plant sap or animal fluids

Mouthparts

Forewings: hemelytra (base hardened, tip membranous)
Hindwings: entirely membranous and shorter than forewings

Wings

Chagas disease, caused by the parasite Trypanosoma cruzi.

What disease is associated with Reduviidae and what parasite causes it?

Kissing bugs, assassin bugs, conenoses, triatomine bugs.

What are common names for bugs in the subfamily Triatominae?

Triatoma infestans
Rhodnius prolixus
Panstrongylus megistus

Name three triatomine species identified as major vectors of Chagas disease.

Infected bug defecates near bite wound after feeding.
Trypomastigotes enter via mucosa or broken skin.
In human: multiply and cause Chagas disease.
In bug: transform to epimastigotes (midgut), then to metacyclic trypomastigotes (hindgut).

Describe the life cycle of Trypanosoma cruzi in relation to kissing bugs.

Length: 5–45 mm
5-segmented antennae, 3-segmented tarsi
Hide during the day; bite at night
Attracted to lights
Found in burrows, plant hollows, and dusty house corners

What are the physical and behavioral characteristics of triatomine bugs?

5 nymphal stages before adulthood
Both nymphs and adults are blood-feeders
Adults can fly up to 5.6 km, but prefer walking

Describe the development of kissing bugs.

Triatoma rubrofasciata

What is the recorded kissing bug species in the Philippines?

Contaminated feces via skin/mucosa
Blood transfusion
Organ transplant
Congenital transmission
Breastfeeding
Lab accidents
Rare customs (e.g., insect aphrodisiac use)

How is Chagas disease transmitted?

Residual insecticides (house spraying)
Integrated pest management (plugging crevices)
Bed nets and personal protection
Hygiene in food handling
Screening of blood, organs, and infants from infected mothers

What control measures are used against Reduviidae vectors?

Flat-bodied, brown, no functional wings (have wing pads)
~5 mm adult size
5 preimaginal stages; juveniles resemble adults
Almost 100 species (mostly on bats and birds; 2 on humans)

What are general characteristics of Cimicidae?

Cimex lectularius
Cimex hemipterus
(Leptocimex boueti is bat-associated but may bite humans)

Which Cimicidae species are associated with human infestation?

Nocturnal feeders
Feed on blood at all stages and in both sexes
Hide in cracks, wood, wall crevices
Can feed during day if host is at rest

What is the feeding behavior of bed bugs?

Egg: Pearly white; hatch in 12–14 days
Nymph: 5 stages; must feed and molt after each
Adult: Live 6–12 months; females lay 1–3 eggs daily (up to 200 total)

Describe the life cycle of Cimicidae.

Cause direct injury via multiple bites (Cimicosis; 1-2-3 pattern)
Allergic reactions may occur
May reduce hemoglobin levels in chronic infestations
No confirmed disease transmission, but rarely found to carry Hepatitis B in labs

What is the medical importance of Cimicidae?

Aerosols (pyrethroids), smoke generators (e.g., diatomaceous earth)
Physical cleaning, boiling water, sunlight exposure
Vacuuming and decluttering
Isolate or heat-treat infested items
Use of skin repellents and mosquito nets

How can bed bugs be controlled or prevented?