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Learn about the Hemiptera insects, including their unique characteristics and diverse species. Discover the potential dangers of Kissing Bugs and their association with Chagas Disease. Explore control methods and watch educational videos to deepen your understanding.
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True Bugs Announcements Read Chapter 6 - Lice FIRST QUIZ – THURSDAY Covers Chapters 5, 6, and 7 Speakers Today: Logan Minter, Magda Stewart On Deck for Thursday: Lindsey Henderson,Rachel Leneweaver
True Bugs Hemiptera Homoptera Heteroptera Atypical Problems Species Not Medically Important Reduviidae Kissing Bugs Cimicidae Bed Bugs
Characteristics of Hemiptera (Heteroptera) • Front wing = “hemielytron”; Two parts: • Clavum (leathery part) • Corium (membrane part)
Characteristics of Hemiptera (Heteroptera) Mouthparts • Beaklike • Arises from front of head • Visible part of beak is the labium • Maxillae & mandibles form stylets inside the beak. • Food & salivary channels are separate.
Heteroptera is a big group Stink Bug Water Strider Backswimmer Damsel Bug Big-Eyed Bug Giant Water Bug Tarnished Plant Bug
Atypical Problems • The entire group has piercing mouthparts & takes in liquid. • Many spp. will sample a person if given the opportunity. • Those which are numerous & small occasionally create perceived problems. • These problems are always temporary, associated with specific times/places, usually outside (especially garden areas).
Kissing Bugs • Family Reduviidae • Subfamily Triatominae • Most Important Genera: Triatoma (67 spp.), Rhodnius (16 spp.), Parastrongylus(13 spp.), & Paratriatoma (1 sp.) • About 130 spp worldwide, all feed on vertebrate blood • Most species are found in the Americas • Domestic, Peridomestic & Sylvatic species Rhodnius prolixus Triatoma infestans
Known by many names • US: Kissing bug, cone-nose bug • Generic Spanish: Cinche besucona (kissing bug) or Cinche hocicona (cone-nose bug) • Mexico (Nahuatl): Pik (sound of bug hitting the wall) • Colombia: Pito (whistle or horn) • Ecuador (Quechua): Chinchorro (large bug) • Peru (Quechua): Cherimacha (bug that dislikes the cold) • Paraguay (Guarani): Chichá guazu (big bug); (Ayoreo): Itchajuponja (sucking bug); (Aché) Sham buí ta (Insect that does harm by injections) • Bolivia, Chile, Argentina, Uruguay (Quechua): Vinchuca (Bug that lets itself fall). • Brazil (Portugese): Barbiero (barber or shaving bug).
Kissing Bugs • Hide in crevices during the day, come out at night • Are attracted by heat, CO2 and other volatiles of the victim. • Usually crawl over the ceiling (T. infestans) • Drop onto the sleeping victim. Continue to orient to CO2 and often bite victim on/near lips (thus the name). • Biting near the eyes is also common • Feeds for about 15 min.
Main Problem of Triatomines: Chagas Disease • An example from Argentina
Chagas Disease = American Trypansomiasis • Named after Carlos Chagas – 1909 • Trypanosoma cruzi • Affects maybe 100 million people, kills up to 50K/year, about 200K new cases/year in South America • 4th leading cause of death in Latin America • Typically takes 5 – 20 years to kill • No effective treatment • Currently affects up to 20% of blood donations in the US.
Animated Infection Cycle of Chagas • Click here to play the animation of life cycle in the human host. • Click here for the animation of the life cycle in the bug.
Chagas Symptoms -- 3 Stages • Parasite’s entry site sore – Parasite exits bug through feces, feces often in the immediate area of feeding site, patient rubs/scratches the feeding site then rubs wound/eyes/mouth/etc. • Acute phase (Romaña’s sign), mortality in young/immuno-compromised may occur here. • Chronic phase
Factors Limiting Chagas Management • No effective prophylactic or therapeutic pharmacology • Primarily a problem of the poor. • S. America doesn’t get the international attention of other regions. • S. American govts. traditionally underfund public health efforts • The vector is highly mobile
Vector Mobility Example – Arequipa, Peru • 2nd Largest City of Peru • Experiment in 2004/2005 exterminated all T. infestans in a neighborhood. • Resampled 2 years later
Vector Control Options • Treated bed nets (permanets) • Improved Public Education • Adaptive Strategies – respecting cultural/social needs • Plastering walls, sealing cracks/crevices • Protecting animal cages/stalls • Residual Insecticide Application • National Programs in Argentina, Bolivia, Brazil, Chile, Paraguay, Uruguay and Venezuela • Insecticidal Paints have been effective • Most work now is on insecticide-impregnated resin formulations
Chagas Videos in Spanish • These are descriptions of the state of Chagas in various South American Countries. Viewing these videos are optional: • Argentina (4 min) • Brazil (2 min) News Report (in Portugese) • Colombia (4 min). • Ecuador (5 min) educational video • Venezuela (5 min) histological/diagnostic video
A major nuisance problem recently resurfaced Watch the UK Video (Emmy Award Winner). It covers many of the topics covered here in a very entertaining manner. This video is 7 minutes long. To watch that video, click: HERE
Cimicidae • Affects many vertebrates • 23 genera, 91 spp. • Most common pest of humans: Cimex lectularius • All are dorsoventrally flattened Bedbug in action video
Curious Biofact –Traumatic Insemination Male pierces the female's abdomen with his penis and injects his sperm through the wound into her bloodstream. Female is permanently scarred by this. In dense colonies, high female mortality results. Interspecific matings occasionally occur (e.g. C. lectularius X C. hemipterus) and are usually fatal to the female.
Bedbug history • Common throughout European history • First pest control company formed in the 1600’s as a bedbug control service using tobacco. • Introduced to N. America by colonists • Suddenly disappeared from most of the developed world in the early 1950’s • Suddenly reappeared in the mid – late 1990’s
Reasons for Reappearance • Use of long-residual insecticides declined • Increased movement of people & material • Increased used of specific pest controls (e.g. baits). • Improved personal/environmental measures? • Decrease in smoking • Decrease in toxic materials for furniture/carpet manufacturing
Medical Significance • No substantiated significant disease transmission • Dermatological conditions/complications from bites • Psychological/Psychiatric associated with long-term exposure (e.g. months) • Irritability from lack of sleep • Continued discomfort from bites • Financial/family stresses
Bed Bug Control • Bed bug control is expensive, difficult, problematic, highly disruptive. • Thorough vacuuming. • Bedding/furniture encasement or discard. • Heat treatment effective for fabrics. Includes carpet steamers. • Insecticide treatments are generally the last step (though may precede encasement).