Ants, Wasps, & Bees

1. Ants, Wasps, & Bees Announcements • Speaking Today: Amanda Meadows • Speaking Next Tuesday: Elizabeth Andrews • QUIZ NEXT TUESDAY OVER CHAPTERS 25, 26, 21, 24

2. New Spider Threat in N America • Tegenaria agrestis, Hobo Spider • Introduced from Europe to Seattle in 1930’s • Moved into homes • Bite is similar to brown recluse • Now responsible for more necrotic envenomations in US than any other sp.

3. Spiders & MRSA • MRSA = methicillin-resistant Staphylococcus aureus • Community-Acquired has been associated with spiders • Association is two-fold • Transmission of MRSA via spider bites • Misdiagnosis of MRSA as spider bites • Misdiagnosis has been largely corrected by including MRSA screen as part of the spider bite diagnostic protocol. Example • Educational effort continues in the medical community

4. Other effects: Urticating Hairs • Barbed hairs on the abdomen of many New World tarantulas • Used as a defense, territorial marker. • Commonly encountered by pet owners when they clean tarantula cages • Nonvenomous but some people have allergies.

5. Order Hymenoptera: Ants, Bees, & Wasps • Relatively recent evolutionary origin • Generally the most beneficial group of insects to man • Useful products (e.g. honey) • Biological control • Members have the most advanced communication, learning, and vision • Most of the social insects in this group • Including specializations for social defense • Most attacks on humans are colony defense actions

6. Medical significance of this group is in its sting • Stingers are modified ovipositors so only females sting • Most stinging females are not reproductive • Stinger itself can be a problem but mostly it’s the venom • Hymenopteran families of most medical significance are: • Ants • Formicidae – Social • Solitary Wasps • Mutilidae – Velvet ants; Cow Killers • Social Wasps • Vespidae – Yellow Jackets; Hornets; Paper Wasps • Social Bees • Apidae – Honey bees; Bumble Bees

7. Hymenopteran Stinger Source

8. Wasp Stinger

9. Hymenopteran venoms • Depending on the size/species one sting is generally 0.01 – 0.15 mg venom • Typical Human LD50 is ~100 mg • Most are chemically similar to snake venom and can be deactivated with ethanol • Neurotoxins and agents to assist them • In vertebrates, neurotoxins cause temporary pain, the other agents cause real damage • Often contain non-toxic components • Pheromones (trail marking, alarm, marking)

10. Example: Apitoxin (Honeybee)

11. Reactions to Hymenopteran Stings • Immediate localized reaction or swelling (non-allergic responses) • Mild: erythema, swelling, and transient pain at the sting site that subsides within a few hours • More Severe: may involve an entire extremity. Swelling of the airway, tongue etc can occur. • Systemic toxic response from multiple stings • Mild: Hives • More Severe: vomiting, dizziness, confusion, rash, general weakness, shortness of breath and wheezing, and chest pain • Systemic allergic reactions - rare • May occur from an initial sting or may be acquired • anaphylactic shock, difficulty in breathing, and death within 30 minutes

12. Example Symptoms Adult Onset Allergy Bee sting hives on arm from a sting on leg Paper wasp sting near eye

13. Ants • ~10,000 spp world wide only a few are medically important • Ant “venom” varies dramatically across species, most are non-toxic to vertebrates. • Medically important species • Fire ants • Bull-dog ant

14. Fire Ants • Solenopsis spp. • S. invicta, Red Imported Fire Ant (RIFA) the most important • Introduced into US in the 1930’s, now in most of SE US. • Have had many ecological ramifications. Ex. here • Sting 15 – 25 million/year in US • Cause $750 million damage in Agriculture/year

15. Bulldog Ants • Ants in the genus, Myrmecia. M. pilosula is the “Jack Jumper”. • Australia & Tasmania (Jack Jumpers). • In Tasmania, they cause more deaths than spiders, wasps, snakes & sharks combined. • Generate anaphylactic shock in high incidence. Life-threatening reactions in 1-2% of cases. • Antivenom stocks maintained throughout their range. Jack Jumper

16. Solitary Wasps • Velvet ants, several spp. • Nest parasites of ground-nesting bees & wasps • Very painful sting

17. Social Wasps • Yellowjackets, hornets & paper wasps • Yellowjackets are the important group. • Large, annual nests • Aggressively defended by workers • Often in situations with human contact. • Baldfaced hornets are actually yellow jackets which act like hornets. Above: Western Yellow Jacket Bald faced hornet (right) & nest (above) Above: European hornet

18. Hornets vs Wasps

19. Bees • Insects in the unranked taxon, Anthophila, several families • 20,000 spp most of which are harmless • A group that switched from predation to feeding on nectar & pollen • Co-evolved with flowers. • Few are agressive

20. Africanized Bees • Hybrids of the European honey bee and the African honey bee (different subspecies) • Originally imported to Brazil to increase honey production • Defends hive more aggressively • Kill 1 – 2 people/year in US Animated map of spread

21. Probable Eventual Distribution of Africanized Bees

22. First Aid • Topical steroid cream (hydrocortisone), • Cream containing aloe vera. • Fire ant creams: • regular toothpaste. • Solution of half bleach and half water applied immediately to the area can reduce the pain, itching and, perhaps, pustule formation. • Oral medicines: antihistamines.

23. Medical Use of Hymenoptera • Ant head sutures • Uses soldier ant heads • Used for at least 3,000 years • Bee venom therapy • 1980 FDA licensed its use for desensitation • Now >500 human and veterinary applications • American Apitherapy Society