I. b. Imported Fire Ant Identification and Biology

2. I. b. Imported Fire Ant Identification and Biology Teaching Module for Master Gardener Training

3. Identification • Location – found in open, sunny areas • Mounds – large, no activity on surface • Ants – very aggressive when disturbed • Stings – Painful, leave white pustule, sting more than once

4. Medical Importance Pustules Bite and Sting Multiple Times Stinger and Poison Gland

5. Types of Adult Fire Ants Winged female Winged male Workers UC Statewide IPM Program

6. Polymorphism in Worker Ants major queen minor media Adult fire ant workers have different morphs (polymorphic), i.e. major, media and minor that vary greatly in body size. Majors are often used in identification because of their large size. Not all ant species exhibit polymorphism.

7. Reproduction • Mating flights on sunny days 1-2 days after a rain when temperatures are above 75ºF • Flights usually occur in spring and fall but can occur at any time of year

8. Reproduction • Mating takes place 300 to 800 feet above the ground. • After mating, female seeks moist or reflective surfaces on which to land; male dies. • Female vulnerable to predators during and just after mating flight, especially other fire ants.

9. Colony Formation • New colonies are founded by newly mated females (queens). • Once a queen lands, she removes her wings, burrows into the soil and begins to lay eggs.

10. eggs Colony Formation • First batch of eggs grows up to be worker ants. • Worker ants are all sterile females capable of stinging. • Workers begin foraging and constructing mound.

11. eggs Colony Formation A queen can live 5-7 years and lay up to her own weight in eggs per day (800-3000 eggs).

12. Development Worker immature and mature stages • Large workers live about 90-150 days as adults • Small workers live about 60-90 days as adults • Regardless of size, they change jobs as they age • nurse • guard/excavator • forager

13. Mound Development • Mounds often are not clearly visible within first few months. • A small mound with several thousand ants may be visible within six months.

14. Mound Development • Fire ant mounds can be recognized by their dome or cone-shape. • Mounds can be quite large (sometimes 60 cm tall and 60 cm wide). • Mounds usually found in open areas. • Unlike the nests of most other ants, fire ant mounds have no openings and little visible activity on the mound surface, unless disturbed.

15. Lateral foraging tunnel Exit / Entrance Interconnected chambers Lateral foraging tunnel Deep tunnels to water source

16. If the mound is disturbed, the workers rush to save the queen and the immature ants.

17. Workers move the immature fire ants and the queen around the nest, for near constant temperature and humidity, often more than once per day.

18. Eggs Adult Pupa Larvae The fire ant has 4 life stages

19. Larval Stages Larvae molt four times over a 12-15 day period.

20. Fourth instars are the only stage that can feed on solid food (black arrow points to food particle).

21. Food Sources Fire ants eat a variety of foods Reagan, LSU AgCenter and are excellent foragers.

22. Trophallaxis • Foraging ants bring the food back to the nest. • The ants pass the food to one another by regurgitating it from their crops as liquid until food is distributed to all members of the colony, including the queen (trophallaxis). • Adults cannot digest solid food.

23. Single Queen Colony • 15-80 mounds per acre, 7 million ants per acre • One queen per colony • Worker ants are territorial • The majority of fire ant colonies are of the single queen type

24. Multiple Queen Colony • 200-800 mounds per acre, 14 million ants per acre • More than one queen in each colony • Colonies reproduce by budding • Worker ants are not territorial • Typical form in Texas

25. Reproduction Type • Single queen (monogyne) • territorial and aggressive • limited life to colony • Multiple queens (polygyne) • non-territorial and not aggressive toward each other • will adopt new queens • long-lived colonies