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BIOLOGICAL CONTROL OF THE MEXICAN BROMELIAD WEEVIL

BIOLOGICAL CONTROL OF THE MEXICAN BROMELIAD WEEVIL. Ronald D. Cave Indian River Research & Education Center Ft. Pierce, FL. How long has the weevil been in Florida?.

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BIOLOGICAL CONTROL OF THE MEXICAN BROMELIAD WEEVIL

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  1. BIOLOGICAL CONTROL OF THE MEXICAN BROMELIAD WEEVIL Ronald D. Cave Indian River Research & Education Center Ft. Pierce, FL

  2. How long has the weevil been in Florida? • The weevil was first discovered in 1989 in a bromeliad nursery in Fort Lauderdale and is believed to have arrived on plants imported from Veracruz, Mexico. • Via movement of infested plants and its own flight capabilities, it is now widespread in south Florida

  3. Mexican Bromeliad Weevil Distribution in Florida Reported in 22 Florida counties from 1989 to 2006 (2 new county infestations in 2006) Currently known to occur in 21 counties (not seen in Miami- Dade County since before Hurricane Andrew) Orange Pinellas

  4. Which of Florida’s native bromeliads are under weevil attack? Tillandsia utriculata giant airplant (endangered) Tillandsia fasciculata cardinal airplant (endangered)

  5. Which of Florida’s native bromeliads are under weevil attack? Tillandsia flexuosa twisted airplant (threatened) Tillandsia paucifolia potbelly airplant Tillandsia balbisiana northern needleleaf (threatened)

  6. WEEVIL LARVA AND PUPA • After hatching from the egg, the developing larva (the immature stage) tunnels into the base of the stem. • Before changing to an adult, the mature larva becomes a pupa, resting within a chamber it constructs inside the stem from shredded plant material.

  7. WEEVIL ADULT • Feeds mainly on leaves; may feed on the inflorescence. • Females lay eggs in slits in the leaves close to where they feed.

  8. What are the symptoms of weevil damage? • Gel produced by plant • Browning of leaves • Decomposition of leaves at base (center leaves of plant can be pulled out easily)

  9. How are bromeliad populations in parks and other natural areas being affected? In many county and state parks, bromeliads are disappearing at an alarming rate. For example, in the Savannas Preserve State Park in St. Lucie County, an area of terrestrially-growing T. utriculata was reduced to debris within a matter of months.

  10. What federally protected natural areas is the weevil affecting? B. Larson / UF The weevil is destroying Tillandsia fasciculata populations in the Loxahatchee National Wildlife Refuge andthe Big Cypress National Preserve.

  11. How can we manage the weevil? Chemical control is notappropriate, because the weevil is found in parks and other natural areas where chemicals would adversely affect other organisms. Bromeliads are also inaccessible, due to their tree-dwelling lifestyle. Parasites that kill the weevil naturally have not been found in Florida. Classical biological controloffers the most likelyoption.

  12. How does classical biological control work? • A natural enemy (called a biological control agent) is brought from the pest’s homeland. • After testing shows the biological control agent will NOT attack beneficial organisms and appropriate permits are obtained, it is released where pest densities are greatest, with the hope it will become established in the area. • The pest population is not eradicated completely, but is maintained over the long term at a very low level.

  13. What biological control agent can we use against the weevil? A potential biological control agent was found in Honduras and is now colonized in quarantine. • It is a species of parasitic fly called Lixadmontia franki. • It specializes in eating bromeliad weevils ONLY. • It does parasitize larvae of Metamasius mosieri, a native bromeliad-eating weevil, but prefersM. callizona larvae.

  14. Fly Life Cycle

  15. Fly Biology Preferably parasitize 3rd and 4th instar hosts Development time is 5-6 weeks Adult females live up to six weeks when provided hummingbird food and honey Adults are only attracted to bromeliads damaged by weevils

  16. What has been done so far? • A thriving colony maintained at the Panamerican School of Agriculture in Honduras, financed in large part by the Florida Council of Bromeliad Societies

  17. >2,000 puparia received during 2005-2007 and a fly colony established at the Biological Control Research and Containment Laboratory in Ft. Pierce Space Hosts Food

  18. What needs to be done? 1. Increasethe fly colony and produce large quantities. 2. Release the fly in areas of high weevil concentration. 3. Evaluate the fly’s effectiveness (Teresa Cooper et al.)

  19. Sites for release of Lixadmontia Northwest Equestrian Park Enchanted Forest 27 females on June 29 Savannas Preserve State Park Highlands Hammock State Park Myakka River State Park Loxahatchee NWR59 females on July 20 Bear Island area Big Cypress National Preserve NASA

  20. Release of Lixadmontia franki at Loxahatchee NWRJuly 20, 2007 QUESTIONS?

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