Since January 2001 I have been doing field research in Myakka River State Park (Sarasota County, Florida) on an invasive weevil and its host bromeliads. The weevil in photograph 2 is Metamasius callizona and was brought into Florida on bromeliad shipments coming in from Mexico. About 10 years ago, the weevil escaped into the wild, succesfully colonized, and has spread across south Florida, destroying huge populations of bromeliads in its wake. Dr. Howard Frank (Entomology and Nematology Department, University of Florida) has been working towards a biological control solution to resolve this problem. Biological control uses living organisms to control pests. In this case, a fly whose larvae feeds upon the larvae of the weevil is being studied. If this fly can be shown to be specific to the weevil and capable of being reared in large numbers, then it will be released in areas infested by the weevil. The fly larvae will consume a portion of the weevil larvae and therefore the weevil population will be reduced and the host plants will suffer a lesser assault from the weevil.

Photograph 2

The host plants affected by the weevil are bromeliads. The two species of host plants found in Myakka River State Park, and also the two species that are being hit the hardest by the weevil, are Tillandsia utriculata (photograph 3) and Tillandsia fasciculata (photograph 4).

The host plants live in the canopy. Sometimes they fall to the ground or some brushy mid-point and continue to grow there. They get their nutrients from rain water that runs over the leaves of overhead trees. They grow slowly and take many years to reach the age of reproduction. The infloresence is set out in the springtime. The T. fasciculata pictured has a newly emerging bloom stalk. As the bloom stalk overwinters, the seeds mature. The following spring, the pods open and wind-borne tufts of white fluff, each clutching a small brown seed, are released and carried away (photograph 5).

Photograph 3 (top) and 4 (bottom)

Photograph 5

The parent plant of T. utriculata and T. fasciculata both die after making seed. Nothing remains after T. utriculata is gone; but after T. fasciculata dies, it leaves behind pups, small clones of itself that keep growing, eventually producing blooms and seeds to promote the next generation..

This work is intended to help the biological control efforts being conducted by Dr. Frank. Every month, I make a trip to the park and revisit selected host plants within selected areas. I see whether or not they are still present; if they are doing well or poorly; if they have shifted postion; and just generally look for any worthy observations. If they are dead, or removed, or stressed, I search for the cause. I also search for the weevil and take note where I find it and under what conditions. I look for explanations for the observations and will offer these explanations to help determine how a biological control agent may fit beneficially into the weevil-host plant system.

Kim, Austin and Ryan had three weeks to design a study, collect and work the data, write a paper and give a presentation. They began, it seems to me, in the best way to begin a natural study: They met the subjects of study - the host plants and the weevil- and made notes about the world the subjects live in. From these observations, they created an hypothesis about some phenomena related to the weevil and/or the host plant.

Photograph by J. Yawn

They created the following hypothesis:
Tree type of greatest density = primary host for bromeliads.

In other words, if an area with a host plant population has 25% pines, 25% sabal palms, and 50% oak, then one would expect a like distribution of trees hosting host plants. If this hypthesis is true, then it would indicate a degree of randomness in the host plant seed preference for tree type.

They set out to prove or disprove this hypothesis.

They collected data in three different habitats in the park. Each habitat supported some host plant growth and had different tree type density and ratio. They used my method of mapping to collect information on tree type and location, as well as which trees have host plants. These maps function like any other map and the trees that are plotted can easily be relocated. This is the gift they left me. I still have the maps and have made two trips since they've left. From their maps I have selected host plants to add into the host plant population I am monitoring. Their efforts have given me not only expansion in the host plant population, but also expansion in geographic area under observation, as well as inclusion of more habitat type.

Kim, Austin and Ryan spent long days in the field. They rode dirt bikes through miles of deep sand and bumpy roads. The mapping is hard and tedious labor. They spent nights drawing maps, pulling data, working their numbers and putting together both a paper and a presentation.

We presented to the faculty at Selby Botanical Gardens on the 28th of January. I gave a brief overview about the weevil and the host plants, about the research I'm doing, and how and why I benefited from the efforts of the Cornell Crew. Kim, Austin and Ryan presented their study. They offered their hypothesis and then disproved it. They discussed their method of research, the assumptions inherent in their method, and the possible reasons for the outcome of the study.

To read about their experience in their own words, see their PAPER: Distribution Patterns of Tillandsia utriculata and Tillandsia fasciculata in Myakka River State Park

Marty was tireless through it all and was always ready for the adventure, right up to the last moment after the presentation and they had one day left to relax in Florida. To the beach!

Photographs by J. Yawn

The Cornell Crew saved me a great amount of time and effort and have expanded my data base. In return, they have a better understanding of biological field research. Besides these important practical benefits are the deeper, less defined ones we found in our opportunity to exchange ideas and to gain new experiences. The best part of humanity may be found in the pursuit of honest knowledge of ourselves and the world we live in and communication is important to the growth and maintenance of the knowledge we gain. Entities such as Selby Botanical Gardens and the State Park system offer places for congregating, communicating and pursuing knowledge. I am grateful to the individuals who make up these entities and who work diligently to keep them going.

Once more, they jumped my dead car battery. The task was performed with quick efficiency and in a flash they were driving off to the beach, to crash and splash away the tension built up from a long and arduous task. I put the car in gear and began my own journey back to Gainesville.

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Teresa Cooper, February 2002

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