Archbold Biological Station, Biennial Report 1997-1998

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Mark Deyrup examines a pygmy mole cricket at Archbold's newly-acquired Calamintha Scrub tract, photo by Nancy Deyrup.

 

       Accomplishments 1997-98
  • Published 11 papers in peer-reviewed journals.
  • Described 6 species new to science, including 3 ants, 2 flies, and 1 grasshopper.
  • Consulted with many scientists about Florida scrub arthropods.
  • Participated in numerous field trips, meetings, workshops, and advisory groups on conservation of Florida scrub.

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Leafcutting bee, Megachile sp. (Hymenoptera: Megachilidae) on saw palmetto flowers; photo by Peter Carmichael


Entomological Research

Project Director: Mark A. Deyrup
Interns: Kimberly A. Keyser, Johanna M. Kraus, Joshua Ladau
Outside Collaborators: James E. Carrel, University of Missouri; Stephan Cover, Harvard University; Margaret A. Hodge, The College of Wooster; Karl V. Krombein and Beth B. Norden, National Museum of Natural History; Sam D. Marshall, Miami University; Lubomir Masner, Canadian National Collection of Arthropods

[Biennial Contents | Biennial 95-97

While other biologists are demonstrating new ecological models out on the showroom floor, the entomologist tends to find himself perpetually doing the inventory in a back room. There he is, happily hunched over his microscope, muttering cheerfully to himself, "One thousand two hundred and forty-three species of beetles1, 1,244, 1,245, 1,246, ...." The apparently endless enumeration of species extends beyond faunal lists to include ecological studies that one might think would be relatively simple.

     In 1997, for example, the Archbold Entomology Lab began a survey of insect visitors on saw palmetto flowers. This produced 109 species of flies, 91 bees and wasps, 43 beetles, 20 moths and butterflies, and 31 miscellaneous insects, for a total of 294 species. These occur at various levels of abundance in various places on the Station, and at different times of day. Fortunately, the student intern working on this project, Kim Keyser (Wake Forest Univ.) was able to stay awake through the night to catch moths, crickets, roaches, and beetles that are not active by day. Most of the palmetto flower insects are just stopping by to fuel, like commuters at a doughnut shop on the way to work. Males of many bees, wasps, and flies, however, hang around the flowers after feeding, watching for potential mates. Their advances disrupt the feeding of females, often driving them to an inflorescence on another palmetto plant. Hassling by cruising males may be an important facilitator of cross-pollination in saw palmetto. Almost all the insects feeding at palmetto flowers have other ecological roles as predators or herbivores, or pollinators of other plant species. The burst of spring flowering in saw palmettos supports hundreds of other ecological relationships. In some years this whole system is severely perturbed by masses of exotic honey bees or love bugs, which charge through the pollinator community like a Mongol horde sacking Byzantium. How does the insect ecologist deal with all this diversity, complexity, and variability?

     Apparently learning no prudence from this bewildering experience with saw palmetto, in 1998 the denizens of the Entomology Lab began a project on the insect visitors of gallberry (Ilex glabra). Karl Krombein (Archbold Research Associate) and Beth Norden were instigators in this study. So far, only 72 species have been found on gallberry flowers, but even this is a large number of species to study simultaneously. A special feature of gallberry is that it is both highly clonal and dioecious. This means that bees which are gathering pollen probably have little effect on pollination, as they do not visit the female plants. Nectar feeders, such as hover flies, visit both male and female plants. The smaller species of nectar feeders, however, may do most of their foraging within a single clone. All this should be quantified by following flower visitors, but there are so many visitors buzzing about so quickly amid the tangle of shrubs that it is difficult to get any useful data. Gallberry shares many of its flower visitors with saw palmetto, so the two systems are linked in some obscure way.

     Parasitic Wasps. Intensive, specialized studies, such as those of flower visitors, usually reveal some species of insects not previously recorded from the Station. Even these intensive studies, however, pale in the production of novelties compared with a new technique of general collecting. In 1998 the Canadian hymenopterist Lubomir Masner came swooping down from his aerie in the Canadian National Collection, armed with a new collecting method, the "yellow bowl system." This uses small, plastic, yellow dessert dishes that are set out and filled with water and a few drops of detergent. For some unknown reason, many tiny insects throw themselves into these bowls. Insects that feed on yellow flowers are not particularly attracted. Insects that breed in water almost never fall into these bowls. Among the commonest insects in the bowls are small parasitic wasps. If one puts out 50 of these bowls in a small area, after a day or so one can strain out a total of a tablespoon of granular sludge. Under the microscope this proves to be thousands of specimens of minuscule flies and wasps. Many of these are specimens of insects unknown from the Station. In any such harvest there are usually several species unknown to science. There is little in common in the species composition from different habitats, such as the disturbed hammock around the main buildings, the scrub up on Red Hill, and the shore on the west side of Lake Annie. Masner is especially interested in parasitic wasps of the family Scelionidae, which live in the eggs of other insects. Since each wasp completes its development in a single egg of its host, they are very small. A few species were known from the Station before the advent of Dr. Masner; the actual number could be in the hundreds, based on our impression of the shape of the species accumulation curves and the disconcerting faunal changes from one habitat to another. Most of the genera of these egg parasites are specialized, so there is a genus in cricket eggs, another in the eggs of spiders, another in the eggs of web spinners (Embioptera), and so on.

     On global, state, and local scales, the biological diversity of the world is in decline. Every day there are fewer species on earth than in all of the history of mankind, and every day there are more species than there ever will be again, even should human culture persist for a million years. Here at the Archbold Biological Station, however, we enjoy a glorious illusion: the recorded biological diversity of small animals seems to be expanding explosively before our eyes.

     The years 1997–98 in the Entomology Lab were not completely filled with huge, open-ended projects. About a dozen or more modest studies actually got completed, written, and published during this time. These deal with pollination ecology; a new species of grasshopper and of a fly; the ant fauna of the Bahama Islands; and the adaptations of a beetle that feeds on millipedes. There were ongoing projects on species of spiders, bees, pygmy mole crickets, and ants. The Ants of Florida project produced descriptions of several new species, accumulated new distribution data, and unraveled some taxonomic problems.

     1 The current number of beetle species known from Archbold Biological Station.

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Archbold Biological Station, 2000 March
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