Location: Invasive Plant Research LaboratoryTitle: Does Lilioceris egena burrow for tubers
|GOLDSTEIN, SCOTT - Broward Community College|
|Dray, F Allen|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/9/2016
Publication Date: N/A
Interpretive Summary: The invasive vine Dioscorea bulbifera (air potato) is a serious weed of natural areas in Florida and is spreading into adjoining states, with the potential to spread as far north as Tennessee/southern Virginia. A beetle being vetted for use as a possible biological control of this vine preferentially attacks aerial storage organs (bulbils), but it is unknown whether the beetle will burrow through the substrate to attack underground storage organs (tubers). This study investigated the beetles’ ability to burrow to this potential food resource, and compared the resulting volume of tissue consumed and numbers of eggs deposited on these tubers against damage and eggs from bulbils deposited.
Technical Abstract: The invasive Asian vine Dioscorea bulbifera (air potato) trellises up native trees in a variety of habitats in Florida and displaces native understory vegetation with its associated fauna, thereby altering community composition. A biological control program directed at this vine has already released one leaf beetle, Lilioceris cheni, that has rapidly spread throughout the state and is significantly stressing the target weed. Ongoing research suggests that the closely related L. egena, discovered in China, prefers aerial tubers (called bulbils) to foliage as a food resource and ovipositional substrate. However, it is unclear whether these beetles will detect and damage subterranean tubers. This study seeks to answer that question. METHODS Air potato tubers, collected from field sites in southern Florida, were planted individually in plexiglass cylinders containing vermiculite. Tubers and bulbils were planted on the surface, and tubers at 0.5, 10.0, and 25.0 cm depths. Assessment metrics included (1) volume of tissue consumed, and (2) numbers of eggs oviposited, on the tubers and bulbils during a seven-day period. Data were analyzed using single factor ANOVAs. RESULTS We expect to discover that L. egena has the ability to burrow modest distances into soil to attack and damage air potato tubers which would have the effect of greatly reducing a plant’s ability to recover from foliar damage produced by L. cheni. CONCLUSION The one-two punch of Lilioceris cheni and L. egena should sufficiently stress individual D. bulbifera plants that multi-year recovery is disrupted and population declines become widespread.