Location: Invasive Plant Research Laboratory
Project Number: 6032-22000-013-141-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jun 1, 2024
End Date: May 31, 2026
Objective:
Objective 1: Conduct biological control surveys for insects associated with cogongrass in Australia, Japan, Korea, Indonesia, Africa and, opportunistically, other Southeast Asian countries
Objective 2: Curate collected insects from foreign surveys
Objective 3: Colonize and initiate suitability tests of potential biological control agents of cogongrass
Objective 4: Phylogenomic investigation of Imperata cylindrica and curation of plant specimens
Approach:
Objective 1: Surveys will be conducted for potential biological control agents throughout the known range, especially in southeastern Queensland, Japan and Korea. These surveys will search for Acrapex azumai boring in stems of cogongrass in Japan. Several locations will be visited in Saga and Kagoshima Prefectures on the island of Kyushu. In addition to A. azumai, a second, much smaller stemborer was found at a few locations in Kagoshima Prefecture.
A gall midge Contarinia sp. causes a dead-heart symptom of infested cogongrass. This species was collected in Japan from the Ito campus of Kyushu University and several other locations in Fukuoka and Saga prefectures on Kyushu Island. As many members of this insect family are known to be narrow specialists that cause significant damage to their hosts, these species warrant further investigation as potential biological control agents.
Objective 2: Curation of collected insect material will be accomplished through both traditional morphological and molecular techniques.
Objective 3: New collections from Australia will be colonized on live plants in cages located in local laboratories and greenhouses. To optimize insect acceptance of rearing, plants will be grown with regular irrigation, fertilizer, and pruning. Plants propagated either from seed or whole plants will be collected from local populations and will be maintained under optimal conditions to produce healthy robust growth.
Objective 4: Imperata cylindrica is morphologically and genetically diverse, and the global context of this diversity is not adequately resolved by existing molecular and taxonomic research. The inability to differentiate between plants that are morphologically similar, but biologically different, frequently confounds biological control programs. We will investigate this diversity through both molecular and morphological approaches.
