Biological Control of Chinese Tallow Triadica Sebifera, Euphorbiaceae
Biological control of Chinese tallow Triadica sebifera, Euphorbiaceae
• Greg Wheeler, USDA/ARS/IPRL Ft Lauderdale, FL • S. Steininger, C. Nguyen, K. Dyer, S. Wright, USDA/ARS • Jianqing Ding, Yi Wang, Wei Huang, Jialiang Zhang – Chinese Academy of Sciences, Wuhan China • Matt Purcell, CSIRO, Australia Biological control of Chinese tallow
• Overseas surveys • Quarantine host testing • Preparation for field release of agents Triadica sebifera
(Chinese Tallow, Popcorn Tree, Tallowtree, Florida Aspen) Tallow distribution in China
• Distributed in China south of the Yellow river to Hong Kong • Cultivated sp. • Possibly 200 spp of herbivore pests that are potential biological control agents Tallow’s distribution US • The dominant woody sp in many forests & wetlands • Infestations impact endangered Whooping crane and Attwater’s prairie chicken populations • Expanding range, $200- $400 million to control over next 20 yrs EDDMapS 2012 • biological control is a sustainable, cost- effective alternative
Tallow biological control agents
Heterapoderopsis bicallosicollis Bikasha collaris
Gadirtha fusca Caloptilia triadicae
Heterapoderopsis bicallosicollis Bikasha collaris flea beetle
Bikasha collaris Adult Feeding Larval Feeding
Bikasha collaris
Damaged roots Results (Larvae) • 68 & 78 non-target species tested by Chinese & USDA/ARS/IPRL • All larvae quickly died on non-targets, except: – Hippomane mancinella (manchineel) (3 of 80 larvae ate roots - died) – Ricinus communis (castorbean) (2 of 50 larva matured to adult - died) • Choice tests of 10 spp completed with little damage to non-targets Results (Adults) • 78 non-target species have been tested no- choice starvation tests – Feeding (nibbling) occurred on three species • Ditrysinia (=Sebastiania) fruticosa (Gulf Sebastian bush) • Gymnanthes lucida (Oysterwood) S. Fla sp • Hippomane mancinella (manchineel) S. Fla sp • Eggs only produced when adults fed tallow – – no reproduction on other spp • Choice tests with non-targets indicates < 1% feeding compared with control on H. mancinella, Euphorbia hypericifolia (sandmat), and Manihot esculenta (cassava)
Bikasha impact
• Larvae 0, 5,10/plt • Adults 0, 5, 10/plt • Both larvae & adults decrease biomass • Greatest impact from both larval & adult feeding Number of larvae | Number of adults New Insects on Tallow •Gadirtha fusca (Nolidae) Gadirtha inexacta •Narrow host range from Chinese larvae field surveys and lab tests •Quarantine 2012 and being tested now (Jan 2015) •Larvae safe (38 spp tested) •Very damaging
Leaves fed to Leaf damage of one late instar one larva after larva 2 days (135 cm2) New Insects on Tallow - insects being developed
•Unidentified stem galling midge •Abundant in many Midge stem gall areas of China •Work continues in China The Adventive Biological Control Agent • Appeared nr Tampa & Gainesville in 2008 • From China (Caloptilia triadicae) • Heavy damage to Tallow plants Tallow biological control release study
•Sites in North Florida •Pre-release description of the plant population •Population recruitment, growth and mortality (~100 plants/site) •Plant biomass allocation (~30 plants/site) •Monitor each year & compare impact of biological control pre- release vs post-release
Tallow demographics in North Florida sites • Factors influence demography (mortality, growth, reproduction)? • Possible factors: – Water depth and duration of flooding • data suggests increased mortality and decreased growth. Reproduction? – Herbivory
Tallow demographics in North Florida sites • Survival
greatest 100 for large 80 trees 60 • Seedlings had Survival (%) 40 Seedlings 20 Saplings highest Reproductive trees mortality 0 2012 2013 2014 Years Could flood influence tree mortality?
Response to flooding • hypertrophy of lenticels • adventitious roots Caloptilia Impact on tallow • What is the effect of Caloptilia on tallow demographics? • Our studies show complete defoliation, suggesting more herbivores needed Tallow biological control
Priorities 2015: China
•Gall midge rearing & specificity Florida •Continue: • flea beetle TAG • moth Gadirtha fusca - TAG •Gall midge Bikasha collaris Gadirtha fusca specificity larvae • Pre-release demographics
Acknowledgements • Funding: Florida Fish Wildlife Conservation Commission (D. Schmitz, D. Leslie, G. Jubinsky) National Park Service (T. Pernas) USDA/ARS • Work: S. Steininger, C. Nguyen, S. Wright, K. Dyer USDA/ARS Jianqing Ding, Yi Wang, Wei Huang, Jialiang Zhang, Chinese Academy of Science Purcell, M. CSIRO A. Christman, Paynes Prairie Preserve, DEP M. Cole, G. Nichols, SJRWMD