Chinese tallow grows well in warm, moist climates and has spread throughout Louisiana and most of the southeastern U.S. It prefers wet areas, such as ditches and swamps, but is also well-established in many upland forests and urban areas.
Chinese tallow may grow up to 60 feet (18.3 m) high and 3 feet (0.9 m) in diameter. They can be identified by broad, waxy-green leaves, which often have an extended tip or “tail”. New growth often appears reddish.
Tallow’s other common name, “grey popcorn tree”, is based on the form of the mature fruit which turns black and opens to reveal white, waxy seeds. These seeds develop from trilobed greenish fruit which appears in clusters at branch tips during September and October.
Chinese tallow is monoecious, producing male and female flowers on the same tree. Trees typically flower in April and June, producing yellow flowers on dangling spikes up to 8 inches (20 cm) long. Trees may grow from cuttings, but development from seeds is most common.
Chinese tallow outcompetes native shrubs and trees, creating monoculture stands in natural settings. The tree has also infiltrated urban settings and is a common sight in neighborhood yards throughout Louisiana.
Because of its long taproot and ability to sprout from break points in lateral roots, physical and mechanical removal (as well as removal by burning) are not ideal. These methods in conjunction with chemical control via an herbicide may prove effective, but caution should be used when applying herbicides near trees growing near water.
Note: Photo by Doug Streett, USDA Forest Service, Pineville, LA
Bikasha collaris, a flea beetle native to China, is currently being evaluated for potential as a control agent. In tests, larvae feed on roots and adults feed on foliage, causing significant and highly-specific damage to Chinese tallow. Similarly, Gadirtha fusca, a nolid moth native to China, is also being assessed as a biocontrol agent. Larvae effectively defoliate trees in field trials in China, reducing densities of tallow stands.
Flea beetle (Bikasha collaris)
This species of flea beetle is a natural enemy of Chinese tallowtree. It is native to China and, after extensive testing, has demonstrated high levels of specificity for and damage to T. sebifera. It is currently being evaluated by the USDA for potential release.
Bikasha collaris adults are slightly over 2 mm long and just under 1 mm wide. They are ovate in form with black and reddish-brown coloration. Larvae (right) are minute, grublike and feed on roots beneath the ground.
Note: Figure by G. Wheeler.
Adult beetles lay pale, cylindrical eggs which hatch after about 9 days. Larvae begin feeding below the ground on roots and soil-covered stems. After about 18 days of feeding, larvae pupate in the surrounding soil. Adults emerge and continue feeding on young tallow leaves. Multiple generations can occur in a season and adults are long-lived (up to 6 months).
Note: Figure by G. Wheeler.
Adult flea beetles feed on leaves with a preference for tender, new growth. Evidence of frass or droppings can sometimes be found on emergent plant tissues. Larval damage occurs on roots and plant tissues below the soil surface and can be difficult to observe.
Note: Figure by Greg Wheeler.
Impact. Feeding by flea beetles may destroy stands over time by reducing both the plant’s ability to uptake nutrients (larval root damage) and new growth (adult feeding). Weakening of the plant is particularly evident in young saplings. Initial observations suggest that feeding is specific to Chinese tallow and flea beetles may be an optimal candidate for suppression of stands in the U.S.
Note: Figure by Greg Wheeler.
Noctuid moth (Gadirtha fusca)
This species of moth is a natural enemy of Chinese tallowtree (Triadica sebifera). It is native to China and, after extensive testing, has demonstrated high levels of specificity for and damage to Chinese tallow. It is currently being evaluated by the USDA for potential release in the United States.
Gadirtha fusca adults have a wingspan of about 1.75 inches and a body length of about 0.75 inches. Adults (left) have brown and grey patterned forewings and light brown hindwings. Adults bear a resemblance to many noctuid moth species in the U.S. Detailed examination of morphological characters is necessary for accurate species-level identification. Caterpillars (right) feed on leaves.
Note: Photo of caterpillar by Michael Pogue
Adult moths lay pale, cylindrical eggs on newly developing leaves in the spring. Eggs overwinter and hatch in May. Larvae develop through 5 instars in about 15 days, causing extensive defoliation of trees, and then pupate underground. Adults emerge and disperse to find mates. Four to five generations can occur in a season in native ranges.
Larvae of G. fusca cause extensive damage to leaf tissues, completely defoliating trees, especially young saplings or those growing in shady conditions. Large quantities of frass (droppings) may indicate active larval feeding.
Note: Photo by Greg Wheeler.
Caterpillar feeding may reduce the size of an infestation over time by destruction of plant tissues and multiple generations may cause sapling mortality and significant reduction of biomass. Pre-release studies suggest that larval feeding may result in complete defoliation of seedlings and is highly specific to Chinese tallow, suggesting the moth may be an optimal candidate for suppression of Chinese tallow stands in the U.S.
Impact of Chinese tallowtree to ecosystems
Bruce, K.A., G. N. Cameron, P. A. Harcombe, and G. Jubinsky. 1997. Introduction, impact on native habitats, and management of a woody invader, the Chinese tallow tree, Sapium sebiferum (L.) Roxb. Nat. Areas J. 17: 255-260.
EDDMapS. 2018. Early Detection & Distribution Mapping System. http://www.eddmaps.org/.(accessed on 25 April 2018).
Wang, H. H., W.E. Grant, J. Gan, W.E. Rogers, T.M. Swannack, T.E. Koralewski, J.H. Miller, and J.W. Taylor.2012. Integrating Spread Dynamics and Economics of Timber Production to Manage Chinese Tallow Invasions in Southern U.S. Forestlands. PLoS ONE 7: e33877.
Safety of biological control agents proposed for release
Huang, W., G.S. Wheeler, M.F. Purcell, and J. Ding. 2011. The host range and impact of Bikasha collaris (Coleoptera: Chrysomelidae), a promising candidate agent for biological control of Chinese tallow, Triadica sebifera (Euphorbiaceae) in the United States. Biol. Control 56: 230-238.https://www.sciencedirect.com/science/article/pii/S1049964410002495
Wang, Y., Zhu, Lin, Wheeler, G. S., Purcell, M., and J. Ding. 2012. Pre-release assessment of Gadirtha inexacta, a proposed biological control agent of Chinese tallow (Triadica sebifera) in the United States. Biological Control 63: 304-309. https://www.sciencedirect.com/science/article/pii/S1049964412001727
Wheeler, G. S., Steininger, M. S., and S. Writght. 2017. Quarantine host range of Bikasha collaris, a potential biological control agent of Chinese tallowtree (Triadica sebifera) in North America. Entomologia Experimentalis et Applicata 163: 184-196. https://onlinelibrary.wiley.com/doi/full/10.1111/eea.12573
Wheeler, G. S., Duncan, J. G., and S. Wright. 2017. Predicting spillover risk to non-target plants pre-release: Bikasha collaris a potential biological control agent of Chinese tallowtree (Triadica sebifera). Biological Control 108: 16-21. https://www.sciencedirect.com/science/article/pii/S1049964417300294
Author: Brittany Owens
Instructor: Dr. Rodrigo Diaz, email@example.com