|Deloach Jr, Culver|
Submitted to: XI Symposium on Biological Control of Weeds
Publication Type: Proceedings
Publication Acceptance Date: 1/10/2004
Publication Date: 1/10/2004
Citation: Deloach, C.J., Carruthers, R.I., Dudley, T.L., Eberts, D., Kazmer, D.J., Knutson, A.E., Bean, D.W., Knight, J., Lewis, P.A., Milbrath, L.R., Tracy, J.L., Knight, J., Tomic-Carruthers, N., Herr, J.C., Abbott, G., Prestwich, S., Harruff, G., Everitt, G.H., Thompson, D.C., Mityaev, I., Jashenko, R., Li, B., Sobhian, R., Kirk, A., Robbins, T.O., Delfosse, E.S. 2004. First results for control of saltcedar (Tamarix spp.) in the open field in the western United States. In: Cullen, J.M., Briese, D.T., Kriticos, D.J., Lonsdale, W.M., Morin, L., Skott, J.K., editors. Proceedings of XI International Symposium on Biological Control of Weeds, CSIRO Entomology, Canberra, Australia. p. 505-513. Interpretive Summary: Saltcedars, exotic small trees introduced from the Old World, cause great damage to natural and agricultural ecosystems of the western United States; they are heavy users of scarce groundwater (thus reducing water supplies for agriculture and municipalities), increase soil salinity and wildfires, displace native plant communities and damage wildlife habitat. During several years of testing overseas and in quarantine at Temple, TX and Albany, CA, we have demonstrated that a foliage-feeding beetle from China and Kazakhstan will not damage American native plants or crops. Experimental releases into the open environment in 2001 have now produced dramatic damage to saltcedar at several locations in the West. Continued control and spread to other areas is expected to control most of the saltcedar, to substantially increase water supplies in this drought stricken area, and to allow recovery of natural ecosystems.
Technical Abstract: Saltcedars (Tamaricaceae: Tamaricales) are among the most devastating exotic weeds ever to invade western U.S. riparian ecosystems. The ARS began biological control research in 1987 at Temple, TX and in 1998 at Albany, CA. Many prospective control insects are reported in the homeland of saltcedar in Eurasia. A leaf beetle, Diorhabda elongata deserticola from Fukang, China and Chilik, Kazakhstan, was released into field cages at 10 sites in Texas, Colorado, Wyoming, Utah, Nevada and California during 1999 and 2000, and into the open field at 6 of these sites in May 2001. It successfully overwintered at 4 sites north of the 38th parallel in 4 states, but not in Texas or southern California, presumably because of too short a daylength at the southern sites. During the summer of 2002, we observed dramatic defoliation of saltcedar at Lovelock, NV; good defoliation at Pueblo, CO; and substantial population increases but not defoliation at Lovell, WY and Delta, UT. Diorhabda beetles from Turpan, China; Greece; Uzbekistan and Tunisia are active at shorter daylengths and are promising for control in the more southern areas. Predators (ants and birds) have reduced populations at Lovell, Delta and Bishop, CA and control insects with predator protective behaviors, such as gall formers, may be required in those areas.