By J. Goolsby1, D. Thomas1, A. Perez de Leon2, P. Moran3, A. Kirk4, M.C. Bon4, J. Kashefi4, G. Desurmont4, L. Smith4, M. Cristofaro5, C. Yang6, J. Gaskin7, P. Gowda8, M. Grusak9, M. Ciomperlik10, A. Racelis11, A. Vacek11, J. Landivar12, A. Pepper13, R. Lacewell14, E. Rister14, M. Martinez JimÌ©nez15, M. Marcos16 E. CortÌ©s Mendoza16, L. Gilbert17, R. Plowes17, T. Vaughn18, A. Rubio18
The use of insects as biological control against carrizo cane has reduced the invasive weed’s dominance in the Rio Grande Basin.
Arundo donax L., also known as giant reed and carrizo cane, is native to the Old World from the Iberian Peninsula of Europe, across the Mediterranean to south Asia, including North Africa, the Arabian Peninsula and the Caspian Basin. It has been cultivated in the Old World for thousands of years and has been widely introduced around the world as an ornamental, and for its fiber uses. Subsequently, it has become naturalized and invasive in many tropical, subtropical, and warm-temperate regions of the world. Carrizo cane was introduced into North America from Mediterranean Spain in the early 1500s by colonists for use as roof thatching and quickly became naturalized (21, 36). It is now found throughout the southern half of the United States from Maryland to California, but is most invasive in the southwestern U.S. and northern Mexico (3, 15, 20, 22, 27, 30).
Carrizo cane is an extremely invasive weed of riparian habitat, drainage ditches and irrigation canals of the Rio Grande River Basin of Texas and Mexico (RGB). Carrizo cane has historically dominated these habitats where it competes for scarce water resources and reduces riparian biodiversity (33). Carrizo cane also facilitates the invasion of cattle fever ticks from Mexico into Texas, and impedes law enforcement activities along the international border (8, 10, 13, 31).
A binational biological control program between the U.S. Department of Agriculture, Agricultural Research Service (Edinburg, Texas) and Instituto Mexicano de TecnologÌ_a del Aguas (Jiutepec, Morelos, Mexico) (14, 33, 41) was initiated in 2007. Additional funding was provided by the U.S. Department of Homeland Security, Customs and Border Protection to meet the operational needs of the U.S. Border Patrol working along the international border with Mexico. Biological control of the invasive cane with specialized insects from the native range of the weed in Spain was considered to be the best long-term option for managing this highly invasive weed, because it is low cost, sustainable and suitable for use in large areas such as the RGB (5,8,11, 26, 35).
Two specialist, insect biological control agents from the native range of carrizo cane in Spain, the arundo wasp, Tetramesa romana Walker (Hymenoptera: Eurytomidae) and the arundo scale, Rhizaspidiotus donacis (Leonardi) (Homoptera: Diaspidae) were mass-reared, released and established in Texas and Mexico (2009 and 2012), as well as in California (2013) (11, 12, 14, 28, 29, 34, 39). These insects are highly specialized and only develop on Mediterranean genotypes of A. donax (1, 4, 6, 9, 23).
The arundo wasp lays eggs in arundo canes and side shoots, causing formation of galls (abnormal plant growth) that are fed on by the developing larvae, with adults emerging from the galls via characteristic exit holes (2, 7,). The wasp can complete its life cycle in 35-60 days and has now colonized carrizo cane along 600 river-miles or more of the Rio Grande and in several regions of Mexico.
In 2016, six years after the release of the wasp, above ground biomass of carrizo cane had decreased on average by 32 percent along the Rio Grande (38, 40, 41). This change in biomass (above ground growth) was associated with damage caused by the arundo wasp to main and lateral shoots. Declines in biomass, live shoot density and shoot lengths, especially from arundo wasp damage, appears to be leading to a consistent decline of carrizo cane all along the Rio Grande from Del Rio to Brownsville, Texas. We also have documented significant changes in riverine plant biodiversity, with more than 54 native plant species recorded where there was once a solid monoculture of carrizo cane (40). Damage to stems and shoots of the invasive weed by the arundo wasp appears to have opened the once closed canopy to penetration of sunlight, which is stimulating the regrowth of understory vegetation (40).
The arundo scale, R. donacis, feeds below ground on rhizomes and the bases of side shoots of carrizo cane (6, 9, 16, 17, 32). Females release tiny ‘crawlers’ that settle on suitable tissues, become immobile, and complete their life cycle in five to six months. In its native range in France and Spain, this scale reduces shoot growth and rhizome size by 50 percent (17). The arundo scale has been established at more than 50 sites along the Rio Grande in Texas and Mexico, and its impact in combination with the arundo wasp is under ongoing evaluation (40).
A third biological control agent, Lasioptera donacis Coutin (Diptera: Cecidomyiidae), the arundo leaf miner, was recently permitted and releases along the Rio Grande are underway. The arundo leaf miner larvae feed and develop in the leaf sheath of the cane (37). Damage to leaf sheaths by the leaf miner ultimately leads to death and defoliation of the entire leaf. This defoliation increases light penetration through the canopy, which may accelerate the recovery of the native riparian plant community along the Rio Grande. In addition, defoliation will make the environment less suitable for survival of cattle fever ticks, Rhipicephalus microplus and Rhipicephalus (B.) annulatus; and increase within-stand visibility, which improves safety and effectiveness of law enforcement personnel and cattle fever tick personnel working along the international border in Texas 18, 31, 32.
Biological control also has successfully integrated with mechanical topping of the cane. Topping cane at 3 feet tall causes dense formation of side shoots, which are heavily attacked by the biological control agents leading to long-term stunting of the cane. This integrated method accelerates the decline of carrizo cane and provides immediate visibility of the international border for law enforcement personnel (24, 25).
Field monitoring of the carrizo cane biological control program is continuing. Thus far, we have documented consistent declines in above ground biomass of the invasive weed and return of desirable native vegetation, such as black willow and sugar hackberry trees along the Rio Grande (19, 33). Economically, the reduction in carrizo cane biomass is estimated to save 6,000 acre-feet of irrigation water per year (which is equal to the yearly needs of McAllen, Texas, a city of 147,000 people), worth $4.4 million (38, 40). The biological control technology also is being transferred to the end users along the Rio Grande and other areas in Mexico and the Southwestern U.S. where this plant is invasive.
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 Racelis, A. E., Goolsby, J. A. and Moran, P. J. 2009. Seasonality and movement of adventive populations of the arundo wasp (Tetramesa romana) a biological control agent of giant reed (Arundo donax L.) in South Texas. Southwestern Entomologist 34: 347-357.
 Goolsby, J. A., Moran, P. J., Adamczyk, J. A., Kirk, A. A., Jones, W. A., Marcos, M. A. and CortÌ©s, E. 2010. Host range of the European, rhizome-stem feeding scale Rhizaspidiotus donacis (Leonardi) (Hemiptera: Diaspididae), a candidate biological control agent for giant reed, Arundo donax L. (Poales: Poaceae) in North America. Biocontrol Science and Technology 19: 899-918.
 Goolsby, J. A., Spencer, D., and Whitehand, L. 2010. Pre-release assessment of impact on Arundo donax by the candidate biological control agents, Tetramesa romana (Hymenoptera: Eurytomidae) and Rhizaspidiotus donacis (Homoptera: Diaspididae) under quarantine conditions. Southwestern Entomologist 34: 359-376.
 Seawright, E. K., Rister, M. E., Lacewell, R. D., McCorkle, D. A., Sturdivant, A. W., Yang, C. and Goolsby, J. A. 2010. Economic implications for the biological control of Arundo donax in the Rio Grande Basin. Southwestern Entomologist 34:377-94.
 Moran, P. J., and Goolsby, J. A. 2010. Biology of the armored scale Rhizaspidiotus donacis (Hemiptera: Diaspididae), a candidate agent for biological control of giant reed. Annals of the Entomological Society of America 103: 252-263
 Moore, G.W., Watts, D.A., and Goolsby, J.A. 2010. Ecophysiological Responses of Giant Reed (Arundo donax) to Herbivory, Invasive Plant Science and Management 2010 3: 521ÛÒ529.
 Racelis, A.E., Goolsby, J.A., Penk, R., Jones, W.K., and Roland, T.J. 2010. The development of an inundative, aerial release technique for the arundo wasp, a biological control agent of the invasive Arundo donax. Southwestern Entomologist. 35: 495-501.
 Goolsby, J.A., and Mangan, R.M. 2010. Use of Spinosad bait (BF-120) for management of Chaetopsis massyla in shadehouse grown Arundo donax. Southwestern Entomologist. 35: 573-574.
 Gowda, P.H., J.A. Goolsby, C. Yang, S. Basu, A. Racelis, and T.A. Howell. 2011. Estimating water use by giant reed along the Rio Grande usingåÊa Large Aperture Scintillometer. Subtropical Plant Science, 63: 1-6.
 Goolsby, J.A., A. A. Kirk, P. J. Moran, A. E. Racelis, J. J. Adamczyk, E. CortÌ©s, Ma. Marcos GarcÌ_a, M. Martinez Jimenez, K. R. Summy, M. A. Ciomperlik, and D. P.A. Sands. 2011. Establishment of the Armored Scale Rhizaspidiotus donacis, a Biological Control Agent of Arundo donax. Southwestern Entomologist 36: 373-374.
 Yang, C., Everitt, J. H. and Goolsby, J. A. åÊ2011. Using aerial photography for mapping giant reed infestations along the Texas-Mexico portion of the Rio Grande. Invasive Plant Science and Management. 4: 402ÛÒ410.
 Cortes, E., J.A. Goolsby, P. Moran and M.A. Marcos-Garc±a. 2011a. The effect of the armored scale, Rhizaspidiotus donacis (Hemiptera: Diaspididae), on shoot growth of the invasive plant Arundo donax (Poaceae: Arundinoideae). Biocontrol Science and Technology 21: 535-545
 CortÌ©s, E., A.A. Kirk; J.A. Goolsby; P.J. Moran, A.E. Racelis and M.A. Marcos-GarcÌ_a. 2011b. Impact of the Arundo scale Rhizaspidiotus donacis (Leonardi) (Hemiptera; Diaspididae) on the weight of Arundo donax L. (Poaceae; Arundinoideae) rhizomes in Languedoc southern France and Mediterranean Spain. Biocontrol Science and Technology 21: 1369-1373.
 Racelis, A.E., R. B. Davey, J. A. Goolsby, A. A. PÌrez de LeÌn, K. Varner, and R. Duhaime. åÊ2012. Facilitative ecological interactions between invasive species: Arundo donax (Poaceae) stands as favorable habitat for cattle ticks (Acari: Ixodidae) along the US-Mexico border. Journal of Medical Entomology 49: 410-417.
 Racelis, A., A. Rubio, T. Vaughan, and J. Goolsby. 2012. Passive restoration potential of areas invaded with giant reed in south Texas. Ecological Restoration 30: 112-116.
 Chenghai Yang, John A. Goolsby, James H. Everitt & Qian Du. 2012. Applying six classifiers to airborne hyperspectral imagery for detecting giant reed, Geocarto International. 27: 413-424.
 Tarin, D. Manhart, J. Pepper, A., Goolsby, J., Moran, P. Contreras Arquieta, B., and Kirk, A. 2013. Microsatellite markers indicate multiple origins of Arundo donax L. in North America. Invasive Plant Science and Management 6: 328-338.
 Summy, K.R., Lieman, J., Gandy, Y.P., Mamachen, A, Mamachen, A., Goolsby, J.A., and Moran, P.J. 2013. Effects of leaf excision and sample storage methods on spectral reflectance by foliage of giant reed, Arundo donax. Subtropical Plant Science. 63: 54-64.
 Goolsby, J.A, E. Cortes Mendoza, P.J. Moran, J.J. Adamczyk, Ma. Marcos Garcia, and A.A. Kirk. 2013. Evaluation of Spanish Arundo scale Rhizaspidiotus donacis (Leonardi) (Hemiptera; Diaspididae) survival and fecundity on three New World genotypes of Arundo donax (Poaceae; Arundinoideae). Biocontrol Science and Technology. 23: 499-506.
 Racelis, A. E., P.J. Moran, and J.A. Goolsby. 2013. Topping of Arundo donax as a pre-treatment to biological control Journal of Subtropical Plant Science 64:54-60.
 Racelis, A. E. and J. A. Goolsby. 2013. Rapid assessment of above-ground biomass of giant reed using visibility estimates. Subtropical Plant Science 64:61-66.
 Goolsby, John A., Racelis, Alex E., Goolsby, Julia B., Kirk, Alan A., Cristofaro, Massimo, Grusak, M. and Perez de Leon, Adalberto. 2013. Evaluation of biogeographical factors in the native range to improve the success of biological control agents in the introduced range. Biological Control Science and Technology. 23:1213-1230.
 Yang, C., Westbrook, J.K., Suh, C.P., Martin, D.E., Hoffmann, W.C., Lan, Y., Fritz, B.K., Goolsby, J. 2014. An airborne multispectral imaging system based on two consumer-grade cameras for agricultural remote sensing. Remote Sensing. 6:5257-5278.
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 Moran, P.J., Goolsby, J. 2014. Effect of nitrogen fertilization on growth of Arundo donax and on rearing of a biological control agent, the shoot gall-forming wasp Tetramesa romana. Biocontrol Science and Technology. 24:503-517.
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 Esteve-Gassent, M.D., PÌ©rez de LeÌ_n A. A., Romero-Salas, D., Feria-Arroyo, T. P., Patino, R., Castro-Arellano, I., Gordillo-PÌ©rez, G., Auclair, A., Goolsby, J., Rodriguez-Vivas, R.I., and Estrada-Franco, J.G. (2014) Pathogenic landscape of transboundary zoonotic diseases in the MexicoÛÒUS border along the Rio Grande. Frontiers Public Health, 2: 1-23.
 Velez-Bonner, A., W.L.A. Osbrink, K.R. Summy, D.W. Thomas, A.T. Showler, A. PÌ©rez de LeÌ_n, and J.A. Goolsby. 2013. Mitigating Predatory Ants Promotes Establishment of Biological Control of Arundo by Arundo Scale in the Cattle Fever Tick Quarantine Zone Subtropical Plant Science 65:38-44.
 Rubio, A., A. E. Racelis, T. C. Vaughan, and J. A. Goolsby. 2014. Riparian Soil Seed Banks and the Potential for Passive Restoration of Giant Reed Infested Areas in Webb County, Texas. Ecological Restoration. 32:347-349; doi:10.3368/er.32.4.347.
 Goolsby, J.A., Gaskin, J. F., Tarin, D. V., Pepper, A. E., Henne, D. C., Auclair, A., Racelis, A. E., Summy, K. R., Moran, P. J., Thomas, D. B., Yang, C., MartÌ_nez JimÌ©nez ,M., Ciomperlik, M. J., PÌ©rez de LeÌ_n, A. A., &. Kirk, A. A. 2014. Establishment and spread of a single parthenogenic genotype of the Mediterranean arundo wasp, Tetramesa romana, in the variable climate of Texas. Southwestern Entomologist, 39: 675-689.
 Goolsby, J. A., Racelis, Alex E., Goolsby, J. B., Kirk, A. A., Cristofaro, Massimo, Grusak, M. and Perez de Leon, Adalberto. 2013. Evaluation of biogeographical factors in the native range to improve the success of biological control agents in the introduced range. Biological Control Science and Technology. 23:1213-1230.
 Barrero, R., Guerrero, F., Moolhuijzen, P., Goolsby, J., Bellgard, S., Tidwell, J.P., Bellgard, M. 2015. Shoot transcriptome of the Giant Reed, Arundo donax. Genomics Data. 3:1-6.
 Thomas, D.B., Goolsby, J. 2015. Morphology of the pre-imaginal stages of Lasioptera donacis Coutin (Diptera: Cecidomyiidae), a candidate biocontrol agent of giant arundo cane. Psyche. Available: 10.1155/2015/262678.
 Goolsby, J., Moran, P.J., Racelis, A.E., Summy, K.R., Martinez-Jimenez, M., Lacewell, R.D., Perez De Leon, A.A., Kirk, A.A. 2015. Impact of the biological control agent, Tetramesa romana (Hymenoptera: Eurytomidae) on Arundo donax (Poaceae: Arundinoideae) along the Rio Grande River in Texas. Biocontrol Science and Technology. 26: 47-60.
 Villarreal, J.M., J. A. Goolsby, A. T. Vacek, A. Perez de Leon and Alex E. Racelis. 2016. Horticultural technique for rearing and redistribution of the sessile biological control agent, Rhizaspidiotus donacis on its host plant, Arundo donax Subtropical Agriculture and Environments 67: 19-23.2016
 Patrick J. Moran, Ann T. Vacek, Alexis E. Racelis, Paul D. Pratt & John A. Goolsby. 2017. Impact of the arundo wasp, Tetramesa romana (Hymenoptera: Eurytomidae), on biomass of the invasive weed, Arundo donax (Poaceae: Arundinoideae), and on revegetation of riparian habitat along the Rio Grande in Texas, Biocontrol Science and Technology, 27: 96-114, DOI: 10.1080/09583157.2016.1258453
 MartÌ_nez JimÌ©nez, M., J. A. Goolsby, A. E. Racelis, A. Perez de Leon, and D. Negrete Arroyos. IntroducciÌ_n, Establecimiento y DispersiÌ_n en MÌ©xico de la avispa Tetramesa romana, agente de control biolÌ_gico del carrizo gigante. Southwestern Entomologist. (In Press).
John Goolsby, Ph.D., is a research entomologist and specialist in biological control of invasive species. Goolsby is the program leader for the Carrizo Cane Biological Control Program.
1United States Dept. of Agriculture, Agricultural Research Service (ARS), Knipling-Bushland U.S. Livestock InsectsåÊResearch Laboratory, Cattle Fever Tick Research Laboratory, 22675 N. Moorefield Rd., Moore Airbase, Building 6419, Edinburg, Texas, USA 78541, Email: firstname.lastname@example.org; 2USDA-ARS Knipling Bushland U.S Livestock Insects Research Laboratory, Kerrville, TX; 3USDA-ARS, Albany, CA; 4USDA-ARS, European Biological Control Laboratory, Montpellier, France; 5BBCA Rome, Italy; 6USDA-ARS, College Station, TX; 7USDA-ARS, Sidney, MT, 8USDA-ARS, El Reno, OK; 9USDA-ARS, Houston, TX;åÊ10USDA-APHIS, åÊMoore Airbase, Edinburg, TX; 11Dept. of Biology, Univ. of Texas ÛÒ Rio Grande Valley, Edinburg, TX; 12Texas Agrilife Research, Weslaco, TX; 13Dept. of Biology, Texas A & M University; 14Dept of Ag. Economics, Texas A & M University, College Station, TX; 15Instituto Mexicano de TecnologÌ_a del Agua, Jiutepec, Mexico; 16CIBIO, Universidad de Alicante, Alicante, Spain; 17Department of Biology, Univ. of Texas, Austin, TX; 18Texas A&M International, Laredo, TX.