BEETLE-MANIA IS A NEWSLETTER ON BIOLOGICAL CONTROL OF SALTCEDAR IN , AND IS WRITTEN AND PRODUCED BY ALLEN KNUTSON, TEXAS AGRILIFE EXTENSION. TO BE INCLUDED ON THE MAILING LIST, PLEASE CONTACT ALLEN KNUTSON. BEETLE - MANIA BIOLOGICAL CONTROL OF SALTCEDAR IN TEXAS

VOL. 4 NO. 1 SPRING 2012 The Beetles Are Back ! : From Big Bend to the Texas Panhandle The saltcedar leaf beetle feeds only on saltcedar and athel. Saltcedar leaf beetle num- has since been released and is north of Presidio to the east- Athel is a closely bers and impact are increas- now well established and dis- ern side of Big Bend National ing at many locations across persing at many locations on Park. Some of the largest related species that the state this year. Popula- the upper and middle Pecos. stands of saltcedar in Texas are grows along the Rio tions of the Crete species, Much of the saltcedar along found on this section of the River in devastated by the late-winter drainages in southern Reeves Grande. freeze of February, 2011, County was entirely defoli- Texas. have recovered at some sites. ated this year, including some Basin. The The Tunisian species has de- 125 acres on the Balmorhea Crete species was well estab- If saltcedar or foliated large areas of saltce- Reservoir. In adjacent Pecos lished in the upper Colorado athel trees are not dar in West Texas and a new County, Tunisian beetles de- River basin (Howard, Martin, population of leaf beetle was foliated saltcedar at Leon Borden, Mitchell Counties) present, the larvae unexpectedly discovered in Lake and dispersed widely. until the February 2011 freeze. starve to death. the Texas Panhandle. From On the at Iraan, Few beetles were found here the Red River in the north to beetles defoliated saltcedar last year but following the mild the Rio Grande of west for about 5 river miles this winter of 2012, populations Saltcedar beetles Texas, saltcedar leaf beetles year and have dispersed along have recovered in some areas. were first estab- are defoliating more saltcedar the Pecos for at least 35 This year, beetles again defoli- lished in Texas in that ever before. The mild miles. Overall, Tunisian bee- ated large stands of saltcedar 2004 at Big Spring, winter and warm early spring tle populations are present at along Sulfur Draw in Martin is the most likely explanation sites along about 150 river County. Saltcedar trees appear TX. Since then, for the rebound in beetle miles of the Pecos River. The to be dying in this area from there have been no populations this year. Tunisian species appears to beetle defoliation and possible reports of beetles or be more effective at increas- drought stress. Beetle num- Pecos/Rio Grande River ing and defoliating saltcedar bers in Howard County are still larvae feeding on Basin. The Crete species of than the Crete species in this low in many areas. Much of the any other plant. leaf beetle was released at region. Barring another un- saltcedar infesting the western except saltcedar several sites on the Pecos usually cold winter or late edge of Lake Thomas and adja- and its close relative River beginning in 2006. In spring freeze, it’s likely that cent Colorado River is also 2010, a population north of the Tunisian beetle will be defoliated again and beetles are athel (Tamarix Pecos, TX defoliated all of distributed throughout the present on the Colorado River aphylla). the saltcedar along 11 river upper and middle Pecos River from Lake Thomas to south of miles. However, this species within 2-3 years. Colorado City in Mitchell appears to have died out in Further south, the Tunisian County. Motorists crossing the this region following the beetles again defoliated es- I-20 bridge at Colorado City 2011 freeze. The Tunisian sentially all of the saltcedar can view a large expanse of species, also known as the along more than 150 miles of defoliated saltcedars on the subtropical tamarisk beetle, the Rio Grande River from Colorado River below. ››››››

Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age or national origin. SPRING 2012 PAGE 2 Long Lost Uzbek Species Discovered in Texas Panhandle

››› continued from previ- species of leaf beetle in the ous page . Texas Panhandle. The Larvae of the Uzbek species, Diorhabda Upper Ba- carinata, was released at saltcedar leaf sin. The Crete species Lake Meredith beginning in survived the 2011 freeze on 2005 and at Palo Duro beetle feed on White River Lake in State Park in 2007, but did

Crosby County and contin- not establish there. Re- saltcedar leaves ues to defoliate trees there, leases of this species in 2008 and 2009 in Borden, and tender bark. but Crete populations in Motley and Swisher County Swisher, Kent and Garza Larvae feed for Counties have not in- and at Lake Kemp also creased as expected and failed to establish. Thus, it about 12-14 days are undetectable as some was exciting when an ob- The Uzbek species, or Lar- servant rancher reported locations. Recently, the ger Tamarisk beetle, looks during the finding beetles on his ranch Tunisian species was re- very much like the Crete near Clarendon in early July summer. Full leased at two sites on the species of leaf beetle. Iden- of this year. These beetles Double Mountain Fork of tification requires training grown larvae are the Brazos River to see if proved to be the long lost and skill in dissecting and this beetle might be better Uzbek beetles. This spe- microscopic examination of about 1/3 inch adapted than the Crete cies was found defoliating large areas of saltcedar the male reproductive or- long. Several beetle to this area. gans. along the Prairie Dog Town generations are Red River Basin. After Fork of the Red River and releasing beetles for three the near handle and areas north into completed per years at a site on the South Oklahoma. Subsequent Colorado and this beetle in King surveys found the Uzbek seems to be proving the year. The adult County, a population of beetle in Donley, Motley, model correct. With this Crete beetles dramatically Armstrong, Hall and Cottle stage overwinters discovery, Texas is now increased there this year. Counties. home to three species of on the ground These beetles defoliated all Apparently, beetles from saltcedar leaf beetles: the of the trees in dense stands the initial releases dis- Uzbek beetle in the Pan- under leaf litter along about two river miles persed from the release handle, the Crete beetle in and were found along 12 sites and populations per- the Brazos and Colorado and in clump miles of river. Beetles sisted at undetectable num- River Basins and the Tuni- were well established here bers for several years until sian species in the Pecos/ grasses. the recent mild winter, or in 2010, but could not be Rio Grande River Basin. possibly time alone, allowed found in 2011 following the earlier freeze. The great their numbers to increase Thanks to the following for increase in population and sufficiently to defoliate contributing information on damage to saltcedar trees trees and attract notice. leaf beetle distribution and in 2012 at this site was a Climate matching models activity: Ed Bynum and Mark suggested that the Uzbek Muegge, Texas AgriLife Exten- surprise sion, Jerry Michels, Texas However, the greatest beetle (originally collected from Uzbekistan) is best AgriLife Research, and James surprise this summer was Tracy, Entomology Dept., adapted to the Texas Pan- the discovery of the Uzbek Texas A&M.

BEETLE - MANIA VOL. 4 NO. 1 PAGE 3

Exotic Weevil Found Feeding on Saltcedar A new and exotic insect, a small Adult weevils are very small, about young leaves at the end of branches. In weevil in the genus Coniatus, has been 0.18 inch (4-5 mm) long, and are Texas, significant leaf or branch feeding found throughout much of Texas feed- brightly colored with metallic areas of has not yet been observed. ing on saltcedar. The native home of dark brown, bright green and shades of the Coniatus weevil is the Mediterranean pink. Adults quickly drop off branches region and areas east as far as Iraq. when disturbed. Adults and larvae feed Although studied as a potential candi- on saltcedar leaves. The larvae spin a date for importation into the US for net-like cocoon that is fastened to salt- biological control of saltcedar, there is cedar leaves. The larva pupates inside no known record of any intentional or the cocoon and the adult later emerges unintentional releases of any Coniatus from the cocoon. These cocoons per- species in North America. How it sist on the foliage, are more easily seen came to be in the US is a mystery. than the adults and are often the first The Coniatus weevil was first evidence that Coniatus is present. reported in the US in 2006 from speci- Little is known about the biology of mens, identified as C. splendidulus, col- C. splendidulus, but like other species lected near Phoenix, AZ. It is now within this genus, it is believed to feed widespread in Arizona, New Mexico, only on saltcedars (Tamarix species). Nevada and Utah. The Coniatus weevil The adults of a related species in France was first found in Texas near Big Spring, feeds on saltcedar leaf buds in the TX in 2010 and it is now widely distrib- spring and this feeding slows the growth uted in west TX. This year Coniatus of new stems. Once leaves are avail- The Coniatus weevil is very small, 4- weevils are commonly found on the able, adults prefer to feed on the tips of 5 mm long, and brightly colored. Pecos River, Upper Colorado River and branches and often cut off the tips while Photo by K.V. Makarov. http://www.zin.ru/ as far north as the Texas Panhandle. feeding. Larvae also feed on the tender Animalia/Coleoptera/eng/consplkm.htm

Tunisian Beetle Released at Lake Ivie and Lake Spence Water levels in Lake Ivie and Lake Spence have receded due to the ongoing drought, exposing mud banks which have been quickly invaded by saltcedar. In 2010, an estimated 9,000 acres infested the Lake Ivie basin. Following the 2011 drought, the infested area has continued to increase. In 2010, about 113,000 Crete beetles were released at Lake Ivie and 80,000 at Lake Spence. Following the 2011 late winter freeze, no Crete beetles could be found last year at either site. In hopes that the Tunisian beetle would be more effective than the Crete species, 8,000 Tunisian beetles were released at Lake Ivie in 2011. These beetles overwintered and defoliated a small area in 2012. This year, 23,000 and 49,000 Tunisian beetles have been released at Lake Spence and Lake Ivie, respectively. Given a series of mild winters, these beetles will hopefully begin to have an impact.

Saltcedar trees defoliated by the Tunisian leaf beetle and larvae feeding on the few green branches re- maining. Balmorhea Reservoir, Reeves Co, TX. July, 2012.

BEETLE-MANIA is a newsletter on biological For more information about this program, control of saltcedar in Texas, and is written contact Allen Knutson at 972-952-9222 or via and produced by Allen Knutson, Texas e-mail [email protected] or Mark Muegge AgriLife Extension. To be included on the mailing list, please contact Allen Knutson. Texas AgriLife Extension Entomologist at Ft. Stockton, 432-336-8585, , e-mail: ma-muegge @tamu.edu Allen Knutson

Professor and Extension Entomologist Texas AgriLife Research and Extension 17360 Coit Road Dallas, TX 75252 For more information on biological control of saltcedar and other

invasive weeds in Texas, go on-line Phone: 972-952-9222 at: bc4weeds.tamu.edu. Fax: 972-952-9632

E-mail: [email protected]