BEETLE - MANIA BIOLOGICAL CONTROL OF SALTCEDAR IN

VOL. 5 NO. 1 SUMMER - F A L L 2 0 1 3

2012. 2013. AAnother Very Good Good Year Year forfor : TamariskSaltcedar Leaf Leaf Beetles Beetles inin Texas !! The saltcedar leaf beetle feeds only on Saltcedar leaf beetles re- saltcedar on the Pecos and Upper . turned again in large numbers Rivers. Saltcedar The Mediterranean leaf beetle saltcedar and athel. in many areas of trees in this area have been is found in this region and again Athel is a closely in 2013, further weakening defoliated for three consecu- defoliated stands of saltcedar related species that trees defoliated in 2012. The tive years, and many trees stretching along Sulphur Springs grows along the Rio year did not start off well as now have large dead limbs Draw and at some sites on several late spring freezes, with only a few green branch- Mustang Draw in Howard and Grande River in the last in early May, raised es. In 2013, beetles dispersed Martin Counties and at Lake Texas. concern that beetle and lar- through El Paso and into New Thomas. However, this species vae would be killed by the Mexico following saltcedar has been slow to recover fol- frost. Although these cold along the Rio Grande and by lowing the February 2011 If saltcedar or temperatures may have de- late August were found about freeze. Overall, the Mediterra- athel trees are not layed beetle reproduction, 17 miles south of Las Cruces, nean has not increased or dis- present, the larvae populations in most areas NM. Beetles also dispersed persed as rapidly as has the along the into starve to death. increased by early summer two other species in Texas. and again defoliated large New Mexico and by late sum- This species was released at areas of saltcedar. There are mer were found near Artesia, Lake Spence and Lake Ivie but Saltcedar beetles now three species of saltce- NM. A small population of did not establish. In 2012 and were first estab- dar leaf beetles established in Mediterranean leaf beetle was 2013, large numbers of the found at Artesia, apparently a subtropical and larger tamarisk lished in Texas in Texas. Rio Grande, Pecos Rivers. remnant population of earlier beetle were released at Lake 2004 at Big Spring, The subtropical tamarisk bee- releases made at that site Ivie but there is no evidence TX. Since then, tles defoliated large areas of several years ago. to date that any of these popu- lations have established on there have been no these reservoirs. Red import- reports of beetles or ed fire ants are common at larvae feeding on Lake Ivie and Lake Spence and any other plant. may be feeding on the beetle larvae and pupae. except saltcedar and Tribu- and its close relative taries. The larger tamarisk athel (Tamarix beetle, originally collected from Uzbekistan, defoliated saltcedar aphylla). trees on many of the tributar- ies of the upper Brazos River that drain the Rolling Plains Approximate distribution of the Subtropical leaf beetle in the Trans Pecos re- Region in 2013. Areas defoliat- gion, the Mediterranean leaf beetle in the upper Colorado River (red area), and ed by leaf beetles increased the Larger leaf beetle in the Rolling Plains and Panhandle of Texas. Beetles are not present throughout the shaded regions, but if not present, are likely to again in Garza County and disperse in the future to new sites within the shaded region.

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Beetles on West Texas River Systems.

beetles dispersed into the Lake Allen Henry ties and along the South Wichita in King area in 2013. Widespread defoliation was County. Beetles moved south into north- also seen for the first time in southeastern ern and western Stonewall County and Lynn County and a few beetles were found tree defoliation was widespread here for in adjacent Terry County. It is not yet the first time in 2013. Larvae of the known if the beetles in Lynn County are Beetles Arrive in Kansas. Saltcedar leaf Mediterranean leaf beetles from the popula- beetles were found for the first time in saltcedar leaf tions to the south or are the larger species October, 2013 in three counties in south- beetle feed on that moved along the Double Mountain west Kansas. Beetles are believed to have Fork of the Brazos from Garza County. moved north from beetle populations along saltcedar leaves , Red River and its the Texas/Oklahoma border, crossed the Tributaries. The larger tamarisk beetle Oklahoma Panhandle and entered Kansas and tender bark. and tree defoliation were again widespread this past summer. Saltcedar is considered a in the Lake Meredith area and east along quarantine pest by the Kansas Department Larvae feed for the Canadian River. Beetles also returned of Agriculture. about 12-14 days again and defoliated much of the saltcedar Thanks to Chris Ritzi, Sul Ross Univ., J. along the tributaries of the Red River Michels, E. Jones, M. Muegge and J. Tracy, during the throughout the eastern Texas Panhandle Texas A&M, T. Royer, OSU, and C. Suther- and adjacent counties in western Oklaho- land, New Mexico for information on bee- summer. Full ma. Beetles gain defoliated saltcedar along tle activity in their areas. the Pease River in Motely and Cottle Coun- grown larvae are about 1/3 inch Insects on Satlcedar Trees That long. Several May Be Confused with Leaf Beetles. generations are Scale insects feeding on saltcedar trees can completed per cause foliage to turn yellow and brown in late year. The adult summer and this damage, especially from a distance, may be confused with feeding by salt- stage overwinters cedar leaf beetles. Scales are tiny insects that suck sap and cause saltcedar leaves to turn on the ground yellow. Scales appear as white, waxy specks under leaf litter and large numbers can create a white, crusty layer on saltcedar leaves. Infested leaves re- and in bunch main firmly attached to the branches while leaves damaged by leaf beetles turn brown and are easily pulled and fall grasses. from branches. Feeding by leafhoppers can also cause saltcedar leaves to turn yellow to brown in late summer. Leafhoppers are about 1/8 inch long, bright green and wedge shaped insects which quickly jump and fly when disturbed. Twice-stabbed lady beetles do not feed on saltcedar but feed on the scale insects discussed above. These lady beetles can be very common when scale insects are abundant. Lady beetles are black with two red dots (hence twice-stabbed) and are oval shaped, thus easily distinguished from the saltcedar leaf beetles.

B E E T L E - MANIA VOL. 5 NO. 1 P A G E 3

Can Saltcedar Biological Control Help Preserve Habitat for Rare Minnows in the Brazos River ?

Dense thickets of saltcedar grow- side as critical habitat. These actions natural streamflow regime by impound- ing along and in streams and waterways are proposed at this time. A decision is ments, drought, groundwater withdraw- can change natural stream flow patterns expected in August, 2014. al, and saltcedar encroachment. Other and alter the habitat of native plants and The sharpnose shiner and smalleye secondary factors, such as water pollu- animals. The saltcedar invasion of the shiner are native to arid prairie streams tion and golden alga and commercial upper Brazos River, along with im- of Texas. Both species require wide, harvesting for fish bait, are also likely poundments, drought and groundwater shallow, flowing waters generally less impacting the shiners. For more infor- withdrawal, are believed to have played than about 1.6 feet deep with a sandy mation, see: a part in degrading the habitat require- bottom. It is estimated that shiners re- http://www.texasahead.org/texasfirst/ ments of two small native fish, the quire approximately 170 miles of unob- species/fact_sheets/ sharpnose shiner and the smalleye shin- structed, flowing water during the er. The U.S. Fish and Wildlife Service breeding season to support survival of is proposing to protect these two shin- the eggs and larva. This length of stream ers under the under the Endangered allows the eggs and larvae to remain Species Act (ESA). These fish, about 2 suspended in the water column and inches long, are currently restricted survive until they mature sufficiently to almost entirely to the contiguous river swim on their own. Historically, these segments of the upper Brazos River shiners existed throughout the Brazos basin in north-central Texas. The U.S. River and several of its major tributaries Fish and Wildlife Service is also propos- and were also present in the Colorado ing to designate approximately 623 River and the in Texas. miles of the upper Brazos River basin The two primary factors affecting Sharpnose and Smalleye Shiners and the upland areas extending beyond these shiners are river fragmentation by Photographs courtesy of Chad Thomas/Texas State University - San Marcos the river channel by 30 meters on each impoundments and alterations of the

Prescribed Burns and Leaf Beetles on the Pecos River.

As part of the Pecos River Watershed Protection Plan, saltcedar trees along the Pecos River have been treated either by herbicides or heavily defoliated by leaf beetles. As a result, large areas of dead trees or trees with mostly dead canopies remain. Prescribed burns have been used recently to remove this dead wood which poses a risk to bridges and other structures should this de- bris be carried by flood waters. Also, burning prepares a good seedbed for re- establishment of vegetation. But how does burning impact leaf beetles? No formal studies have been done, but Amy Porter, with the Upper Pecos Soil and Water Conservation District, reported that beetles quickly returned to a burned area this spring to fed on the saltcedar regrowth emerging from the root crown of burned trees. As her photos show, the upper portion of the regrowth has turned brown as a result of the feeding by beetle larvae. In the lower photo, all of the green shoot has been fed upon by larvae and have turned brown. While beetles can presumably escape fire by flying away, eggs and larvae on trees with green foli- age would be destroyed. Fire during the late fall, winter and early spring, be- fore beetles emerge from overwintering beneath leaf litter and in bunch grass- es, could kill overwintering adults. Beetles could fly into burned areas from surrounding unburned trees and thus re-populate a burned area. These obser- vations suggest fire and beetles might be a good combination once beetles are well established in an area. Studies are needed to define when prescribed burns would have the least impact on beetles while still providing the benefit of reducing dead wood.

For more information about this program, BEETLE-MANIA is a newsletter on biological control of saltcedar in Texas, and is written contact Allen Knutson at 972-952-9222 or via e and produced by Allen Knutson, Texas A&M -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 Allen Knutson Professor and Extension Entomologist @tamu.edu Texas AgriLife Research and Extension

17360 Coit Road Dallas, TX 75252

Phone: 972-952-9222 For more information on biological control of saltcedar and other Fax: 972-952-9632 invasive weeds in Texas, go on-line E-mail: [email protected] at: bc4weeds.tamu.edu.