Open field host selection and behavior by tamarisk beetles (Diorhabda spp.) (Coleoptera: Chrysomelidae) in biological control of exotic saltcedars (Tamarix spp.) and risks to non-target athel (T. aphylla) and native Frankenia spp.

Abstract

Open field host selection and behavior by tamarisk beetles (Diorhabda spp.) (Coleoptera: Chrysomelidae) in biological control of exotic saltcedars (Tamarix spp.) and risks to non-target athel (T. aphylla) and native Frankenia spp. Open field host selection and behavior by tamarisk beetles (Diorhabda spp.) (Coleoptera: Chrysomelidae) in biological control of exotic saltcedars (Tamarix spp.) and risks to non-target athel (T. aphylla) and native Frankenia spp. , an evergreen tree used for shade and as a windbreak in the southwestern U.S. and México, and occasionally feed on native Frankenia spp. plants. The ability of tamarisk beetles to establish on these potential field hosts was investigated in the field. In no-choice tests in bagged branches, beetle species from Crete and Sfax, Tunisia produced 30-45% as many egg masses and 40-60% as many larvae on athel as on saltcedar. In uncaged choice tests in south Texas, adult, egg mass and larval densities were 10-fold higher on saltcedar than on adjacent athel trees after 2 weeks, and damage by the beetles was 2-to 10-fold greater on saltcedar. At a site near Big Spring, in west-central Texas, adults, egg masses and 1st and 2nd instar larvae were 2-to 8-fold more abundant on saltcedar than on athel planted within a mature saltcedar stand being defoliated by Crete beetles, and beetles were 200-fold or less abundant or not found at all on Frankenia. At a site near Lovelock, Nevada, damage by beetles of a species collected from Fukang, China was 12-78% higher on saltcedar than on athel planted among mature saltcedar trees undergoing defoliation. The results demonstrate that 50-90% reduced oviposition on athel and beetle dispersal patterns within resident saltcedar limit the ability of Diorhabda spp. to establish populations and have impact on athel in the field. Published by Elsevier Inc.

Distribution of the subtropical tamarisk beetle,Diorhabda sublineata(Lucas, 1849) (Coleoptera: Chrysomelidae), in Mexico

“…The above findings indicate that if these beetles are released along the Rio Grande in south Texas, they may cause small damage to athel, but not enough to inhibit its use as a shade tree, or may cause no damage (Moran et al 2009). If the scenario in the Big Spring tests develop, the beetles may damage athel temporarily if near a saltcedar stand being defoliated but probably will not search for and find athel at a distance of 200 m or more.…”

“…8). At Kingsville, beetles were released into an existing stand of saltcedar intermixed with transplanted athel trees (both 8-15 ft tall) with no established beetles, and onto large roadside athel trees with no saltcedar or beetles present (Moran et al, 2009).…”

“…If the scenario in the Big Spring tests develop, the beetles may damage athel temporarily if near a saltcedar stand being defoliated but probably will not search for and find athel at a distance of 200 m or more. If the scenario of the Kingsville tests develops, athel probably will receive no damage (Moran et al 2009). Our cage tests at Temple and open-field tests at Big Spring predict that the four Frankenia species that occur from Colorado to the Chihuahuan Desert of Mexico would not be damaged.…”

“…Over 15,000 adults were used in several types of tests conducted under a variety of conditions: no-choice, paired-choice and multiple choice tests; in small, medium and large cages; and in the laboratory, greenhouse and outdoor cages (Table 11). In 2005 and 2006, outdoor, uncaged tests were made at Big Spring and at Kingsville, TX (Moran and DeLoach 2009;Dudley and Kazmer 2005;and Herr and Carruthers 2009b and in press). The four species in general responded similarly, with heavy damage to saltcedars, much less to athel, and very little or none to Frankenia.…”

Reproductive Biology of T. chinensis and T. ramosissima (Tamaricaceae: Theineae) from Gansu, Northwestern China

“…Their flowers and leaves can be used as medicine (Li et al, 1990). Understanding the mechanisms of flowers and fruits production is particularly important for both species, since their flowers and fruits are important economic income resource for local people.Previous studies on Tamarix have focused mostly on geographical distribution, biological characteristics, physiological stress and molecular biology (Glenn & Nagler, 2005;Milbrath & DeLoach, 2006;Whiteman, 2006;Hudgeons et al, 2007;Morman et al, 2009). Based on the understanding of the above research and practical concern, as well as the scarcity of studies on reproductive biology and pollen limitation data of T. chinensis and T. ramosissima, we served to improve their reproductive efficiency.…”