This article was downloaded by: [USDA National Agricultural Library] On: 24 May 2010 Access details: Access Details: [subscription number 917340536] Publisher Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37- 41 Mortimer Street, London W1T 3JH, UK Biocontrol Science and Technology Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713409232 Biology and Nymph Host Range of Anchocoema bidentata and Astroma saltense (Orthoptera: Proscopiidae), Potential Biocontrol Agents for Creosotebush, Larrea tridentata (Zygophyllaceae) in the U.S.A. Guillermo Logarzo ;Miguel Casalinuovo To cite this Article Logarzo, Guillermo andCasalinuovo, Miguel(2004) 'Biology and Nymph Host Range of Anchocoema bidentata and Astroma saltense (Orthoptera: Proscopiidae), Potential Biocontrol Agents for Creosotebush, Larrea tridentata (Zygophyllaceae) in the U.S.A.', Biocontrol Science and Technology, 14: 1, 39 — 50 To link to this Article: DOI: 10.1080/09583150310001506589 URL: http://dx.doi.org/10.1080/09583150310001506589 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Biocontrol Science and Technology (February 2004), Vol. 14, No. 1, 39Á/50 Biology and Nymph Host Range of Anchocoema bidentata and Astroma saltense (Orthoptera: Proscopiidae), Potential Biocontrol Agents for Creosotebush, Larrea tridentata (Zygophyllaceae) in the U.S.A. GUILLERMO LOGARZO AND MIGUEL CASALINUOVO Agricultural Research Service, US Department of Agriculture, South American Biological Control Laboratory, 3130 Buenos Aires Place, Washington, DC 20521- 3130, USA (Received 2 August 2002; returned 9 October 2002; accepted 10 April 2003) Two stick-like acridids (Orthoptera: Proscopiidae) from Argentina, Anchocoema bidentata Mello-Leitao and Astroma saltense Mello-Leitao, were evaluated as potential biological control agents of creosote bush (Larrea tridentata (DC.) Coville) in the southwestern United States. Their biology, behavior and geographic distribution of those species were studied. The host plant ranges for both insects were established through nymph feeding preference and development tests in the laboratory and in the field. A total of 33 species of plants belonging to 13 families were tested. Anchocoema bidentata and A. saltense are mimetic species, having as many as three generations a year, and exhibit strong sexual dimorphism; females are larger and less mobile than males. In both species, females laid egg masses in the soil. First instars appeared in the field at the end of the spring, the second generation at mid-summer, and a third at the end of the summer. Adults of A. bidentata and A. saltense appeared in the field at the Downloaded By: [USDA National Agricultural Library] At: 12:53 24 May 2010 beginning of the spring. The laboratory multiple-choice feeding test showed that A. bidentata preferred Larrea divaricata Cav., whereas A. saltense preferred L. divaricata and L. cuneifolia Cav. In the nymph development test (no choice), A. bidentata was able to complete its development only on L. divaricata and L. cuneifolia, while Astroma saltense completed its development on six plant species: L divaricata, L. cuneifolia, Bulnesia retama (Gillies ex Hooker et Arnott), B. schickendantzi Hieron (all Zygophyllaceae), Zuccagnia punctata Cav., and Prosopis torquata (Cav. Ap. Lag.) (both Fabaseae). We concluded that A. bidentata could be a biocontrol agent for L. tridentata because the first instar can complete its development only on Larrea spp. Regarding A. saltense, this species showed a wide host range and should not be considered as a biological control agent of L. tridentata. Correspondence to: Guillermo Logarzo, USDA-ARS SABCL, 3130 Buenos Aires Place, Washington, DC 20521-3130, USA. Tel.: /54-11-4452-1882, ext. 111; Fax: /54-11-4452-1882, ext. 104; E-mail: [email protected] ISSN 0958-3157 (print)/ISSN 1360-0478 (online)/04/010039-12 # 2004 Taylor & Francis Ltd DOI: 10.1080/09583150310001506589 40 G. LOGARZO & M. CASALINUOVO Keywords: Larrea tridentata, biological control, weed, acridid, South America, creosote bush, Anchocoema bidentata, Astroma saltense, Zygophyllaceae, Orthoptera, Proscopiidae INTRODUCTION Creosote bush (Larrea tridentata (DC.) Coville) is a common woody, perennial and slow- growing weedy shrub, covering 19 million ha in the United States (Platt, 1959), that competes with rangeland forage plant species. This desert plant has been increasing its geographical range in the last 150 years, replacing grasslands, probably due to overgrazing (York & Dick- Peddie, 1969). In New Mexico, Melgoza et al. (1984) found that good stands of grasses rapidly appeared after Larrea plants were killed with herbicides. The genus Larrea originated in South America (Hunziker et al., 1972, 1977; Hunziker, 1975; Wells & Hunziker, 1976), and has four South American, and one North American species: L. tridentata (Hunziker et al., 1977). Creosote bush arrived to North America around 11 000 years ago (Van Devender, 1973; Wells, 1976) and is supposed to be a subspecies of the South American L. divaricata (Hunziker et al., 1977). Biological control of creosote bush could be feasible by introducing phytophagous insects from the South American species of Larrea to the United States. Previous studies on the natural enemies of South American species of Larrea determined that the best candidates for biological control of L. tridentata were the proscopiids, Anchocoema bidentata Mello-Leitao (Astroma riojanum originally) and Astroma saltense Mello-Leitao (Cordo & De Loach, 1993) Proscopiidae, endemic to South America, are very similar to walking sticks (Phasmida) in appearance and in their cryptic nature, and all species are apterous or brachypterous. The biology of this family, which contains more than 100 species, is poorly known. Although several studies mention proscopiids of Larrea (Mares et al., 1977; Orions et al., 1977; Rhoades 1977; Schultz et al., 1977; Schultz, 1979), none analyzed their host range in detail. The purpose of this research was to document the biology and assess the natural and potential host plant range of A. bidentata and A. saltense through field and laboratory tests to evaluate their potential as biocontrol agents for creosote bush in the United States. MATERIALS AND METHODS To identify the insects used in this study, we compared specimens of A. bidentata and A. saltense with the original descriptions made by Mello-Leita˜o and with the type specimens of A. riojanum and of A. saltense deposited in the Museo de Ciencias Naturales de La Plata. Cordo and De Loach provided us with the specimens used in the publications of 1993. The life history and host range studies were carried out in Buenos Aires and Catamarca Downloaded By: [USDA National Agricultural Library] At: 12:53 24 May 2010 Provinces, Argentina from 1991 to 1993. Most of the laboratory studies were carried out at the USDA-ARS SABCL lab in Buenos Aires. All host range studies were carried out at a temporary substation in Catamarca Province. Proscopiid Biology, Distribution and Host Plant Associations The field work and collection of A. bidentata were carried out mainly in the area of Miraflores, 70 km S of Catamarca City. This area is an ecotone between the phytogeo- graphical regions of Chaco (dry forest ecosystem) and Monte (shrub desert ecosystem). The collection sites of A. saltense were Santa Marı´a (350 km NW of Catamarca City) and Andalgala´ (130 km W of Catamarca City) (Monte phytogeographical region). Adults and large nymphs of both proscopiids were collected by hand, and first instars by sweeping and beating. Adults and nymphs were kept in 350-mL transparent plastic containers at room temperature (22Á/288C), and fed fresh leaves of Larrea every other day. A maximum of six adults or large nymphs were placed in a single container. BIOLOGY AND HOST RANGE OF TWO ARGENTINE ACRIDIDS 41 During 1992 and 1993, we conducted behavior observations in the field (copulation, feeding, oviposition, and movement) at different times of the day (from 07:00 to 01:00 h) on both adults and nymphs of A. bidentata at Miraflores (almost daily), and of A. saltense at Villa Marı´a (two to three times a month). First instar A. bidentata were sampled by beating 10 plants of each of the following species: L. cuneifolia Cav., L. divaricata Cav., Cercidium praecox (Ruiz & Pav.) Harms, Geoffroea decorticans (Hooker et Arnott), Acacia sp., A. aroma Gillies, Prosopis chilensis (Mol). Stunz, P. torquata (Cav. Ap. Lag.) DC., P. nigra Griseb, Cassia aphylla Cav.: Zisyphus mistol Griseb; and Aspidosperma quebracho-blanco. 2 Astroma saltense densities (adults