DOCSLIB.ORG

A Faunistic Approach to Assess Potential Side-Effects of Genetically Modified Bt-Corn on Non-Target Arthropods Under Field Conditions

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Faunistic Approach to Assess Potential Side-Effects of Genetically Modified Bt-Corn on Non-Target Arthropods Under Field Conditions Biocontrol Science and Technology (March 2004), Vol. 14, No. 2, 129Á/170 A Faunistic Approach to Assess Potential Side-Effects of Genetically Modified Bt-Corn on Non-Target Arthropods Under Field Conditions 1 2 1 1 M. P. CANDOLFI ,K.BROWN, C. GRIMM , B. REBER AND H. SCHMIDLI1 1Syngenta Crop Protection AG, CH-4002 Basel, Switzerland; 2Ecotox Limited, Tavistock, Devon, UK (Received 31 October 2001; accepted 13 May 2003) A faunistic study investigating the potential side-effects of corn (Zea mays) genetically modified to express a truncated Cry1Ab protein derived from Bacillus thuringiensis subsp. kurstaki, on non-target arthropods was carried out under field conditions. The communities of non-target arthropods in the soil, on the leaves and flying in the crop area were monitored throughout the growing season. Water-treated, untransformed corn served as a control, and a spray application of a bacterial Bt insecticide (Delfin WG) and a synthetic insecticide (Karate Xpress) used to control the European corn borer (Ostrinia nubilalis; Lepidoptera: Pyralidae) acted as positive reference treatments. Results were analyzed using a principal response curve. Significantly lower infestations by the lepidopteran target species O. nubilalis were observed in the Bt-corn plots compared to the control. No effects of Bt-corn on the communities of soil dwelling and non-target plant dwelling arthropods were observed. A trend towards a community effect on flying arthropods was observed with lower abundance of adult Lepidoptera, flies in the families Lonchopteridae, Mycetophilidae and Syrphidae, and the hymenopteran parasitoids Ceraphronidae. Effects were weak and restricted to two sampling dates corresponding to anthesis. A short but statistically significant effect of Karate Xpress and Delfin was observed on the community of plant dwellers and a prolonged effect of Karate Xpress on the soil dwellers. Keywords: non-target arthropods, fauna, side-effects, Bt-corn, transgenic plants, Bacillus thuringiensis, Cry1Ab, pesticides, Delfin, Karate Xpress, lambda-cyhalothrin, biosafety Correspondence to: Dr. Marco Candolfi, RCC Ltd., Zelgliweg 1, CH-4452 Itingen, Switzerland. Tel.: /41-61- 975-1193; E-mail: [email protected] ISSN 0958-3157 (print)/ISSN 1360-0478 (online)/04/020129-42 # 2004 Taylor & Francis Ltd DOI: 10.1080/09583150310001655701 130 M. P. CANDOLFI ET AL . INTRODUCTION Insecticide formulations containing Bacillus thuringiensis (Bt) have been used in agriculture since the 1950s (Frankenhuyzen, 1993). Toxicity of these products to arthropods is predominantly due to a range of crystal proteins produced by the bacterium. Because most represent protoxins that need to be activated by insect midgut proteases to yield toxic fragments (Lereclus et al., 1993), susceptible insects must have a strongly alkaline mid-gut, proteolytic enzymes, and suitable tissue receptor-sites (Gill et al., 1992). Sprayed Bt-toxins degrade very rapidly under field conditions on foliage (Ignoffo & Garcia, 1978; Krieg, 1986; Glare & O’Callaghan, 2000) and thus plant dwelling arthropods are exposed only during a very limited period of their life span. These factors contribute to the high selectivity of Bt- based insecticides which are used to control lepidopteran and coleopteran pests, mosquitoes and black flies. Side-effects on non-target arthropods have only very rarely been observed under laboratory conditions. Peacock et al. (1998) found 27 of 42 lepidopteran species tested suffered increased mortality. Babrikova et al. (1982) and Babrikova and Kuzmanova (1984) reported higher mortality of the lacewing Chrysoperla carnea (Neuroptera: Chrysopidae) when adults, but not when larvae were fed with food contaminated with three different Bt- spray formulations under laboratory conditions. Petrova and Khrameeva (1989) reported highly deleterious effects of a spray formulation on the predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae), and detrimental effects on Bracon brevicornis (Hymenoptera: Braconidae) were described by Temerak (1980) and Salama et al. (1991). However, the field use of Bt-based insecticides following good agricultural practices is generally considered safe (Flexner et al., 1986; Krieg, 1986; Melin & Cozzi, 1989; Croft, 1990, Meadows, 1993; Glare & O’Callaghan, 2000). One constraint of conventional spray application of Bt-formulations is to reach pests that feed within the plant tissues. The economically most important such pest in corn is the European corn borer, Ostrinia nubilalis (Lepidoptera: Pyralidae). Eggs are laid on leaves, but larvae migrate to the relative protection of the whorls to develop, bore in to the stalk and can lead to plant breakage or lodging (Ely, 1993). In southern Europe the Mediterranean corn borer, Sesamia nonagrioides (Lepidoptera: Noctuidae), is one of the most damaging pests of corn and is also characterized by its endophytic larval behavior (Gonza´lez-Nu´n˜ez et al., 2000). Corn has been genetically modified to express the CryIAb protein derived from B. thuringiensis, thus providing a high level of resistance to larval feeding of corn borers (Koziel et al., 1993; Gonza´lez-Nu´n˜ez et al., 2000). Bt-corn was first commercially released in the US in 1996 (Roush, 1997) and was grown commercially on 9.9 million ha in 2002 (including stacked varieties expressing insect resistance and herbicide tolerance) in the USA, Canada, Argentina, South Africa, Spain, Honduras and Germany (James, 2002). In the Bt-corn used in this trial, the CryIAb protein is expressed in a truncated and thus partly inactivated form, under the control of the promoter phosphoenolpyrovate carboxylase in green tissues and a pollen-specific promoter in pollen, and is therefore present in significant levels in the leaves and the pollen. Highest levels related to plant fresh weight were found in the seedling stage, but on a per acre rate at anthesis (Fearing et al., 1997). Much of the selectivity data generated in the past 30 years on Bt-insecticide formulations can be applied to Bt-corn. However, potential side-effects on non-target arthropods need verification to account for the different concentration, mode and duration of exposure and the fact that CryIAb protein expressed in Bt-corn is already partially activated. A number of studies have addressed this issue in recent years. Laboratory studies conducted with Coleomegilla maculata (Coleoptera: Coccinellidae), Orius insidiosus (Heteroptera: Antho- coridae) and Chrysoperla carnea (Neuroptera: Chrysopidae) showed no detrimental effects on pre-imaginal development and survival when insect larvae were fed transgenic Bt-corn pollen (Pilcher et al., 1997). Hilbeck et al. (1998a) reported that C. carnea larvae raised with Bt-corn-fed prey Á/ O. nubilalis or Spodoptera litoralis (Lepidoptera, Noctuidae) Á/ showed POTENTIAL EFFECTS OF Bt -CORN 131 higher pre-imaginal mortality (62%) than larvae raised on CryIAb-free prey (37%). Subsequent studies showed that C. carnea larvae fed with a liquid artificial diet mixed with the purified CryIAb toxin (concentration of 100 mg CryIAb/ml diet) exhibited a higher pre-imaginal mortality (57%) when compared to CryIAb-free diet (30%) (Hilbeck et al., 1998b). However, Lozzia et al. (1998a) found no differences in postembryonic developmental time, fecundity or survival of the aphid Rhopalosiphum padi (Homoptera: Aphididae) reared on Bt- versus untransformed corn and also reported no detrimental effects on pre-imaginal development and mortality of C. carnea fed on R. padi that had been reared on Bt-corn when compared to untransformed corn plants. A further tritrophic experiment in the laboratory also showed no effects when Orius majusculus (Heteroptera: Anthocoridae) was fed with the thrips Anaphothrips obscurus (Thysanoptera: Thripidae) reared on Bt-corn expressing CryIAb (Zwahlen et al., 2000), a result that was confirmed in the field when comparing abundances of nymphs and adults of O. insidiosus on Bt-corn with untrans- formed corn (Al-Deeb et al., 2001). Corn plants genetically modified to contain the event 176, encoding for a truncated CryIAb toxin, have been shown to release toxin into the soil environment by root exudates. These toxins can be persistent when bound to clay or humic acids, since they are protected against microbial degradation, and they have been shown to remain biologically active in bioasssays with tobacco hornworm, Manduca sexta (Lepidoptera: Sphingidae), and the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) (Saxena et al., 1999, 2002; Saxena & Stotzky, 2000). Under field conditions, Orr and Landis (1997) reported no significant negative effect of Bt-corn on the densities of O. insidiosus, coccinellids and chrysopids with a tendency towards higher densities of predators in Bt-corn fields compared to isogenic corn. Pilcher et al. (1997) reported no significant effects of Bt-corn on the abundance of species in the families Anthocoridae, Coccinellidae and Chrysopidae. Field data on additional non-target taxa were published by Lozzia and Rigamonti (1998) and Lozzia et al. (1998b). These authors reported no significant effects of Bt-corn on the abundance of carabid beetles, cicadellids, alticini beetles, parasitic hymenopterans, and syrphids. All of these studies above have compared non-target effects of Bt-corn on selected bio-indicator species with an untreated isoline. There has been little work done to compare the community-level effects of Bt-corn with the alternative of using conventional insecticides. Due to the
Load more

Recommended publications
  • Research Article Ecological Observations of Native Geocoris Pallens and G
    Hindawi Publishing Corporation Psyche Volume 2013, Article ID 465108, 11 pages http://dx.doi.org/10.1155/2013/465108 Research Article Ecological Observations of Native Geocoris pallens and G. punctipes Populations in the Great Basin Desert of Southwestern Utah Meredith C. Schuman, Danny Kessler, and Ian T. Baldwin Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoll-Straße¨ 8, 07745 Jena, Germany Correspondence should be addressed to Ian T. Baldwin; [email protected] Received 5 November 2012; Accepted 16 April 2013 Academic Editor: David G. James Copyright © 2013 Meredith C. Schuman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Big-eyed bugs (Geocoris spp. Fallen,´ Hemiptera: Lygaeidae) are ubiquitous, omnivorous insect predators whose plant feeding behavior raises the question of whether they benefit or harm plants. However, several studies have investigated both the potential of Geocoris spp. to serve as biological control agents in agriculture and their importance as agents of plant indirect defense in nature. These studies have demonstrated that Geocoris spp. effectively reduce herbivore populations and increase plant yield. Previous work has also indicated that Geocoris spp. respond to visual and olfactory cues when foraging and choosing their prey and that associative learning of prey and plant cues informs their foraging strategies. For these reasons, Geocoris spp. have become models for the study of tritrophic plant-herbivore-predator interactions. Here, we present detailed images and ecological observations of G. pallens Stal˚ and G.
    [Show full text]
  • A Comparative Study of Two Seed Bugs, Geocoris
    A COMPARATIVE STUDY OF TWO SEED BUGS, GEOCORIS BULLATUS (SAY) AND G. DISCOPTERUS STAL (HEMIPTERA: LYGAEIDAE) IN THE YUKON. By JENNIFER J. ROBINSON B.Sc. Trent University, 1980 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES DEPARTMENT OF ZOOLOGY We accept this thesis as conforming te trie required standard June, 1985 (c) Jennifer J. Robinson, 1985 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of The University of British Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 )E-6 C3/81) Abstract Geocoris bullatus (Say 1831), (Henriptera: Lygaeidae) has been collected and studied across North America but the present work is the o first detailed study of western North American CL discopterus Stal 1874. In fact, it has been claimed that 6^. discopterus is solely a species of the east. As the two species are taxonomically difficult to separate, when they were apparently discovered together at several localities in the southwestern Yukon, a detailed investigation of their systematics and distribution seemed necessary. Species status of Yukon Q. bullatus and iG.
    [Show full text]
  • Complete Issue More Information About This Article Journal's Webpage in Redalyc.Org Basso, C.; Cibils-Stewart, X. Foundations An
    Agrociencia Uruguay ISSN: 1510-0839 ISSN: 2301-1548 [email protected] Universidad de la República Uruguay Basso, C.; Cibils-Stewart, X. Foundations and developments of pest management in Uruguay: a review of the lessons and challenges Agrociencia Uruguay, vol. 24, no. 2, 2020, July-December, pp. 1-28 Universidad de la República Uruguay DOI: https://doi.org/10.31285/AGRO.24.409 Complete issue More information about this article Journal's webpage in redalyc.org Agrociencia Uruguay 2020 | Volume 24 | Number 2 | Article 409 DOI: 10.31285/AGRO.24.409 ISSN 2301-1548 Foundations and developments of pest management in Uruguay Editor a review of the lessons and challenges Martín Bollazzi Universidad de la República, Montevideo, Uruguay. Cimientos y desarrollo del manejo de Correspondence plagas en Uruguay César Basso, [email protected] una revisión de las lecciones y los desafíos Received 08 Sep 2020 Accepted 01 Oct 2020 Fundamentos e desenvolvimento do Published 13 Oct 2020 manejo de pragas no Uruguai Citation Basso C, Cibils-Stewart X. Foundations and developments uma revisão das lições e desafios of pest management in Uruguay: a review of the lessons and challenges. Agrociencia Uruguay [Internet]. Basso, C. 1; Cibils-Stewart, X. 2 2020 [cited dd mmm yyyy];24(2):409. Available from: http://agrocienciauruguay. uy/ojs/index.php/agrocien- 1Universidad de la República, Facultad de Agronomía, Unidad de cia/article/view/409 Entomología, Montevideo, Uruguay. 2Instituto Nacional de Investigación Agropecuaria (INIA), Programa Nacional de Investigación en Pasturas y Forrajeras, Entomología, Protección Vegetal, Colonia, Uruguay. History of pest management in Uruguay Abstract FAO has proclaimed 2020 as the “International Year of Plant Health”.
    [Show full text]
  • Geocoris Punctipes</Emphasis>
    EntomoL exp. appl. 64: 195-202, 1992. 1992 Kluwer Academic Pubhshers. Printed & Belgium. 195 Geocoris punctipes as a predator of Bemisia tabaci: a laboratory evaluation A. C Cohen I & D. N. Byrne2 1 U.S. Department of Agriculture, Agr&ultural Research Service Western Cotton Research Laboratory, 4135 E. Broadway Rd., Phoenix, AZ 85040, USA; 2Department of Entomology, University of Arizona, Tucson, AZ 85721, USA Accepted: February 28, 1989 Key words: Geocoris, Bemisia, predator, handling time Abstract Geocoris punctipes (Say), a predaceous lygaeid not previously documented as a whitefly predator, was tested in the laboratory as a natural enemy of the sweet potato whitefly, Bemisia tabaci (Genn.). Its stalking behavior with whiteflies as prey was similar to that observed with aphids. A previously unob- served behavior was noted that involves the predators using salivary secretions to fasten the wings of prey to various surfaces, allowing labial probing and feeding. Prey consumption as a function of prey number appeared to follow the pattern of the Holling type II functional response. Handling time per prey item ranged from about 180 to 240 seconds. No changes were observed in handling time devoted to earlier versus later catches. Nutritional quality of whiteflies was measured using crude protein, lipids and carbohydrates as criteria. Performance, in terms of predator behavior, total daily handling time, func- tional response, energy budget and nutritional quality all support the hypothesis that G. punctipes is a promising candidate for biological control of sweet potato whiteflies. Introduction with photosynthesis (Perkins, 1983). These facts indicate a great need for effective control strate- The sweet potato whitefly, Bemisia tabaci (Genn.) gies.
    [Show full text]
  • Guía Para La Identificación De Insectos Benéficos
    Insectos Benéfi cos Guía para su Identifi cación MIGUEL B. NÁJERA RINCÓN Investigador en Manejo Agroecológico de Insectos Plaga Campo Experimental Uruapan INSTITUTO NACIONAL DE INVESTIGACIONES FORESTALES, AGRÍCOLAS Y PECUARIAS (INIFAP) BRÍGIDA SOUZA Profesora – Investigadora Departamento de Entomología UNIVERSIDADE FEDERAL DE LAVRAS (UFLA) MINAS GERAIS, BRASIL NOVIEMBRE DE 2010 1 Insectos Benéfi cos. Guía para su Identifi cación Primera Edición: 13 de Noviembre de 2010. D.R. Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias (INIFAP) Campo Experimental Uruapan Av. Latinoamericana No. 1101. Col. Revolución C.P. 60500 Uruapan, Michoacán ISBN: En trámite. El presente libro es una edición del Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP) y la Universidade Federal de Lavras (UFLA), Minas Gerais, Brasil, con el apoyo fi nanciero de la Fundación Produce Michoacán y diseño del Consejo Estatal de Ciencia y Tecnología del Estado de Michoacán (COECyT). Queda prohibida su reproducción total o parcial por cualquier medio sin la previa autorización por escrito de dichas instituciones. Diseño Editorial y Formación: C3 Diseño, [email protected] Composición fotográfi ca: Miguel B. Nájera Rincón. Diseño Gráfi co de Portada y Contraportada: LDG. Mariana López López, Consejo Estatal de Ciencia y Tecnología. Fotografías. Portada: Cycloneda sanguinea en busca de presas, Antonio Marín Jarillo. Contraportada: Braconidae parasitando una larva de lepidóptero, Miguel B. Nájera Rincón. Impreso en México/Printed in
    [Show full text]
  • Synopsis of the Heteroptera Or True Bugs of the Galapagos Islands
    Synopsis of the Heteroptera or True Bugs of the Galapagos Islands ' 4k. RICHARD C. JROESCHNE,RD SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY • NUMBER 407 SERIES PUBLICATIONS OF THE SMITHSONIAN INSTITUTION Emphasis upon publication as a means of "diffusing knowledge" was expressed by the first Secretary of the Smithsonian. In his formal plan for the Institution, Joseph Henry outlined a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge." This theme of basic research has been adhered to through the years by thousands of titles issued in series publications under the Smithsonian imprint, commencing with Smithsonian Contributions to Knowledge in 1848 and continuing with the following active series: Smithsonian Contributions to Anthropology Smithsonian Contributions to Astrophysics Smithsonian Contributions to Botany Smithsonian Contributions to the Earth Sciences Smithsonian Contributions to the Marine Sciences Smithsonian Contributions to Paleobiology Smithsonian Contributions to Zoology Smithsonian Folklife Studies Smithsonian Studies in Air and Space Smithsonian Studies in History and Technology In these series, the Institution publishes small papers and full-scale monographs that report the research and collections of its various museums and bureaux or of professional colleagues in the world of science and scholarship. The publications are distributed by mailing lists to libraries, universities, and similar institutions throughout the world. Papers or monographs submitted for series publication are received by the Smithsonian Institution Press, subject to its own review for format and style, only through departments of the various Smithsonian museums or bureaux, where the manuscripts are given substantive review.
    [Show full text]
  • Banisteria, Number 20, 2002 © 2002 by the Virginia Natural History Society
    Banisteria, Number 20, 2002 © 2002 by the Virginia Natural History Society Thirteen Additions to the Known Beetle Fauna of Virginia (Coleoptera: Scirtidae, Bothrideridae, Cleridae, Tenebrionidae, Melyridae, Callirhipidae, Cerambycidae, Chrysomelidae) Richard L. Hoffman Virginia Museum of Natural History Martinsville, Virginia 24112 Steven M. Roble Virginia Department of Conservation and Recreation Division of Natural Heritage 217 Governor Street Richmond, Virginia 23219 Warren E. Steiner, Jr. Department of Systematic Biology - Entomology National Museum of Natural History, NHB-187 Smithsonian Institution Washington, D. C. 20560 INTRODUCTION SCIRTIDAE Ongoing inventories of the arthropod faunas of Ora troberti (Guérin) Virginia by our respective agencies continue to augment New northernmost and state records the lists of known resident species. Often these newly Members of this genus and the related Scirtes documented species are small and rarely collected, and resemble the chrysomelid “flea beetles” in having the hind their discovery in Virginia represents dramatic extensions femora greatly enlarged for jumping. Ora troberti is in their established areas of distribution, sometimes by listed for FL and TX (Peck & Thomas, 1998; Young, hundreds of miles. 2002a) and AL (Löding, 1945). There is a specimen We take this occasion to formally register thirteen labeled “La.” in the Casey Collection (USNM). White beetle species, most of which fall into the category just (1983) apparently used a specimen of O. troberti for his described, as native to Virginia. Eight of these species are field guide illustration of the genus. Its occurrence along resident in the southeastern Coastal Plain of the state and the Atlantic coast northward from Florida is not reported, three inhabit the Appalachians.
    [Show full text]
  • Orius Insidiosus (Say) and ENTOMOPATHOGENS AS POSSIBLE BIOLOGICAL CONTROL AGENTS for THRIPS
    Orius insidiosus (Say) AND ENTOMOPATHOGENS AS POSSIBLE BIOLOGICAL CONTROL AGENTS FOR THRIPS Ronald D. Oetting and Ramona J. Beshear Department of Entomology University of Georgia College of Agriculture, Experiment Stations Georgia Station Griffin, Georgia USA The entomology program in ornamental floriculture at the University of Georgia places primary emphasis on commercial production of flowering and foliage plants under greenhouse conditions. Thrips management is a major part of that program. Several species of foliage and flower inhabiting species are pests on greenhouse crops. The western flower thrips, Frankliniella occidentalis (Pergande), has become the most important pest of the thrips complex during this decade. Other thrips species have also become more difficult to control or occur more frequently on greenhouse crops in different areas of the country. The subject of this paper is the potential use of natural enemies for the management of thrips under greenhouse and other environments. The use of predatory mites for thrips management is discussed in the previous paper and we will focus on two other potential natural enemies: entomopathogens and a hemipteran predator in the genus Orius. Neither of these natural enemies have been utilized in commercial programs for thrips control in greenhouses in the United States but both occur as natural enemies limiting populations of thrips in their respective environments. They should both be considered as potential tools for thrips management. Entomopathogens Entomopathogens are organisms utilized for management of insect populations and the fungi are the only group of pathogens which have been studied for thrips control. There have been three genera of fungi reported from thrips: Verticillium, Entomophthora, and Paecilomyces.
    [Show full text]
  • Arthropod Communities and Transgenic Cotton in the Western United States: Implications for Biological Control S.E
    284 Naranjo and Ellsworth ___________________________________________________________________ ARTHROPOD COMMUNITIES AND TRANSGENIC COTTON IN THE WESTERN UNITED STATES: IMPLICATIONS FOR BIOLOGICAL CONTROL S.E. Naranjo1 and P.C. Ellsworth2 1U.S. Department of Agriculture, Agricultural Research Service, Phoenix, Arizona, U.S.A. 2University of Arizona, Maricopa, Arizona, U.S.A. INTRODUCTION Cotton, transgenically modified to express the insecticidal proteins of Bacillus thuringiensis (Bt), has been available commercially in the United States since 1996. Bt cotton is widely used throughout the cotton belt (Layton et al., 1999), and more than 65% of the acreage in Arizona has been planted to Bt cotton since 1997. In the low desert production areas of Arizona and California, Pectinophora gossypiella (Saunders), the pink bollworm, is the major target of Bt cotton. A number of other lepidopterous species occur in this area, but they are sporadic secondary pests of cotton whose population outbreaks are typically induced by indiscriminate use of broad-spectrum insecticides. As a result of the adoption of Bt-cotton and the coincident introduction and adoption of selective insect growth regulators for suppression of Bemisia tabaci (Gennadius), insecticide usage in Arizona cotton over the past decade as declined from a high of 12.5 applications per acre in 1995 to 1.9 in 1999 (Ellsworth and Jones, 2001). These reductions in insecticide use have broadened opportunities for all biological control approaches in cotton. Beyond concern for the maintenance of susceptibility in target pest populations there also are a number of ecological and environmental questions associated with use of transgenic crops, one of the most prominent being effects on non-target organisms.
    [Show full text]
  • E0020 Common Beneficial Arthropods Found in Field Crops
    Common Beneficial Arthropods Found in Field Crops There are hundreds of species of insects and spi- mon in fields that have not been sprayed for ders that attack arthropod pests found in cotton, pests. When scouting, be aware that assassin bugs corn, soybeans, and other field crops. This publi- can deliver a painful bite. cation presents a few common and representative examples. With few exceptions, these beneficial Description and Biology arthropods are native and common in the south- The most common species of assassin bugs ern United States. The cumulative value of insect found in row crops (e.g., Zelus species) are one- predators and parasitoids should not be underes- half to three-fourths of an inch long and have an timated, and this publication does not address elongate head that is often cocked slightly important diseases that also attack insect and upward. A long beak originates from the front of mite pests. Without biological control, many pest the head and curves under the body. Most range populations would routinely reach epidemic lev- in color from light brownish-green to dark els in field crops. Insecticide applications typical- brown. Periodically, the adult female lays cylin- ly reduce populations of beneficial insects, often drical brown eggs in clusters. Nymphs are wing- resulting in secondary pest outbreaks. For this less and smaller than adults but otherwise simi- reason, you should use insecticides only when lar in appearance. Assassin bugs can easily be pest populations cannot be controlled with natu- confused with damsel bugs, but damsel bugs are ral and biological control agents.
    [Show full text]
  • Comparative Study of Head Structures of Larvae of Sphindidae and Protocucujidae (Coleóptera: Cucujoidea)
    Eur. J. Entorno?. 98: 219-232, 2001 ISSN 1210-5759 Comparative study of head structures of larvae of Sphindidae and Protocucujidae (Coleóptera: Cucujoidea) Rolf Georg BEUTEL1 and Stanislaw Adam SLIPIÑSKI2 'Institut für Spezielle Zoologie und Evolutionsbiologie, FSU Jena, 07743 Jena, Germany; e-mail:[email protected] 2Muzeum i Instytut Zoologii PAN, ul. Wilcza 64, 00-679 Warszawa, Poland, e-mail:[email protected] Key words.Cucujoidea, Sphindidae, Protocucujidae, larvae, morphology, phylogeny Abstract. Selected representatives of Cucujoidea, Cleroidea, Tenebrionoidea, Chrysomelidae, and Lymexylidae were examined. External and internal head structures of larvae ofSphindus americanus and Ericmodes spp. are described in detail. The data were analyzed cladistically. A sister group relationship between Sphindidae and Protocucujidae is suggested by the vertical position of the labrum. The monophyly of Cucujiformia is supported by the reduced dorsal and anterior tentorial arms, fusion of galea and lacinia, and the presence of tube-like salivary glands. Absence of M. tentoriopraementalis inferior and presence of a short prepharyngeal tube are potential synapomorphies of Cleroidea, Cucujoidea and Tenebrionoidea. The monophyly of Cleroidea and Cucujoidea is suggested by the unusual attachment of the M. tentoriostipitalis to the ventral side of the posterior hypopharynx. Cucujoidea are paraphyletic. The families Endomychidae, Coccinellidae and Nitidulidae are more closely related to the monophyletic Cleroidea, than to other cucujoid groups. Separation of the posterior tentorial arms from the tentorial bridge and presence of a maxillolabial complex are synapomorphic features of Cleroidea and these cucujoid families. For a reliable reconstruction of cucujoid interrelation­ ships, further characters and taxa need to be studied. INTRODUCTION for a reconstruction of the phylogeny of the cucujoid, Sphindidae and Protocucujidae are two small families tenebrionoid and cleroid families.
    [Show full text]
  • Building-Up of a DNA Barcode Library for True Bugs (Insecta: Hemiptera: Heteroptera) of Germany Reveals Taxonomic Uncertainties and Surprises
    Building-Up of a DNA Barcode Library for True Bugs (Insecta: Hemiptera: Heteroptera) of Germany Reveals Taxonomic Uncertainties and Surprises Michael J. Raupach1*, Lars Hendrich2*, Stefan M. Ku¨ chler3, Fabian Deister1,Je´rome Morinie`re4, Martin M. Gossner5 1 Molecular Taxonomy of Marine Organisms, German Center of Marine Biodiversity (DZMB), Senckenberg am Meer, Wilhelmshaven, Germany, 2 Sektion Insecta varia, Bavarian State Collection of Zoology (SNSB – ZSM), Mu¨nchen, Germany, 3 Department of Animal Ecology II, University of Bayreuth, Bayreuth, Germany, 4 Taxonomic coordinator – Barcoding Fauna Bavarica, Bavarian State Collection of Zoology (SNSB – ZSM), Mu¨nchen, Germany, 5 Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, Technische Universita¨tMu¨nchen, Freising-Weihenstephan, Germany Abstract During the last few years, DNA barcoding has become an efficient method for the identification of species. In the case of insects, most published DNA barcoding studies focus on species of the Ephemeroptera, Trichoptera, Hymenoptera and especially Lepidoptera. In this study we test the efficiency of DNA barcoding for true bugs (Hemiptera: Heteroptera), an ecological and economical highly important as well as morphologically diverse insect taxon. As part of our study we analyzed DNA barcodes for 1742 specimens of 457 species, comprising 39 families of the Heteroptera. We found low nucleotide distances with a minimum pairwise K2P distance ,2.2% within 21 species pairs (39 species). For ten of these species pairs (18 species), minimum pairwise distances were zero. In contrast to this, deep intraspecific sequence divergences with maximum pairwise distances .2.2% were detected for 16 traditionally recognized and valid species. With a successful identification rate of 91.5% (418 species) our study emphasizes the use of DNA barcodes for the identification of true bugs and represents an important step in building-up a comprehensive barcode library for true bugs in Germany and Central Europe as well.
    [Show full text]