PLEASE SCROLL DOWN FOR ARTICLE

Size: px

Start display at page:

Download "PLEASE SCROLL DOWN FOR ARTICLE"

Martin Sharp
5 years ago
Views:

This article was downloaded by:[university of Queensland] On: 9 May 2008 Access Details: [subscription number 789191423] Publisher: Taylor & Francis Informa Ltd Registered in England and Wales

1 This article was downloaded by:[university of Queensland] On: 9 May 2008 Access Details: [subscription number ] Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: Registered office: Mortimer House, Mortimer Street, London W1T 3JH, UK Biocontrol Science and Technology Publication details, including instructions for authors and subscription information: Biology and Host Specificity of the Stem Galling Weevil Conotrachelus albocinereus Fiedler (Col.: Curculionidae), a Biocontrol Agent for Parthenium Weed Parthenium hysterophorus L. (Asteraceae) in Queensland, Australia R. E. Cruttwell McFadyen Online Publication Date: 01 April 2000 To cite this Article: McFadyen, R. E. Cruttwell (2000) 'Biology and Host Specificity of the Stem Galling Weevil Conotrachelus albocinereus Fiedler (Col.: Curculionidae), a Biocontrol Agent for Parthenium Weed Parthenium hysterophorus L. (Asteraceae) in Queensland, Australia', Biocontrol Science and Technology, 10:2, To link to this article: DOI: / URL: PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: This article maybe 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 (2000) 10, 195±200 Biology and Host Speci city of the Stem Galling Weevil Conotrachelus albocinereus Fiedler (Col.

2 Biocontrol Science and Technology (2000) 10, 195±200 Biology and Host Speci city of the Stem Galling Weevil Conotrachelus albocinereus Fiedler (Col.: Curculionidae), a Biocontrol Agent for Parthenium Weed Parthenium hysterophorus L. (Asteraceae) in Queensland, Australia R. E. CRUTTWELL McFADYEN Queensland Department of Natural Resources, Alan Fletcher Research Station, PO Box 36, Sherwood Q 4075, Australia (Received for publication 31 August 1999; revised manuscript accepted 11 December 1999) The stem-galling weevil Conotrachelus albocinereus Fiedler has been investigated as a potential biological control agent against parthenium weed (Parthenium hysterophorus L.) in Australia. Adults were tested in multiple-choic e feeding and oviposition tests on 56 plant species in 51 genera. No feeding or oviposition was recorded on any non-target plant except annual ragweed (Ambrosia artemisiifolia L.), a closely related weed. Field releases of the weevil in Queensland, Australia, commenced in 1995 and establishment has been recorded at several sites. Keywords: biocontrol, host speciwcity, non-target evects, parthenium weed INTRODUCTION Parthenium weed, Parthenium hysterophorus L., is native to the countries bordering the Gulf of Mexico and to central South America. It has become widely distributed throughou t the tropics and sub-tropics, and is a major weed in India, and an increasing problem in Taiwan, Ethiopia and other tropical countries (Navie et al., 1998a). Parthenium weed was rst recorded in Australia in Queensland in 1955, and now occurs throughou t central Queensland and in isolated infestations west to Longreach and south into New South Wales. The weed is an aggressive invade r of disturbed and degraded pastures, rapidly displacing pasture species and forming near monocultures in suitable soils. Contact with the plant produces severe allergic reactions in susceptible humans, and ingestion by stock may result in unacceptable tainting of meat (McFadyen, 1992). A survey showed that it is costing the grazing industry at least Au$$16 million per year in control costs and lost production (Chippendale & Panetta, 1994), and is continuing to spread south into southern Queensland and New South Wales. The biologica l control programme against parthenium weed in Queensland commenced Correspondence to: R. E. McFadyen. Tel: ; Fax: ; Rachel.Mcfadyen@dnr.qld.gov.au ISSN (print)/issn (online)/00/ Taylor & Francis Ltd

3 196 R. E. CRUTTWELL MCFADYEN in 1977 with investigation s in South and Central America (McFadyen, 1992). Seven insect species and a rust were introduced into Queensland, six of which have established, but control of the weed is still not adequate (Dhileepan et al., 1996). This paper presents the results of investigations on a stem-galling weevil from Argentina, Conotrachelus albocinereus Fiedler. DISTRIBUTION AND BIOLOGY C. albocinereus is known from Colombia, north-west Argentina and Brazil. The adults are small (4±5 mm), greyish-brown in colour, and live up to 3 months, feeding nocturnally on stem tips and leaves of parthenium. The eggs are oval-cylindrical, 1 mm long, and are laid singly on the stem surface or leaf base, covered with a layer of plant trichomes severed by the female and stuck down with a clear secretion. Eggs are initially white and darken to cream or beige over the 10 to 14 days before hatching. Newly-hatched larvae bore into the stem at an axil or leaf base, where feeding induces the formation of a cylindrical or oblong gall up to 10 mm long. Galls form in both auxillary and main stems. Larvae remain inside the galls until mature, when they leave to pupate in the soil. There are three generations a year in northern Argentina. Adults over-winter in leaf-litter or in the top few cm of soil, and commence oviposition in spring (November) after the parthenium has germinated following storm rains. Larvae and galls become abundan t in December and adults from the rst generation are found in January. Adults of the second generation emerge and lay in March, and the third generation adults emerge at the end of April and during May. These adults then remain in reproductive diapause until November (C. Garcia, Queensland Department of Natural Resources, pers. comm., 1991). In the laboratory, development from egg to pupa takes 8 to 10 weeks at 20±25ëC. The pupal period is about 30 days and newly-emerged adults have a 1±2 week pre-oviposition period. In the laborator y, adults ceased feeding and ovipositio n in response to shortening days in late March (autumn in the southern hemisphere). In the laborator y colony, this overwintering diapause could be prevented by providin g extra light to extend day-length to 14 hours and keeping night temperatures above 15ëC. The impact on the plant of adult feeding damage is negligible. Larval galls usually kill axillary shoots and weaken the main stem. Galls probably act as resource sinks, reducing ower and seed production by the plant (Abrahamson & McCrea, 1986). During this study, two parasites were reared from the larvae in Argentina, a braconid and a tachinid. No egg or pupal parasites were encountered. HOST SPECIFICITY Adult weevils from Parthenium hysterophorus near Tucuman, Argentina, were sent to Dr C. W. O Brien, Florida A & M University, USA, who identi ed the species as Conotrachelus albocinereus Fiedler (Curculionidae, Cryptorhynchinae, Ithyporini), originally described from adults collected in Brazil (Fiedler, 1940). There are no publishe d host records for the species. In eld surveys in Argentina, C. albocinereus was collected or reared only from parthenium weed and Ambrosia elatior L. ( 5artemisiifolia L.) (C. Garcia, pers. comm., 1991) Conotrachelus is a very large mostly American genus, with over 1200 described species, 280 in North and Central America (O Brien & Wibmer, 1982) and the rest from South America (Wibmer & O Brien, 1986). Most of the relatively few species with known hosts are from fruit or seeds, with diverent species attacking pome fruits, pecans, sapodillas, avocados and guavas. Costa Lima (1968) lists the hosts of 57 species in Brazil, all but two of which are fruits or seeds; Conotrachelus phaseoli Marshall is recorded as causing galls in navy bean Phaseolus vulgaris, and C. lanei Bondar as feeding in the stems of a Labiateae. Nearly all species are recorded attacking only one or a few closely related plant species.

4 STEM GALLING WEEVIL FOR THE BIOCONTROL OF PARTHENIUM 197 LABORATORY TESTING Method Multiple-choice oviposition and larval development tests were conducted in quarantine in Brisbane. Gauze-covered metal-framed cages ( cm and 90 cm tall) containing six test and two parthenium plants were used. The stems of all plants entered the cage through holes in the wooden base; the holes were stopped with cotton wool and all cracks and edges sealed with tape. Fifteen unsexed mature adults were placed in the centre of the oor of each test cage. After three weeks all adults were removed, the cage was dismantled and all plants checked for adult feeding damage and oviposition. The plants were held for a further four weeks, and then carefully examined and the number of larval feeding sites recorded. Each plant species was tested three times but no attempt was made to replicate the combinations of plants used in the tests. Plants tested were those in the list drawn up in consultation with the Australian Quarantine Inspection Service (AQIS) in 1991 (Table 1). Parthenium is in the sub-tribe Ambrosiinae of the tribe Heliantheae of the Asteraceae. There are no native or ornamental plants in Australia in this sub-tribe: the only plants in the sub-tribe occurring in Australia are introduced weeds in the genera Iva, Xanthium and Ambrosia. Parthenium argentatum, guayule, was included as a test plant as it is a suggested source of rubber although it is not grown commercially in Australia or elsewhere. Within the tribe Heliantheae there are 11 genera with species native to Australia. Three genera, Chrysogonum, Blainvillea and Moonia, have limited distribution s in far north Queensland, Western Australia and the Northern Territory, and seed of these genera could not be obtained. Seven more widely-occurring native genera as well as six genera of ornamental or economic importance in this tribe were included in the test list. The major crop plant in the tribe is sun ower, Helianthus annuus, and six cultivars of this in common use were tested, together with Helianthus argophyllus, used as a parent line in some cultivars. Of the other 11 tribes of the Asteraceae represented in Australia, representatives of 20 genera were included, of which 12 are native plants and the rest ornamentals or crop plants. The native daisy Calotis cuneata (tribe Astereae) was in the agreed list but could not be obtained. As there was no attack on the other genera tested in this tribe, testing of this species was not considered necessary. Fifteen representative genera from 10 other plant families which are hosts to Conotrachelus (from Costa Lima, 1968) were also included in the test list, which therefore consisted of 56 species from 51 genera in 11 families. Results At the end of the tests, between 5 and 14 adults were found alive (mean 10; n 28), of which half (mean 5; range 2±10) were found on the parthenium weed plants. Adult feeding damage to all leaves occurred on all parthenium weed plants by the end of each test. There was minor feeding on Gazania hybrida, Xanthium occidentale, Wedelia bixora, Helianthus argophyllus and Dahlia, in only one of the three tests of each species. There was feeding on each of the three plants of Ambrosia artemisiifolia tested, but no adults were found on the plants at the end of the tests. Larvae were present in all parthenium weed plants, with an average of 20 larval feeding sites (range 1±111; n 28) in each parthenium weed plant, and an average of 50% of all nodes attacked. No signs of larval feeding or larvae were seen in any of the test plants with the exception of A. artemisiifolia, on which a total of 22 larvae were present in the three plants tested (range 0 to 13) and an average of 45% of nodes were attacked. Larvae in the parthenium weed and A. artemisiifolia plants developed normally to adults. DISCUSSION Laboratory tests and eld observations demonstrated that C. albocinereus is host-speci c,

5 198 R. E. CRUTTWELL MCFADYEN TABLE 1. Plants used in Host Speci city Testing of Conotrachelus albocinereus ASTERACEAE Tribe Arctotidae: Gazania hybrida (ornamental) Tribe Astereae: Aster novii-belgii (ornamental) Brachycome multiwda (native) Olearia subspicata (native) Vittadinia sulcata (native) Tribe Heliantheae: Sub-Tribe Ambrosiinae: Ambrosia artemisiifolia (annual ragweed) Parthenium argentatum (guayule) Xanthium occidentale (noogoora burr) Other Sub-Tribes: Coreopsis lanceolata (ornamental) Cosmos sp. (ornamental) Dahlia sp. (ornamental) Eclipta platyglossa (native) Enydra sp. (native) Flaveria australasic a (speedy weedðnative) Gaillardia sp. (ornamental) Glossogyne tenuifolium (native) Helianthus annuus (sun ower) (6 common cultivars) Helianthus argophyllus (silver-leafed sun ower) Siegesbeckia orientalis (Indian weedð?native) Spilanthes grandixora (native) Wedelia bixora (native) Zinnia sp. (ornamental) Tribe Inuleae: Cassinia laevis (native) Gnaphalium sp. (native) Helichrysum bracteatum (native) Tribe Senecionideae: Senecio lautus (native) Tribe Anthemideae: Artemisia sp. (wormwood) Chrysanthemum cinerariifolium (pyrethrum) Cotula australis (native) Tribe Eupatorieae: Adenostemma lavenia (native) Tribe Vernonieae: Vernonia cinerea (native) Tribe Cichorieae: Cichorium intybus (chicory) Lactuca sativa (lettuce) Picris evae (native) Tribe Mutisae: Gerbera sp. (ornamental) Tribe Cynareae: Carthamus tinctorius (sazower) Tribe Calenduleae: Calendula sp. (ornamental) Representatives of plant families which are hosts to other Conotrachelus ANNONACEAE Annona muricata (custard apple) CAESALPINIACEAE Bauhinia /Lysiphyllum sp. (native bauhinia)

6 STEM GALLING WEEVIL FOR THE BIOCONTROL OF PARTHENIUM 199 TABLE 1.Ðcontinued FABACEAE Phaseolus vulgaris (bean) JUGLANDACEAE Carya illinoensis (pecan nut) LABIATAE Mentha sp. (mint) LAURACEAE Persea americana (avocado) MYRTACEAE Angophora sp. Eucalyptus sp. Eugenia sp. Melaleuca sp. Psidium guajava (guava) ROSACEAE Prunus domestica (plum) Malus sylvestris (apple) SAPOTACEAE Planchonella sp. URTICACEAE Urtica sp. (nettles) and that there is minimal risk of damage to any non-target plants except annual ragweed, also an introduced weed in Australia. Because parthenium weed occurs over a wide area of central and north Queensland, in semi-arid climatic zones experiencing wet seasons of variable length and intensity interspersed by long dry periods, we believe that successful control will only be achieved by a complex of agents, each abundant in diverent seasons and under diverent conditions. Five insects introduced as biologica l control agents are already established and widespread on parthenium weed in Queensland: a stem- and tipgalling moth Epiblema strenuana Walker, a leaf-mining moth Bucculatrix parthenicola Bradley, a stem- and crown-boring weevil Listronotus setosipennis (Hustache), a seed-feeding weevil Smicronyx lutulentus Dietz, and a leaf-feeding chrysomelid Zygogramma bicolorata Pallister (Dhileepan et al., 1996). Of these, only the rst two are found throughout the distribution of parthenium, and the last is con ned to the Comet river drainage in central Queensland where rainfall is more reliable and more evenly distributed through the year. We believe that C. albocinereus has the potential to be a useful addition to this complex, although utilizing the same resources (galling stem tips and axillary buds) as the moth E. strenuana. In north-west Argentina where the weevil is native, there is also a long winter and spring drought, and adult emergence in spring is triggered by rainfall as well as increased temperatures. It is therefore probable that the weevil phenology will match that of the weed, with adult emergence and oviposition coinciding with the rst germination of the weed each year. Diapause in the moth E. strenuana is terminated by temperature and day-length irrespective of rainfall, and as a result spring emergence is often poorly synchronized with that of the host plant (Navie et al., 1998b). Permission for the release of C. albocinereus was granted by AQIS in 1993, but no eld releases were made until The weevil is believed to be established at several sites in central Queensland but we have no information on increase or spread rates. Monitoring is diycult because many plants are heavily infested with larvae of the moth E. strenuana and the weevil L. setosipennis, so that dissection of plants and rearing larvae to adults is required to con rm the presence of C. albocinereus. We expect that it will be several years before the impact of this additiona l agent can be properly evaluated. Annual ragweed in Australia is largely con ned to the east coast from Grafton to just north of Brisbane (30ëS to 25ëS), which does not overlap with the main parthenium weed infestations.

7 200 R. E. CRUTTWELL MCFADYEN Given that C. albocinereus occurs naturally on annual ragweed A. elatior in Argentina, it is probable that it will also attack A. artemisiifolia, and releases onto this plant have commenced. ACKNOWLEDGEMENTS Cesar Garcia (Queensland Department of Natural Resources, South American Field Station) was responsible for the collections and eld data from Argentina. Tonya Girle was responsible for rearing the quarantine colony in Brisbane and assisted with host testing. Kylie Webster, Mariano Trevino and Fe Ambatali were responsible for mass-rearing and eld releases from Their assistance is gratefully acknowledged. REFERENCES Abrahamson, W.G. & McCrea, K.D. (1986) Nutrient and biomass allocation in Solidago altissima: evects of two stem gall makers, fertilization and ramet isolation. Oecologia 68, 174±180. Chippendale, J.F. & Panetta, F.D. (1994) The cost of Parthenium weed to the Queensland cattle industry. Plant Protection Quarterly 9, 73±76. Costa Lima, A.M. Da (Ed.) (1968) Quarto Catalogo dos insetos que vivem nas plantas do Brasil: seus parasitas e predadores, Part 2, 1st Vol. Lab. Central de Patologia Vegetal, Rio de Janeiro, Brasil. Dhileepan, K., Madigan, B., Vitelli, M., McFadyen, R., Webster, K. & Trevino, M. (1996) A new initiative in the biological control of parthenium, in Proceedings of the 11th Australian Weeds Conference, Melbourne (Shepherd, R.C.H., Ed.), Melbourne, Australia, pp. 309±312. Fiedler, C. (1940) Monograph of the South American weevils of the genus Conotrachelus. British Museum (Natural History), London. v pp., illus. McFadyen, R.E. Cruttwell (1992) Biological control against parthenium weed in Australia. Crop Protection 11, 400±407. Navie, S.C., McFadyen, R.E., Panetta, F.D. & Adkins, S.W. (1998a) Parthenium hysterophorus L., in The Biology of Australian Weeds: Vol. 2 (Panetta, F.D., Groves, R.H. & Shepherd, R.C.H., Eds), R.G. & F.J. Richardson, Meredith, Victoria, Australia, pp. 157±176. Navie, S.C., Priest, T.E., McFadyen, R.E. & Adkins, S.W. (1998b) EYcacy of the stem-galling moth Epiblema strenuana Walk. (Lepidoptera: Tortricidae) as a biological control agent for ragweed parthenium (Parthenium hysterophoru s L.). Biological Control 13, 1±8. O Brien, C.W. & Wibmer, G. (1982) Annotated checklist of the weevils (Curculionidae sensu lato) of North America, Central America and the West Indies (Coleoptera: Curculionidae). Memoirs of the American Entomological Institute No. 34, Michigan, USA, 382 pp. Wibmer, G. & O Brien, C.W. (1986) Annotated checklist of the weevils (Curculionidae sensu lato) of South America (Coleoptera: Curculionidae). Memoirs of the American Entomological Institute No. 39, Michigan, USA.

Kassahun Zewdie et. al

Host-specificity sytudy on the leaf feeding beetlle, of Zygograma bicolorata (Coleoptera: Chrysomelidae) for the control of Parthenium hysterophorus in Ethiopia Kassahun Zewdie et. al Parthenium Weed bio-control