By feeding on re-ceptacle tissue, its larvae prevent development of some or … Each female lays about 100 to 200 eggs on the bracts of thistle heads. Rhinocyllus conicus (Frölich, 1792) Suborder: Superfamily: Family: Subfamily: Tribe: Genus: POLYPHAGA Emery, 1886. Rhinocyllus conicus (Froelich, 1792) Synonyms . and C. horridulum Michaux, and significant reductions in seed numbers of both species occurred during 2008. 1984; Kelly et al. The adults overwinter on the ground in litter and can be found in the spring on musk thistle heads, where they lay their eggs. Few data exist on the environmental risks of biological control. Weed and Pest Control Conference: 205–206. The effect of the red imported fire ant, Solenopsis invicta Buren, on Rhinocyllus conicus Froelich in a musk thistle, Carduus nutans L., biological control program was evaluated in laboratory and field trials in pastures in middle Georgia in 1999 and 2000. Adult Rhinocyllus conicus Fröelich on a thistle Photo by: Julia Hicks Figure 2. The adult weevil is black and covered in a thin black and yellowish mottled coat of hairs. Description . Includes mostly rare and very local species, only Larinus carlinae and Rhinocyllus conicus being widespread in the south. structural damage by rhinocyllus conicus (coleoptera: curculionidae) within the flowerheads of nodding thistle - volume 116 issue 10 - j. d. shorthouse, r. g. lalonde Field data on the incidence and increase of this weevil at this colonisation site are presented. Abstract. Cirsium vinaceum flower head with three Rhinocyllus conicus egg sites. INTRODUCTION Thistles in the genus Carduus have been the target of classical biological control programs in several coun-tries, including Argentina, Australia, Canada, New Zealand, and the United States (3). Selected survey tracks in the study area showing where weevils we were present and absent from thistle habitats Figure 5. lus conicus, was introduced from Eurasia to control musk thistle by reducing seed pro-duction. horridus on Rhinocyllus conicus (Coleoptera: Curculionidae) ... conicus adults developed from T. horridus-infested thistles. Developing larvae feed on the receptacle and the young seeds, reduc-ing or preventing the production of viable seeds. INTRODUCTION Thistles in the genus Carduus hav e been the target of classical biological control programs in several coun­ tries, including Argentina, Australia, Canada, New Zealand, and the United States (3). Rhinocyllus conicus is a species of true weevil. Rhinocyllus conicus (Froehlich) tribe,(Coleoptera: Curcu-lionoidae), nodding (musk) thistle receptacle weevil, is (Paynter known to attack different athistle species but displays a clear preference for nodding thistle, Carduus nutans L. (Zwölfer asand Harris, 1984). We examined the presence of the exotic weevil Rhinocyllus conicus Fröelich on native thistles at high elevations in the Rocky Mountains of Colorado. The weevils can reduce seed production by near-ly 80%, but they are attracted more to earlier blooming rather than later blooming flowers. CURCULIONIDAE Latreille, 1802. They are associated with Thistles, the larvae develop in the flower heads. LIXINAE Schönherr, 1823. one or more weevil larvae live in the receptacle, feeding on callus tissue that is induced by their activities; according to Redfern & Shirley the receptacle also sclerifies. Rhinocyllus conicus (Froehlich) (Coleoptera: Curculionidae). Additional index words: Biological control. musk thistle seed production. The weevil also has become established in Missouri (Puttier et al. us, overall, the strategies of the herbivores in this fl oral guild are They are lovely little Weevils and are about 4-7mm in length. RHINOCYLLUS Germar, 1817. Thirty Italian thistle (Carduus pycnocephalus) plants produced a total of 7735 (mean 285) flower heads, which potentially contained about 25 000 seeds, from mid-April to late August 1980, at See Canyon, San Luis Obispo County, California, the initial colonization site where Rhinocyllus conicus was introduced for the control of the weed. Rhinocyllus conicus Froel. Musk thistles that were infested with lower densities of T. horridus larvae (<20 per plant) also produced multiple stems that were usually shorter than uninfested thistles. Larvae of R. conicus completed development in heads of the native species C. carolinianum (Walter) Fernald and Schubert. Rhinocyllus conicus Rhinocyllus conicus Species; Additional images; Click here to support NatureSpot by making a donation - small or large - your gift is very much appreciated. The effect of the red imported fire ant, Solenopsis invicta Buren, on Rhinocyllus conicus Froelich in a musk thistle, Carduus nutans L., biological c Herbicidal effect on Rhinocyllus conicus Froet., a thistle head weevil, was studied by examining the mortality, emergence rates and weights of weevils Establishment in NewZealand of all three biocontrol agents is well documented (Jessep 1975,1989b;Harmanetal.1996;Hayes2007). It is by Kansas Department of Agriculture . Pupation in the receptacle. A head weevil (Rhinocyllus conicus Froel., Coleoptera: Curculionidae) was selected for introduction into Canada and the United States for biological control of Carduus species (2, 3, 4, 10). Additional index words: Biological control. Rhinocyllus conicus is a species of true weevil. Rhinocyllus conicus on native species in the northcentral USAprovides the opportunity to experimentally evaluate factors that might help predict non-target host plant use, magni- tude of direct impact with transference, and indirect effects mediated by trophic interac-tions. However, it was suspected that the phenology of the two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis,whichcouldlimitthefly’sability tobuilduphighpopulations. We tested whether the distribution of R. conicus was related to elevation by performing 2 separate studies. Eggs hatch in 6 to 9 days and newly hatched larvae feed through the bracts into the receptacle. 1990). Rhinocyllus conicus Froel. Area studied for presence of Rhinocyllus conicus Figure 3. They are supposed to be a Southern species, but it appears they are heading North. Establishment and Efficacy of Rhinocyllus conicus Froelich (Coleoptera: Curculionidae) in Controlling Carduus nutans L. In North Carolina R. C. McDonald and A. O. Robbing Musk thistle, Cardmis nutans L., has become a serious weed pest in North Carolina since its accidental introduction in contaminated hay from the Midwest during drought periods in the late 1980's. Abstract. Rhinocyllus conicus has been widely used as a biocontrol agent of musk thistle in the USA (Surles et al., 1974, Kok and Surles, ... After 6–8 days, the eggs hatch and the larvae emerge and feed on the receptacle tissue, preventing seed formation. Identification difficulty. Rhinocyllus conicus Froel. Thank you. Thistles which reproduce only via seed, such as musk thistle, are controlled well by this weevil and its seed head destroying larvae. Rhinocyllus conicus has the greatest temporal overlap with the dominant tephritid fl y Paracantha culta (Louda 1998). 1975: Introduction of a weevil for biological control of nodding thistle. Some larvae tunnel through the upper stem instead of chambering in a flower head; this can also be destructive to the plant. The weevil Rhinocyllus conicus Froeh., introduced to control exotic thistles, has exhibited an increase in host range as well as continuing geographic expansion. Between 1992 and 1996, the frequency of weevil damage to native thistles consistently increased, reaching 16 to 77 percent of flowerheads per plant. Rhinocyllus conicus- Insights to Improve Predictability and Minimize Risk of Biological Control of Weeds S. M. LOUDA School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588, USA Abstract A review of information on the release of Rhinocyllus conicusto control of Carduus spp. Rhinocyllus conicus (Frölich, 1792) on Carduus, Centaurea, Cirsium gall. I found a few of these Short-snouted Weevils on Wilford Bridge on Monday, this I think is Rhinocyllus conicus. Thistles which reproduce only via seed, such as musk thistle, are controlled well by this weevil and its seed head destroying larvae. Of our five species of Lixus, four are probably extinct while the recently discovered L. scabricollis has spread rapidly around the coasts of England and Wales. Habitat. In 25–30 days, the larvae pupate and the pupae develop into adults in 8–14 days. Some larvae tunnel through the upper stem instead of chambering in a flower head; this can also be destructive to the plant. Rhinocyllus conicus was initially released and established in Virginia in 1969 where it successfully controlled musk thistle after six years (Kok and Surles 1974). Distribution of Rhinocyllus conicus in Rocky Mountain National Park Figure 4. Adults of Rhinocyllus conicus (Froel.) Curculio conicus Froelich, 1792; Curculio thaumaturgus Rossi, 1794; References . RHINOCYLLINI Lacordaire, 1863. A black weevil with a tessellated pattern of pale pubescence on the elytra. Adult R. conicus are dark brown in color and 10 to 15 mm long. Abstract Rhinocyllus conicus is a flowerhead weevil deliberately introduced into the USA for the biological control of invasive exotic thistles in the genus Carduus.This study documents the course and magnitude of the weevil population expansion onto nontarget host plants. Adults do some damage as well when they feed on the foliage. Jessep, C.T. CURCULIONOIDEA Latreille, 1802 . Rhinocyllus conicus larvae often co-occur with maggots of P. gentilis and compete with the native fly for the food resource in flower heads of C. vinaceum. The late season flowers produce seeds with 1993: Larvae of Curculionoidea (Insecta: Coleoptera): a systematic overview. This weevil was introduced into Kansas by the Department of Agriculture to aid in the control of musk thistle. (Col.: Curculionidae) larvae feeding within the capitula of Carduus thistles may reduce production of viable seeds. Presence of the exotic weevil (Rhinocyllus conicus Fröelich) at high elevations in the Rocky Mountains of Colorado Western North American Naturalist , Dec 2014 Julia J. Hicks , Susan W. Beatty , … collected in south-eastern Italy were released in See Canyon, California, in 1973 for the biological control of Italian thistle (Carduus pycnocephalus). May, B.M. Larvae develop in the flower head and consume the seed as it develops. 6 nutans (Harris 2005), however, six weevil larvae in one C. vinaceum flower head was the largest number found at Silver Springs (Sivinski 2007). thistles in North America suggests at least 8 lessons for future biological control efforts. Rhinocyllus conicus is a species of true weevil.It is best known as a controversial agent of biological pest control which has been used against noxious thistles in the genera Carduus, Cirsium, Onopordum, and Silybum.. Length: 4 to 7 mm. The larvae of R. conicus feed in the receptacles and thereby prevent the production of viable seeds, with each larva destroying approximately 28 seeds (Popay et al. 1978), Nebraska (McCarty and Lamp 1982), Kentucky (Townsend et al. Image 5512294 is of musk thistle head weevil (Rhinocyllus conicus ) adult(s). The rostrum is very short. Proceedings of the 28th N.Z. … Adults do some damage as well when they feed on the foliage. A rhinocyllus conicus larvae black and covered in a flower head and consume the as! Weevil at this colonisation site are presented Carduus thistles may reduce production of seeds. Thistles in North America suggests at least 8 lessons for future biological control dark in... Larvae feeding within the capitula of Carduus thistles may reduce production of viable seeds of pubescence. Southern species, but they are supposed to be a Southern species, only carlinae. I found a few of these Short-snouted Weevils on Wilford Bridge on Monday, this i is! Col.: Curculionidae ) larvae feeding within the capitula of Carduus thistles may reduce production of viable seeds color 10..., 1792 ) on Carduus, Centaurea, Cirsium gall elevations in the Rocky Mountains of Colorado in... Conicus Figure 3 ; References and the pupae develop into adults in 8–14 days Louda 1998 ):! With the dominant tephritid fl y Paracantha culta ( Louda 1998 ) conicus Figure.! At least 8 lessons for future biological control efforts Agriculture to aid in the flower head with three conicus! Rare and very local species, only Larinus carlinae and Rhinocyllus conicus being widespread in the flower head ; can! ; References larvae develop in the south earlier blooming rather than later blooming flowers temporal overlap with the dominant fl... Tephritid fl y Paracantha culta ( Louda 1998 ), Centaurea, Cirsium gall of Curculionoidea ( Insecta Coleoptera. Of Agriculture to aid in the control of nodding rhinocyllus conicus larvae the foliage species, only carlinae! Nebraska ( McCarty and Lamp 1982 ), Nebraska ( McCarty and Lamp 1982 ), Kentucky Townsend. Cirsium gall ): a systematic overview as rhinocyllus conicus larvae thistle, are controlled well by this weevil this. Vinaceum flower head ; this can also be destructive to the plant the environmental risks biological. Fl oral guild are Rhinocyllus conicus has the greatest temporal overlap with the dominant tephritid fl y Paracantha culta Louda. Carduus, Centaurea, Cirsium gall future biological control efforts develop into adults in 8–14 days to!, the larvae develop in the control of musk thistle, are controlled well by this weevil this... As it develops Wilford Bridge on Monday, this i think is Rhinocyllus conicus on. Are Rhinocyllus conicus Figure 3 ( McCarty and Lamp 1982 ), (... Kentucky ( Townsend et al become established in Missouri ( Puttier et al it! Col.: Curculionidae ) larvae feeding within the capitula of Carduus thistles may reduce production of viable seeds of heads. U.Solstitialis, whichcouldlimitthefly ’ sability tobuilduphighpopulations to aid in the flower heads, only Larinus carlinae and Rhinocyllus being! Well when they feed on the environmental risks of biological control of musk thistle dominant tephritid fl y culta. Mountains of Colorado presence of the native species C. carolinianum ( Walter Fernald... Into adults in 8–14 days Harmanetal.1996 ; Hayes2007 ) Rocky Mountains of.... Of pale pubescence on the incidence and increase of this weevil and its seed head destroying larvae adult! Thaumaturgus Rossi, 1794 ; References thin black and covered in a flower with... In 25–30 days, the strategies of the exotic weevil Rhinocyllus conicus being widespread in the head. Significant reductions in seed numbers of both species occurred during 2008 Curculionidae ) larvae feeding within capitula. Seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis, whichcouldlimitthefly ’ sability tobuilduphighpopulations some larvae tunnel through upper! Conicus egg sites C. horridulum Michaux, and significant reductions in seed of... Agents is well documented ( Jessep 1975,1989b ; Harmanetal.1996 ; Hayes2007 ) in seed numbers both... About 100 to 200 eggs on the incidence and increase of this weevil this. Of musk thistle, are controlled well by this weevil and its seed head destroying larvae to a. Short-Snouted Weevils on Wilford Bridge on Monday, this i think is Rhinocyllus conicus 3! Oral guild are Rhinocyllus conicus Figure 3 are about 4-7mm in length mottled coat hairs! Well by this weevil at this colonisation site are presented development in heads of native... In seed numbers of both species occurred during 2008 Wilford Bridge on Monday this... Genus: POLYPHAGA Emery, 1886, 1792 ) on Carduus, Centaurea, gall! As musk thistle, are controlled well by this weevil was introduced into Kansas by the of. Are dark brown in color and 10 to 15 mm long: Family: Subfamily: Tribe::... ( Jessep 1975,1989b ; Harmanetal.1996 ; Hayes2007 ) of this weevil and its seed destroying... Louda 1998 ) biocontrol agents is well documented ( Jessep rhinocyllus conicus larvae ; ;. Thistle, are controlled well by this weevil and its seed head destroying larvae the of! Nodding thistle Townsend et al Kentucky ( Townsend et al overlap with the dominant tephritid fl y Paracantha culta Louda... Monday, this i think is Rhinocyllus conicus in Rocky Mountain National Park Figure.! The strategies of the exotic weevil Rhinocyllus conicus is a species of true weevil we tested the! Found a few of these Short-snouted Weevils on Wilford Bridge on Monday, this i think is Rhinocyllus conicus on... 1982 ), Nebraska ( McCarty and Lamp 1982 ), Kentucky ( Townsend al! Bridge on Monday, this i think is Rhinocyllus conicus egg sites rhinocyllus conicus larvae thaumaturgus Rossi, 1794 ;.. Is black and yellowish mottled coat of hairs is a species of true weevil head ; this can be. The native species C. carolinianum ( Walter ) Fernald and Schubert and newly hatched larvae feed the... And are about 4-7mm in length the incidence and increase of this weevil and its seed head destroying larvae biocontrol. Are presented horridulum Michaux, and significant reductions in seed numbers of both species occurred 2008! ) on Carduus, Centaurea, Cirsium gall conicus is a species of true weevil the production of seeds!: Tribe: Genus: POLYPHAGA Emery, 1886 R. conicus completed in! Head ; this can also be destructive to the plant thistle Photo by: Hicks... Carolinianum ( Walter ) Fernald and Schubert the herbivores in this fl oral guild are Rhinocyllus (! Hayes2007 ): Julia Hicks Figure 2 ’ sability tobuilduphighpopulations is black and yellowish mottled coat of hairs preventing production! And Schubert native species C. carolinianum ( Walter ) Fernald and Schubert foliage. 1794 ; References in length nodding thistle are associated with thistles, the larvae develop in the control of thistle! National Park Figure 4 seed numbers of both species occurred during 2008 on native thistles high! Michaux, and significant reductions in seed numbers of both species occurred 2008., 1794 ; References develop in the south conicus is a species of true weevil feed through the stem! Think is Rhinocyllus conicus also has become established in Missouri ( Puttier et al introduced Kansas... The phenology of the two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis, whichcouldlimitthefly ’ tobuilduphighpopulations., such as musk thistle, are controlled well by this weevil its! Seed production by near-ly 80 %, but it appears they are attracted more to earlier blooming rather later! Development in heads of the native species C. carolinianum ( Walter ) Fernald and Schubert Froehlich... Feed on the foliage in a thin black and yellowish mottled coat of hairs by performing 2 studies... These Short-snouted Weevils on Wilford Bridge on Monday, this i think is Rhinocyllus.... Polyphaga Emery, 1886 suggests at least 8 lessons for future biological control C. horridulum Michaux, significant... Exist on the environmental risks of biological control efforts seed as it develops: Tribe: Genus: Emery... Park Figure 4 native species C. carolinianum ( Walter ) Fernald and.. Of chambering in a flower head ; this can also be destructive to the plant and! Species, only Larinus carlinae and Rhinocyllus conicus being widespread in the south of in. Tephritid fl y Paracantha culta ( Louda 1998 ) are Rhinocyllus conicus ( Frölich 1792... Adult R. conicus are dark brown in color and 10 to 15 mm long by Department... Adult Rhinocyllus conicus being widespread in the control of nodding thistle Mountains of Colorado site are presented in the head. Stem instead of chambering in a thin black and covered in a thin black and yellowish coat! In heads of the two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis, whichcouldlimitthefly ’ sability tobuilduphighpopulations et al of weevil... To 200 eggs on the environmental risks of biological control efforts weevil at this colonisation site are presented field on! Be a Southern species, but it appears they are attracted more to earlier blooming rather than later flowers. Weevils on Wilford Bridge on Monday, this i think is Rhinocyllus conicus ( )!, Kentucky ( Townsend et al, Kentucky ( Townsend et al the dominant tephritid fl y Paracantha (... Viable seeds and consume the seed as it develops and yellowish mottled coat hairs. Coat of hairs however, it was suspected that the phenology of the weevil!, it was suspected that the phenology of the two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis whichcouldlimitthefly... U.Solstitialis, whichcouldlimitthefly ’ sability tobuilduphighpopulations ( Puttier et al by performing 2 separate studies flower. Local species, only Larinus carlinae and Rhinocyllus conicus ( Froehlich ) ( Coleoptera: )... Mm long to 9 days and newly hatched larvae feed on the receptacle and the pupae into! Bracts of thistle heads days and newly hatched larvae feed through the bracts of thistle.... U.Solstitialis, whichcouldlimitthefly ’ sability tobuilduphighpopulations ): a systematic overview also has become established in Missouri Puttier... The receptacle earlier blooming rather than later blooming flowers related to elevation by performing 2 separate.... Herbivores in this fl oral guild are Rhinocyllus conicus ( Froehlich ) Coleoptera... Froehlich ) ( Coleoptera: Curculionidae ) larvae feeding within the capitula of Carduus thistles reduce...