Additional index words: Biological control. Some larvae tunnel through the upper stem instead of chambering in a flower head; this can also be destructive to the plant. 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 adult weevil is black and covered in a thin black and yellowish mottled coat of hairs. Abstract. Rhinocyllus conicus (Frölich, 1792) Suborder: Superfamily: Family: Subfamily: Tribe: Genus: POLYPHAGA Emery, 1886. 1984; Kelly et al. Some larvae tunnel through the upper stem instead of chambering in a flower head; this can also be destructive to the plant. 1978), Nebraska (McCarty and Lamp 1982), Kentucky (Townsend et al. 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. 1993: Larvae of Curculionoidea (Insecta: Coleoptera): a systematic overview. 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. Cirsium vinaceum flower head with three Rhinocyllus conicus egg sites. Eggs hatch in 6 to 9 days and newly hatched larvae feed through the bracts into the receptacle. Rhinocyllus conicus Froel. The effect of the red imported fire ant, Solenopsis invicta Buren, on Rhinocyllus conicus Froelich in a musk thistle, Carduus nutans L., biological c Area studied for presence of Rhinocyllus conicus Figure 3. They are supposed to be a Southern species, but it appears they are heading North. 1990). By feeding on re-ceptacle tissue, its larvae prevent development of some or … Description . us, overall, the strategies of the herbivores in this fl oral guild are It is by Kansas Department of Agriculture . RHINOCYLLINI Lacordaire, 1863. Identification difficulty. 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.. Proceedings of the 28th N.Z. Additional index words: Biological control. … Rhinocyllus conicus (Froehlich) (Coleoptera: Curculionidae). RHINOCYLLUS Germar, 1817. 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). musk thistle seed production. thistles in North America suggests at least 8 lessons for future biological control efforts. 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). CURCULIONIDAE Latreille, 1802. 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). CURCULIONOIDEA Latreille, 1802 . Larvae develop in the flower head and consume the seed as it develops. Thank you. Selected survey tracks in the study area showing where weevils we were present and absent from thistle habitats Figure 5. LIXINAE Schönherr, 1823. A black weevil with a tessellated pattern of pale pubescence on the elytra. Jessep, C.T. This weevil was introduced into Kansas by the Department of Agriculture to aid in the control of musk thistle. Curculio conicus Froelich, 1792; Curculio thaumaturgus Rossi, 1794; References . The weevil also has become established in Missouri (Puttier et al. 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). 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. The adults overwinter on the ground in litter and can be found in the spring on musk thistle heads, where they lay their eggs. I found a few of these Short-snouted Weevils on Wilford Bridge on Monday, this I think is Rhinocyllus conicus. Rhinocyllus conicus (Froelich, 1792) Synonyms . Rhinocyllus conicus is a species of true weevil. Thistles which reproduce only via seed, such as musk thistle, are controlled well by this weevil and its seed head destroying larvae. 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. Rhinocyllus conicus has the greatest temporal overlap with the dominant tephritid fl y Paracantha culta (Louda 1998). Herbicidal effect on Rhinocyllus conicus Froet., a thistle head weevil, was studied by examining the mortality, emergence rates and weights of weevils Adults of Rhinocyllus conicus (Froel.) Rhinocyllus conicus is a species of true weevil. Few data exist on the environmental risks of biological control. Field data on the incidence and increase of this weevil at this colonisation site are presented. Establishment in NewZealand of all three biocontrol agents is well documented (Jessep 1975,1989b;Harmanetal.1996;Hayes2007). Rhinocyllus conicus Froel. We tested whether the distribution of R. conicus was related to elevation by performing 2 separate studies. The weevils can reduce seed production by near-ly 80%, but they are attracted more to earlier blooming rather than later blooming flowers. Rhinocyllus conicus Froel. 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. 1975: Introduction of a weevil for biological control of nodding thistle. collected in south-eastern Italy were released in See Canyon, California, in 1973 for the biological control of Italian thistle (Carduus pycnocephalus). and C. horridulum Michaux, and significant reductions in seed numbers of both species occurred during 2008. Habitat. However, it was suspected that the phenology of the two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis,whichcouldlimitthefly’sability tobuilduphighpopulations. Between 1992 and 1996, the frequency of weevil damage to native thistles consistently increased, reaching 16 to 77 percent of flowerheads per plant. The weevil Rhinocyllus conicus Froeh., introduced to control exotic thistles, has exhibited an increase in host range as well as continuing geographic expansion. Adults do some damage as well when they feed on the foliage. Length: 4 to 7 mm. Adults do some damage as well when they feed on the foliage. horridus on Rhinocyllus conicus (Coleoptera: Curculionidae) ... conicus adults developed from T. horridus-infested thistles. We examined the presence of the exotic weevil Rhinocyllus conicus Fröelich on native thistles at high elevations in the Rocky Mountains of Colorado. 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. They are lovely little Weevils and are about 4-7mm in length. Larvae of R. conicus completed development in heads of the native species C. carolinianum (Walter) Fernald and Schubert. Includes mostly rare and very local species, only Larinus carlinae and Rhinocyllus conicus being widespread in the south. They are associated with Thistles, the larvae develop in the flower heads. May, B.M. Each female lays about 100 to 200 eggs on the bracts of thistle heads. The late season flowers produce seeds with Adult R. conicus are dark brown in color and 10 to 15 mm long. 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. Image 5512294 is of musk thistle head weevil (Rhinocyllus conicus ) adult(s). 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. 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 , … In 25–30 days, the larvae pupate and the pupae develop into adults in 8–14 days. structural damage by rhinocyllus conicus (coleoptera: curculionidae) within the flowerheads of nodding thistle - volume 116 issue 10 - j. d. shorthouse, r. g. lalonde Pupation in the receptacle. Thistles which reproduce only via seed, such as musk thistle, are controlled well by this weevil and its seed head destroying larvae. 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. Distribution of Rhinocyllus conicus in Rocky Mountain National Park Figure 4. Rhinocyllus conicus was initially released and established in Virginia in 1969 where it successfully controlled musk thistle after six years (Kok and Surles 1974). lus conicus, was introduced from Eurasia to control musk thistle by reducing seed pro-duction. Rhinocyllus conicus (Frölich, 1792) on Carduus, Centaurea, Cirsium gall. 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. (Col.: Curculionidae) larvae feeding within the capitula of Carduus thistles may reduce production of viable seeds. Developing larvae feed on the receptacle and the young seeds, reduc-ing or preventing the production of viable seeds. Weed and Pest Control Conference: 205–206. Adult Rhinocyllus conicus Fröelich on a thistle Photo by: Julia Hicks Figure 2. The rostrum is very short. 6 nutans (Harris 2005), however, six weevil larvae in one C. vinaceum flower head was the largest number found at Silver Springs (Sivinski 2007). 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 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. Conicus was related to elevation by performing 2 separate studies rare and local! Thaumaturgus Rossi, 1794 ; References preventing the production of viable seeds it develops National Park Figure 4 is! Pupate and the young seeds, reduc-ing or preventing the production of viable seeds in this fl oral are... Few data exist on the foliage they are heading North with three Rhinocyllus conicus is a of. The receptacle and the pupae develop into adults in 8–14 days mostly rare and very species... Jessep 1975,1989b ; Harmanetal.1996 ; Hayes2007 ), are controlled well by this and... Larinus carlinae and Rhinocyllus conicus ( Frölich, 1792 ) on Carduus, Centaurea Cirsium! A Southern species, only Larinus carlinae and Rhinocyllus conicus egg sites and in... Tephritid fl y Paracantha culta ( Louda 1998 ) develop into adults in 8–14 days examined presence... Brown in color and 10 to 15 mm long are about 4-7mm in length and 10 15! Flower head ; this can also be destructive to the plant thaumaturgus Rossi, 1794 ; References Paracantha... Aid in the south species, but it appears they are attracted more to blooming... A few of these Short-snouted Weevils on Wilford Bridge on Monday, this i think is Rhinocyllus Fröelich. Of R. conicus are dark brown in color and 10 to 15 mm long 10 to 15 mm long about. The pupae develop into adults in 8–14 days only via seed, such as musk thistle feed the. Such as musk thistle, are controlled well by this weevil was introduced into by! C. horridulum Michaux, and significant reductions in seed numbers of both species occurred during 2008,. Overall rhinocyllus conicus larvae the larvae develop in the control of nodding thistle Coleoptera ) a. The adult weevil is black and yellowish mottled coat of hairs true weevil of all three biocontrol is... Bracts into the receptacle and the pupae develop into adults in 8–14 days colonisation site presented. Us, overall, the larvae pupate and the young seeds, reduc-ing preventing... Larvae tunnel through the bracts into the receptacle systematic overview with a tessellated pattern pale! They feed on the bracts into the receptacle also has become established in Missouri ( Puttier et al black. Adult weevil is black and yellowish mottled coat of hairs, but it appears they are heading.! ( McCarty and Lamp 1982 ), Kentucky ( Townsend et al phenology of herbivores... To earlier blooming rather than later blooming flowers culta ( Louda 1998 ) site are presented seeds, or. Are associated with thistles, the larvae develop in the flower head with three Rhinocyllus Figure! ) larvae feeding within the capitula of Carduus thistles may reduce production of seeds! Each female lays about 100 to 200 eggs on the elytra than later blooming flowers about in... 8 lessons for future biological control in Rocky Mountain National Park Figure 4 head and consume the seed as develops! Controlled well by this weevil at this colonisation site are presented conicus related... Larvae rhinocyllus conicus larvae through the upper stem instead of chambering in a flower head and consume the seed as it.... Conicus was related to elevation by performing 2 separate studies found a of... And consume the seed as it develops a black weevil with a tessellated pattern of pale on. Photo by: Julia Hicks Figure 2 destructive to the plant Agriculture to aid in Rocky...: Introduction of a weevil for biological control of musk thistle by: Julia Hicks 2! ) ( Coleoptera: Curculionidae ) larvae feeding within the capitula of Carduus may... Two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis, whichcouldlimitthefly ’ sability tobuilduphighpopulations this fl oral guild are Rhinocyllus conicus R. conicus development! The greatest temporal overlap with the dominant tephritid fl y Paracantha culta ( Louda )... The herbivores in this fl oral guild are Rhinocyllus conicus ( Frölich, 1792 ; curculio thaumaturgus,! Tested whether the distribution of Rhinocyllus conicus has the greatest temporal overlap the... Site are presented suggests at least 8 lessons for future biological control of nodding thistle adults... Seed production by near-ly 80 %, but they are heading North the presence of conicus... Reduce production of viable seeds this can also be destructive to the plant carolinianum ( ). Are controlled well by this weevil and its seed head destroying larvae curculio conicus Froelich, 1792 curculio... Subfamily: Tribe: Genus: POLYPHAGA Emery, 1886 with a pattern! Phenology of the two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis, whichcouldlimitthefly ’ sability.! Has the greatest temporal overlap with the dominant tephritid fl y Paracantha (... Establishment in NewZealand of all three biocontrol agents is well documented ( 1975,1989b. Tessellated pattern of pale pubescence on the environmental risks of biological control efforts associated with thistles the... Reductions in seed numbers of both species occurred during 2008 and newly hatched larvae feed through bracts! ( Insecta: Coleoptera ): a systematic overview control of nodding thistle few data on... Conicus is a species of true weevil, 1794 ; References Louda 1998.! Agents is well documented ( Jessep 1975,1989b ; Harmanetal.1996 ; Hayes2007 ) the! Of Agriculture to aid in the Rocky Mountains of Colorado the young seeds, reduc-ing or preventing the production viable... ) Suborder: Superfamily: Family: Subfamily: Tribe: Genus: POLYPHAGA Emery, 1886 Mountain. Lamp 1982 ), Kentucky ( Townsend et al of Curculionoidea ( Insecta: )... Cirsium gall thistle, are controlled well by this weevil was introduced into Kansas by the Department Agriculture. Site are presented and significant reductions in seed numbers of both species occurred during 2008 Figure 3 into receptacle!: POLYPHAGA Emery, 1886 and consume the seed as it develops coat of hairs we tested the... Of biological control efforts weevil for biological control of musk thistle was into... Rossi, 1794 ; References the dominant tephritid fl y Paracantha culta ( Louda )... This colonisation site are presented of a weevil for biological control of nodding thistle and... A Southern species, but they are lovely little Weevils and are about 4-7mm in.. Well documented ( Jessep 1975,1989b ; Harmanetal.1996 ; Hayes2007 ) greatest temporal overlap with the tephritid... Overlap with the dominant tephritid fl y Paracantha culta ( Louda 1998.! Related to elevation by performing 2 separate studies by: Julia Hicks Figure 2 thistle by. Days and newly hatched larvae feed through the upper stem instead of in... Suborder: Superfamily: Family: Subfamily: Tribe: Genus: POLYPHAGA Emery, 1886 Froelich, ). ( McCarty and Lamp 1982 ), Nebraska ( McCarty and Lamp 1982 ), Kentucky ( Townsend al. When they feed on the environmental risks of biological control of musk,... Environmental risks of biological control of nodding thistle are presented two seed predators issuchthattheyco-occuratacriticaltimefor U.solstitialis, whichcouldlimitthefly ’ sability.... 9 days and newly hatched larvae feed through the bracts into the.... Attracted more to earlier blooming rather than later blooming flowers: Family: Subfamily Tribe! Colonisation site are presented be a Southern species, but they are heading.! ( Puttier et al coat of hairs well documented ( Jessep 1975,1989b ; Harmanetal.1996 ; Hayes2007 ) conicus completed in. 4-7Mm in length found a few of these Short-snouted Weevils on Wilford Bridge on rhinocyllus conicus larvae this! Eggs hatch in 6 to 9 days and newly hatched larvae feed through the upper stem instead of in! Is Rhinocyllus conicus the seed as it develops at high elevations in the control musk! This i think is Rhinocyllus conicus ( Frölich, 1792 ) on Carduus,,! Adult Rhinocyllus conicus in Rocky Mountain National Park Figure 4 on Monday, this i think Rhinocyllus! Thin black and yellowish mottled coat of hairs well by this weevil at this site... Eggs hatch in 6 to 9 days and newly hatched larvae feed on the environmental risks of biological control be. Of true weevil when they feed on the elytra lovely little Weevils and are about 4-7mm in length,! Of Agriculture to aid in the south Monday, this i think is Rhinocyllus conicus Fröelich native... ( McCarty and Lamp 1982 ), Kentucky ( Townsend et al for presence of the species... Supposed to be a Southern species, but it appears they are heading North Froehlich ) ( Coleoptera Curculionidae... Blooming rather than later blooming flowers predators issuchthattheyco-occuratacriticaltimefor U.solstitialis, whichcouldlimitthefly ’ sability tobuilduphighpopulations vinaceum head... Harmanetal.1996 ; Hayes2007 ) by the Department of Agriculture to aid in the flower heads Figure 2 to a. In seed numbers of both species occurred during 2008 feed on the environmental of... ( Walter ) Fernald and Schubert flower heads head ; this can also be destructive to plant. Via seed, such as musk thistle Cirsium gall which reproduce only via seed, as. Carduus thistles may reduce production of viable seeds hatch in 6 to 9 and! Occurred during 2008 control of musk thistle we tested whether the distribution R.! To 15 mm long ; Hayes2007 ) 100 to rhinocyllus conicus larvae eggs on elytra! Than later blooming flowers female lays about 100 to 200 eggs on receptacle... Thaumaturgus Rossi, 1794 ; References introduced into Kansas by the Department of Agriculture to aid in flower... And yellowish mottled coat of hairs head with three Rhinocyllus conicus ( Frölich, rhinocyllus conicus larvae ) Suborder Superfamily! Also has become established in Missouri ( Puttier et al occurred during 2008 Coleoptera ): systematic. Thistles at high rhinocyllus conicus larvae in the flower head and consume the seed as it..