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Musk Thistle Flower Fly - Cheilosia corydon
State Rank Reason (see State Rank above)
Cheilosia corydon was introduced from Italy into the United State of America (USA; Maryland) in 1990 to control non-native thistles and create the balance of a plant species with its natural predator (Winston et al. 2012). Cheilosia corydon has been released in Montana, but there is no reported establishment, and in the USA is not widespread (Winston et al. 2012). Populations are established in Oregon (Winston et al. 2012). A conservation status rank is not applicable (SNA) because Cheilosia corydon is a non-native insect in Montana that is not a suitable target for conservation activities.
General Description
Musk Thistle Flower Fly (Cheilosia corydon) is an insect, specifically a type of hover fly in the Family Syrphildae.
ADULTS: Fuzzy with orange-tan hairs and large black eyes. They grow to 15 mm in length (including the wings). Source: Winston et al. 2012
LARVAE: Grub-like and tan-colored. They grow to 19 mm long. Source: Winston et al. 2012
Diagnostic Characteristics
Musk Thistle Flower Fly can resemble bees (Winston et al. 2012).
Range Comments
Musk Thistle Flower Fly is native to Europe (Winston et al. 2012).
Habitat
Populations of Musk Thistle Flower Fly can tolerate a wide array of climatic conditions throughout the range of their host thistle species (Winston et al. 2012). the insect does better in places where thistles flower early in the growing season (Winston et al. 2012).
HOST PLANTSMusk Thistle Flower Fly feeds on Bull (
Cirsium vulgare), Italian (
Carduus pycnocephalus), Marsh (
Cirsium palustre), Musk (
Carduus nutans), Spiny Plumeless (
Carduus acanthoides), and Slenderflower (
Carduus tenuiflorus) Thistles (Winston et al. 2012). It is unknown if other members in the tribe Cardueae might be marginal host plants.
Food Habits
Adult flies feed on nectar from thistle flowers.
Larvae feed on tissues in the shoots, stems, and roots of thistle plants.
Ecology
DAMAGE TO PLANTS [Adapted from Winston et al. 2012]
Musk Thistle Flower Fly predates on Bull, Italian, Marsh, Musk, Spiny Plumeless, and Slenderflower Thistles.
Larvae mine through plant tissues which interferes with physiological functions, ultimately reducing seed production and sometimes causing death.
Reproductive Characteristics
LIFE CYCLE [Adapted from Winston et al. 2012]
Musk Thistle Flower Fly has one generation per year. Adults overwinter and emerge in very early spring (mid-March to mid-May). Adults deposit eggs on young leaves when the stem of the host plant bolts (late March to mid-May). Larvae hatch and tunnel into shoots and stems; As the season progresses, larvae tunnel into roots. Larve develop (mid-April to mid-October) through three larval stages (instars). Pupation occurs from late June to early November. Pupae overwinter in roots or in soil litter (November to late March). Larvae burrow into the flower head to feed on the receptacle tissue and developing seeds. Pupation occurs in the flower head during late summer as the seeds mature. Adults emerge for a short time before overwintering in protected places.
Management
Stewardship Responsibility
Threats or Limiting Factors
Musk Thistle Flower Fly is an introduced biocontrol insect. It is unknown if Musk Thistle Flower Fly negatively impacts native thistle host plant species in the tribe Cardueae (Winston et al. 2012).
References
- Literature Cited AboveLegend:
View Online Publication- Winston, Rachel, Rich Hansen, mark Schwarzlander, Eric Coombs, Carol Bell Randall, and Rodney Lym. 2012. Third Edition, April. FHTET-2007-05. Forest health Technology Enterprise Team, US Department of Agriculture.
- Web Search Engines for Articles on "Musk Thistle Flower Fly"
- Additional Sources of Information Related to "Insects"
