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TERRESTRIAL SNAILS Helix aspersa, Helix spp. & Predatory Rumina decollata (Contacts) ----- CLICK on Photo to enlarge & search for Subject Matter with Ctrl/F. GO TO ALL: Bio-Control Cases The European brown garden snail, Helix
aspersa, and other species of Helix have invaded agricultural and
residential areas around the world. In
California Helix spp. have long been considered economic pests in
gardens, nurseries and orchards. They
are omnivorous, eating living and decaying vegetation, flowers, ground
covers, citrus leaves and fruit. They
are also cannibalistic on cadavers of their own species. Various
attempts at biological control have been made, such as the introduction of
the decollate snail, Rumina decollata (L.), which is predatory on Helix
immatures and adults. Prior to the
introduction of Rumina decollata, the predatory staphylinid beetle Ocypus
alens adapted to these snails in California and flies in the genus
Sciomyzidae were also active. As of
2014 a ninety-eight percent decline of both Helix and the decollate
snail has been observed in many areas of southern California. Because the decline occurred only after
the introduction of R. decollata, this species interacting with the
other natural enemies is probably primarily responsible for the dramatic
decline of Helix spp. [For aquatic snails Please See <bc-37>]. Please CLICK on blue highlighted references for further details: PERTINENT REFERENCES: [Additional references may be found at: MELVYL
Library ] Basinger, A. J.
1931. The European brown snail
in California. Bull. Univ. Calif.,
College Agric. Exp. Stn., No. 515.
Berkeley, Calif. 22 pp., 16
figs. Binney, W. G. 1878. The terrestrial air-breathing molluscs of
the United States and the adjacent territories of North America. Bull. Mus. comp. Zool. IV. 439 pp., illus. Fisher, T. W. & R. E. Orth.
1983. The marsh flies of
California (Diptera: Sciomyzidae).
Bull. Calif. Insect Surv. 24:
7, 1-117. Univ. of Calif.
Press. Fisher, T. W. & R. E.
Orth. 1985. Biological control of snails.
Occas. Papers. No. 1, Dept. of Entomology, Univ. of Calif. Riverside
111: pp. 1-8. 154. Fisher, T. W., I. Moore, E. F. Legner & R. E. Orth. 1976.
Ocypus olens, a predator of brown garden snail. Calif. Agric. 30(3): 20-21, 3 figs. Fisher, T. W., R. E. Orth & S.
C. Swanson. 1980. Snail against snail. Calif. Agric. 34(11-12) 18-20. Gordh, G. & R. E. Orth.
1987. Book Review. Insects and Mites: Techniques for collection and
preservation. G. C. Steyskal, W. L.
Murphy & E. Hoover. eds. Proc.
Entomol. Soc. Wash. 89(4): 842-847. Hanna, G. D. 1966.
Introduced mollusks of western North America. Occ. Pap. Calif. Acad. Sci., No. 48.
108 pp., 85 figs., 4 pl. Knutson, K. & R. E. Orth. 1984.
The Sepedon sphegea complex in the Palearctic and Oriental
regions: identity, variation and
distribution (Diptera: Sciomyzidae).
Ann. Entomol. Soc. Amer. 77:
687-701. Knutson, L., R. E. Orth, T. W.
Fisher & W. L. Murphy. 1986. Catalog of Sciomyzidae of America north of
Mexico. Entomography 4: 1-53. Knutson, L., R. E. Orth & R.
Rozkosny. 1990a. New North American Colobaea, with a
preliminary analysis of related genera (Diptera: Sciomyzidae). Proc. Entomol. Soc. Wash. 92(3): 483-492. Knutson, L., S. Manguin & R. E.
Orth. 1990. A second Australian species of Pherbellia
Robineau-Desvoidy (Diptera:
Sciomyzidae). J. Aust. Ent.
Soc. 29: 281-286. Orth, R. E. 1982.
Five new species of Pherbellia Robineau-Desvoidy, subgenus Oxytaenia
Sack, from North America (Diptera: Sciomyzidae). Proc. Entomol. Soc. Wash. 84(1): 23-37. Orth, R. E. 1983.
Two new species of Pherbellia from North America (Diptera:
Sciomyzidae). proc. Entomol. Soc.
Wash. 85(3): 537-542. Orth, R. E. 1984a.
A new species of Pherbellia from Montana (Diptera:
Sciomyzidae). Proc. Entomol. Soc.
Wash. 86(3): 599-601. Orth, R. E. 1984b.
A new species of Dicta from Mexico (Diptera: Sciomyzidae). Proc. Entomol. Soc. Wash. 86(4): 893-897. Orth, R. E. 1986.
Taxonomy of the Sepedon fuscipennis group (Diptera:
Sciomyzidae). Proc. Entomol. Soc.
Wash. 88(1): 63-76. Orth, R. E. 1987.
A new species of Pherbellia from North America with range extensions
for P. hackmani and P. griseicollis (Diptera:
Sciomyzidae). Proc. Entomol. Soc.
Wash. 89(2): 260-271. Orth, R. E. 1991.
A synopsis of the genus Dictya Meigen with ten new species
(Diptera: Sciomyzidae). Proc.
Entomol. Soc. Wash. 93(3): 660-689. Orth, R. E. & T. W.
Fisher. 1982. A new species of Tetanocera Dumeril
from Colorado (Diptera: Sciomyzidae).
Proc. Entomol. Soc. Wash. 84(4):
685-689. Orth, R. E. & T. W.
Fisher. 1983. A new species of Dictya from idaho
(Diptera: Sciomyzidae). Proc.
Entomol. Soc. Wash. 85(2): 217-221. Orth, R. E. & L. Knutson. 1987.
Systematics of snail killing flies of the genus Elgiva in North
America and biology of E. divisa (Diptera: Sciomyzidae). Ann. Entomol. Soc. Amer. 80(6): 829-840. Orth, R. E. & Ian Moore. 1980.
A revision of the species of Cafius Curtis from the west coast
of North America with notes on east coast species (Coleoptera:
Staphylinidae). Trans. San Diego Soc.
of Natural History 19(13: 181-211. Orth, R. E. & G. C.
Steyskal. 1981. A new species of Pherbellia
Robineau-Desvoidy separated from a previously described North American
species (Diptera: Sciomyzidae). Proc.
Entomol. Soc. Wash. 83(1): 99-104. 138. Orth, R. E., I. Moore, T. W. Fisher & E. F. Legner. 1975.
A rove beetle Ocypus olens, with potential for biological
control of the brown garden snail, Helix
aspersa, in California, including a
key to the Nearctic species of Ocypus. Canad. Entomol. 107(10): 1111-1116. 156. Orth, R. S., I. Moore, T. W. Fisher & E. F. Legner. 1975.
Biological notes on Ocypus olens, a predator of brown garden
snail, with descriptions of the larva and pupa (Coleoptera:
Staphylinidae). Psyche 82(3-4): 292-298. Orth, R. E., G. C. Steyskal &
T. W. Fisher. 1980. A new species of Pherbellia
Robineau-Desvoidy with notes on the P. ventralis group (Diptera:
Sciomyzidae). Proc. Entomol. Soc.
Wash. 82(2): 284-292. Stearns, R. 1881.
On Helix aspersa in California, and the geographical distribution of
certain west American land-snails, and previous errors relating thereto,
etc. Ann. N. Y. Acad. Sci. 2: 129-139. Tryon, G. H. 1888.
Manual of oncology: structure
and systematics. Pulmonata (Ser. 2)
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