Fróðskaparrit - 01.01.2009, Side 124

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PLANT GALLS AND GALL MIDGES OF THE FAROE ISLANDS IN THE ATLANTIC OCEAN
acarisuga from Dijon (France). It is one of the most
effective and widespread natural enemies of spider
mites and is used in biological control.
Mycodiplosis melampsorae (Rubsaamen, 1889)
Larvae feed on uredospores of Meiampsora caprearum
on the leaves of Salixphylicifolia L. (Salicaceae). Larvae
were found in samples of leaves of this willow brought
forexamination.
Locality: Streymoy, Tórshavn, town park, 7.8.2005.
Distribution. It is a Euro-Siberian species (Skuhravá,
1997). Rubsaamen (1889) described this species from
Germany under the name Diplosis melampsorae. He
found mycophagous larvae feeding on Melampsora
salicina on leaves of Salix sp.
Eriophyoid mites (Acarina: Eriophyoidea)
Aceria pseudoplatani (Corti, 1905)
Small eriophyid mites cause galls in the form of
erineum (a patch of small hairs) on the lower side of
the leaves of Acer pseudoplatanus L. (Aceraceae). The
host plant is not native to Faroe Islands.
Locality: Streymoy, Tórshavn, town park, 6.8.2005.
Distribution. A. pseudoplatani is a European species. It
was originally described based on material found in
Italy by Corti (1905). In central Europe this species
occurs abundantly (Vanecková-Skuhravá, 1996a,
1996b).
Aculus anthobius (Nalepa, 1892)
Small eriophyid mites cause galls on stems of Calium
anisophyllum Vill. (Rubiaceae). The terminal part of the
stem is deformed, shortened and compact, flowers are
green and dwarfed. This host plant is not native to
Faroe Islands.
Locality: Streymoy, Tórshavn, near the hotel, 6.8.2005.
Distribution. A. anthobius is a European species. This
species was originally described by Nalepa (1892)
based on material collected in Lorraine (France). It may
attack various host plant species of the genus Calium.
Fungi (Uredinales)
Cronartium ribicola J.C. Fisher
This fungus of the family Cronartiaceae induces galls
on the leaves of Ribes rubrum L. (Grossulariaceae).
Leaves bear yellow raised areas with orange aecia. This
host plant is not native to Faroe Islands.
Locality: Streymoy, Tórshavn, private garden, 8.8.2005.
Melampsora caprearum Thuem.
This fungus of the family Melampsoraceae induces
galls in the form of irregular thickened spots, bearing
orange-yellow uredinia, on leaves and leaf petioles of
Salix phylicifolia L. (Salicaceae). Salix phylicifolia is a
native tree to Faroe Islands.
Locality: Streymoy, Tórshavn, city park, 6.8.2005.
Puccinia violae DC
This fungus of the family Pucciniaceae induces galls in
the form of swollen areas on the leaves and leaf
petioles of Viola riviniana (Violaceae). In the swollen
areas dark sporangia occur. The host plant is native to
Faroe islands.
Locality: Streymoy, Tórshavn, near the hotel, 6.8.2005.
Results of catch of insects in three small
dishes filled with water were very poor. Dur-
ing one week we caught only 35 insect spec-
imens. Of them 26 specimens belong to
Diptera (3 Cecidomyiidae, 3 Sciaridae, 3 Psy-
chodidae, 5 Tipulidae and 12 specimens of
other groups) and 9 specimens of Hymeno-
ptera. On average, only four insect speci-
mens were caught in three dishes during one
day. We have not met with such low num-
bers of specimens caught per day in any
country of Europe where we used this
method. In some countries it is possible to
catch hundreds of various insects in such
dishes during one day. However, it may be
concluded from this method, that the
species richness not only of gall-causing or-
ganisms, but also of flying insects in the
Faroe Islands is much poorer than in conti'
nental Europe.