Libro 1.indb

GALL MIDGES (DIPTERA: CECIDOMYIIDAE) OF THE IBERIAN PENINSULA 131
territory into six frequency groups, viz. the species occurring very scarcely,
scarcely, medium frequently, frequently, very frequently and most frequently.
These terms expressing the frequency are used also in paragraphs of each
species in the Annotated list. These frequency data has been referred to
the actual knowledge. Nevertheless, future studies could change this actual
frequency but the present knowledge is presented here. Mayetiola destructor,
a widely distributed pest of cereals, is not included in the following
evaluation.
In the Iberian Peninsula 115 species (44%) occur very scarcely. Each
of them was recorded in the Iberian Peninsula at only one locality. Some
of these species were described by Tavares and other researchers and subsequently
they have not been found anywhere, as for example, Blastodiplosis
thalictricina, Contarinia camphorosmae, Dasineura bragancae and some
of other species described by Tavares; Baldratia suaedae, Stefaniola gloma
and S. vastita by Möhn; Dasineura erodiicola and Dasineura mariae by
Sylvén; Etsuhoa thuriferae by Skuhravá; Aprionus wildeni and Peromyia
suberis described by Jaschhof. Many species that occur abundantly in
Central Europe reach in Iberian Peninsula the southern boundary of their
distribution, as for example Putoniella pruni causing galls on leaves of
Prunus spinosa (Fig. 104). Dasineura oleae causing galls on leaves of Olea
europaea, which is very abundant and is considered to be a pest in central
and eastern Mediterranean, was found at only one locality in the Iberian
Peninsula (Fig. 48).
Eighty seven species (33%) occur scarcely. Each of them has been found
at 2, 3 or 4 localities. Mikiola fagi causing galls on leaves of Fagus sylvatica
was recorded at four localities in north-eastern part of Spain (Fig. 94). It
is the representative of European fauna. It occurs abundantly in Central
Europe and reaches in north-eastern Spain the most southern limits of its
distribution area. Nevertheless, we have to mention that this species attacks
leaves of Fagus sylvatica and, although this host tree is only restricted in
some areas of north and the northest parts of the Iberian Peninsula, M. fagi
is very abundant in these areas. On the other side, Baldratia salicorniae
causing galls on Arthrocnemum fruticosum is a Mediterranean species which
was found at four localities situated along the seaside of the Mediterranean
Sea and of Atlantic Ocean (Fig. 16).
Thirty four species (13%) occur medium frequently. Each of them has
been found at 5, 6, 7 or 8 localities. Of these species, the most interesting
is Stefaniola salsolae causing rosette-like galls on buds of Salsola vermiculata
was found at 5 localities (Fig. 122); Dasineura asparagi causing galls
at tips of young shoots of Asparagus aphyllus was found at 5 localities
(Fig. 34) and D. broteri causing cone-shaped galls on buds of Erica ciliaris
Boln. Asoc. esp. Ent., 30 (1-2): 93-159, 2006