Autor(es):
Pinheiro, Lara A.
; Torres, L.
; Gomes, Alexandre
; Santos, Sónia A.P.
Data: 2012
Identificador Persistente: http://hdl.handle.net/10198/8963
Origem: Biblioteca Digital do IPB
Descrição
Syrphids are known as biological control agents of hemipteran pests and, in the olive grove,
several species have been identified as predators of Euphyllura olivina (Costa). The objectives of this
work were: (1) to study the syrphid community in organic olive groves and (2) to test the potential for
the use of syrphid morphospecies as a surrogate for species. The field work was conducted in two
organic olive groves located near Mirandela (Northeast of Portugal). The sampling period occurred in
two seasons, from the middle of August to the end of October 2009 and from the beginning of April to
the end of July 2010. Syrphids adults were separated in morphospecies by a parataxonomist in
accordance with their morphological differences. Then, the species were identified by a taxonomist.
The number of individuals collected was 64 in 2009 and 27 in 2010, for a total of 91. The
morphological identification showed the presence of 12 morphospecies that corresponded to six
species: Episyrphus balteatus (De Geer) the most abundant with 51.7% of relative abundance,
followed by Sphaerophoria scripta (L.) with 23.1% and Eupeodes corolla (Fabricius) with 18.6%.
The proportion of correctly assigned morphospecies to taxonomic species was 3.3%. However, during
the identification, a 93.4% splitting and a 3.3% lumping error occurred. This study showed that
species identification was relatively difficult when based only on parataxonomic traits, requiring a
careful examination of characteristics such as the size of the eyes and their hair, the form of the
antennae, the humeral plate and the squama, as well as the femur color and the size of the bands on the
abdomen.