1 The patterns of abundance of coccinellid species associated to the main agricultural
tree crops of north-eastern Portugal namely olive, chestnut and almond were studied.
2 During three to four crop seasons, eight olive, five chestnut and one almond groves
were sampled. In each grove, five samples were collected from 10 randomly selected
trees using the beating technique and the coccinellids were counted and identified
to species. Principal component analysis was used to establish associations among
crop and coccinellid species.
3 The mean species richness was higher in chestnut, with 15 ± 3.81 species/grove,
followed by olive and almond, with 13 ± 2.76 and 10 ± 2.97 species/grove,
respectively. Scymnus mediterraneus was the most abundant species in olive
and almond, whereas Scymnus interruptus was dominant in chestnut. Brumus
quadripustulatus, Chilocorus bipustulatus, Scymnus subvillosus, S. mediterraneus
and Rhyzobius chrysomeloides were associated with olive, whereas S. interruptus,
Coccinella septempunctata and Adalia decempunctata were associated with chestnut
and Hippodamia variegata, Oenopia conglobata and Adalia bipunctata with almond.
Both Stethorus punctillum and Scymnus apetzi species were similarly associated with
chestnut and almond.
4 The differences in coccinellid communities could have been related to the kind of
prey item present in the different trees. This knowledge can be used to develop
integrated pest management programmes that encourage greater natural enemy
biodiversity in agroecosystems.
This work was funded by INTERREG III-A, project ‘PIREFI:
Est´udios sobre protecci´on integrada y recursos fitogen´eticos
en cultivos tradicionales de las regiones de Tr´as-os-Montes
y Castilla y Le´on’. We thank the owners of the groves who
permitted access for the present study. We would like to thank
the kind comments made by the anonymous peer reviewers that
contributed to improving this paper.
