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Diversity and phenology of hoverflies (Diptera: Syrphidae) in pine forests (Pinus
halepensis Miller) of Algeria
Abstract
Hoverflies are good indicators of ecosystem integrity, especially in drylands. However, no study
investigated the key factors explaining hoverfly diversity in forested areas of northern Africa. The
current study provides data on the diversity, structure and functional trophic groups (FTG) of the
hoverfly community, as well as their responses to climatic variations in Aleppo pine forests under
a semiarid climate in northeastern Algeria. Using an entomological net, hoverflies were weekly
sampled during 2008–2009. Alpha and beta-diversity of hoverflies and FTG were analyzed using
several parameters and indices (e.g. species composition, richness, occurrence, diversity,
estimations, similarity, etc.). In total, 602 individuals classified into 21 species were collected
with a constant species (Eupeodes corolla) and three common species (Episyrphus balteatus,
Chrysotoxum intermedium, Eristalis arbustorum and Eristalix tenax). Most species (17/21)
occurred accidentally or very accidentally in samples. The highest diversity was recorded during
spring, corresponding to the flowering season of most understory plant species. Seasonal
rarefaction and extrapolation curves indicated that the expected species richness would be higher
in autumn and spring compared to summer and winter. The spectrum of FTG ranked predators
first with 52.4% of species, followed by saprophages (42.8%) and then phytophages (4.8%).
Generalized linear models revealed that diversity parameters responded differently to
meteorological factors. Species and functional diversity of hoverfly assemblages subservient to
North African semiarid forests are influenced by local climatic factors.
Keywords: Syrphidae; insect diversity; North African forests; functional groups; climate
effects;