Seasonal and diel flight activity patterns of aquatic Coleoptera and Heteroptera

摘要

It is a well known fact that most aquatic insects can fly. Data collected by light trapping (BENEDEK & JAszAI 1972, NOVINSZKY 2003) and field observations are not suitable to analyze daily flight activity patterns of aquatic insects because the attraction of light traps is considerably reduced by day due to the higher ambient light intensity. At the same time, the seasonal and diurnal flight patterns have been inves-tigated effectively only several times (FERNANDO 1958, POPHAM 1964, PAJUNEN & JANSSON 1969, FERNANDO & GALBRAITH 1973, LANDIN 1980, BEHR 1990, 1993, BODA et al. 2003, CSABAI et al. 2003, 2004,). Aquatic insects recognize aquatic habitats by means of the horizontal linear polarization of light reflected from the water surface (SCHWIND 1991). Numerous earlier field experi- ments (SCHWIND & HORVATH 1993, HORVATH 1995, HOR-VATH & VARJU 1997) have shown that the horizontal polari-zation of reflected light is the major optical cue that attracts water insects to shiny surfaces; therefore, using horizontal shiny black plastic sheets is a suitable method throughout the day because it always polarizes the reflected light strongly and horizontally (HORVATH & VARJU 2003). Utilizing this phenomenon of aquatic insects landing on the shiny black plastic foils while foraging for water surfaces, we collected samples over one entire day per week for 2 years. In this paper, only the dispersal activities of the most abundant spe-cies are discussed in detail.