Life Cycle, Feeding and Production of Isoptena serricornis(Pictet, 1841) (Plecoptera, Chloroperlidae)

Abstract

Some aspects of the biology and ecology (life cycle, feeding and production) of a population of Isoptena serricornis in the Rudava River (Slovakia) are studied, reported and discussed. The life cycle is annual, with slow growth in autumn-winter and fast growth in late summer and spring. The growth decreased two weeks before the Fall Equinox and increased two weeks after the Spring Equinox. The flight period spans from the end of May to the beginning of July. The presence of large sand particles in the gut of all studied nymphs is of note, and indicates that I. serricornis acts as a depositcollector species. Nymphal food is principally composed of detritus, unicellular organisms and, in nymphs of intermediate or large size, Chironomidae larvae. Adult food is composed fundamentally of different types of pollen grains. Males usually have lower food content than females. Annual production of this species (~694 -750 mg · m -2 ) is very high in relation to other previously studied Chloroperlidae. This is probably largely responsible for I. serricornis being one of the most abundant components of the macroinvertebrate community in its habitat in the Rudava River. A negative correlation between production and temperature was observed.

The adult diet of Xanthoperla apicalis and Siphonoperla torrentium (Plecoptera, Chloroperlidae) in the Danube basin (Slovakia)

“…Our results (particularly the high percentage of pollen grains in the diet) agree with the general pattern shown for other Chloroperlidae adults (Zwick 1990;Tierno de Figueroa & Sánchez-Ortega 1999;Derka et al 2004), but the presence of animal suggests an interesting and new finding. Up to now, data about animal feeding in adult stoneflies were limited to scarce observations and almost every time in Nemouroidea (Frison 1929;Salveit 1977;Rotheray & Liston 1985;.…”

“…1 (2001) and Derka et al (2004), i.e., we introduced every individual in a vial with Hertwig's liquid (a variation of Hoyer's liquid) for 20-24 hours and put them into an oven at 65 • C. Afterwards we put the specimens already transparent on a slide glass with a cover glass on, and we estimated the absolute content percentage (measured as percentage of occupied area) at 40× and the relative percentage of each component present in the gut at 400× in an Olympus microscope.…”

“…Tierno de Figueroa & Sánchez-Ortega (1999) showed that Chloroperla nevada Zwick, 1967 adults change the proportion of dietary components over the flight period in relation to their availability. Finally, Derka et al (2004) studied the Isoptena serricornis (Pictet, 1842) adult diet and found that pollen grains are the main component.…”

A new model estimating stonefly species production in the West Carpathian torrents

“…Food consumption, respiration, and assimilation efficiency increased with increasing water temperature. On the contrary, for Chloroperlidae and Perlidae the original Morin-Dumont's method is more suitable (Derka et al 2004), because our modified version significantly overestimates the annual P/B ratio.…”

“…The sampling sites for the population production were situated in different streams, in the West Carpathian mountain ranges (Krno 1982(Krno , 1996(Krno , 1997(Krno , 1998(Krno , 2000 and to the adjacent Pannonian lowland (Derka et al 2004). These streams were characterized by different temperature and hydrological regime.…”