Emergence, maturation and upstream oviposition flights of Plecoptera from the Breitenbach, with notes on the adult phase as a possible control of stream insect populations

Abstract

Upstream oviposition flights of several Plecoptera species of the genera Leuctra, Nemoura, Isoperla and Siphonoperla along the Breitenbach, Hesse, Germany are inferred from 1. oviposition occuring upstream from emergence areas; 2. size differences and size-shifts between emerging and egg-laying females; 3. concentration of oviposition in upstream sections of the emergence area. The last point relies on direct catches of egg-laying females with sticky traps, and on over-representation of old, mature females in upstream emergence traps towards the end of, or even after actual emergence periods. Criteria for age class discrimination of the respective taxa are described. The validity of the present and of other indirect evidence for directed adult flights and the significance of adult upstream displacement are discussed. Optical orientation cues are suggested.Females of Leuctra prima and Siphonoperla torrentium are shown to gain 25-50% dry weight by feeding in the terrestrial environment; general information indicates many other Plecoptera may be similar in this respect. Terrestrial adult life is shown to last for 3-8 weeks. This long time, evidence of important flight activity and feeding together suggest that the terrestrial phase is spent as an active adult, the inevitable risks of which may form an important control of population dynamics.

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;.…”

“…Rotheray & Liston (1985) observed a Chloroperla tripunctata (Scopoli, 1763) that seemed to feed on a sawfly (Tenthredinidae). More recently, Rupprecht (1990) demonstrated that Siphonoperla torrentium (Pictet, 1842) can metabolize food ingested during the adult stage and Zwick (1990) pointed out that this species gains weight during its adult life by ingesting food (consisting in Pinaceae pollens). 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.…”

Life history and emergence patterns of stonefly species in mountain streams of the Futaleufú basin, Patagonia (Argentina)

“…Differences in sex ratio have been observed for several species of stoneflies (Zwick 1990, Sheldon 1999, Petersen et al, 2006. Our study suggests that sex ratios of K. kuscheli and A. michaelseni were male-biased in Baggilt stream.…”

Riparian forestry management and adult stream insects

“…Many of the taxa that are numerically abundant in upland streams, notably Plecoptera, Trichoptera and Diptera, have adult stages which are effectively terrestrial, and which spend their lives in the riparian zone (Collier and Smith, 1998;Petersen et al, 1999;Delettre and Morvan, 2000;Briers et al, 2002). Mortality of adult stages in the terrestrial environment is high, in the region of 90% (Jackson and Fisher, 1986;Werneke and Zwick, 1992;Enders and Wagner, 1996), and hence factors influencing the distribution, survival and reproductive success of adults may be important in determining the abundance and distribution of larval stages (Statzner, 1977;Zwick, 1990;Timm, 1994;Harrison and Hildrew, 1998).…”