Caddisfly life histories along permanence gradients in high‐altitude wetlands in Colorado (U.S.A.)

Abstract

SUMMARY 1. Larvae of cased caddisflies (Limnephilidae and Phryganeidae) are among the most abundant and conspicuous invertebrates in northern wetlands. Although species replacements are often observed along permanence gradients, the underlying causal mechanisms are poorly understood. In this paper, we report on the distributional patterns of caddisflies in permanent and temporary high‐altitude ponds, and how those patterns reflect differences in life history characteristics that affect desiccation tolerance (fundamental niches) versus constraints related to biotic interactions (realised niches). 2. Species (Hesperophylax occidentalis and Agrypnia deflata) that were encountered only in permanent ponds are restricted in distribution by life history (no ovarian diapause, aquatic oviposition, and/or inability to tolerate desiccation). Although the egg masses of H. occidentalis tolerate desiccation, the larvae leave the protective gelatinous matrix of the egg mass because adults oviposit in water. 3. Three species (Asynarchus nigriculus, Limnephilus externus and L. picturatus) have life history characteristics (rapid larval growth, ovarian diapause and terrestrial oviposition of desiccation‐tolerant eggs) that should facilitate the use of both permanent and temporary habitats. However, A. nigriculus is rare or absent in most permanent ponds, and L. externus and L. picturatus are rare or absent in most temporary ponds. Experimental data from a previous study on the combined effects of salamander predation and interspecific interactions among caddisflies (e.g. intraguild predation) suggest that biotic interactions limit each species to a subset of potentially exploitable habitats. 4. Many wetland invertebrates exhibit species replacements along permanence gradients, but few studies have separated the relative importance of the effects of drying per se from the effects of biotic interactions. Our results emphasise the complementary roles of comparative data on life histories and experimental data on competition and predation for understanding invertebrate distributions along permanence gradients.

Influences of forest harvest and environmental gradients on aquatic invertebrate communities of seasonal ponds

“…These nets produce samples with high abundance, richness, evenness, and precision, integrate a relatively large area, usually capture a high proportion of the taxa that are present, and are cost-effective (Kaminski and Murkin, 1981;Cheal et al, 1993;Turner and Trexler, 1997;New, 1998). This technique is recommended as a method of choice for sampling wetland invertebrates (Cheal et al, 1993;Turner and Trexler, 1997), is the most common method used in sampling shallow, vegetated freshwater wetlands (U.S. EPA, 2002), and has been used in other studies of mountain wetland invertebrates (e.g., Wissinger et al, 1999Wissinger et al, , 2003.…”

Life histories and life history strategies of invertebrates inhabiting intermittent streams in Hawke's Bay, New Zealand

“…Since many mayflies, caddisflies and other insect taxa either survive the dry season in situ as eggs (e.g. Dieterich & Anderson 1990;Williams 1996;Wissinger et al 2003) or recolonise from nearby perennial waterways by laying eggs in rewetted channels (Williams 2006), we may expect that in intermittent streams the start of a generation will be clearly discernible, allowing larval growth rates and longevity to be determined. The second aim of our study was to describe the growth rates and longevity of a few common intermittent stream taxa by examining their size distributions and, for the insects, flight periods, over several months.…”

Relaciones de abundancia de órdenes de hexápodos terrestres en vegas altoandinas del desierto-transicional de Chile

“…Esto es probable que se deba a que ellas ofrecen un conjunto diverso de microhábitats y recursos alimentarios en abundancia para su colonización y explotación. Estudios realizados en humedales alpinos (p.e., Wissinger et al 2003) y de tierras bajas (p.e., Batzer & Wissinger, 1996;Keiper et al 2002) sugieren que la variabilidad propia de estos ambientes desempeña un papel importante en la determinación de los patrones de invertebrados. Una situación similar puede ocurrir en las vegas de este estudio.…”