Offspring performance in dynamic habitats: key factors for a riparian carabid beetle

Abstract

1. Knowledge of the ecology of carabid species is largely restricted to adults, although larval mortality is assumed to be the key factor in overall mortality. As low-mobility larvae are unable to avoid unfavourable conditions, habitat selection of reproducing adults should be clearly affected by the habitat factors which determine offspring performance.2. The present study examines the key habitat factors governing the distribution patterns of Bembidion velox larvae and adults on the river banks of the River Elbe by means of habitat suitability models. The validity of the determined habitat factors for offspring performance and survival was tested in laboratory experiments.3. In the field, B. velox adults as well as larvae show a strong association with semiterrestrial, sandy, open soil habitats.4. In the laboratory, overall mortality of larvae reared in different substrates was lowest in sand of medium grain size mixed with fine and coarse sand. The first larval instars in particular reacted sensitively to variations in grain size. Furthermore, flood resistance of eggs was demonstrated, as 90% of larvae hatched under permanently flooded conditions. 5. Short development times were recorded, with 4 -7 days for hatching of young larvae from eggs after oviposition and approximately 28 days for the development of adults from newly hatched larvae. This probably increases the survival probability for the preimaginal stages in dynamic habitats.6. In conclusion, it can be said that reproductive success is strongly dependent on oviposition site selection by adults as this reflects the ecological demands of the immature stages.

Effects of alternative food on cannibalism and herbivore suppression by carabid larvae

“…Preferential oviposition is not a likely explanation, because previous research has shown that pupae do not increase the abundance of adult carabids in field plots (Frank, 2007). Further, the short duration (15 days) of our experiments did not provide enough time for eggs to be laid, hatch, and reach second and third instars (Ernsting & Isaaks, 1997;Lundgren et al, 2005;Kleinwächter & Bürkel, 2008). As an example, at 28 • C, P. chalcites requires 4 days to hatch and an additional 34 days to reach pupation (Lundgren et al, 2005).…”

Notes on the Reproductive Ecology and Description of the Preimaginal Morphology of Elaphrus sugai Nakane, the Most Endangered Species of Elaphrus Fabricius (Coleoptera: Carabidae) Ground Beetle Worldwide

“…It might be assumed that eggs laid in mud would suffocate. However, ovipositioning into mud has been reported in other riparian carabids ( Carabus clatratus : [ 23 ]; Bembidion velox : [ 24 ]; Nebria yatsugatakensis : [ 25 ]). Notably, in B .…”

Integrating Life Stages into Ecological Niche Models: A Case Study on Tiger Beetles

“…We modelled the ecological niche of the species, separately for each life stage (adult and larva), and also, the partial niches of sexes (male and female) and larval instars (larva_1, larva_2 and larva_3) (see [26], [28]). We analysed the following response variables: 1) presence-absence data (PA), where adult presence was recorded by the traps and larval presence on the maps, and 2) abundance data (AB), as the sum of distinctively identified individuals (i.e., individually marked adults and monitored larvae) recorded by the traps and on the maps.…”

“…For many species, inclusion of accurate biotic information in such broad-scale models is unfeasible [6], since the biotic niche component is too fine-grained and dynamic (e.g., [12]) to be mapped at high resolution over the entire distribution range of a species. Such a shortcoming may be critical for organisms with complex life histories (e.g., holometabolous insects; see [25]), for which detailed biological information is essential to avoid misleading interpretations of ENM results [3], [26], [27]; this is particularly important when considering conservation actions [4].…”