Convergence between a mosquito-eating predator's natural diet and its prey-choice behaviour

Abstract

On the basis of 1115 records of Evarcha culicivora feeding in the field, we can characterize this East African jumping spider (Salticidae) as being distinctively stenophagic. We can also, on the basis of laboratory prey-choice experiments, characterize E. culicivora as having a specialized prey-classification system and a hierarchy of innate preferences for various categories of mosquitoes and other arthropods. Prey from the field belonged to 10 arthropod orders, but 94.5% of the prey records were dipterans. Mosquitoes were the dominant prey (80.2% of the records), with the majority (82.9%) of the mosquitoes being females, and thereafter midges were the most common prey (9.2% of the records). Preference profiles that were determined from experiments showed strong convergence with natural diet in some, but not all, instances. In experiments, E. culicivora adults appeared to distinguish between six prey categories and juveniles between seven, with blood-carrying anopheline female mosquitoes being ranked highest in preference. For adults, this was followed by blood-carrying culicine female mosquitoes and then anopheline female mosquitoes not carrying blood, but these two preferences were reversed for juveniles. Moreover, for juveniles, but not for adults, anopheline male mosquitoes seem to be a distinct prey category ranked in preference after blood-carrying culicine females and, for both adults and juveniles, preference for midges is evident when the alternatives are not mosquitoes. These findings illustrate the importance of going beyond simply specifying preferred prey categories when characterizing predators as ‘specialized’ and a need to make clear conceptual distinctions between a predator's natural diet, the prey categories that are relevant to the predator, and the predator's prey-choicebehaviour.

Effects of the removal or reduction in density of the malaria mosquito, Anopheles gambiae s.l., on interacting predators and competitors in local ecosystems

“…These authors make a clear distinction between preference and natural diet that is important when discussing predatory specialization because, although natural diet is simply what a predator eats in the field, preference is an inherent product of a predator's perceptual processes, decision‐making capacities and motivation. In terms of dependence, there is no evidence that these Salticids require Anopheles mosquitoes and they will readily feed on blood‐fed Culex (Jackson & Cross, ; Jackson et al ., ).…”

Behavioral variation according to feeding organ diversification in glossiphoniid leeches (Phylum: Annelida)

“…These changes can often result in behavioral convergence, where different species exhibit similar behaviors due to a structure or behavior being advantageous in both environments (e.g., Rodent turbinate; Arachnid web architectures) 37 , 38 . Among various environmental factors, the specific behavioral convergence about food that is essential for survival manifests in various aspects (e.g., Ultrasonic predator whale and bat) 39 , 40 . These behavioral convergences cannot be explained phylogenetically, suggesting that behavioral convergence is the result of evolutionary convergence depending on the choice of similar food sources via speciation.…”

Diversification of Leech Proboscis Structure According to Prey Ingestion Behavior

“…These changes resulted in behavioral convergence despite differences across the species [27,28]. Among various environmental factors, the speci c behavioral convergence about food that is essential for survival manifests in various aspects [29,30]. These behavioral convergences beyond species cannot be explained phylogenetically, suggesting that convergence is due to morphological similarity.…”