Trophic relations between adult water beetles from the Dytiscidae family and non-biting midges (Diptera: Chironomidae)

• Published in: Biológia Vol. 71; no. 8; pp. 931 - 940
• Main Authors: Frelik, Anna, Koszałka, Jacek, Pakulnicka, Joanna
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.08.2016; De Gruyter; Springer Nature B.V
• Subjects: adult biting-midges; Aquatic plants; autumn; Beetles; Biting; Body size; Cell Biology; Ceratopogonidae; Chironomidae; Chironomidae larvae; Coleoptera; Competitiveness; Detritus; Diet; Diptera; Dytiscidae; Glyptotendipes; imagos; Insects; Larvae; Life Sciences; Microbiology; midges; Natural environment; Plant Sciences; Population number; population size; Predation; Predators; Prey; seasonal variation; Seasonal variations; Selectivity; spring; Statistical analysis; Zoology; predation; Chironomidae larvae; Dytiscidae; adult biting-midges
• ISSN: 0006-3088; 1336-9563; 1336-9563
• DOI: 10.1515/biolog-2016-0115

Predation is an exceptionally important interaction observed in the natural environment. It regulates the pop-ulation size of potential prey and at the same time decreases competitiveness between them. Among predators inhabiting water environments, especially notable predators are water beetles, particularly adults of Dytiscidae. The results presented herein are an attempt to learn the trophic relations between adult Dytiscidae and non-biting midges (Diptera: Chironomidae). The studies were conducted in one-month intervals from April to September 2012–2013. In the diet structure of adult Dytiscidae of two size categories, the genus Glyptotendipes was found to be prevalent. The largest beetles tended to choose Chironomidae larvae significantly larger than those selected by medium-sized beetles. The diet was mainly composed of Chironomidae larvae related to aquatic vegetation, while larvae inherently connected with detritus were fewer. Statistically significant correlations were confirmed between the population size of Chironomidae larvae and adult insects consumed by beetles of medium body size. No such correlation was found in case of the largest beetles. The study revealed that despite the unquestionable influence of body size and the predation environment on the dietary selectivity of predatory Dytiscidae, the structure of consumed food is subject to noticeable seasonal variations, occurring from spring to autumn.