Prokin A.A.1, Zemlyanukhin A.I.2, Seleznev D.G.1 2018. Damage to diving beetles (Dytiscidae) from willow traps in Lipetsk oblast (Russia) and features of Cybister lateralimarginalis and Dytiscus circumcinctus populations in winter // Russian Entomol. J. Vol.27. No.1: 11–14 [in English].
1 Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Nekouzsky District, Yaroslavl Oblast’, 152742 Russia. E-mail: email@example.com
2 Semenov-Tian-Shansky Lipetsk State Pedagogical University, Lenina street 42, Lipetsk, 398020 Russia. E-mail: firstname.lastname@example.org
KEY WORDS: Dytiscidae, Dytiscus, Cybister, overwintering population, sex ratio, femail morphs, damage.
ABSTRACT. The amount of damage from the use of willow traps for Dytiscinae in the oxbow lake in Lipetsk Oblast was 400 g/trap-day. The sex ratio (?/?) in the winter was 0.60 for Cybister lateralimarginalis and 1.73 for Dytiscus circumcinctus. The average biomass of C. lateralimarginalis females was significantly higher than in males, there were no significant differences for D. circumcinctus. The number of reticulate females in comparison with smooth ones was an order larger in the population of C. lateralimarginalis, and only 1.6 times larger in D. circumcinctus. Probably, the predominance of reticulate females in the C. lateralimarginalis population, in comparison with Dytiscus, is one of the mechanisms that ensure the expansion of the species range to the north.