This is the first record of the harlequin ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) occurring in the Caucasus (Sochi region of Krasnodar territory, Russia). All the adults collected in the field there and reared from collected eggs, larvae and pupae, and their progeny were H. axyridis f. succinea, which is the most common morph in natural populations in South-Eastern Asia and the Russian Far East as well as in invasive populations in the Americas and Europe. In contrast in Western Siberia f. axyridis predominates and this indicates that an occasional introduction from the closest native range in Siberia cannot be considered as the source of the Caucasian population. It is known that populations of H. axyridis can also differ in their photoperiodic responses. The results of earlier experiments on H. axyridis, which originated from the Russian Far East, indicate that the threshold day lengths for the acceleration of preimaginal development and deceleration of reproductive maturation were 13–14 h, while for the invasive populations of this species in Europe these two thresholds are approximately 12 h. In the population studied, the thresholds for both of these photoperiodic responses were also approximately 12 h. Thus, it is concluded that the population of H. axyridis studied is a further eastward continuation of the invasion of this species in Europe., Natalia A. Balyakova, Sergey Ya. Reznik., and Seznam literatury
Ovipositing females from invasive (Krasnodar Territory of Russia) and native (Far East of Russia) populations of Harmonia axyridis were fed one of a set of diets ranging from 50 Myzus persicae aphids every day to 1 aphid every 10 days and all were also provided with a 10% sugar solution. The experiment was conducted at 20°C under short (12 h) and long (18 h) day conditions. Most of the females from the native population that consumed 50 or 10 aphids per day continued to oviposit under both long and short day conditions. Females that consumed 1 aphid per day or every 2 days practically stopped laying eggs but under long day conditions their ovaries were still active, whereas under short day conditions ca 50% of them were reproductively inactive (only germaria present) and had a well-developed fat body. Further reduction in diet resulted in an increase in the proportion of reproductively inactive females. However, about half of the females that terminated oogenesis under long day conditions had poorly developed fat bodies, which indicates that diapause was not induced. For the females from the invasive population, both photoperiodic and trophic effects were weak: under short day conditions, some females entered diapause when prey was abundant, whereas about 50% (independent of photoperiod) did not enter diapause when starved. This risk-spreading strategy, possibly, facilitates the adaptation of this invasive ladybird to unpredictable environmental conditions., Antonina A. Ovchinnikova, Andrey N. Ovchinnikov, Margarita Yu. Dolgovskaya, Sergey Ya. Reznik, Natalia A. Belyakova., and Obsahuje bibliografii