HARMONIA AXYRIDIS (PALLAS, 1773) (COLEOPTERA: COCCINELLIDAE) IN MOSCOW CITY AND YALTA CITY: ITS COMPETITION WITH NATIVE SPECIES OF COCCINELLIDS AND THE INFLUENCE OF PARASITOIDS ON ITS NUMBER

The Asian ladybird Harmonia axyridis is an invasive species that is rapidly spreading around the world. Occupying new territories, H. axyridis often causes a decrease in the biodiversity of native species of coccinellids, competing with them for food resources. A comparison of H. axyridis with six species of ladybirds was made in terms of the ratio of the number of individuals and the degree of infestation with parasitoids. In Moscow city, the most widespread species of ladybirds was Adalia bipunctata (67.1%), H. axyridis ranks second (16.5%). The total infestation of H. axyridis pupae with parasitoids is 1.8% in Moscow city and 12.2% in Yalta city. Infestation with parasitoids of other ladybird species in Moscow city is much higher: from 11.0% to 36.4%. Thus, parasitoids effectively regulate the number of native ladybird species, but have an insignificant effect on the number of the invasive species H. axyridis .

Drop when the stakes are high: adaptive, flexible use of dropping behaviour by aphids

For herbivorous insects, dropping from the host plant is a commonly-observed antipredator defence. The use of dropping compared to other behaviours and its timing in relation to contact with a predator was explored in both pea aphids (Acyrthosiphon pisum) and potato aphids (Macrosiphum euphorbiae). Pea aphids dropped more frequently in response to ladybird adults (Adalia bipunctata) than lacewing larvae (Chrysoperla carnea). Potato aphids mainly walked away or backed-up in response to both predator types; but they dropped more frequently relative to other non-walking defences when faced with ladybird adults. Contact with a predator was an important influencer of dropping for both species, and most drops occurred from adjacent to the predator. Dropping appears to be a defence adaptively deployed only when the risk of imminent predation is high; factors that increase dropping likelihood include presence of faster-foraging predators such as adult ladybirds, predator proximity, and contact between aphid and predator.

Recent progress in the synthesis of homotropane alkaloids adaline, euphococcinine and N-methyleuphococcinine

The 9-azabicyclo[3.3.1]nonane ring system is present in several insect- and plant-derived alkaloids. (−)-Adaline (1) and (+)-euphococcinine (2), found in secretions of Coccinelid beetles, and (+)-N-methyleuphococcinine (3), isolated from the Colorado blue spruce Picea pungens, are members of this alkaloid family. Their unique bicyclic system with a quaternary stereocenter, and the potent biological activity exerted by these homotropane alkaloids, make them attractive synthetic targets. This work aims briefly to review the chemical ecology of Adalia bipunctata and the recent methodologies to obtain adaline (1), euphococcinine (2), and N-methyleuphococcinine (3).

Long Term Monitoring in Switzerland Reveals That Adalia bipunctata Strongly Declines in Response to Harmonia axyridis Invasion

A long-term monitoring was conducted at 40 sites in four different habitats in north-western Switzerland to observe changes in populations of native ladybirds, following the invasion of the Asian harlequin ladybird, Harmonia axyridis. From 2006 to 2017, the same trees and meadows were sampled at least seven times per year using standard protocols. On 15 broadleaved hedges, H. axyridis quickly became the dominant species, representing 60 to 80% of adult ladybirds collected. It was second in abundance at five pine (Pinus sylvestris) stands and was a minor component of the ladybird complex at five spruce (Picea abies) stands and in 15 meadows. This survey revealed the severe decline of Adalia bipunctata, which was the most abundant native ladybird on broadleaved trees in 2006–2009 and has almost disappeared since 2010. So far, other native ladybirds do not seem to decline significantly, including species occupying the same ecological niches as H. axyridis. The total number of aphidophagous ladybirds did not decline either, suggesting that the biological control function of ladybirds on aphids living in these habitats has not been affected by the arrival of H. axyridis. Recommendations are given to further assess the impact of H. axyridis on native ladybirds and aphids.

Ecological genetics of beetles of the genus Adalia: Composition of A. bipunctata populations from Italy but not France depends on climatic factors

The composition of 13 populations of Adalia bipunctata L. collected in France and Italy was studied. The proportion of black individuals varies from 7.7% to 84.7%. Comparison of the composition of color forms with climatic parameters of habitats showed that the proportion of black individuals in the Italian populations negatively correlates with the mean temperatures of the period of reproduction of beetles (May-July). No such relationship was found for the more Northern populations living in France