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Start Over Creator Verheggen, Francois J.

1. Intraguild interactions between the predatory hoverfly Episyrphus balteatus (Diptera: Syrphidae) and the Asian ladybird, Harmonia axyridis (Coleoptera: Coccinellidae): Effect of larval tracks

Creator:
Almohamad, Raki, Verheggen, Francois J., Francis, Frédéric, and Haubruge, Eric
Type:
article, model:article, and TEXT
Subject:
Syrphidae, Coccinellidae, Episyrphus balteatus, Harmonia axyridis, larval tracks, Vicia faba, aphids, and oviposition-deterring substances
Language:
English
Description:
The effects of the larval tracks of Episyrphus balteatus DeGeer (Diptera: Syrphidae) and Harmonia axyridis Pallas (Coleoptera: Coccinellidae) on the egg laying behavior of females of the predatory hoverfly E. balteatus were investigated in two-choice experiments. The oviposition response of H. axyridis to larval tracks of E. balteatus was also tested in one-choice experiments. Gravid E. balteatus females laid significantly fewer eggs on leaf discs with aphids and contaminated with tracks of conspecific or heterospecific larvae than on control leaf discs. H. axyridis females laid similar numbers of eggs in Petri dishes with aphids and contaminated with the tracks of E. balteatus larvae as in control Petri dishes. This indicates that E. balteatus females lay fewer eggs at sites where there are conspecific and heterospecific larval tracks, whereas the tracks of the syrphid larvae did not deter H. axyridis females from laying eggs.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Occurrence of Harmonia axyridis (Coleoptera: Coccinellidae) in field crops

Creator:
Vandereycken, Axel, Brostaux, Yves, Joie, Emilie, Haubruge, Eric, and Verheggen, Francois J.
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, zoologie, entomologie, Coleoptera, Coccinellidae, Harmonia axyridis, habitat, crops, agroecosystems, ladybird, exotic species, 2, and 59
Language:
English
Description:
The Multicoloured Asian Ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is known to thrive principally in shrubby and arboreal habitats. This study focuses on the occurrence of this exotic species and its seasonal abundance in various field crops. The abundance of adults, larvae and pupae of H. axyridis was evaluated over a three-year period, from 2009 to 2011, in four important agronomical crops (wheat, corn, broad bean and potato) in Belgium. From May to September, 48 1-m² quadrats were visually inspected in each of the fields sampled on several farms every seven days. H. axyridis colonized and reproduced in all of the four crops studied, with the largest numbers recorded in corn and broad bean crops. Larvae and adults of H. axyridis were recorded mainly in corn and to a much less extent in wheat and potato crops. From 2009 to 2011, the mean weekly abundance of H. ayxridis remained constant except in corn crops, where the recorded densities of all the immature stages and adults were higher in 2011 than in 2009. The population dynamics of aphids and H. axyridis are well described by a symmetric logistic function (S-shape) of cumulative population size. H. axyridis was not always recorded where aphids were abundant, e.g. aphids were abundant on wheat where no H. axyridis were recorded. H. axyridis start reproducing after the peak in aphid population, suggesting that H. axyridis is able to complete its development by feeding on alternative prey such as larvae and pupae of the same and other species of ladybird and other aphidophagous species. H. axyridis is often considered to be bivoltine but it only completes one generation per year in field crops. The second generation generally develops late in the season in other habitats., Axel Vandereycken ... [et al.]., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public