Tag Archives: Meligethes aeneus

548-554 E. Veromann, M. Saarniit, R. Kevväi and A. Luik
Effect of crop management on the incidence of Meligethes aeneus Fab. and their larval parasitism rate in organic and conventional winter oilseed rape
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Effect of crop management on the incidence of Meligethes aeneus Fab. and their larval parasitism rate in organic and conventional winter oilseed rape

E. Veromann, M. Saarniit, R. Kevväi and A. Luik

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi 1, 51014 Tartu, Estonia; e-mail: eve.veromann@emu.ee

Abstract:

The occurrence of Meligethes aeneus adults, larvae and larval parasitism rate was studied in organic and conventional winter oilseed rape fields in Estonia. No insecticides were used in fields with either management. In the conventional field, significantly more M. aeneus adults and larvae were found than in the organic field, whereas the larval parasitism rate was significantly greater in the organic winter rape field. This study showed that organic cropping system enhanced the occurrence of parasitoids and diminished the incidence of pest attack in winter oilseed rape.

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447-450 E. Veromann, A. Luik and R. Kevväi
The impact of field edges on the incidence of Meligethes aeneus Fab. larvae and their parasitisation in spring and winter oilseed rape
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The impact of field edges on the incidence of Meligethes aeneus Fab. larvae and their parasitisation in spring and winter oilseed rape

E. Veromann, A. Luik and R. Kevväi

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi St. 64, EE51014 Tartu, Estonia; e-mail: eve.veromann@loodusfoto.ee

Abstract:

The occurrence of Meligethes aeneus larvae and their parasitism rate was studied at the edges and in the centres of commercial spring and winter oilseed rape fields in Estonia. Insecticides were used in spring oilseed rape but not in winter oilseed rape fields. Significantly more larvae were found at the field edges than in centres of both crops, but they were more abundant in winter oilseed rape. The larval parasitism rate was significantly greater at field edges than in centres only in winter rape; in spring oilseed rape parasitism was more evenly distributed. But there were no differences in pollen beetle parasitisation rates between crops.

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465-470 I. H. Williams
Integrating parasitoids into management of pollen beetle onoilseed rape
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Integrating parasitoids into management of pollen beetle onoilseed rape

I. H. Williams

Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ,UK

Abstract:

Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ,UK Hymenopterous parasitoids can exert substantial natural control on oilseed rape pest populations. This paper reviews recent work at Rothamsted Research on integrating parasitoids into the management of rape pests. It focuses on the pollen beetle, Meligethes aeneus, and its two larval endoparasitoids, Phradis interstitialis and Tersilochus heterocerus. Strategic research on the behavioural ecology of the parasitoids is described. Phradis interstitialis was shown to use upwind anemotaxis to locate the crop. Within-field spatio-temporal distributions of M. aeneus adults and larvae were complex with irregular patterns of aggregation. Whereas P. interstitialis was closely associated temporally and spatially with the distribution of its host, T. heterocerus larvae were as abundant outside dense host patches as within them and showed little pattern. Both parasitoid species overwinter in the soil of the rape field and emerge the following spring. Post-harvest soil cultivations, particularly ploughing, can reduce their survival, whereas non-inversion tillage is less harmful. Phenological studies show that pyrethroid applications during flowering threaten parasitoid populations. Implications of the research for conservation biological control and the development of more environmentally-friendly crop protection is discussed.

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17–29 K. Hiiesaar, L. Metspalu, P. Lääniste, K. Jõgar, A. Kuusik and J. Jõudu
Insect pests on winter oilseed rape studied by different catching methods
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Insect pests on winter oilseed rape studied by different catching methods

K. Hiiesaar¹, L. Metspalu¹, P. Lääniste², K. Jõgar¹, A. Kuusik¹ and J. Jõudu²

¹Department of Plant Protection, Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia; e-mail: hkelly@eau.ee
²Department of Field Crop Husbandry, Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia

Abstract:

The distribution, species association and number of pest insects on winter oilseed rape of varieties ‘Wotan’ and ‘Express’ were studied in field experiments. Three catching methods were used: black plastic basins on the soil surface between plants, yellow flight traps filled with water at the height of the crop canopy and the shaking of plants above a plastic basin. The most abundant pest species was the pollen beetle,Meligethes aeneus, while the number of individuals from the species M. virescens in traps was much lesser. The other  important group of pest insects were weevils Ceutorrhynchus spp., the most common of which was the cabbage seed weevil, C. assimilis.  Three species of flea beetlesPhyllotreta undulata, Ph. vittata and Ph. nemorum were typical contents of traps during May. In the last decade  of May, there was a large number of thrips (Thysanoptera, Tripidae) in traps.
Winter oilseed rape began to flower to some extent later, when pest insects of cruciferous plants had ended their hibernation. Therefore, the pests first inhabited weeds and already flowering plants, from where they later moved onto winter oilseed rape.
    In the field of winter oil seed rape, chemical pest control with a pyrethroid, Fastac, did not significantly influence the abundance of  pest insects. In the last decade of May, the total number of beetles in all test variants was relatively small, but, at the beginning of June, it increased almost to an equal extent. On the basis of flight traps, heavy damage of pods could be assumed, however, only a few larvae fell into traps on the soil surface, and virtually no damaged pods were detected. Thus the spraying with Fastac had no significant effects on the number of insects caught in traps.

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