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Jorg Romeis - One of the best experts on this subject based on the ideXlab platform.

  • Development of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on pollen from Bt-transgenic and conventional maize
    Scientific Reports, 2014
    Co-Authors: Michael Meissle, Jan Zünd, Mario Waldburger, Jorg Romeis
    Abstract:

    Development of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on pollen from Bt-transgenic and conventional maize

  • use of maize pollen by adult Chrysoperla carnea neuroptera chrysopidae and fate of cry proteins in bt transgenic varieties
    Journal of Insect Physiology, 2010
    Co-Authors: Michael Meissle, Jorg Romeis
    Abstract:

    We investigated the use of maize pollen as food by adult Chrysoperla carnea under laboratory and field conditions. Exposure of the insects to insecticidal Cry proteins from Bacillus thuringiensis (Bt) contained in pollen of transgenic maize was also assessed. Female C. carnea were most abundant in a maize field when the majority of plants were flowering and fresh pollen was abundant. Field-collected females contained an average of approximately 5000 maize pollen grains in their gut at the peak of pollen shedding. Comparable numbers were found in females fed ad libitum maize pollen in the laboratory. Maize pollen is readily used by C. carnea adults. When provided with a carbohydrate source, it allowed the insects to reach their full reproductive potential. Maize pollen was digested mainly in the insect's mid- and hindgut. When Bt maize pollen passed though the gut of C. carnea, 61% of Cry1Ab (event Bt176) and 79% of Cry3Bb1 (event MON 88017) was digested. The results demonstrate that maize pollen is a suitable food source for C. carnea. Even though the pollen grains are not fully digested, the insects are exposed to transgenic insecticidal proteins that are contained in the pollen.

  • Impact of snowdrop lectin (Galanthus nivalis agglutinin; GNA) on adults of the green lacewing, Chrysoperla carnea
    Journal of Insect Physiology, 2008
    Co-Authors: Jorg Romeis
    Abstract:

    Based on the finding that Galanthus nivalis agglutinin (GNA) has direct negative effects on larvae of Chrysoperla carnea, laboratory experiments were conducted to investigate its toxicity to the adults. While the ingestion of GNA dissolved in an artificial diet did not affect adult longevity, there were concentration-dependent negative effects on the pre-oviposition period, daily fecundity and total fecundity (number of eggs laid). When GNA was ingested by larvae of C. carnea, it caused a significant extension of larval development time. Adults that had emerged from GNA-fed larvae did not differ from those that developed from control larvae in terms of adult fresh weight, pre-oviposition period and daily or total fecundity. However, fertility (proportion of hatching eggs) was significantly decreased in adults raised from GNA-treated larvae. Western blots revealed that GNA ingested by larvae of C. carnea was partly transferred to the adult stage and was subsequently excreted or digested within a few days. Our toxicity studies (Tier-1 tests) clearly established a hazard of GNA to adult C. carnea when administered to larvae or adults at high concentrations. Implications of these toxicity data for the non-target risk assessment of GNA-expressing transgenic crops are discussed.

  • prey mediated effects of bacillus thuringiensis spray on the predator Chrysoperla carnea in maize
    Biological Control, 2003
    Co-Authors: Anna Dutton, Jorg Romeis, Heiri Klein, F Bigler
    Abstract:

    Abstract Bacillus thuringiensis ( Bt ) bioinsecticides are generally considered safe to beneficial insects. However, negative effects of transgenic Bt -expressing maize on an important predator, Chrysoperla carnea , have previously been reported. Here, we make an ecological assessment of the effects of Dipel, one of the most widely used Bt -sprays in agriculture, on C. carnea larvae. Indirect effects due to a reduction of prey were tested by rearing three prey species of C. carnea (the aphid Rhopalosiphum padi , the spider mite Tetranychus urticae , and Lepidoptera larva Spodoptera littoralis ) on either maize plants sprayed with Dipel (at the recommended field concentrations) or on control plants. Effects of Dipel on C. carnea were assessed by performing greenhouse experiments in which chrysopid larvae were kept on Bt -sprayed or control plants and fed with herbivores reared on Bt -sprayed or control plants. Dipel had no effect on aphids; however, negative effects on spider mites were observed. Spider mites reared on Bt -sprayed plants had a significantly lower intrinsic rate of natural increase compared to those reared on control plants. Similarly, S. littoralis larvae were significantly affected by Dipel as the developmental time required by larvae which were fed Bt -sprayed plants was prolonged when compared to larvae on untreated plants. Negative effects on C. carnea larvae were also shown through prey-mediated exposure to Dipel. A significant increase in mortality, a prolonged developmental time and a slight decrease in weight was observed for C. carnea fed with ‘ Bt -contaminated’ S. littoralis larvae. The effects of Dipel on C. carnea larvae shown in this study, are comparable to earlier published results obtained with Bt maize. The ecological relevance of these results is discussed in comparison with the possible risks that the deployment of Bt -expressing maize plants pose to the predator C. carnea .

Hongsheng Pan - One of the best experts on this subject based on the ideXlab platform.

Ruifeng Ding - One of the best experts on this subject based on the ideXlab platform.

Michael Meissle - One of the best experts on this subject based on the ideXlab platform.

Ahtam Uwais - One of the best experts on this subject based on the ideXlab platform.