Side effects of fungicides on the abundance and the species diversity of the natural populations of Drosophila and their hymenopterous parasitoids in orchards
- 140 Downloads
Within entomophagous insects, hymenopterous parasitoids are important regulators of natural populations of insects including pests. Pesticide treatments are largely used in orchards for economic reasons. These treatments allow for greater productivity, but they may also impact upon non-target insect populations. Drosophila and their hymenopterous parasitoids are abundant in orchards and are not direct targets of pesticide treatments. In this work, natural populations of Drosophila and their parasitoids were monitored from June to November, and their abundance was reported from two types of orchards. One type was under conventional pesticide treatments, mostly fungicides (“Treated plot”), and the other was under low-input treatments (“Low-input plot”). Five Drosophila species and five parasitoid species were present in both types of orchards. A time effect on abundance was found with two peaks of abundance, one in August and the other in autumn (October), corresponding to a fluctuation of numbers depending on the availability of resources. When comparing insect abundance between the two types of plots, the abundance in the Treated plot was found to be lower than or equal to that in the Low-input plot. Furthermore, a significant decrease in the abundance of two scarce parasitoid species (Leptopilina heterotoma and Asobara tabida) that could lead to their disappearance was also observed. The results are discussed in the context of the diverse lethal and sub-lethal effects of pesticides on the development and reproduction of natural populations of insects and their importance as natural enemies.
KeywordsAsobara Leptopilina Pesticides Sampling Traps
We are thankful to INRA station Gotheron (F. Combe), F. Fleury and C. Lemaitre for their help. This work has benefited from a PNETOX grant from the French Ministry of Environment.
- Allemand, R., Fleury, F., Lemaitre, C., & Boulétreau, M. (1999). Dynamique des populations et interactions competitives chez deux espèces de Leptopilina, parasitoïdes de drosophiles, dans la vallée du Rhône (Hymenoptera: Figitidae). Annales de la Société Entomologique de France (Nouvelle série), 35, 97–103.Google Scholar
- Biddinger, D. J., Felland, C. H., & Hull, L. A. (1994). Parasitism of tufted apple bud moth (Lepidoptera: Tortricidae) in conventional insecticide and pheromone-treated Pennsylvania apple orchards. Environmental Entomology, 23, 1568–1579.Google Scholar
- Croft, B. A. (1990). Arthropod biological control agents and pesticides. New York, NY: J. Wiley.Google Scholar
- Delpuech, J. M. (1993). La drosophile ou mouche du vinaigre. Lutte chimique, protection physique et autres possibilités de maitrîse. Phytoma – La Défense des Végétaux, 454, 45–47.Google Scholar
- Delpuech, J. M., Froment, B., Fouillet, P., Pompanon, F., Janillon, S., & Boulétreau, M. (1998a). Inhibition of sex pheromone communications of Trichogramma brassicae (Hymenoptera) by the insecticide chlorpyrifos. Environmental Toxicology and Chemistry, 17, 1107–1113.Google Scholar
- Fleury, F., Ris, N., Allemand, R., Fouillet, P., Carton, Y., & Bouletreau, M. (2004). Ecological and genetic interactions in Drosophila–parasitoids communities: a case study with D. melanogaster, D. simulans and their common Leptopilina parasitoids in south-eastern France. Genetica, 120, 181–194.PubMedCrossRefGoogle Scholar
- Godfray, H. C. J. (1994). Parasitoids. Behavioral and evolutionary ecology. Princeton, NJ, USA: Princeton University Press.Google Scholar
- Johansen, N. S., Moen, L. H., & Egaas, E. (2007). Sterol demethylation inhibitor fungicides as disruptors of insect development and inducers of glutathione S-transferase activities in Mamestra brassicae. Comparative Biochemistry and Physiology C - Toxicology & Pharmacology, 145, 473–483.CrossRefGoogle Scholar
- Komeza, N., Fouillet, P., Boulétreau, M., & Delpuech, J. M. (2001). Modification, by the insecticide chlorpyrifos, of the behavioral response to kairomones of a Drosophila parasitoid, Leptopilina boulardi. Archives of Environmental Contamination and Toxicology, 41, 436–442.PubMedCrossRefGoogle Scholar
- Michaud, J. P. (2001). Responses of two ladybeetles to eight fungicides used in Florida citrus: Implications for biological control. Journal of Insect Science, 1, 1–6.Google Scholar
- Moura, A. P., Carvalho, G. A., Moscardini, V. F., Marques, M. C., & Souza, J. R. (2009). Toxicity of pesticides recommended in the integrated apple production (IAP) to populations of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae). Neotropical Entomology, 38, 395–404.PubMedCrossRefGoogle Scholar