Although the structure of the ovipositor of parasitic Hymenoptera is largely uniform, interspecific variation in its morphology can be observed. Such variability may be related to the diversity of hosts attacked. To verify such an hypothesis, we compared, using correspondence analysis, the morphological characteristics of the ovipositors of 20 species in three categories: (i) species belonging to the same taxonomic unit and attacking the same type of host, (ii) species belonging to the same taxonomic unit but attacking different types of host, and (iii) species belonging to different taxonomic units but attacking the same type of host. Results show that variability in some morphological traits of the ovipositor can be related to host characteristics. Adaptive convergence in morphological variations observed between species is discussed.

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The effects of two pyrethroids and one organophosphorous broad s ectrum insecticides were tested in laboratory conditions on the main European parasitoid of the cereafaphids at the recommended rates. The 3 compounds were found to kill both the host aphid and its parasitoid when living parasitized aphids were sprayed. When the mummies were sprayed, the number of emergences was significantly reduced by dimethoate and deltamethrin. The longevity and the percentage of females in the F1 offsprings was reduced by all 3 insecticides and the number of offsprings from emerged adults was only reduced by dimethoate. When adults were in contact with either pyrethroid during one hour, their longevity was reduced and the sex ratio of their offsprings became unbalanced in favour of males.

Au moment où les introductions de nouveaux phytophages ravageurs augmentent de façon préoccupante dans la zone paléarctique, un bilan de la lutte biologique classique en France depuis l’origine est présenté. Les références‐clefs concernant les expériences d’acclimatations réussies sont complétées par des informations inédites et des commentaires d’ensemble. Cet acquis devrait servir de base à un renforcement de la mise en œuvre de cette stratégie de lutte qui représente toujours une méthode efficace, économique et durable pour répondre à l’afflux de nouvelles espèces invasives.