Biweekly field visits starting from January to the end of April 2011 were conducted to tomato fields (open and plastic houses) heavily infested with the tomato borer Tuta absoluta, in order to survey natural enemies associated with this pest. Three hemipterans were found: Orius albidipennis, Orius sp. (Anthocoridae) and Nesidiocoris tenuis (Miridae). In addition, the parasitic wasp Bracon (Habr...

MONG species of insects that have been used for genetic studies, there Aoccasionally appear adults which are composed of two or more different genomes. In Drosophila melanogaster, where most of these mosaics were of the gynandromorph type, it has been shown that elimination of an X chromosome during early cleavage was involved (MORGAN and BRIDGES 1919; PATTERSON 1931). In a few instances, ferti...

N THE parasitic wasp Habrobracon juglandis (Ashm.), when a cross of I unrelated stocks is made, males (haploid) come from unfertilized eggs and females (diploid) from fertilized eggs. When the parental stocks are closely related, not only males from unfertilized eggs but also males (diploid) from fertilized eggs appear. That such biparental males should be produced was puzzling until WHITING br...

In short, testis size in F1 hybrids is determined by an interaction between the chromosome complement and the cytoplasm. We are dealing either with a real cytoplasmic effect (determination by the intrinsic properties of the cytoplasm, independent of the chromosomes it carries or carried), or with a maternal effect (determination of the properties of the cytoplasm by those of the chromosomes it ...