Relationship between Wolbachia density and sex-ratio in a Trichogramma strain

Abstract

A controlled thermal cure was applied to a Trichogramma cordubensis strain completely infected by endosymbionts belonging to the Wolbachia genus and which induce the thelytokous mode of reproduction. Varying the conditions of the cure led to the production of a variable number of males among the progeny, and it was possible to examine the correlation between sex-ratio and bacterial density estimated by means of the Dot-blot technique, using the Trichogramma gene 18S and the Wolbachia gene wsp. A slight positive correlation was observed between the two variables. An additional statistical analysis confirmed that a relationship exists between the host sex-ratio and bacterial density but that this relationship is partially concealed by methodological problems.