Fertility life table of <i>Trichogramma pretiosum</i> (Hym., Trichogrammatidae) in eggs of <i>Tuta absoluta</i> and <i>Phthorimaea operculella</i> (Lep., Gelechiidae) at different temperatures

Abstract

Abstract: The aim of this work was to study the reproductive potential of Trichogramma pretiosum reared on Tuta absoluta and Phthorimaea operculella eggs through fertility life tables at different temperatures. The development cycle and the parasitization capacity of this parasitoid was determined in order to calculate the net reproductive rate ( R o ), the infinitesimal increase ratio ( r m ), the finite increase rate ( λ ) and the mean duration of the generation ( T ). The mean duration of one generation of T. pretiosum kept on both eggs was observed to show an inverse relation with the increase of temperature. The net reproduction rate varied according to the temperature variation for both species. The maximum increase in capacity of T. pretiosum on the first host ( T. absoluta ) was reached at 22°C and on the second host ( P. operculella ) between 22 and 25°C. The infinitesimal increase rate and the finite increase rate for both moths had a relationship with the increase of temperature ranging from 18 to 30°C. The highest value of λ for both moths occurred at 30 and 32°C according to the lesser duration of a generation.