Genetic variability of Trichogramma pretiosum Riley, 1879, in its role as a biological control agent

Author(s)

Aloisio Coelho Junior

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2015-07-06

Examining board members

José Roberto Postali Parra; Odair Aparecido Fernandes; Joao Roberto Spotti Lopes; Dori Edson Nava; Ranyse Barbosa Querino da Silva

• Advisor: José Roberto Postali Parra

Abstract

The knowledge on genetic variability in populations of natural enemies, especially parasitoids, has a vital importance for the optimization of biological control programs. Thus, this study aimed to determine the influences of genetic variability on different biological parameters of Trichogramma pretiosum Riley, 1879, in laboratory and field experiments. We evaluated: 1) the effect of selection of T. pretiosum isofemale strains in laboratory conditions, marked by mitochondrial DNA, on the subsequent field performance; 2) the effects of RH on flight capacity isofemale lines, marked by the mitochondrial DNA, of T. pretiosum specimens from Brazil and the USA; 3) the reproductive compatibility between USA and Brazilian isofemale lines of T. pretiosum, through an integrative approach, and 4) the possible establishment of a T. pretiosum strain from Colombia in a new ecosystem in the Brazilian Northeast. The results allow to conclude that genetic variability of T. pretiosum has great influence on biological parameters of the parasitoid, since: 1) the different reproductive performance of isofemale strains in laboratory conditions corresponded to those under field conditions, and mitochondrial DNA was accurate and efficient, marking technique for the evaluation of T. pretiosum performance in field conditions; 2) for some isofemale lines, the environmental conditions of the release sites, if distinct from the natural habitat of the parasitoid, may adversely affect flight capacity of the parasitoid; 3) slight reproductive incompatibility and more pronounced morphological differences were observed between American and Brazilian isofemale lines, genetically variable; 4) there is strong evidence that T. pretiosum line introduced in Petrolina, PE, 22 years ago, brought from Palmira, Colombia, has established in that region. (AU)

• FAPESP's process: 11/17397-5 - GENETIC VARIABILITY OF Trichogramma pretiosum RILEY, 1879, IN ITS ROLE AS A BIOLOGICAL CONTROL AGENT
• Grantee: Aloisio Coelho Junior
• Support Opportunities: Scholarships in Brazil - Doctorate