13.2 Insect Endosymbionts
13.2.1 Wolbachia
13.2.1.1 Introduction
In the last decade, insect microbiome research in Iran has begun. Most studies have
been related to Wolbachia in parasitoids and culicids. The Trichogrammatidae
family are egg parasitoids and are widely used as biocontrol agents against the
lepidopteran insects. These species have two reproductive systems, including
arrhenotoky and thelytokous. Sometimes, thelytoky associated with Wolbachia act
as master manipulators of arthropods. The application of thelytokous populations
increases rate of parasitism in biocontrol programs.
Wolbachia pipientis is an intracellular symbiont bacterium belongs to
Anaplasmatacae (Class Alphaproteobacteria, Order Rickettsiales) that first described
by Hertig (1936). This diverse endosymbiont has subdivided into 13 supergroups
named A to F and H to L on the basis of molecular phylogenetic analysis (Casiraghi
et al. 2001). Wolbachia symbiont of most insects is from supergroups A and B
supergroups (Vandekerckhove et al. 1999).
13.2.1.2 Wolbachia in Trichogramma Wasp
Wolbachia induces reproductive manipulations in its host including parthenogenesis, feminization, male killing, and most commonly, cytoplasmic incompatibility
(CI). Farrokhi et al. (2008), surveyed thelytoky and its relation to Wolbachia in
Iranian populations of Trichogramma spp. In this work, 22 populations from
different provinces of the country were studied. The Trichogramma strains were
collected from Mazandaran (10 populations), Razavi Khorasan, Ardabil
(2 populations), Hormozgan (2 populations), Sistan and Balouchestan, Khuzestan,
Golestan (4 populations), and Guilan provinces. All populations were identified
using morphological characteristics and DNA sequencing of the ITS gene. In three
populations, Baboulsar (Mazandaran), Nava (Mazandaran), and Mashhad (Razavi
Khorasan), thelytoky was observed. The obtained results indicated that the
Trichogramma brassicae (Bezdenko 1968) (Hym.: Trichogrammatidae) from
Baboulsar was infected with Wolbachia, while thelytoky of Mashhad and Nava
populations had a genetic origin. Following these observations, Farrokhi et al.
(2010), surveyed the potential of using a thelytokous Wolbachia-infected population
and an arrhenotokous uninfected population of T. brassicae to control the Angoumois grain moth, Sitotroga cerealella (Olivier 1789) (Lep.: Gelechidae). The results
indicated that there was no significant difference in parasitism rate between the two
strains, while handling time was greater in the infected populations than the
uninfected population.
13 Insect Pathogenic Viruses, Microsporidians and Endosymbionts
519
13.2.1 Wolbachia
13.2.1.1 Introduction
In the last decade, insect microbiome research in Iran has begun. Most studies have
been related to Wolbachia in parasitoids and culicids. The Trichogrammatidae
family are egg parasitoids and are widely used as biocontrol agents against the
lepidopteran insects. These species have two reproductive systems, including
arrhenotoky and thelytokous. Sometimes, thelytoky associated with Wolbachia act
as master manipulators of arthropods. The application of thelytokous populations
increases rate of parasitism in biocontrol programs.
Wolbachia pipientis is an intracellular symbiont bacterium belongs to
Anaplasmatacae (Class Alphaproteobacteria, Order Rickettsiales) that first described
by Hertig (1936). This diverse endosymbiont has subdivided into 13 supergroups
named A to F and H to L on the basis of molecular phylogenetic analysis (Casiraghi
et al. 2001). Wolbachia symbiont of most insects is from supergroups A and B
supergroups (Vandekerckhove et al. 1999).
13.2.1.2 Wolbachia in Trichogramma Wasp
Wolbachia induces reproductive manipulations in its host including parthenogenesis, feminization, male killing, and most commonly, cytoplasmic incompatibility
(CI). Farrokhi et al. (2008), surveyed thelytoky and its relation to Wolbachia in
Iranian populations of Trichogramma spp. In this work, 22 populations from
different provinces of the country were studied. The Trichogramma strains were
collected from Mazandaran (10 populations), Razavi Khorasan, Ardabil
(2 populations), Hormozgan (2 populations), Sistan and Balouchestan, Khuzestan,
Golestan (4 populations), and Guilan provinces. All populations were identified
using morphological characteristics and DNA sequencing of the ITS gene. In three
populations, Baboulsar (Mazandaran), Nava (Mazandaran), and Mashhad (Razavi
Khorasan), thelytoky was observed. The obtained results indicated that the
Trichogramma brassicae (Bezdenko 1968) (Hym.: Trichogrammatidae) from
Baboulsar was infected with Wolbachia, while thelytoky of Mashhad and Nava
populations had a genetic origin. Following these observations, Farrokhi et al.
(2010), surveyed the potential of using a thelytokous Wolbachia-infected population
and an arrhenotokous uninfected population of T. brassicae to control the Angoumois grain moth, Sitotroga cerealella (Olivier 1789) (Lep.: Gelechidae). The results
indicated that there was no significant difference in parasitism rate between the two
strains, while handling time was greater in the infected populations than the
uninfected population.
13 Insect Pathogenic Viruses, Microsporidians and Endosymbionts
519