CanWolbachiainfection improve qualitative characteristics ofTrichogramma brassicaereared on cold stored eggs of the host?

Abstract

The mass production cost of parasitoids is an important limiting factor in the development of successful biological control program. Parasitoids cannot be stored for a long time, thus should be produced shortly before use. Storage of host in low temperatures is an alternative technique to increase time flexibility of parasitoids production, thus contribute to reduction of production expenses. In this study, the influence of cold storage time (1 to 16 days) of host (Ephestia kuehniella Zeller) eggs on some qualitative characteristics of the egg parasitoid, Trichogramma brassicae Bezdenko (Hym.: Trichogrammatidae), was studied under laboratory conditions. The stored eggs were exposed to two different strains of T. brassicae, which were infected or uninfected with the endosymbiotic bacteria, Wolbachia, and the interactions between the host storage time and Wolbachia infection was studied. Increased host storage time negatively affected some qualitative characteristics of T. brassicae, such as fecundity, longevity, wing deformity and sex ratio. Some of these effects (e.g. fecundity, longevity and sex ratio) were different among Wolbachia-infected and uninfected strains. Given that the Wolbachia-infected strain produces higher proportion of females, they may compensate for other negative effects of Wolbachia as well as prolonged storage time of the host from biological control point of view.

Molecular identification of Trichogramma egg parasitoids of Ostrinia nubilalis in northeastern Serbia

“…Since only female wasps have the potential for pest control, the sex ratio is of particular importance for the mass rear-ing of parasitoids for release [45]. The use of thelytokous strains has been proposed to provide advantages for biological control because they produce a higher proportion of females [46]. However, the evidence for this is somewhat conflicting.…”

Abiotic and biotic factors influence diapause induction in sexual and asexual strains of Trichogramma brassicae (Hym: Trichogrammatidae)

“…kuehniella caused a significant reduction in some biological characteristics of T . brassicae , such as fecundity, longevity, wing deformity and sex ratio 25 . The differences between the effect of host qualities on the diapause induction here were significant but the magnitude of the difference was small (37.2% and 35.7% of individuals with eggs of high and low qualities entering diapause, respectively).…”

Co-occurrence of thelytokous and bisexual Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) in a natural population

“…In supergroup A, two groups (i.e., Dro and Uni) cause thelytoky of four species, including Telenomus nawai , Muscidifurax uniraptor , and two Aphytis species 62,82–84 . Meanwhile, three such groups (i.e., Dei, Div and Sib) are found in supergroup B: Dei and Sib are responsible for the thelytoky of 9 Trichogramma species, including T. brassicae , T. chilonis , T. cordubensis, T. deion , T. dendrolimi , T. embryophagum , T. kaykai , T. oleae and T. pretiosum , while Div only induces thelytoky in Apoanagyrus diversicornis 10,28,62,85–90 . Since for many host species the Wolbachia group information was not supplied (e.g., Bryobia praetiosa ) 91 , the thelytokous groups listed here could be incomplete.…”

“…However, we still lack the comprehensive studies and integrate evaluation to determine the biocontrol potential of our thelytokous strain before it can be used in practice. And our further studies will focus on this aspect by evaluating indicators like body size, vagility 101 , decision-making 20 , and adaptive capacity to the long-term storage 90 .…”