بررسی تأثیر باکتری همزیست ولباکیا بر نقطه انجماد زنبورهای Habrobracon hebetor در مراحل مختلف زندگی

Habrobracon hebetor wasps are known as one of the important parasitoid wasps in agricultural pest control. Symbiotic bacteria, especially Wolbachia, can have different effects on survival and temperature tolerance in these wasps. A better understanding of symbiotic interactions and the effects of symbiotic bacteria on these wasps can lead to the optimization of pest control methods and increase the efficiency of these wasps in agricultural ecosystems. Also, considering climate changes and its effects on habitats, investigating the ability to tolerate cold in these wasps can help predict their behavior in changing conditions. Therefore, the ability of Wolbachia on cold tolerance in wasps was studied to investigate the effect of symbiosis in unfavorable conditions of low temperature. In this research, the two wasp lines, in which the first line had Wolbachia symbiotic bacteria and the second line did not have this symbiosis, were fed with the combination of the antibiotic rifampicin and water and honey, and were bred for 8 generations in laboratory conditions, in the form of a randomized block design. were investigated with eight repetitions. During the experiment, 16 wasp pupae and 32 adult insects (16 males and 16 females) of the same age were studied. The freezing point (SCP) of each treatment was determined using a programmable cooling device (Binder GmbH, model MK 53, Germany) and a device (Thermometer LUTRON, model TM-947SD, Taiwan) to measure temperature. Data were analyzed using SPSS version 27 software. The analyzes included descriptive and inferential analyzes to investigate the differences and effects of the presence and absence of Wolbachia bacteria on the freezing point of wasps. The obtained results showed the effect of gender with an average of -1.18±0.9 for males and 17.35±1.02 for females, the effect of Wolbachia with an average of -21±1.07 for the treatment without Wolbachia and 0.92 19.3 for treatment with Wolbachia, the effect of life stages with an average of -25±0.74 for pupae and 17.73±0.67 for adult insects, as well as the effect of repetition and mutual effects of repetition on Wolbachia, Wolbachia on gender and repetition were significant on life stages (P<0.01). This is while the mutual effect of the presence and absence of Wolbachia symbiosis on the life stages was not significant. According to these results, the presence of Wolbachia symbiotic bacteria can reduce the ability of wasps to face freezing temperatures, and this has a negative effect on the efficiency of these wasps as biological control agents.