| Summary: | In this study, virulence of the culture broth of Photorhabdus temperata subsp. temperata and its
aqueous and organic extracts were investigated for 3rd and 4th instars of Pieris brassicae (Lepidoptera:
Pieridae) larvae. Virulent efficacy was found in all the treatments. However, the culture broth of
bacteria showed greater mortality effect. Also, this study presents the response of P. brassicae
immune system factors, phenoloxidase, lysozyme and hemocytes, to infection by Heterorhabditis
bacteriophora, its symbiotic bacteria and their aqueous and organic extracts. Results showed that
after injecting infective juveniles (IJs) with phenoloxidase, specific activity was suppressed after
primary increase. However, the phenoloxidase specific activity suppression was observed earlier after
injecting P. temperata subsp. temperata, aqueous and organic extracts. Also, results indicate more
phenoloxidase activity of 4th instars larvae in comparison with 3rd instars larvae, which can show
higher activity of phenoloxidase in the 4th larval stage. After injecting IJs into hemocel, the total
hemocyte count was increased until five h post-injection and then decreased at seven hours postinjection.
Differential Hemocyte Count (DHC) indicated granolucytes and plasmocytes as frequent
hemocytes after treatment. Lysozyme consideration showed an increase after injecting living and
heat-killed bacteria into hemocel.
|
|---|