[Insecticidal and immunosuppressive effect of ascomycete Cordyceps militaris on the larvae of the Colorado potato beetle Leptinotarsa decemlineata].

The immunosuppressive and insecticidal activity of cultures of the entomopathogenic fungus Cordyceps militaris on the larvae of the Colorado potato beetle Leptinotarsa decemlineata has been established for the first time. It was found that the peroral effect of the fungal culture resulted in dose-dependent decrease in survival, delayed in development time and molting, decreases in the total hemocyt counts, increased activity of phenoloxidases in the hemolymph, and reduced activity of the enzyme in the cuticle, as well as increased sensitivity of larvae to the fungus Beauveria bassiana at the level of the synergistic effect.

[Generation of reactive oxygen species and activity of antioxidants in larva hemolymph of galleria mellonella (L.) (lepidoptera: piralidae) at development of process of encapsulation].

Activities of enzymatic antioxidants (superoxide dismutase, glutathione-S-transferase, and catalase) have been determined in hemocytes and generation of reactive oxygen species (ROS) has been studied in lymph of larvae of the wax moth Galleria mellonella at development of the process of encapsulation of nylon implants. It has been established that as soon as 15 min after piercing of cuticle with implant the capsule is formed on its surface. The active melanization of the capsule has been shown to last for 4 h. There have been shown a statistically significant increase of the ROS generation in lymph and a decrease of activities of enzymatic antioxidants in hemocytes of the insects after the implant incorporation. The authors suggest that the key role in maintenance of the oxidation-reduction balance in hemolymph at development of the incapsulation process is played by the lymph non-enzymatic antioxidants.

[Changes in superoxide dismutase activity in various larval organs of greater wax moth (Galleria mellonella L., Lepidoptera: Pyralidae) induced by infection with Bacillus thuringiensis ssp. galleriae].

We studied the changes in superoxide dismutase activity in organs of Galleria mellonella larvae infected with two strains of Bacillus thuringiensis. A considerable increase in superoxide dismutase activity was observed at the initial stages of infection, later the enzyme activity decreased and this decrease was timed to cessation of feeding and development of sepsis in the infected larvae. Changes in the enzyme activity in the organs of larvae infected with a highly virulent strain of B. thuringiensis correlated with the stages of infection. Involvement of superoxide dismutase in prevention of oxidative stress in the infected larvae is discussed.

[Regulator gene of phenyl oxidase activity in Drosophila melanogaster]. / Gen-reguliator fenoloksidaznoi aktivnosti u Drosophila melanogaster.

A recessive lethal mutation l(2)hemo causing the occurrence of melanotic tumors in homozygous Drosophila larvae was found. The study of phenoloxidase (PO) activity revealed that the number of hemocytes with PO activity in homozygous larvae was significantly reduced (0.4 +/- 0.24%), compared to wild-type larvae (6.3 +/- 0.5%). On injury followed by injection with bacterial cells, the formation of melanotic thrombus did not occurred and hemocytes with PO activity were not recorded in homozygotes of line P103. Suppression of the activity of PO isozymes A1 and A3 was detected by means of electrophoretic analysis of homozygotes. According to gene mapping data, the localization of this mutation did not match any structural gene for known PO forms and is therefore related to a regulatory gene controlling the activity of the immune system of Drosophila.