No abstract

Effects of Beauveria bassiana on Andrallus spinidens Fabricius (Hemiptera: Pentatomidae), a predator of lepidopterous larvae in rice fields were investigated. The experiments were conducted at a concentration of 3×10 5 conidia ml -1 (LC 30 ) of B. bassiana on life table and some biochemical parameters of fifth instar nymphs. Insects were infected by dipping in the conidial suspension for 10s. The results showed that pre-oviposition period, fecundity, percent egg hatchability and longevity of treated bugs were not significantly affected compared with the control. Esterase (using β-naphtil as substerate) and glutathione S-transferase activity in A. spinidens increased 48 h after treatment. The fungus did not cause adverse effect on acetylcholinesterase activity. B. bassiana did not cause significant difference on life table parameters of A. spinidens compared to the control. According to the present study, it can be concluded that B. bassiana is compatible with the predatory bug at sublethal concentration (LC 30 ).

No abstract

Th e black citrus aphid, Toxoptera aurantii Boyer de Fonscolombe (Hemiptera: Aphididae), an important pest of citrus species, feeds by sucking sap from plant leaves. It causes some leaf distortion and malformation of growing leaves and shoot tips. In this study, the eff ects of the botanical insecticide, palizin on T. aurantii and its parasitoid, Aphidius colemani Viereck (Hymenoptera: Brachonidae) were compared with the chemical insecticide, imidacloprid. Th e compounds were evaluated at maximum recommended fi eld concentrations: palizin 2,000 ppm, imidacloprid 500 ppm, water (as control) on adult aphids. Spraying was done with a 100-l engine Honda sprayer (GX120T1, 160T1, 200T) until run-off . Th e number of dead aphids was recorded 24, 48 and 72 hours aft er treatment. According to the results, statistically signifi cant diff erences were found between treatments (p ≤ 0.05). Twenty-four hours aft er treatment, imidacloprid was more eff ective than palizin in reducing the T. aurantii population. Palizin showed high effi ciency (95% mortality) 72 hours aft er treatment. However, at that time, there was no statistically signifi cant diff erence between the mean mortality percentages of imidacloprid and palizin. Th is shows that botanical insecticide, palizin can eff ectively control T. aurantii. Also, palizin caused low mortality (10.86%) on A. colemani while imidacloprid was more toxic (31.1% mortality). Th e results of the present study indicated that palizin can be used instead of chemical insecticide, imidacloprid in control programs of T. aurantii.