Composition and biological activity of essential oils against Metopolophium dirhodum (Hemiptera: Aphididae) cereal crop pest.

Background: Natural pesticides based on plant essential oils may represent alternative crop protectants. This study analysed the chemical constituents and bioactivities of essential oils from Schinus areira L., Rosmarinus officinalis L.

Cholinesterase activity during embryonic development in the blood-feeding bug Triatoma patagonica.

Triatoma patagonica Del Ponte (Hemiptera: Reduviidae), a vector of Chagas' disease, is widely distributed in Argentina and is found in sylvatic and peridomiciliary ecotopes, as well as occasionally in human dwellings after the chemical control of Triatoma infestans. Anti-cholinesteratic products can be applied in peridomiciliary areas and thus knowledge of cholinesterase activity during embryonic development in this species might contribute further information relevant to effective chemical control. Cholinesterase activity was characterized by reactions to eserine 10(-5) m, to increasing concentrations of substrate and to varying centrifugal speeds.

Repellence and toxicity of Schinus molle extracts on Blattella germanica.

The biological activities of ethanol and petroleum ether extracts from leaves and fruits of Schinus molle against adults of Blattella germanica were examined by repellence test and topical application. All extracts produced significant repellent effect and mortality.