Exploring genetic biodiversity: secondary metabolites from Neotropical Annonaceae as potential source of new pesticides To investigate potential sources of novel grain protectors, this study evaluated, firstly, the bioactivity of ethanolic extracts (66) prepared from 29 species belonging to 11 different genera of Neotropical Annonaceae against the maize weevil Sitophilus zeamais (Coleoptera: Curculionidae). A screening assay demonstrated that the most pronounced effects (acute and chronic) on S. zeamais were caused by extracts from the Annona montana, A. mucosa, A. muricata and A. sylvatica seeds, and, to a lesser extent, by extracts prepared from leaves of A. montana, A. mucosa, A. muricata, and Duguetia lanceolata. However, the most active extracts (from seeds) did not affect fungal growth and aflatoxin production of Aspergillus flavus (Ascomycota: Trichocomaceae). Using the maize weevil as bioindicator, bioguided fractionations were then conducted in order to isolate, purify and characterize the possible active compound(s) from the most interesting extracts. By means of different chromatographic procedures, nine compounds (five acetogenins, three steroids, and one aromatic compound) were isolated. The acetogenins rolliniastatin-1 and ACG4 (structural determination in progress) and the aromatic compound 2,4,5trimethoxystyrene as well as the steroids campesterol, stigmasterol, and sitosterol [tested in mixture (8.44 + 12.37 + 79.19%, respectively)] showed promising grain protective properties. Furthermore, the obtained results indicate that compounds from different chemical natures have a synergistic effect on the overall biological activity of the crude extracts. In a second study, the acute and chronic toxicity of selected ethanolic seed extracts from Annona species (A. montana, A. mucosa, A. muricata, and A. sylvatica) and an acetogenin-based commercial bioinsecticide (Anosom ® 1EC) were investigated against the cabbage looper Trichoplusia ni (Lepidoptera: Noctuidae) and the green peach aphid Myzus persicae (Hemiptera: Aphididae). In the laboratory, extracts of A. mucosa and A. sylvatica as well as Anosom ® were especially active through oral and topical administration. A greenhouse trial showed that a formulated A. mucosa extract and Anosom ® were highly effective (>98% mortality) against third instar of T. ni larvae, and comparable to a pyrethrin-based commercial insecticide (Insect Spray ®) used as a positive control. Similar to results with T. ni, A. mucosa extract showed the greatest aphicidal either in laboratory or greenhouse bioassays. In a third study, the acaricidal activity [against the citrus red mite Panonychus citri (Acari: Tetranychidae)] of the ethanolic extract from A. mucosa seeds (most active) was investigated. In laboratory tests, it exhibited levels of activity superior to commercial acaricides/insecticides of natural origin [Anosom ® 1EC (annonin), Derisom ® 2EC (karanjin), and Azamax ® 1.2EC (azadirachtin + 3tigloylazadirachtol)] and similar to a synthetic acaricide [Envidor ® 24 SC (sp...