Sesbania species (Fabaceae) are a valuable plant resource in tropical agriculture. Recently, Mesoplatys ochroptera Stål (Coleoptera : Chrysomelidae) has become a serious pest of Sesbania species in agroforestry systems in Africa. The biology of M. ochroptera was studied in eastern Zambia and southern Malawi. Sesbania bispinosa (Jacq.) Wight, S. brevipedunculata Gillet, S. leptocarpa DC, S. macrantha Phil. & Hutch., S. rostrata Bremek & Obrem, S. sericea (Willd.) Link, S. sesban (L.) Merr. and S. tetraptera Hochst. ex Baker were the primary hosts of M. ochroptera in the study area. Females laid on average one egg batch per day in an oviposition period of 18-56 days. Egg batches contained 2-70 eggs. Females that were mated repeatedly produced about 1000 offspring while those mated only once produced 980 offspring. Larval development through three instars, took between 11-34 days. Pupal development occurred in the soil, and took 4-16 days. The survival and developmental periods of pre-imaginal stages differed significantly between the Sesbania species studied. The highest and lowest pre-imaginal survival was recorded on S. leptocarpa and S. rostrata, respectively. The longest developmental period of about 32 days was recorded on S. sesban while the shortest of 14 days was on S. leptocarpa. Annual activity cycle in M. ochroptera followed the unimodal rainfall pattern of southern central Africa. Beetles were only active during the rainy season (November-April) with a single population peak between February and April. Adults overwintered within and around the sesbania fallows during the long dry season (May-October) and emerged with the onset of the rains.
Tag: biological properties
Identification of Bioactive Phytochemicals from Six Plants: Mechanistic Insights into the Inhibition of Rumen Protozoa, Ammoniagenesis, and α-Glucosidase
Rumen protozoa prey on feed-degrading bacteria synthesizing microbial protein, lowering nitrogen utilization efficiency in ruminants. In this in vitro study, we evaluated six plants (Adansonia digitata, Flemingia macrophylla, Kalimeris indica,Brassica rapa subsp. chinensis, Portulaca oleracea, and Calotropis gigantea) for their potential to inhibit rumen protozoa and identified the phytochemicals potentially responsible for protozoa inhibition. Rumen protozoa were anaerobically cultured in vitro in the presence of each plant at four doses. All of the tested plants reduced total rumen protozoa (p ≤ 0.05), but C. gigantea and B. rapa were the most inhibitory, inhibiting rumen protozoa by 45.6 and 65.7%, respectively, at the dose of 1.1 mg/mL. Scanning electron microscopy revealed a disruption of the extracellular structure of protozoa cells. Only C. gigantea also decreased the wasteful ammoniagenesis (p ≤ 0.05). Moreover, the A. digitata extract inhibited α-glucosidase activity by about 70% at 100 µg/mL. Reversed-phase high-performance liquid chromatography analysis detected quercetin, anthraquinone, 3-hydroxybenzoic acid, astragaloside, and myricetin in the tested plant leaves. These plants may hold potential as feed additives to reduce rumen protozoa and α- glucosidase activity. Future research is needed to identify the specific anti-protozoal compound(s), the effects on the rumen microbiome, and its fermentation characteristics.