Liriomyza sativae and L. trifolii are highly invasive leafminer pests of vegetable crops that have invaded southern China in recent years. Liriomyza sativae was the first of these species to invade China, but it is now being displaced by L. trifolii. The rate and extent of this displacement vary across southern China. In Hainan, monocultures of highly valuable cowpea are planted and treated ext...

BACKGROUND Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to simulate an altered gravity environment, as in space. In this study, using Streptomyces avermitilis as the test organism, we investigate whether changes in magnetic field and altered gravity induce changes in morphology and secondary metabolism. We find that a strong magnetic field (12T) inh...

conclusions: the hereditary stability analysis of the uv mentioning 45 minutes revealed the uv exposure time for mutants and 3 represented the colony taken from the plate irradiated for 45 minutes mutant showed that the production of avermectin b1b remained constant and no reverse mutation occurred after 15 generations. results: avermectin b1b-hyper-producing mutant, produced using these three ...

Most microbial secondary metabolites are producec as complexes of closely related compoundsby theii producing organisms. The avermectins1*, milbemycins2 and nemadectins3~5) are typical examples produced ii such a manner. The milbemyciif complex is known t( consist of more than twenty components6 ~ 8), however only a few are commercial products. A rationale for thii phenomenon may be related to ...

Ivermectin (MK-0933, 22, 23-dihydroderivative of amvermectin B1) is a synthetic derivative of a broadspectrum antiparasitic class of macro cyclic lactones known as avermectins. Avermectin B was first isolated by fermentation of a soil microorganism, the actinomycete Streptomyces avermitilis. Ivermectin has a structure similar to that of macrolide antibiotics, but without antibacterial activity ...

Ivermectin has potent systemic activity against numerous species of nematodes and arthropods, but there are some important species in these two groups, such as the cat flea, Ctenocephalides felis (Bouché), that appear to be refractory to it. In an effort to determine if the lack of systemic activity against C. felis is specific to ivermectin, or if it is a class-wide phenomenon, 20 avermectin d...