Auxarthron reticulatum DY-2 was isolated from field soils in Jeonnam Province, South Korea, and its culture filtrate was active as a bionematicide agent against the pine wood nematode Bursaphelenchus mucronatus. The nematicidal activity against B. mucronatus was proportional to the concentration of the culture filtrate. The nematicidal compounds, dimethyl fumarate and bis(2-ethylhexyl)phthalate, were isolated and identified from A. reticulatum DY-2 culture filtrate using silica gel column chromatography combined with high performance liquid chromatography and gas chromatography-mass spectrometry. The bioassays on nematicidal activity revealed that bis(2-ethylhexyl)phthalate and dimethyl fumarate at 1% concentration resulted in 70 and 100% mortality of B. mucronatus, respectively, after 48 h exposure. This is the first report that these two compounds exhibit a property of nematicidal activity, especially on Bursaphelenchus spp.
Plant essential oils from 43 plant species were tested for their nematicidal
activities against the pine wood nematode, Bursaphelenchus xylophilus.
Responses varied with plant material and concentration. Good nematicidal
activity against male, female and juvenile nematodes of B. xylophilus was
achieved with essential oils of Cinnamomum verum, Leptospermum petersonii,
Asiasarum sieboldi, Boswellia carterii, Pimenta racemosa, Cymbopogon
citratus, Mentha spicata, clove and garlic. Garlic and cinnamon oils showed
the most potent nematicidal activity among the plant essential oils.
Analysis by gas chromatography-mass spectrometry led to identification of
three major compounds from garlic and two from cinnamon oil. These five
compounds from two essential oils were tested individually for their
nematicidal activities against the pine wood nematode. Responses varied with
compounds and dose. LC50 values of diallyl trisulphide, diallyl disulphide
and cinnamyl acetate against juvenile nematode were 2.79, 37.06 and 32.81
μl−1, respectively. The essential oils described herein merit further study
as potential nematicides against the pine wood nematode.
This research note presents evidence for the oldest Middle Pleistocene Eastern Saharan human activity from the area referred to as the Eastern Desert Atbara River (EDAR), Sudan, which is currently threatened by gold mining. Preliminary results of multifaceted analyses indicate the activity of Homo sapiens during MIS 5 as well as Homo erectus during MIS 7–11 or earlier.