• Korean journal of applied entomology
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• v.58 no.2
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• pp.159-164
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• 2019

The purpose of this study was to investigate whether leaf damage in pear orchards caused by large black chafer beetles can be controlled through net traps and clove oil treatment. In June 2017, we measured large black chafer beetle population density and leaf damage rates in two orchards, located in Boseong and Hampyeong, under three treatments: net, net plus clove oil, and control. In order to evaluate the effect of net position on the adult beetles, nets were placed outside the orchard and along the upper and lower parts of a horizontal trellis. The adult beetle population density was 20.4 to 34.7% lower in the net alone treatment, and 21.1 to 38.1% lower in the combined net and clove oil treatment than in the control. The adult beetle population density was 10.9-14.4 times higher outside the orchard and 5.1 to 9.1 times higher in the upper parts of the horizontal trellis than in the lower parts of the horizontal trellis. Leaf damage under both the net only and net plus clove oil treatments was significantly lower than that in the control at both sites. Therefore, intensive net installation around orchards may be a practical organic alternative to prevent leaf damage caused by large black chafer beetles.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.85-92
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• 2000

Easy measurement method of orthogonal triple-sensor hot-wire anemometer is developed. Advantages of the new method is that it does not require either the exact orthogonality of the installed wires which cannot be kept during the probe manufacture and repair, nor the knowledge of the wire installation angles and the yaw and pitch coefficient of the wires. The new method introduced yaw and pitch calibration coefficients which are designed to increase monotonically with yaw and pitch angles. So the resulting calibration network is simple to recognize compared with that of the previously suggested calibration method. Verification experiments showed good accuracy and independency of the directional calibration on velocity.

• Korean journal of applied entomology
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• v.56 no.2
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• pp.187-193
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• 2017

The Japanese pine sawyer, Monochamus alternatus Hope, is a representative vector of the pine wood nematode, Bursaphelenchus xylophilus, which causes wilting symptoms in pine trees. A control method using a net has been introduced, which is an alternative method to the fumigation for the control of dead pine trees by pine wilt disease. This study was carried out to investigate the factors that induce gnawing and escaping behaviors of M. alternatus. The behaviors were examined after M. alternatus adult was placed in a confined space at different temperatures. M. alternatus adults could escape through mesh net torn by gnawing when they were confined in a space of 30 mm or less in diameter. The success rate of escape was high at 20 to $30^{\circ}C$, and no adults escaped at $15^{\circ}C$. The enticement of M. alternatus adults by food didn't affect the success rate of escape. In the case of not being confined in a narrow space, the escaping hole could not be formed because the gnawing was not concentrated on one part. M. alternatus moved its body in a narrow space using the tarsus of middle and hind legs, and made an escape hole by concentrically gnawing the obstacle on the front side with mandible, and showed a behavior of getting out while supporting the body by supporting the front legs. The present results will be able to use as an important basic information for evaluating the performance of mesh net which confines M. alternatus adults and suggested by alternative method to fumigation technology.