This study was performed to investigate attraction effect of spearmint oil and to confirm their EAG response against lantern fly, Lycorma delicatula nymphs and adult. In dose responses to spearmint oil, 2nd ∼ 4th nymphs and adult were significantly attracted at a dose of 5㎕. Attraction effect was showed highest (84.8%) at a 4th instar nymph, and mild effect (approximately 60%) was observed at 2nd∼3rd instar nymphs, but the others are not showed the significance. At a dose of 10㎕, 4th instar nymph and adult were significant and only 4th instar nymph was significantly attracted at a dose of 2.5㎕ but the others are not. Carvone, a constituent of spearmint oil, exhibited significantly attraction effect on nymphs and adult except 1st and 2nd instar nymphs. But limonene did not show any attraction effect. The attraction assay of L. delicatula to the mixtures of constituents appeared to be efficient additively. In EAG response to spearmint oil which exhibited attraction effect, antennae of 4th instar nymph and adult responded to only carvone. In conclusion, attraction effect of spearmint oil was more effective in 4th instar nymph and adult than 1st ∼ 3rd instar nymphs.
This study was performed to investigate attraction effect of six plant essential oils and to confirm their electrophysiological response against Lycorma delicatula. Among the tested oils, spearmint oil (94.1%) significantly attracted L. delicatula at a dose of 1.25㎕/cm2 by using an olfactometer. In dose response to spearmint oil, a dose of 2.5㎕/cm2 was very effective. GC-MS analysis revealed that the active components responsible for the effective attraction effect of spearmint oil were carvone (70.6%) and limonene (54.8%). Of the two active components, carvone was more significant than limonene with reference to attraction activity against L. delicatula. Analysis by GC-EAD showed, major components of spearmint oil that elicited response in L. delicatula antennae, indicating the potential role of the essential oil as attractant that determine the choice of the attraction material. In the field test, spearmint oil exhibited attraction effect up to 5 days. This effect was different in accordance with test places and treatment dose.
The author examined the response of Armorclad rockfish, Sebastes hubbsi [MATSUBARA]to the surface attracting lamps (0.5W, 0.8W, 1W) line in the experimental water tank (550L×58W×73Hcm). The attraction rate was investigated in accordance with the intervals of lighting and putting out hour (1,5 minute) when each of the attraction lamps was gradually switched off after they were switched on all at once. The results are as follows : 1. Total distribution rate of fish in the illuminated section was 61.6%(mean 12.3%) in case of 1 minute interval, and 41.0%(mean 8.2%) in case of 5 minutes interval. 2. Mean distribution rate of fish at the illuminated section : ①Distribution rate at interval of 1 minute were 12.7% in 0.8W, 12.4% in 0.5W and 11.9% in 1 W respectively. ②Distribution rate at interval of 5 minutes were 9.0% in 1W, 8.6% in 0.8W and 7.0% in 0.5W respectively. 3. Attraction rates of the last section showed a little increasing as illuminating time elapsed. A difference of attraction rates according to lighting source in 1 minute interval was bigger than that in 5 minute interval. 4. Attraction rate of fish in only last section switched on : ①Attraction rate at interval in case of 1 minute were 52.0% in 0.8W, 46.7% in 0.5%W and 45.3% in 1W respectively. ②Attraction rate at interval in case of 5 minutes were 32.0% in 1W, 24.0% in 0.8W and 14.7% in 0.5W respectively.
The author has examined the response of sting fish, Sebastes inermis and black porgy, Acanthopagrus schlegelii to the attraction lamps(1 W) line in an experimental water tank(550 L× 58 W × 73H cm). Attraction lamp was set up at intervals of 55 cm for each section. The frequency rate was investigated at the illuminated section in accordance with the intervals of lighting on and putting out that was 1, 3 and 5 minutes under two conditions of light stimulus. The results are as follows: 1. Frequency rate at the last section when each of the attraction lamps was gradually switched on and off: (1) Sting fish was 27.2 % in case of 3 minutes interval, and 17.4 % in 1 minutes interval, and 15.8 % in 5 minutes interval. (2) Black porgy was 28.5 % in case of 5 minutes interval, and 25.8 % in 3 minutes interval, and 12.0 % in 1 minutes interval. 2. Distribution of fish at the illuminated section when each of the attraction lamps was gradually switched off after they were switched on all at once: (1) Sting fish was much gathered in the section adjacent to the extinguished section under the condition of 1 and 3 minutes interval, and not regular trend under 5 minutes interval. (2) Black porgy was much gathered last section under the condition of 1 and 3 minutes interval, and almost evenly distributed under 5 minutes interval. 3. Each of the attraction lamps was gradually switched off after they were switched on all at once, and only the last one was on: (1) The frequency rate of Sting fish was 27.2 % in case of 5 minutes interval, and 16.0 % in 1 minute interval, and 8.0 % in 3 minutes interval. (2) The frequency rate of Black porgy was 10.7 % in case of 1 minute interval, and 8.9 % in 3 minutes interval, and 0.8 % in 5 minutes interval.
유도등렬로서 집어된 어류를 목적장소까지 유도하기 위하여 2가지의 유도등 점멸방법 (Normal, Nega 방법), 3가지의 점멸간격 (1,5,10분) 및 3 가지의 적응등용전구 (1, 10, 20 W)를 사용해서 말쥐치 Navodon modestus(GUNTHER)에 광자극을 주었을 때 그에 대한 반응을 조사한 결과는 다음과 같다. 1. Normal 방법에 의한 점멸간격과 적응등의 밝기에 따른 유도율의 변화를 나타내는 변동계수는 각각 16.78% (1 분), 9.71% (5 분), 8.96% (10 분), 9.71% (1 W), 15.00% (10W), 21.08% (20 W)였고, 최종구간에서의 유도율은 각각 80.0% (1 분), 86.0% (5 분), 85.0% (10 분), 86.0% (1 W), 78.7% (10W), 72.7% (20 W)였다. 2. Nega 방법에 의한 각 점멸구간에서의 어류분포는 점멸간격과 적응등의 밝기에 관계없이 거의 모든 점등구간에 분포했으며 그 중 소등구간에 인접한 점등구간에 많이 분포하였다. 3. Nega 방법에 의한 최종구간에 대한 유도율의 변화는 L자형이 되었으며, 최종유도등만 점등되었을 때의 유도율은 각각 96.7% (1 분), 100% (5 분), 96.0% (10 분), 100% (1 W), 100% (10W) and 88.0% (20 W)였다.