The potential abilities of 3-methylbenzaldehyde derived from Myosotis arvensis oil and its structural analogues to actas new acaricide and mite kit (mite color deformation) against Tyrophagus putrescentiae (Schrank) were evaluated in thepresent study. Based on the LD50 values, 2,4,5-trimethylbenzaldehyde (0.78 μg/cm3) had highest vapor action against T.putrescentiae, followed by 2,4-methylbenzaldehyde (1.14 μg/cm3), 2,5-dimethylbenzaldehyde (1.29 μg/cm3), 2-methylbenzaldehyde (1.32 μg/cm3), 2,3-dimethylbenzaldehyde (1.55 μg/ cm3), 3-methylbenzaldehyde (1.97 μg/cm3), and4-methylbenzaldehyde (2.34 μg/cm3). The color deformation of seven methylbenzaldehyde analogues mixed with2,3-dihydroxybenzaldehyde against T. putrescentiae showed mite color deformation, from coloress to reddish brown, andvaluable to distinguish with the naked eye. In addition, there was no antagonistic interactions between 2,3-dihydroxybenzaldehydeand the methylbenzaldehyde analogues. These finding suggests that the methylbenzaldehyde analogues could be developedas dual functional agent to protect from fall in the commercial value of stored food products.

Insecticidal toxicities of the isolated constituent of Eucalyptus dives oil and its analogues were bioassayed. 3-Carvomenthenone was isolated by chromatographic techniques and determined by EI-MS, 13C-NMR,1H-NMR, 1H-1H COSY, and HMQC. In the fumigant bioassay against P. interpunctella, cyclohexenone exhibited the strongest insecticidal toxicity (LD50 against larvae and adults, 2.45 and 3.63 μg/cm3), followed by methylcyclohexenone, seudenone, and 3-carvomenthenone. In the structure-activity relationships between 3-carvomenthenone analogues and insecticidal toxicity, the mode of the insecticidal action of 3-carvomenthenone, cyclohexenone, methylcyclohexenone, and seudenone was through the dermal organs of T. castaneum and P. interpunctella. This study indicates that 3-carvomenthenone, cyclohexenone, methylcyclohexenone, and seudenone have potential capacity for the development as safety natural agents to control the stored grain insects.

The purpose of this study was to isolate an active constituent from the essential oil of Eugenia caryophyllata leaves and evaluate its insecticidal activity against Pochazia shantungensis nymphs and adults. According to chromatographic and spectroscopic analyses, the active constituent of E. caryophyllata leaves was identified as eugenol. Based on LC50 values and structural analogues of eugenola gainst the P. shantungensis nymphs and adults, isoeugenol (LC50, 83.29 and 91.03 mg/L) exhibited the highest insecticidal activity, followed by methyl isoeugenol (105.61 and 114.48 mg/L), eugenol (124.44 and 143.24 mg/L), methyl eugenol (126.31 and 143.84 mg/L), and acetyl eugenol (165.11 and 170.06 mg/L). Insecticidal activity against P. shantungensis was dependent on the presence of a functional group in 4-ally-2-methoxyphenol. These results indicate that E. caryophyllata oil and eugenol analogues might be potential alternative synthetic insecticidal agents.

Phototactic behavioral responses of the Indian meal moth, Plodia interpunctella (Hübner), adults were determined to different light-emitting diodes (LEDs) of seven wavelengths, and their behavioral responses were compared to that using a commercial luring lamp (BLB) under laboratory conditions. Based on the attractive responses under optimal light conditions (60 lx luminance intensity and 30 min light exposure time), the green LED (520±5 nm) showed the highest attractive rate (520±5 nm, 52.2%), followed by the blue LED (470±10 nm, 33.9%), the yellow LED (590±5 nm, 32.2%), BLB (28.9%), UV LED (365 nm, 22.8%), the red LED (625±10 nm, 14.5%), the white LED (450-620 nm, 10.6%), and IR LED (730 nm, 9.5%). In addition, the green LED to P. interpunctella adults was approximately 1.81 times more attractive than BLB. These results indicate that the green LED could be most useful for monitoring of P. interpunctella adults.

Phototactic behavioral responses of Tribolium castaneum adults to light-emitting diodes (LEDs) of seven different wavelengths were determined under various conditions (light exposure times, light sources, and luminance intensities) and compared with those of a black light bulb (BLB) under laboratory conditions. Based on the attractive rate (%) of T. castaneum adults under optimal conditions (50 lx and an 48 h exposure time) in the dark, red LED (625±10 nm) exhibited the highest potential attractive rate (97.8%), followed by yellow (590±5 nm, 68.9%), green (520±5 nm, 55.6%), infrared (IR) (730 nm, 54.4%), white (450-620 nm, 41.1%), blue (470±10 nm, 34.4%), and ultraviolet (UV) (365 nm, 0.06%) LEDs. In comparison, red LED (97.8%) was approximately 3.4 times more attractive to T. castaneum adults than the BLB (28.9%). These results indicate that a red LED trap could be useful to control T. castaneum adults.

The essential oils of three Coriandrum sativum seeds cultivated from India, Russia and America were evaluated for acaricidal toxicities against Dermatophagoides farinae, D. pteronyssinus, and Tyrophagus putrescentiae. The oils of three C. sativum seeds were analyzed by gas chromatography. The oil of C. sativum seeds cultivated from India included substantially linalool (66.8%) and camphor (6.46%). In the fumigant bioassay, based on the LD50 values against D. farinae, D. pteronyssinus, and T. putrescentiae, the oil of C. sativum seeds cultivated from America (LD50, 2.62, 2.74, and 2.88 μg/cm3) was about 3.75, 3.32, and 4.17 times more active higher than benzyl benzoate (9.85, 9.10 and, 12.01 μg/cm3). The acaricidal activity of the oil of C. sativum seeds cultivated from India was 2.27, 2.03, and 2.64 times higher than that of the benzyl benzoate, followed by Russia oil. These results suggest that the oils of three C. sativum seeds might be used as suitable acaricides.

본 연구는 쌀을 비롯한 저장곡물을 가해하는 어리쌀바구미(Sitophilus zeamais) 성충에 대해서 8종의 식물정유의 훈증독성과 Y-tube를 이용한 후각반응으로 기피효과를 조사하였다. 10㎕/L air의 농도에서 훈증독성시험 결과 pennyroyal과 tea tree 오일에서 각각 97%, 63%의 높은 살충효과를 보였다. 특히, pennyroyal oil(LT50, hour=3.87)은 tea tree oil((LT50, hour=4.09)보다 높고 빠른 살충력을 보였다. 10㎕/filter paper의 농도에서 후각계를 이용한 기피효과는 Cedarwood(80%), Cinnamon(83.3%), Cypress(81.1%), pennyroyal(97.1%) oil이 높은 기피활성을 보였으며, 이보다 낮은 1㎕/filter paper의 농도에서도 Cinnamon(82.4%), Cypress(80.0%), pennyroyal(86.7%) 오일은 높은 기피활성을 나타냈다.

Maize weevil is one of the most common and critical storage pest in the world. In this study, the insecticidal activity of the methanol extracts derived from Caesalpinia sappan was evaluated against adults of maize weevil, using by direct contact and fumigant methods. Based on the two methods, ethyl acetate fraction of the C. sappan extracts had 100% mortality against Maize weevil adults at 10 mg. The biological constituent of C. sappan extract was isolated by various chromatographic techniques and identified as juglone. On the basis of 72 h LD50 values, in the direct contact bioassay, the insecticidal activity of juglone (0.010 mg/cm2) was the most effective, followed by 1,4-NQ (0.018 mg/cm2) and menadione (0.087 mg/cm2). In a fumigant bioassay, the insecticidal activity of juglone (0.014 mg/cm2) was the most effective, followed by 1,4-NQ (0.015 mg/cm2) against maize weevil adults. On the other hand, menadione, lawsone, and 2-methoxy-1,4-NQ observed no insecticidal activity or weak. These results suggested that active compound of C. sappan materials could be used as biological control agent against maize weevil. Therefore, further research should be performed to the structure activity relationship of juglone and compared with its derivatives.

In this study, we evaluated the acaricidal activities of AP and its derivatives for their potentials as natural acaricides using the vapor phase and contact toxicity bioassays against Dermatophagoides spp. and Tyrophagus putrescentiae, and then compared with that of commercial acaricide such as benzyl benzoate. The acaricidal constituent of A. koreana was isolated by various chromatographic techniques and identified as 2’-H-4’-MAP. In the vapor phase toxicity bioassay, based on the LD50 values of 2’-H-4’-MAPand its derivatives against D. farinae, 2’-MAP (1.25 ㎍/㎠) was 8.0 times more effective than benzyl benzoate (10.00 ㎍/㎠), followed by 3’-MAP (1.26 ㎍/㎠), 4’-MAP (1.29 ㎍/㎠), 2’-H-4’-MAP (1.75 ㎍/㎠), and 2’-H-5’-MAP (1.96 ㎍/㎠). In the contact toxicity bioassay, 3’-MAP (0.58 ㎍/㎠) was 12.97 times more toxic than benzyl benzoate (7.52 ㎍/㎠), followed by 2’-MAP (0.64 ㎍/㎠), 2’-H-4’-MAP (0.76 ㎍/㎠), 4’-MAP (0.77 ㎍/㎠), and 2’-H-5’-MAP (1.16 ㎍/㎠). The acaricidal activities of 2’-H-4’-MAP derivatives against D. pteronyssinus and T. putrescentiae were similar to those against D. farinae. These results indicated that acaricidal activities of 2’-H-4’-MAP derivatives against the three mite species were changed with the introduction of hydroxyl (-OH) and methyl (-CH3) groups onto the acetophenone skeleton.

The object of this study was the acaricidal activities of acetophenone (AP) and its derivatives for their potentials as natural acaricides using fumigant and contact toxicity bioassays against Dermatophagoides farinae, D. pteronyssinus, and Tyrophagus putrescentiae. Based on the LD50 values of AP derivatives against D. farinae, 3’-methoxyAP (0.41 ㎍/㎠) was 89.9 times more toxic than DEET (36.87 ㎍/㎠), followed by 4’-methoxyAP (0.52 ㎍/㎠), 2’-methoxyAP (0.75 ㎍/㎠), 2’-hydroxy-5’-methoxyAP (1.03 ㎍/㎠), 2’-hydroxy -4’-methoxyAP (1.29 ㎍/㎠), AP (1.48 ㎍/㎠), 2’-hydroxyAP (1.74 ㎍/㎠), 2’,5’-dimethoxyAP (1.87 ㎍/㎠), 2’,4’-dimethoxyAP (2.10 ㎍/㎠), and benzyl benzoate (9.92 ㎍/㎠). With regard to structure-activity relationships between acaricidal activity and functional groups (hydroxyl and methoxy groups) on the AP skeleton, a mono-methoxy group (2’-, 3’-, and 4’-methoxyAP) on the AP skeleton was more toxic than the other groups (2’,4’- and 2’,5’-dimethoxyAP, 2’- and 4’-hydroxyAP, 2’-hydroxy-4’-methoxyAP, 2’-hydroxy-5’-methoxyAP, and 4’-hydroxy-3’-methoxyAP). These results indicated that acaricidal activity against three mite species was changed with the introduction of functional radicals (hydroxyl and methoxy groups) onto the AP skeleton.

The behavioral responses of Plutella xylostella (Lepidoptera: Plutellidae) to four high power light emmitting diodes (HPLEDs) were tested at various illuminance intensity and light exposure time using a HPLED-equipped Y-maze chamber. Preference tests were conducted using the high power light emmitting diodes (HPLEDs) in the dark room at 27±0.5℃ and 60±0.5% relative humidity. Evaluated specific wavelengths were blue, green, yellow and red HPLEDs. The illuminance intensity was tested at 20, 40, 60, 80, and 100 lx and fixed at 30 min. As a result, the attraction rate of the green HPLED at 60 lx was the best effective (98.3%) to P. xylostella, followed by red HPLED of 60 lx (86.5%), yellow HPLED of 60 lx (83.6%), and blue HPLED of 40 lx (72.0%), respectively. Depending on the change of light exposure time (5, 10, 15, 20, and 25 min), green HPLED showed the potential attraction under the 15 min. These results may be used as information for developing an eco-friendly insect pest control system. Further research needs to be performed to evaluate the behavioral responses to single and multiple HPLED sources in the field.

The aim of this study is to observe the attraction of four colored lights against beet armyworm (Spodoptera exigua). The visual preference of the beet armyworm for light-emitting diodes (LEDs) was examined by LED equipped phototactic chamber in the dark room at 27 ± 0.5°C and 60 ± 5% relative humidity. Evaluated specific wavelengths of LEDs were blue (470 ± 10 nm), green (520 ± 5 nm), yellow (590 ± 5 nm) and red (625 ± 10 nm), and compared with that of the commonly luring lamp used fluorescent (380-800 nm) which served as controls. The light intensity was tested at 20, 40, 60, 80 and 100 lx, and light-exposure time was determined at 20, 40, 60, 80 and 100 min. All of the light treatments with 40 lx intensity and the 60 min light-exposure time showed the highest attraction rate to S. exigua. Based on attraction rate of the green LED (88.9%) was the most attractive to S. exigua, followed by blue LED (81.1%), yellow LED (63.3%) and red LED (56.7%). In comparisons with LED and fluorescent light, the attractive rate to green LED against beet worm was more effective than that of fluorescent (80%) light. Overall, these results indicated that the eco-friendly LED could be a more effective substitute for the chemical free insect pest control system because of the various advantages.

5-Hydroxy-1,4-naphthoquinone and its derivatives were evaluated for insecticidal effect against Sitophilus oryzae and S. zaemais adults. This study was examined using fumigant method. Mortality was determined after 72 h of treatment. 5-Hydroxy-1,4-naphthoquinone showed strong (+++) activity at 5 mg and the 1,4-naphthoquinone showed strong (+++) and moderate (++) activity at 5 mg, against S. oryzae and S. zaemais, respectively. However, 5-hydroxy-2-methyl-1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone, and 2-methoxy-1,4-naphthoquinone had non-activity (-) at 5 mg. Based on the LD50 values, the compound most highly effect to S. oryzae was 1,4-naphthoquinone (0.012 mg/cm2), followed by 5-hydroxy-1,4-naphthoquinone (0.013 mg/cm2). However, against S. zeamais, 5-hydroxy-1,4-naphthoquinone (0.044 mg/cm2) was the most toxic compound, followed by 1,4-naphthoquinone (0.155 mg/cm2). These results suggest that the introduction of various functional group (hydroxy, methyl and methoxy) into the 1,4-naphthoquinone skeleton contributes to insecticidal activity. Accordingly, 5-hydroxy-1,4-naphthoquinone and 1,4-naphthoquinone could be used highly effective rice weevil control agents.

The rice weevil, Sitophilus oryzae, is the most serious storage pests worldwide of grocery shops, flour mills, and warehouses. The phototactic response of the rice weevil, S. oryzae, to light emitting diodes (LEDs) at five different wavelengths and various light intensities was tested within an LED-equipped Y-maze chamber, and compared with its response to a luring lamp, which is used in commercial traps. Various wavelengths in this study were UV (365 nm), blue (450 nm), green (520 nm), red (660 nm), and infrared (IR) (730 nm). Based on attraction rate (%), blue (84.3%) was the most attractive to S. oryzae, followed by green (74.3%), red (64.3%), UV (63.3%), and IR (48.7%). Moreover, blue and green wavelengths were 1.5 and 1.3 times more attractive than luring lamp (56.7%), whereas the UV wavelength was slightly less attractive to the weevils than luring lamp. These results suggested that blue and green wavelengths could be more useful than those currently used for monitoring and mass trapping of S. oryzae.

To evaluate potential attractive activity of high power light emitting diodes (HPLEDs) against Plutella xylostella (Lepidoptera: Plutellidae), the specific wavelengths, illuminance intensities (20, 40, 60, 80, 100 lux), and light exposure times were investigated at 5 minute intervals. The evaluated specific wavelengths were blue (450±10 nm), green (520±5 nm), yellow (590±5 nm), red (660±10 nm), and white (450-630 nm). Based on the highest attraction rate, the HPLEDs treated to 60 lux intensity against P. xylostella were significantly more attractive than other illuminance intensities when light exposure time was 10 min. Attraction rate under optimal conditions showed that the green HPLED had the highest attraction rate (98.3%), followed by red HPLED (89.3%), blue HPLED (86.7%), yellow HPLED (76.7%), and white HPLED (70.0%), respectively. These results indicated that phototatic effect of the green HPLED against P. xylostella showed the greatest attraction at 60 lux intensity and 10 min light exposure time. Further research needs to be performed to evaluate the phototatic behavioral responses to single and multiple HPLED sources in the field.

The object of this study is to observe the attraction of specific wavelengths against Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). The attractive effects was examined by the high power light-emitting diodes (HPLEDs) in the dark room at 27±0.5°C and 60±0.5% relative humidity. Evaluated specific wavelengths were blue (470±10 nm), green (520±5 nm), yellow (590±5 nm) and red (625±10 nm) HPLEDs. When a light exposure time was fixed at 60 min and tested with various illuminance intensity at 20, 40, 60, 80, and 100 lux, the attraction rate of the green HPLED at 80 lux was the most effective (94.4%) to B. tabaci, followed by yellow HPLED of 20 lux (78.9%), blue HPLED of 60 lux (71.1%), and red HPLED of 20 lux (60.0%), respectively. According to the change of light exposure time (10, 20, 30, 40, 50, and 60 min), green HPLED showed the potential attractive effects under the 40 min and 50 min. These results suggest that it is possible to develop a green HPLED trap for attracting, monitoring, and lighting system against B. tabaci.

Spodoptera exigua is a significant polyphagous pest in the greenhouse and open field. Our aim of this study was to evaluate light emitting diodes (LEDs) as the potential attractants against Spodoptera exigua on various wavelengths, light intensity, and light duration. The preference response to S. exigua was investigated by the laboratory and field-scale. The wavelengths of LEDs were composed as follows: blue (470 nm), green (520 nm), yellow (590 nm), red (625 nm) and white (450-620 nm). When the optimal light condition was investigated in the laboratory scale, the all light treatments attracted the highest number of S. exigua at 40 lux intensity and 60 min duration. Based on the wavelengths under optimal light condition, the white LED exhibited the highest attraction rate (91.1%), followed by green (88.9%), blue (81.1%), yellow (63.3%) and red (56.7%), respectively. In comparison with the selected white LED and yellow sticky traps in the field-scale, the white LED (81.3%) was about 16.26 times more attractive than yellow sticky trap (5.0%). These results clearly show that the white LED had the greatest attraction against S. exigua.