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.
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.
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 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.