Ethyl formate (EF) and phosphine (PH3) is an alternative fumigant to methyl bromide (MB). For applying import sweet pumpkins in Korea, the efficacy of EF and PH3 was evaluated on Tetranychus urticae adult and egg stage which is pest in sweet pumpkins. The eggs of T. urticae were more tolerance than adults in both EF and PH3. When T. urticae eggs were treated with EF for 4 hrs, LCT99=107.63 mg/L and LCT99=45.37 mg/L at 5°C and 20°C, respectively. PH3 treatment at 5°C and 20°C for 24 hrs, eggs were controlled LCT99=49.44 mg/L and LCT99=17.23 mg/L, respectively. The mixed treatment of EF and PH3 showed no significant synergistic effect on T. urticae. However, EF (80 mg/L) and PH3 (4 mg/L) treatment did not cause any external phytotoxicity damages in sweet pumpkin even when treated with the maximum amount of fumigant at 5℃ and 20℃ for 24hrs.
Ethyl formate (EF) and phosphine (PH3) is an alternative fumigant to methyl bromide (MB). The egg, nymph, and adult stages of Frankliniella occidentalis in asparagus were examined for the fumigation activity of EF and PH3. The eggs of F. occidentalis were more tolerance than other stages (adults and nymphs) in both EF and PH3. When the EF was treated for 4 hrs at 5℃ and 20℃, the eggs of F. occidentalis were LCT99=98.70 mg/L and LCT99=61.13 mg/L, and adults were LCT99=11.50 mg/L and LCT99=3.18 mg/L, respectively. However, at 5℃ and 20℃, the eggs were LCT99=83.76 mg/L and LCT99=53.6 mg/L, and adults were LCT99=4.58 mg/L and LCT99=3.44 mg/L, respectively for 4 hrs treatment of PH3. The PH3 was not any external phytotoxic damages at the maximum dose (4 mg/L), but the EF caused significant phytotoxicity in asparagus.
Zika virus, mosquito-borne disease, caused by mosquitoes has been increased the importance. From March to September, twice a month from 7 different points (3 residential areas, 3 migratory bird sanctuary and 1 cattle shed) were collected using BG trap and BL trap. After identifying the mosquitoes collected, we confirmed the virus infection. Total 26,531 mosquitoes (6 genus 9 species) were collected, virus has been detected from the 3 species (Aedes vexans, Cuilex tritaeniorhynchus, and Amigeres subalbatus) of mosquitoes of them. It showed the highest peak in August, and then gradually decreased. The most common mosquito species was collected Aedes vexan (16,637) in the cattle shed.
Pseudococcus longispinus, a notorious cosmopolitan pest species of mealybugs, known to be distributed indoors in Korea since 2002, is found to be mixed with another species, Pseudococcus orchidicola. Finding P. orchidicola as a pest of tropical plants in Korea is rather unexpected because of their main distribution in Pacific area and South Asia. However, all the available information from morphology, molecule and advices on identification from mealybug specialists indicated this is best matching P. orchidicola. Morphological, molecular and some biological notes on P. orchidicola are provided with some adult and nymphal images, and compared with P. longispinus. A full discussion mainly on identity and distribution of P. orchidicola is given.
Monochamus saltuarius is one of the insect vector of pine wilt disease with Monochamus alternatus. The present study aimed to investigate the dose to induce sterile and the effect of sterility according to the gender of M. saltuarius. As the electron beam irradiation dose increased, the hatchability, adult eclosion rate and longevity of the former mid and late maturation feeding stage of adults was slightly reduced. However, there was no difference between these two adults. In addition, female adults were more sensitive to the electron beam than the male adults. Hatchability of the F1 generation of ♂T × ♀N o r♀T × ♂N (T: 200 Gy electron beam irradiation, N: 0 Gy) was completely suppressed. As electron beam irradiation dose increased, the fecundity of female adults were slightly decreased. Results by comet assay showed that electron beam irradiation induced as dose increased DNA damage in M. saltuarius adults. These results suggest that SIT using electron beam may be useful for control of M. saltuarius.
Mealybugs (Hemiptera: Pseudococcidae) are major pests of a wide range of crops and ornamental plants worldwide, and represented by 56 species in Korea. Occurrence of, or damage by, the longtailed mealybug, Pseudococcus longispinus Targioni-Tozzetti has not been reported since 2002. However, for the first time in many years, P. longispinus was reported at Phalaenopsis orchids by Kim et al in 2015. Therefore, the present study aimed to investigate the distribution of P. longispinus which is usually found inside a greenhouse or a building where the host plants are. We have collected 129 mealybug samples at 254 sites from Korea. Among these, 27 of P. longispinus and 62 of an unidentified Pseudococcus species were found mainly in ornamental plants such as Heteropanax fragrans, commonly known as happy trees in Korea. Morphological characteristics of the unidentified mealybug were very similar to those of P. longispinus. However, the genetic variability in COI sequence comparison was significantly different between the two species. Further studies are needed to clarify the valid name for this unidentified species, and we are currently working on it.