The repellency, insecticidal activity and repellency duration effect of dagalet thyme, Thymus quinquescostatus against Asian tiger mosquito, Aedes albopictus larvae and adults was investigated. Whole plant body of T. quinquescostatus proved to have the repellent activity of 91.2% against A. albopictus adults. The constituents of T. quinquescostatus were analyzed using GC-MS as follows: α -pinene (1.1%), α-thujene (2.7%), camphene (1.3%), myrcene (4.7%), α-terpinene (5.0%), ɤ-terpinene (33.0%), ρ-cymene (8.3%), β-caryophyllene (4.0%), β-bisabolene (8.9%), thymol (29.9%), and carvacrol (1.2%). Among them, thymol has the perfect repellency on A. albopictus adults and confirmed the electrophysiological response on the antenna of A. albopictus adults. To enhance the maintenance, vanillin was added. Duration of effectiveness of mixture with vanillin (0.18 : 0.36 ㎕/㎠) were significantly more prolonged than thymol alone. The constituents on its original oils were applied onto A. albopictus larvae. The thymol, α-terpinene and carvacrol (LC50 = 9 mg litre-1) revealed to have high insecticidal activity.

The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests world wide. In this study, we determined electron beam doses for inhibition of normal development of the L. trifolii and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs, larvae, pupae and adults were irradiated with increasing doses of electron beam irradiation (six levels ranges from 30 to 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and pupae was lower than those of untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein with in 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for sterilization of L. trifolii.

In this study, we compared global proteome profiles and the expression pattern of defense-related genes in Chinese cabbage when infested by Myzus persicae and Plutella xylostella. Four-week-old Chinese cabbage was exposed to each insect for 24 h, and then proteins and total RNA were extracted from leaves. To elucidate the herbivore-induced differentially expressed proteins in Chinese cabbage, proteins were separated by two-dimensional gel electrophoresis, and visualized by staining with Coomassie G250. Approximately 1600 protein spots were separated and 249 protein spots showed reproducible changes in expression. Among them, nine proteins whose expressions were markedly up-regulated in M. persicae-infested group were identified using matrixassisted laser desorption/ionization time of flight mass spectrometry. The identified herbivore-responsive proteins (ribulose-1,5-bisphosphate carboxylase/ oxygenase, ATP synthase CF1, putative mismatch binding protein Mus3, and integrase core domain-containing protein) were involved in regulation of photosynthesis, carbohydrate metabolism and DNA repair. The expression levels of chitinase, b-1,3-glucanse, peroxidase, PR1, and PR4 in herbivore-infested Chinese cabbage were analyzed by reverse transcription-polymerase chain reaction. The results clarify the response of Chinese cabbage to two herbivore attack at the protein level.

Cuticular hydrocarbons (CHCs) were analyzed using GC and GC-MS, and compared with developmental stages of the Lycorma delicatula. Total Carbon numbers on all developmental stages are 21-36, and composition numbers are 51. On the whole, Carbon numbers increased as passed times on developmental stages. Except for eggs, Lycorma delicatula consisted of n-heptacosane on almost all developmental stages, and followed by n-nonacosane. Eggs, however, consisted of 9-; 11-; 13- methylheptacosane. From the above results, CHCs on developmental stages of the Lycorma delicatula consisted of n-alkane with saturated hydrocarbons (36%), followed mono- (34%) or di- (21%) methylalkanes. Above this, CHCs consisted of tri- methylalkanes (3.9%) and olefines (2.3%) that have double bond. The major constituents of CHCs on the developmental stages of Lycorma delicatula is differently proportioned, but hardly showed the difference in their composition.

On the development and reproduction of four major agricultural insect pests including B. tabaci, M. persicae, P. xylostella and T. urticae, electron-beam was irradiated with different doses of 30, 50, 70, and 100 Gy. The effect of electron beam was investigated with respect to the longevity, egg hatching, emergence, and fecundity. Eggs hatching of B. tabaci, P. xylostella and T. urticae were more inhibited as increased irradiation doses. Especially B. tabaci and T. urticae eggs were perfectly inhibited to hatch at a dose of 100 Gy. However, these pests showed no lethal effect on the nymph/larva, pupa, and adult stages. When irradiated on the eggs of B. tabaci, P. xylostella and T. urticae, the emergence was inhibited from nymphs/larvae to adults. Individually, B. tabaci emerged adult did not lay eggs at a dose of 70 Gy. Besides, fecundity of P. xylostella emerged adult decreased at a dose of 100 Gy. On the contrary, irradiation did not affect the longevity of P. xylostella adult. When irradiated on B. tabaci, P. xylostella, Myzus persicae and T. urticae nymphs/larvae, emergence was inhibited at doses of 70 and 100 Gy, and decreased the fecundity and inhibited the hatching of laid eggs. However, the longevity of adults did not affect

Cuticular hydrocarbons (CHCs) were analyzed using GC and GC-MS, and compared with developmental stages of the bean bug, Riptortus pedestris. Carbon numbers on each developmental stages differed from 14-19 in eggs to 4th nymph, 25 in 5th nymph, and over 30 in last nymph that until adult emergence. Carbon numbers are increased to 16-17 carbons over time in newly emerged adults, 18-22 in 1 and 3 days after emergence, respectively; 23-27 in 6 days after emergence; approximately 30 in over 10 days after emergence. Carbon numbers increased as passed days after emergence. Riptortus pedestris consisted of n-nonacosane on almost all developmental stages, and followed by n-hentriacontane and 13,17-;15,19-demethyltritriacontane. Eggs, however, consisted of unknown compounds with high proportion and followed by n-heptacosane, and newly emerged adults also has a high proportion of n-heptacosane. From the above results, CHCs on developmental stages of the bean bug consist of n-alkane with saturated hydrocarbons (36-65 %), followed mono- or di- methylalkanes. However, newly emerged female and male adults mostly consisted of methyl-alkane. The major constituents of CHCs on the developmental stages of Riptortus pedestris is differently proportioned, but hardly showed the difference in their composition.

This study was performed to investigate the correlation between changes of feeding behavior of green peach aphid, Myzus persicae and residual effect of an insecticide, Pyrifluzuinazon, using EPG technique. Pyrifluquinazon was showed the insecticidal activity until three days (72h) after treatment, and the activity was high in nymph than adult of GPA. There was no difference among treatment methods. Lethal sign was observed the slimed the abdomen of GPA after 3 days that rises the insecticidal activity, and dieㅇ as being sticked and/or pulled out the needle. Residual efficacy from 1, 3, 5, 7 to 20 days after treatment, insecticidal activity was showed 70% in 50 ppm, recommended concentration, until 5 days. And waveforms relating to non-probe time and phloem phase time using EPA, feeding inhibition efficacy was showed during 5 days after treatment, but showed similar level with control after 13 days. These results show that the change of feeding behavior of GPA is correlated with the change of residual effect of pyrifluzuinazon.