This study was conducted to develop economic injury level (EIL) and economic threshold (ET) of onion thrips, Thrips tabaci on welsh onion (Allium fistulosum L. var). The changes of welsh onion biomass and T. tabacci density were investigated after introductions of T. tabacci at different densities and days: By the results of the experiment in the early welsh onion cultivation periods (30d after transplanting), the biomass of welsh onion significantly decreased with increasing the initial inoculated density of T. tabacci. The relationship between cumulative insect days (CID) and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL and ET of T. tabacci on welsh onion were estimated at 24 and 20 CID per plant, respectively. By the results of the experiment in the late cultivation periods of welsh onion (about 120d after transplanting), the welsh onion biomass was also significantly different inoculation thrips densities to welsh onion. The EIL and ET were calculated as 35 and 28 thrips per welsh onion plant. Until a more elaborate EIL-model is developed, the present result may be useful for T. tabacci management during the cultivations of welsh onion.

A storage mite (cheese mite), Tyrophagus putrescentiae, is known as the pest in storing grains and common health pest species in the dust around home. The mite directly affect our well-being as parasites, vectors of disease, and producers of allergens. But recently we found damages in horticultural crops especially in greenhouses. It is very difficult to diagnose the damage by the mite because of the tiny size of the mite. And the symptom is not clear at the beginning stage. In this study, observations were done on the mite and the crop damage symptoms in several horticultural crops under dissecting microscope and scanning electron microscope (SEM). The mite body size was 0.3~0.5㎜ and they had long hairs all around their body when observed under SEM. The characteristic damage symptoms in some horticultural crops are as follows. In phalaenopsis, the flower buds became yellow and the lower side of the leaves had white spots. The surface of young cucumber fruits became shiny and soft at the early damage stage. In the crops, the damaged surfaces became corky as the plants grew up. In peach tree, whole the trees lost vigor and flower drops were observed when the mite density was very high in greenhouse cultivation.

Synanthedon haitangvora (Lepidoptera: Sesiidae) is an economically important pest of apple trees in Korea and China. We report here the identification of compounds in pheromone gland extracts of female S. haitangvora, and the male responses to blends of different components and ratios in the field. Two major components from pheromone gland extracts of S. haitangvora females were identified as Z3,Z13-18:OAc and E2,Z13-18:OAc, and the average ratio of these components was about 1:1. Seven minor components, Z9-16:OAc, Z11-16:OAc, Z9-18:OAc, Z13-18:OAc, E3,Z13-18:OAc, Z3,Z13-18:OH, and E2,Z13-18:OH, also were identified from gland extracts. Field tests showed that male S. haitangvora were attracted to Z3,Z13-18:OAc alone, but the maximum number of males was attracted to the binary blend of Z3,Z13-18:OAc and E2,Z13-18:OAc mimicking the blend found in female extracts. The addition of minor components to a 1:1 blend of Z3,Z13-18:OAc and E2,Z13-18:OAc did not increase the numbers of moths captured. The only significant effect of minor components was the strong inhibitory effect of adding Z3,Z13-18:OH to the primary binary blend. Increasing doses of the optimum pheromone blend in the lures from 0.1 to 2.0 mg increased trap catches of male S. haitangvora.

Background : The cultivation of wild greens in a forest farming system is an attractive alternative to wild harvesting, due to its much lower production cost compared with conventional cultivation, and its provision of a second income to the landowner. Yet little is known about the conditions that would maximize the growth and antioxidant activities of wild greens in a forest farming system. Thus, this study was conducted to evaluate the optimal conditions that would maximize antioxidant activities of Ligularia fischeri (Ledeb.) Turcz., being cultivated in three different cultivation systems in Korea. Methods and Results : After the fibrous roots of L. fischeri were planted in three different cultivation systems, this study was conducted to assess the effect on health-related properties such as total phenolic contents, flavonoids, DPPH (1,1-diphenyl-2-picrylhydrasyl) free radical scavenging activities and reducing power. From these harvests in different sites, extracts were prepared using methanol. Total phenolic content in forest farming system (1.061 ㎎·GAE/㎖) was higher than that in other products harvested in conventional and greenhouse system (0.666㎎·GAE/㎖). Also, flavonoid content was higher in forest farming system (0.124 ㎎·QE/ ㎖), compared to conventional and greenhouse system (0.084 ㎎·QE/㎖). Conclusions : Antioxidant activity and cultivation system seem to correlate with total polyphenol and flavonoid contents.