Insect pest may move to near area to forage the food by adverse changes of their environments. Understanding these behaviors of searching the host will be helpful for further control. This study was performed to investigate the host preference and distribution of B. tabaci in a host plant when they needs. Once entered an area including hosts, B. tabaci will select a host rather than non-host and stayed for living. Dispersal within a niche (in a whole plant), B. tabaci was observed in lower part in tobacco and middle in tomato when seedlings, but they dispersed throughout the whole fully grown tomato plants with irregular inclined to the under, outer stretched leaves. Bemisia tabaci was also caught massively in yellow sticky traps in height of 30 cm above soil, and 30 cm above a plant. There was no attraction effect by flower model traps and fly catcher. When introduced with different densities (0, 10, 50, 100, 200, and 400) in square cages, the B. tabaci do damaged at the densities of 200 with mild and 400 with severe symptom on plants in two weeks and four weeks after inoculation.

Economic injury level was estimated for the sweetpotato whitefly, Bemisia tabaci on greenhouse tomato (Lycopersicon esculantum cultivar pinktop). In the greenhouse, seedling tomato transplanted at mid-April and inoculated B. tabaci at late-April with the densities of 0, 1, 3, 9, 27, 54, 108 and 216 per plant. Only 108 and 216 inoculation densities increased until mid-July. Total weight of fruits was not showed the differences by initial whitefly density; however, the total weight of marketable fruits decreased significantly among plots by higher initial whitefly density. The rates of yield loss increased with increasing whitefly density, resulting in 8.3, 14.0, 29.7, 29.7, 25.7, 40.4, and 69.4% reduction in each of the plots, respectively. The relationship between initial whitefly densities and yield losses was well described by a linear regression, Y= 18.09X+6026.5, R2=0.8504. Based on the relationship, the number of adults per plant which can cause 5% loss of yield was estimated to be approximately 17.

This study was performed to investigate the seasonal occurrence, developmental characteristics of each nymphal stages with different temperatures (20, 25, 30℃), longevity and fecundity of ussur brown katydid, Paratlanticus ussuriensis, damaging by outbreaks in the orchard areas of Bitan-ri, Yeongdong, Chungbuk. Paratlanticus ussuriensis occurred from late-March to late-August with peak of mid-May. Newly emerged nymphs appeared from March and do damaged fruit orchards with peak of mid-May when P. ussuriensis existed as 4th and 5th nymphal stages. P. ussuriensis adult occurred from early-June to mid-Aug. with peak of mid-July. Total density of P. ussuriensis was showed highest in mid-May. P. ussuriensis goes through nymphal stages to 7th nymph, the ovipositor began exposed to outside from the 4th instar and the body weight increased heavily from this stage and the wings were observed from 6th instar. Developmental period was longer as increased the nymphal stages. Sex ratio of collected insect was showed as 0.57; females more than males. As increased the temperature, developmental period was to be short. Preoviposition was also to be short as 5.0, 4.3, and 3.4 days at 20, 25, 30℃, respectively, and fecundity increased as 69.0, 87.1, and 104.3 at 20, 25, 30℃, respectively. Longevity of male and female at 25℃ was showed the longest with 35.7, and 32.9 days and showed the shortest with 30.1 and 28.1 days at 30℃, respectively. The difference of developmental period in male and female were showed longer in female without relation of temperature. The eggs laid were frequently distributed 3 to 4 cm from soil surface, and showed the behavior laying eggs intensively when early oviposition period.

Recently, Ussur brown katydid outbreaks caused a serious pest problem in areas of Yeongdong, Chungbuk. This study was performed to control the pest with environment-friendly method. Trap was made of PET plastic bottles that easily found near farmhouse. Attractant materials such as oak (Quercus acutissima) leaf, fruits (peach, apple, grapefruit and pear) sarcocarp or its juices, rice wine (makgeolli) and fish meal were directly applied into the manufactured trap and investigated for the attraction efficacy compared with the funnel trap. During one day, manufactured trap (fish trap) attracted the Ussur brown katydid more than funnel trap. The efficacy of attractant materials were as follows: peach juice (32.7 adults)> rice wine+fish meal (31.3 adults) > rice wine (27.0 adults) > pear juice (19.0 adults) > apple juice (17.2 adults) > fish meal (16.7 adults) > grapefruit juice (14.4 adults) > oak leaf (2.3 adults). The attractive efficacy of fruit juices to ussur brown katydid was more than fruit carcocarps, and the trap hangover 1m in height more than that on ground. The composition of rice wine and fish meal prolonged its efficacy when treated with disinfectant.