Scirtothrips dorsalis Hood is a newly advent pest on citrus in Jeju. Both larvae and adult attack the new shoots and young and matured fruits of citrus. S. dorsalis is highly polyphagous with over 100 recorded species, but not known in Jeju. As a result from investigating the host plants in and/or around citrus orchards in Jeju during 2009 to 2010, they were 25 families 39 species. The total thrips examined on those plants were 13 species, and the richness thrips among them was S. dorsalis, Frankliniella occidentalis, Thrips tabaci and Thrips hawaiiensis. The widespread host plants of S. dorsalis were Mallotus japonicus, Paederia scandens, Hedera rhombea, Cayratia japonica and Clematis apiifolia and they can be also used for monitoring plants. On early May, the larvae of S. dorsalis were first investigated on the shoots of Mallotus japonicus, Lonicera japonica, Paederia scandens, Viburnum awabukira, Fraxinus rhynchophylla and Celtis sinensis. The other thrips species except S. dorsalis and T. tabaci, especially F. intonsa, T. hawaiiensis, T. flavus and T. coloratus were just found on flower stalks during the blooming season.

The males of cryptic mealybug, Pseudococcus cryptus, were attracted on trap baited with or without a synthetic sex pheromone. The attractiveness of sex pheromone trap was higher than yellow-color sticky trap, but both phenologies were similar. There was a positive relationship between mean density of 2nd nymph to adult cryptic mealybug and the density of the male caught on trap. The density of cryptic mealybug per tree was higher correlated with yellow-color sticky trap than sex pheromone trap. The pattern of cryptic mealybug male occurrence had two to three cohorts in a generation resulted from overwintering stage. The maximum occurring time of 1st to 2nd nymph stage could be estimated from the peak time of trap catch by effective temperature accumulation. The higher and lower threshold temperature was estimated as 10.9 and 32.6℃, respectively and its thermal constant was 360 degree-day. The cryptic mealybug parasitoid, Anagyrus sp., which was first recovered in Jeju in 2009, was well attracted on yellow-color sticky trap. There was a high correlation between the density of Anagyrus sp. and of cryptic mealybug males caught on trap.