In this study, Telenomus remus Nixon (Hymenoptera: Scelionidae) was first reported as a natural enemy of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) egg collected from corn fields in Korea, and its biological characteristics was studied. Based on morphological and molecular analysis, the parasitoid emerged from S. frugiperda eggs was identified as T. remus. We found that T. remus can attack the eggs of S. frugiperda, Spodoptera litra and Spodoptera exigua under a laboratory condition. The longevity of T. remus female adult was longer than that of male adult. The egg-to-adult period of T. remus was not affected by the host age and sex. T. remus female adult laid at least 1-3 eggs a day to a maximum of 37 or more eggs, and the most oviposited on the 3rd to 4th day after emergence. The host preference for oviposition of T. remus adult was high in the order of S. litura>S. exigua>S. frugiperda. T. remus preferred to parasitize 1- and 2-day-old host egg rather than 3-day-old host egg. When compared to the sex ratio of T. remus progeny, the rate of female progeny was higher at the initiation time of oviposition, while the proportion of male progeny increased significantly with female adult age, especially after 8-day-old adult. This information may be useful for improving T. remus mass rearing system and developing a biological control program to control S. frugiperda.

Conservation biological control (CBC) is one of the pest management tactics based on protecting and maintaining natural enemies that already exist in the crop environment. Among many appropriate practices to control pests, CBC has been considered as a sustainable means and a less expensive alternatives to chemicals. It contains an introduction of non-crop plants as shelter habitat for providing natural enemies with food sources, overwintering or refuges shelters. As a small scale experiment of CBC, we tried to intercrop six kinds of floral plants (buckwheat, red clover, Agastache rugosa, Chrysanthemum indicum, Allium tuberosum, Lythrum anceps) with napa cabbage in order to attract some natural enemies, especially parasitic wasps that could be fed on them in the cabbage fields, which is a novel way for conservation of natural enemies, but none showed significant result. For the development of integrated pest management system by harmonizing biological and chemical control, we carried out evaluating toxicity of 30 pesticides to parasitoids and investigating effectiveness of traps. With leaf dipping method for adult and body dipping method for cocoons, 12 pesticides showed under 30% of toxicity being selected as safer by IOBC. Using sex-pheromone traps for attracting lepidopteran pests showed that DBM, CAW and CL occurred less than untreated fields; 67.5%, 70.6% and 44.0%, respectively. Also, yellow sticky traps could reduce some pests; 52% for flea beetle, 62% for cabbage sawfly and 41% for Phaedon brassicae. These results are expected to give basic information to develop conservation biological control of DBM with indigenous parasitoids in the cabbage fields on a large scale in the future. Before developing and distributing a promising pest control method, we should consider whether it can be compatible with other agricultural practices or various situations around fields.

Geographic clines in genetic polymorphisms are widely believed as an evidence of climate change. We hypothesized green peach aphid, Myzus persicae Sulzer, one of the major insect pests in highland chinese cabbage cultivation, may also have some interactions with climate change. As the first step, we tried to find the available markers from six local strains (five collected at different heights in Hoengseong and Pyeongchang area and one from laboratory). A strain from Jeju island was used as an out-group. Although there was no significant difference in sequences of partial ribosomal RNA fragment and mitochondrial cytochrome oxidase I, and esterase isozyme pattern, we found four inter-simple sequence repeat (ISSR) markers in 22 used ISSR primers (+AGA, +CCA, +CGA, CGA+). These primers can be used as good markers to trace the M. persicae gene flow because they showed specific bands according to local strains.

A gregarine parasite (Apicomplexa: Protozoa) was observed in the population of daikon leaf beetle, Phaedon brassicae Baly, (Coleoptera: Chrysomelidae) in Daegwallyeong. Gregarines are well known species-specific parasites of various Arthropoda. Based on 1.727kb of 18S rDNA sequence (FJ481523), this gregarine species was grouped in eugregarine and 5.258kb of full length rDNA replicon was cloned. We also observed interaction of tropozoite or gamonto of gregarine and epithelium of host midgut using scanning electron microscope. Although development of the infected host delayed half day in every larval stage, there was no significant difference in the development of daikon leaf beetle whether it is infected or not. Therefore, this gregarine parasite is not promising candidate for bio-insecticide in daikon leaf beetle.