We developed and characterized five polymorphic microsatellites of Nilaparvata lugens from hybridization method using biotin enrichment strategy and two polymorphic microsatellites from Next Generation Sequencing. Also 11 microsatellites that developed by Sun et al. (2011) are employed to carry out genetic analysis of N. lugens in Southeast Asia. The number of alleles per locus ranged from 2 to 12 with an average of 4.63 alleles per locus. The mean observed heterozygosity of the eleven populations ranged from 0.031 to 0.938 and the expected hetetrozygosity ranged from 0.031 to 0.881. Signifiant genetic differentiation was detected among the three N. lugens populations as the FST ranged from 0.028 (Cheong Do and Ha Long) to 0.161 (CH and BN). The results of microsatellite marker suggested that found N. lugens migrated to Korea at least two times in different period or once. Genetic distance of N. lugens between Korea and Hi Pong were mostly closed and genetic distance of Ha Long and HCM were relatively closed. In this study, development of microsatellites should facilitate the study of future population genetics of N. lugens, and eventually elucidate the route of N. lugens migration to Korea. Thus, combining satisfactory microsatellite markers and intensive surveillance methods in paddy field could be easy to understand to the N. lugens migration mechanism.

The legume pod borer, Maruca vitrata (Fabricius) (Lepidoptera: Crambidae) causes serious damage to some legume crops of genus Vigna and Sesbania in Korea. In the current study, laboratory studies on the temperature-dependent development of the insect were performed at 8 constant temperatures ranging from 13℃ to 34℃ at 3℃ intervals. Lower developmental threshold (LDT) for eggs, larvae, and pupae were calculated as 10.0, 12.5 and 13.3℃, respectively, using the linear-regression equations of the developmental rates. Degree-days required to complete a stage were estimated as 48, 187, and 94, for egg, larval, and pupal stages, respectively. The larvae couldn't survive at 13 and 16℃, and the larval survival rate was the highest at 28℃. The egg hatching rate was the lowest at 13℃. In the adult stage, the pre-oviposition period was the shortest at 22℃, and the total egg number was the most with ca. 500 at 25℃. Degree-days for the stages of 1st-4th larval instars, egg, and adult emergence-50% oviposition were calculated during the reproductive development season of red bean using single sine method and Suwon weather station data based on LDTs, respectively. Finally, the adult occurrence time was estimated after the degree-days were cumulated reversely from the distribution data of larval stages observed in a red bean field

Insecticide resistance development of insect pests is one of the main threatening factors against stable crop production and keeping human life safe from insect pest disease vector. To know properties of insecticides resistance is very important to develop a management program against insecticide resistance pests. Insecticide resistance development is an event of evolutionary process. We have to deal with insecticide resistance of insect pests by interaction between insecticide and insect pests in their chemical, physical and biological environment. We can glimpse at and infer the evolutionary process of insects from investigating and comparing the resistance level of insect pests to insecticides. Huge amount and many kinds of insecticides have been sprayed to control insect pests. Development of insecticide resistance of insect such as housefly and mosquito, known as most common medical insect, is a result of adaptation to environment covered with insecticides. We can easily assume that the amount and kind of insecticides sprayed the evolutionary force to the diversity of insecticide resistance. The resistance diversity will be very good character of good markers for determining geographical isolation.

Previous studies indicated that Matsumuraeses phaseoli and M. falcana (Lepidoptera: Tortricidae) are separate species since a few differences were observed in genitalia morphology and female sex pheromone composition. A clear difference was detected in the DNA sequences of cytochrome oxidase I of the two species separately collected in different plants and regions. A hybridization test also showed that a post-zygotic reproductive isolation occurred between the species. In field monitoring, however, both species have been caught simultaneously and together in the separate sex pheromone traps installed for the two species around neighboring soybean and red bean fields. Molecular marker-assisted identification with several adults sampled from the trapped insects showed that only ca. 40% of M. phaseoli adults identified as the species by genitalia morphology was the M. phaseoli, while ca. 97% of M. falcana adults identified as the species was the M. falcana. The result indicated that the observation of genitalia did not make a decisive criterion for classification of the insects. Conclusively, it suggested that the sex pheromones of the two species should be studied more precisely although there is a possibility that the two species are hybridized in fields as in laboratory, and speciation is under process.

A bee-vectoring method has been recently developed against greenhouse insect pests. In this study, we conducted experiments to determine if bumble bees, bombus terrestris L. could vector Bacillus thuringiensis subsp. aizawai from hives equipped with a pathogen dispenser to leaf and flower of sweet pepper. First, in laboratory, insecticidal activity of B. t. subsp. aizawai NT0423 WP (Tobagi, Dongbu Hitek Co.) against 2nd instar larva of Spodoptera litura Fabricius was evaluated to determine if the amount of B. thuringiensis deposited on the leaf and flower would be sufficient to control the tobacco cutworm. The B. t concentration of the product in this experiment was estimated as 2.8-3.1 x 109 CFU/ml. The B. t. concentration on the body of bumble bees that was captured as they exited hives with filled pathogen dispensers was 4.6 x 109 cfu/ml. At the laboratory bioassay, the mortality of tobacco cutworm was serially measured depending on the pathogen concentrations. At the cage trials, the B. t. delivered by bumble bees was detected in bees, flowers and leaves. Through the several trials, the control effect on the tobacco cutworm has been investigating. The side effect on bumble bee from the first trial was not found in this experiment.

Matsumuraeses phaseoli and M. falcana cannot be classified with the external morphological characters. Although differences in the morphology of male genitalia and in the mitochondrial DNA sequence of cytochrome oxidase I between the two species have been found, there is no information that the two species are biologically different species till now. We, therefore in this study, tried to cross the two species to observe postzygotic incompatibility in the next hybrid generations and to know whether the two species are 'biological species' or not. In crossing between the parents, two kinds of F1 hybrids were produced successfully. In inter- and intra-breeding between F1 hybrids, two lines crossed with females of F1 hybrid produced by females of M. phaseoli could not produce F2 adults to show inviability of larvae. The other two lines produced F2 adults successfully and the F2 adults produced F3 larvae in inbreeding. In back-crossing between parents and F1 hybrids, the two lines of 8 breeding lines, in which females of F1 hybrid were produced by females of M. phaseoli, could not produce the next generation of larvae. The other six lines produced F2 adults successfully. The results indicated that maternal factors of F1 hybrid produced by M. phaseoli females contributed to create the incompatibility between the F1 females and other lines. In conclusion, the results showed a postzygotic reproductive isolation between M. phaseoli and M. falcana in part.

The Asian corn borer, Ostrinia furnacalis, over-winters as the last instar larva in Suwon and undergoes diapause during the over-wintering, and it has been postulated that most of the over-wintering larvae be originated from the larvae of 2nd and 3rd generation (Jung et al., 2008). The over-wintered larvae pupate next year and 50% of emerged adults occur by the early June. In order to know whether the emergence has synchronism among over-wintering larvae regardless of the time entering into diapause or not, neonate larvae were reared on artificial diet at two-week intervals from May 28 to Sep. 28, 2008 in an outside condition and their emergence dates were recorded. The over-wintering larvae occurred from the colony treated at Jul. 20, 2007, and totally emerged from May 11 to Jul. 6, 2008. The 50% date of cumulative emergence was June 3, 2008. The maximum success of over-wintering occurred in the colony treated at Aug. 17, whereas any non-over-wintering larvae were not observed from the following colonies. Although the durations of emergence overlapped partially among the colonies treated at different times in the previous year to show a synchronism at some extent, the first and last colonies treated in the previous year showed a pattern of fast emergence. This result suggested that the duration necessary for diapause termination be different according to the time entering into diapause.

(E,E)-8,10-dodecadienyl acetate (E8E10-12:Ac) and (E)-8-dodecaenyl acetate (E8-12:Ac) have been selected as the candidate chemicals for sex pheromone components of the M. phaseoli, female through GC-EAD tests, whereas the two compounds and an additional candidate, (E,Z)-7,9-dodecadienyl acetate (E7Z9-12:Ac), have been found at a ratio of 7:1:1 in the abdominal tip extract (Yum et al., 2008). In order to determine the actual composition of sex pheromone, therefore, several blends using the three chemicals were evaluated for attractiveness to males of M. phaseoli around red bean and soybean fields. Individual components as well as two blends consisted of E8E10-12:Ac/E7Z9-12:Ac and E8-12:Ac/E7Z9-12:Ac did not show attractiveness, whereas the blend of E8E10-12:Ac/E8-12:Ac showed an increased effect in male capture. Of the tested blends with all three chemicals, the 7:1:2 composition of E8E10-12:Ac, E8-12:Ac and E7Z9-12:Ac attracted the most number of males. The results suggested that E7Z9-12:Ac is one of the sex pheromone components and may act as a synergist.