The Asian corn borer, O. furnacalis (Crambidae) and the old world bollworm, H. armigera (Noctuidae) simultaneously cause ear damage in corn in Suwon area. It has been assumed that the second generation of larvae of both insects is responsible for the damage. We, therefore, studied proper spray timing of insecticide in order to reduce the damage. A waxy corn hybrid cultivar, Ilmichal, was sown directly on four plots of a field at April 10, April 20, May 4, and May 18, 2018, respectively. A sodium channel blocker, indoxacarb, was sprayed eight times at 3- or 4-day intervals around the silking stage of corn in each sowing plot. At ear harvest time of each plot, we investigated damaged ratio and length of ear, and the numbers of both insect species. The significantly effective spray timings on reduction of ear damage were the sprays at June 29 and July 2 in the plot sown at April 10, the sprays from July 2 to 13 in the April 20-sown plot, the sprays from July 2 to 19 in the May 4-sown plot, and the sprays at July 19 in the May 18-sown plot, respectively. The damage level was positively related to the insect number. The result indicated that the spray at the silking stage of corn was effective on reduction of ear damage. It was assumed that occurrence time of neonate larvae of the insects at silking stage cause the damage, based on the experimental results using screened pots inoculated with the two species.

Toxicities of Carbofuran showed different patterns by three application methods, Drench(as systemic effect), Leaf dipping(as contact and systemic effects) and Topical(as contact effect) applications. LC50 dropping pattern was L-shape in Drench, low slope line in Topical and intermediate of them in Leaf dipping. Drench application was the most Carbofuran treatment method to Brown planthoppers. Dropping patterns of LC50 were almost same between resistant and susceptible strains. The checking time of Carbofuran toxicity was suggested to be 2nd day after application by SD analysis of mortality. Resistance ratios were peak on 3rd day after application in Drench, 4th day(Susceptible) and 5th day(Resistant) in Leaf dipping and showed steady increase line pattern in Topical application.

Development and fecundity of the foxglove aphid, Aulacorthum solani (Hemiptera: Aphididae) were investigated at ten constant temperatures (photoperiod: 15L:9D) from 2.5 to 30℃ on soybean (Glycine max) leaves. The nymphs couldn’t emerge to adults at 2.5 and 30℃. The lower development temperature threshold and thermal constant of development completion estimated with a linear development model in nymph were 5.02℃ and 131.2 degree-days. The lethal temperatures were estimated as 33.9 and 32.5℃ with Lactin 2 and Logan 6 non-linear models, respectively. Mean generation time (from 78.4 to 11.8 d) decreased with increasing temperatures (from 7.5 to 27.5℃). The highest net reproductive rate (77.4) was observed at 20℃. The highest intrinsic rates of population increase (0.282) and shortest population doubling times (2.07 d) were recorded at 25℃.

관주처리에 의한 벼멸구 흡즙 섭식 독성, 잎 침지처리에 의한 접촉독성과 식물체내 침투에 의한 섭식독성, 미량국소처리에 의한 표피 접촉 독성 등, 처리 방법에 따른 카보퓨란의 벼멸구에 대한 살충 작용 특성을 분석하였다. 카보퓨란 관주처리는 시간에 따른 벼멸구의 살충력 변화가 2 가지 패턴으로 나타났다. 상대적으로 높은 농도(8~30 ppm)의 처리에서는 급격히 사충율이 올라가다가 시간이 지남에 따라 증가율이 낮아지는 로그곡선의 형태와 낮은 농도(1~4 ppm)의 처리에서는 사충율 증가 패턴이 S 자 모양의 곡선 형태를 보였다. 관주처리 시 높은 농도에서는 처리 효과가 즉시 나타나 하루 만에 치사율이 40% 이상 도달하였으나 상대적으로 낮은 1~2 ppm의 농도에서는 처리 5일 후에야 80~100%에 달하는 사충율을 얻을 수 있었다. 침지처리는 사충율이 처리 1일 후 약효가 급격히 증가하고 이 후 증가율이 낮아졌다. 국소처리도 침지처리와 비슷한 경 향을 보이나 침지처리와는 달리 처리 후 3일 이후에는 사충율이 거의 증가하지 않았다. 약효 최적 조사 시간은 관주처리에서 처리 후 2일 (42시 간)이었으며 침지처리와 국소처리에서는 처리 후 1~2일이 약효 조사 적기였다.

The Laodelphax striatellus(SBPH) (Homoptera:Delphacidae) is a major rice insect pest in Asia. It brings the indirect damage by transmitting Rice Stripe Virus (RSV) and Rice Black-Streaked Dwarf Virus (RBSDV). Molecular markers for genetics studies will be very helpful for dynamics of SBPH and viruses. For surveying genetic variation among populations of SBPH by microsatellite analyses, we used an enrichment strategy to develop microsatellite markers from SBPH. Eight polymorphic microsatellite loci were selected to characterize genetic structuring of SBPH populations.

The EAG (Electroantennogram) has been used to find out chemical substance effective to insect. We tried to use EAG recording for catching of responsible acoustic signals to Lirimyza trifolii (Diptera: Agromizidae). In fly auditory organ known as Johnston's organ located on antenna. Pure tone sounds (sine wave) and courtship songs of several kinds of species were broadcasted to excised head of the fly. Significant EAG signals were detected when released the 20 Hz pure tone sound and long pulse train patterns, which were courtship songs of Cryptonevra inquilina and Lipara japonica (Chloropidae). For conformation of it's effectiveness, we further analyzed movement behavior with the signal got from the EAG recording. Information entropy could represent the specimens activities of movement tracks. The entropy with sound was relatively lower than without sound. The combination of EAG responding and behavioral observation would be useful to analyze the response of insect pest against acoustic signals and develop acoustic pest managing tool in agriculture.

The Laodelphax striatellus(SBPH: Small Brown Plant Hopper) is known to be not overwintering in South Korea and migrate from China to Korea every year by now, but these days many evidence support the possibility of SBPH overwintering. These insects do considerable damage to the rice production in Korea. If they will come from China, identification of origin of migration is very important to make countermeasure against SBHP outbreak. So we want to know exact the route of long-distance migration of them. In this study, we have developed some microsatellite markers for basic population genetic analysis of SBPH. We will show the genetic characteristics of them

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.

The Nilaparvata lugesn(BPH) and Laodelphax striatellus(SBPH) are major insect pests of rice in Korea. These BPHs migrate from China to Korea, but we have not exactly known about the route of long-distance migration of them. Molecular markers including microsatellite will be critical to asses gene flow in relation to geographical distance. In our work several microsatellite markers were developed for basic population genetic analysis of BPH and SBPH. Among each 21 microsatellite markers in BPH and SBPH, we could select 6 markers for BPH and 2 markers for SBPH as putative markers for analysis of population genetics. Others are further investigated for the possibility as markers. Development of polymorphic microsatellite loci are final stage of our work. But for good microsatellite markers to population genetics, we should do more experiments. Our work for development of microsatellites should facilitate the study of future population genetics of BPH and SBPH, and eventually elucidate the route of BPH and SBPH migration to Korea.

Six kinds of insecticides, fenpropathrin, dicofol, milbemectin, tebufenpyrad, monocrotophos and propargite, were selected for investigating LC50s to local two spotted spider mite(TSSM) strains. The TSSMs were collected from peach (Cheongdo area) and apple orchards (Chungju, Kunwi and Sobo areas) in 2005, from strawberry plastic house (Nonsan and Damyang areas) in 2006 for experiment and some insecticides selected TSSM strains for more than 20 generations were also used. Each strain was clustered by LC50 value got from six selected insecticides treatment. Every insecticide showed about three-fourfold LC50 difference among TSSMs caught in same area. There are no specific differences in LC50 patterns of TSSM to insecticides within peach orchard and among apple orchards. But TSSMs of apple orchard and peach orchard were clustered into different group each other. Grouping of selected TSSM strains with insecticides in lab artificially showed good relationship between action mechanisms of insecticides. In strawberry strains TSSM showed regional differences between Damyan and Nonsan. The TSSMs of Nonsan showed more resistance to Tebyfenpyrad and Propargite, but TSSM of Damyang was more resistant to fenpropathrin than that of Nonsan. The TSSMs selected with monocrotophos and bifenazate, known as acetylcholinesterase inhibitors, and also pyridaben and chlorfenapyr, known as inhibitors of mitochondrial electron transportation, were grouped close respectively.