톱다리개미허리노린재[Riptortus pedestris (Fabricius) (Hemiptera: Alydidae)]는 콩에서 중요한 난방제 해충이다. 톱다리개미허리노린재와 두 종의 알기생벌의 계절적 발생 패턴을 기주 식물과 연관하여 고찰하였다. 또한 천적 상호간의 상대적 발생 패턴의 차이와 이유를 분석하고 톱다리개미허리노린재의 기주 식물에 대한 적합도 검증 결과를 바탕으로 톱다리개미허리노린재의 관리 전략을 제시하였다. 톱다리개미허리노린재의 효과적인 관리를 위해서 저항성품종의 사용, 과수의 경우 주변 작물에서 콩을 배제하는 것, 기주알 공급을 통한 보존적 생물적 방제, 살충제 사용 시기의 조절 등이 고려되어야 한다.

The larval parasitoid, Bracon hebetor, attacks third or older larvae of indianmeal moth (Plodia interpunctella), which results in laying eggs or simply paralyzing the larvae. We studied the influence of the parasitoid’s attack on the larval development of indianmeal moth. The third larval instars of the same age were collected from the experimental colonies and each larva introduced in an acrylic cube (2 x 2 x 2 cm) treated with: 1) empty, 2) three rice grains, 3) three rice grains and a female parasitoid without ovipositor (by removing) and 4) three rice grains and a paralyzed larva. The larval activity in the experimental cube was photographed every five minutes until the larva died or pupated. Only the larvae in the cube with paralyzed larvae could pupate and emerge. The other larvae in the three treatments died before pupating, although the survival time was significantly different in relation to the treatment (F=5.27; df=2,14; P=0.019); the larvae in the empty cube had a shorter survival time than those in the rest of treatments. The results indicated that the paralyzed larvae could be fed by the health larvae and contribute to prevent population crush in the situation of food shortage with the presence of the parasitoids. The host parasitoid interaction between indianmeal moth and Bracon hebetor might not always be negative to the indianmeal moth population.

Effects of host density and refuge on the sex ratio of progeny of hymenopterous parasitoids was tested with Bracon hebetor Say parasitizing Plodia interpunctella (Hübner). The overall sex ratio (male/total) of progeny produced per female with and without refuge was estimated to be 0.49 and 0.41, respectively. Regardless of refuge, the sex ratio decreased as host density increased. But, at host density of 128 with refuge the sex ratio was significantly lower than that without regfuge (t=-2.17, df=24; P=0.040). The number of pupae per host larva with refuge was similar to that without refuge at the host densities tested (t=-0.10, df=53.4; P=0.921). The number of attacked host larvae showed significantly different at all host densities with and without refuge (t=-3.33, df=209; P=0.001).

In many host-parasite interactions, intraspecific competition among host could have a significant role to the host-parasite population dynamics, yet so far a few studies has been reported theoretically and experimentally(ex. Umbanhowar and Hastings, 2002). We examined the effect of larval competition using a stage-structured matrix model with parameters estimated from the Plodia interpunctella-Bracon hebetor and Sitophilus zeamais-Aniopteromalus calandrae experimental system. The maize weevil population showed a typical growth pattern of populations with contest type competition. After introduction of A. calandrae to the system, maize weevil population was dramatically decreased to be extinct. In contrast, the Indian meal moth population showed a typical pattern of scramble type competition. Introduction of B. hebetor to the system induced higher moth density and longer persistence of the Indian meal moth population than that in the maize weevil system. These results seem to be caused by differences in intraspecific competition between Indian meal moth and maize weevil. The applications of these results should be considered in biological control of Indian meal moth.

DNA in the eukaryotic nucleus is packaged into highly organized chromatin. The basic structural unit of chromatin is the nucleosome, which consists of approximately 146 base pairs of DNA wrapped around a histone octamer core containing two molecules each of core histones H2A, H2B, H3, and H4. Histone covalent modification at the protruding N-terminal region from the nucleosomal core can change the chromatin conformation in order to regulate gene expression. A viral H4 was found in the genome of Cotesia plutellae bracovirus (CpBV). The obligate host of the virus is an endoparasitoid wasp, C. plutellae, which parasitizes the diamondback moth, Plutella xylostella, and interrupts host development and immune reactions. CpBV-H4 has been regarded as an immunosuppressive gene. Its extended N-terminal region contains nine lysine residues which are the target for modification. Previous report showed that CpBV-H4 inhibited hemocyte-spreading after transient expression. Here, transient expression of truncated CpBV-H4 (without N-terminal region) did not show high inhibitory effects on hemocyte-spreading. Moreover, the truncated CpBV-H4 induced acetylation of nucleus histone H4. Host H4 was found to be decreased in transcription after parasitization compared to nonparasitized larvae. Atransient expression of CpBV-H4 significantly inhibited host H4 transcription, suggesting a role of CpBV-H4 in controlling gene expression. Point mutagenesis study showed that two lysines (K6 and K16) of CpBV-H4 were found to have high inhibitory effects on hemocyte spreading. These results indicate the importance of CpBV-H4 and its N-terminal region to control gene expression and suppress host immunity.

Three new species of aphid parasitoids and their host-plant associations are described: Pauesia koraiensis Stary(Cinara cembrae Inouye and C. sp. on Pinus koreaiensis), Pauesia holmani Stary(Cinara sp. and C. watanabei Inouye on Pinus koraiensis, and C. laricis Hartig on larix olgensis) and Pauesia gwangleungensis Stary(Cinara shinjii Inouye on Pinus parviflora).

쌀바구미좀벌은 쌀바구미의 3영유충과 4영유충에 생난, 기생하였으며, 4영유충에 대해 현저한 선호성을 보였다. 기주가 4영유충일 때의 성비가 3영유충일 때에 비해 유의하게 높아서 생난시 암컷에 의해 인식되는 기주의 크기에 따라 좀벌의 성비가 조걸됨을 암시하였다.