간행물
한국응용곤충학회 학술대회논문집
- 발행기관 한국응용곤충학회
- 자료유형 학술대회
- 간기 반년간
- 수록기간 2000 ~ 2024
- 주제분류 농수해양 > 농학 농수해양 분류의 다른 간행물
- 십진분류KDC 495DDC 595
권호리스트/논문검색
2008년도 정기총회 및 춘계학술발표회 (2008년 5월) 160건
일반학술발표
21.
2008.05
구독 인증기관·개인회원 무료
South Korean species of the bethylid wasps, genus Holepyris are reviewed. Ten species are recognized and eight of them are described as new to science: H. crinitus sp. nov., H. dimidium sp. nov., H. discedo sp. nov., H. mucro sp. nov., H. multo sp. nov., H. profundus sp. nov., H. secedo sp. nov., H. tantillus sp. nov.; Holepyris benten Terayama 2006 and H. susanowo Terayama 1999 are recorded for the first time from South Korea. Diagnostic characteristics and illustrations of each species are provided.
22.
2008.05
구독 인증기관·개인회원 무료
Taxonomic studies of Taiwan moths have been done by only a few Taiwanese and foreign entomologists. The earliest significant collections and studies of Taiwan Lepidoptera began in 1856 with the arrival of Robert Swinhoe (1836-1877) as British Consul in Taiwan. The Japanese Occupation (Sino-Japanese War of 1895-1945) enabled studies by mainly Japanese scientists, and post- 1945 many Japanese and some others scientists visited Taiwan to study and collect moths and butterflies. In 1992, Heppner and Inoue (eds.) reported over 3,900 species in the checklist of "Lepidoptera of Taiwan" for the first time, based on the materials from 62 collecting sites and previous records. Recently,the Lepidoptera series of guide books to Insects in Taiwan was published by Mr. H.Y. Wang. Also the 2nd author has a publication plan of a total of 10 volumes in the series of "Lepidoptera of Taiwan", and a color introduction due out this year.
In this study, we identified over 3,000 specimens of the subfamily Olethreutinae belonging to the family Tortricidae, collected at 62 sites in Taiwan from 1982 to 2006 by the 2nd author and some of collection’s of Y.S. Bae and K. T. Park in 1996-1999. We recognize the results of identification that more than 280 Taiwan tortricids, including over 35 newly recorded or new species, are in the Taiwan fauna.
23.
2008.05
구독 인증기관·개인회원 무료
Recent taxonomic works on Lecithoceridae in the South East Asia by author, which published or will be published in 2008, are listed as follows and will be summarized. From these studies, 3new genera of the family including 23 new species are described from the Philippines and Thailand.
1. New genus Pectinimua Park, with description of four new species (Lepid., Lecithoceridae)/KT Park & BK Byun- Florida Entom. 91(1): 110-115.
2. A world review of Homaloxestis Meyrick (Lepid., Lecithoceridae)/KT Park, C. Wu, & A. Kun- Lepidoptera Rev. (accepted)
3. A new genus ChrysonasmaPark (Lepid., Lecithoceridae), with description of a new species from the Philippines/KT Park & BK Byun- Florida Entom (accepted)
4. A review of Torodora recurvata species-group (Lepid., Lecithoceridae), with ten new species from the Philippines/KT Park- Entom. Science (accepted)
5. A new genus Notialis Park, with description of two new species (Lepid., Lecithoceridae) from the Philippines/KT Park & MY Kim Proc. Entom. Soc. Wash. (submitted).
6. Four new species of Torodora Meyrick and a new species of AntiochthaMeyrick from the Philippines (Lepid., Lecithoceridae)/KT Park- J. Asia-Pacific Entomol. (submitted).
7. An additional new species of the monotypic genus Anaxyrina Meyrick (Lepid., Lecithoceridae)/KT Park- Kor. J. Syst. Zool. (submitted).
24.
2008.05
구독 인증기관·개인회원 무료
Resistance-breaking ability of wild brown planthopper (BPH), Nilaparvata lugens, on resistant rice cultivars has been reported in many Asian countries. To understand the development of resistance-breaking ability of wild BPH in Korea, we conducted the nymphal survivorship test and the electrical penetration graph (EPG) on susceptible and resistant rice cultivars with four different BPH populations, which were collected in the early 1980s (S-BPH), 2005, 2006, and 2007, respectively. The S-BPH showed low survival rates on resistant rice cultivars carrying Bph1 and bph2, respectively. On the other hand, recent(2005~2007) wild BPH populations seemed to have high resistance-breaking ability because they maintained elevated survival rates on most other resistant rice cultivars except Gayabyeo (Bph1 and bph2) and Rathu Heenati (Bph3). In the EPG monitoring, however, wild BPHs could not easily feed on the phloem sap of resistant rice cultivars, Cheongcheongbyeo (Bph1), ASD7 (bph2), and Gayabyeo. Wild BPHs spent more time on reaching the phloem sieve elements of resistant cultivars. Ph waveform duration and honeydew excretion amount of wild BPHs also decreased. From the results, we suggest that though recent wild BPHs collected in Korea have high resistance-breaking ability simultaneously on rice cultivars carrying Bph1 and bph2 through the increase of survivorship, they still have to pay some cost to feed on the phloem sap of resistant rice cultivars.
25.
2008.05
구독 인증기관·개인회원 무료
사과 해충으로서 복숭아순나방(Grapholita molesta)은 과실에 피해를 주는 일차해충이다. 이에 따라 과실 내부에서 피해를 주는 유충이 방제 대상이나, 살충제와 접촉이 어려워 방제가 어렵다. 이를 극복하기 위한 방제기술이 성페로몬을 이용한 교미교란제 처리이다. 그러나 소규모로 흩어져 있는 국내 사과원 구도는 단일 과원의 교미교란제 처리는 교미된 암컷의 이주에 따라 유효성을 얻기가 힘들다. 이에 따라 광범위한 교미교란제 처리가 불가피하나, 현실적으로 어느 정도의 규모가 처리 대상인지 결정하기 어렵고 불필요한 광역화는 비용면에서 현실성이 없다. 대안으로 복숭아순나방 성충의 교미 반경을 측정할 수 있다면 교미교란제 처리 규모를 합리적으로 결정할 수 있다. 이러한 복숭아순나방 교미 반경 결정을 위해서는 집단간 차이를 보이는 분자지표의 개발이 우선적이다. 본 연구는 이를 위해 세 가지 전략으로 접근하였다. 첫째로, 복숭아순나방 미토콘드리아 전체 염기서열 분석으로 이를 통해 집단간 변이를 보이는 부위를 결정하려 했다. 둘째로 PCR-RFLP 기술로서 미토콘드리아 DNA의 제한효소 다형부위 결정기술이다. 끝으로 PCR-RAPD로서 전체 게놈에 대한 임의적 증폭물에 대한 다형 유전좌위 개발 전략이다.
26.
2008.05
구독 인증기관·개인회원 무료
The diamondback moth, Plutella xylostella, is reluctant to a baculovirus, Autographa california nucleopolyhedrosis virus (AcNPV) at its oral administration. However, parasitization by an endoparasitoid wasp, Cotesia plutellae, enhances the viral susceptibility. This study analyzed an antiviral activity of P. xylostella in response to the viral infection and determined the parasitic factor inhibiting the antiviral mechanism. For the analysis of antiviral activity of P. xylostella, a recombinant AcNPV expressing enhanced green fluorescence (AcNPV-EGFP) was orally adminstered to lavae of P. xylostella. After 24 h, EGFP expression was observed in the midgut tissue at a confocal-FITC mode. At the same time, a characteristic midgut melanotic response (MMR) was observed in some midgut regions under a phase contrast microscope. Thereafter, the EGFP signal was attenuated, while MMR spread on most midgut region. When the MMR was scored from 0 to 5 by the intensity of melanized cell density, it increased in time- and dose-dependent manners at the viral administration per os. These results suggest that the MMR is an antiviral activity of P. xylostella. This antiviral activity was significantly attenuated by C. plutellae parasitism. The parasitized P. xylostella showed significant decrease in the MMR score compared to nonparasitized larvae when they were orally administered with the same dose of AcNPV. To determine the parasitic factor(s) inhibiting the antiviral activity from the symbiotic polydnavirus of C. plutellae (C. plutellae bracovirus: CpBV), CpBV-IkB, which is a viral homolog of NFkB inhibitor and has been considered as an antiviral factor as in other polydnaviruses, was tested. A recombinant AcNPV expressing CpBV-IkB (AcNPV-IkB) was constructed and administered to P. xylostella larvae. As expected, AcNPV-IkB significantly decreased the antiviral activity measured by the MMR score compared to AcNPV-EGFP treatment. This study suggests that CpBV-IkB plays an antiviral parasitic role in the molecular interactions between P. xylostella and C. plutellae.
27.
2008.05
구독 인증기관·개인회원 무료
Monoamines have been known to mediate cellular immune responses such as hemocyte nodulation and phagocytosis in some insects. Eicosanoids also mediate the cellular immune reactions responsible for clearing bacterial infection from hemolymph circulation in various insects. In this study, we investigated a functional relationship of both mediators in expressing hemocyte nodulation and phagocytosis of fifth instar larvae of the beet armyworm, Spodoptera exigua. Addition of octopamine or serotonin along with bacteria enhanced hemocyte nodulation and phagocytosis of S. exigua larvae. Phentolamine (octopamine inhibitor) and ketanserin (serotonin inhibitor) suppressed hemocyte nodulation and phagocytosis of S. exigua in response to a bacterial challenge. Each inhibitory effect of both monoamine inhibitors was recovered by addition of either octopamine or serotonin, suggesting their independent signaling pathways. Both inhibitor effects were also recovered by addition of arachidonic acid (a precursor of eicosanoid biosynthesis). Furthermore, the stimulatory effects of monoamines on the cellular immune responses were prevented by addition of dexamethasone (a specific phospholipase A2). However, the inhibitory effect of dexamethasone was not recovered by excess amounts of monoamines. These results suggest that monoamines mediate hemocyte nodulation and phagocytosis through a downstream eicosanoid signal pathway in S. exigua.
28.
2008.05
구독 인증기관·개인회원 무료
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.
29.
2008.05
구독 인증기관·개인회원 무료
A cysteine- rich protein encoded by Cotesia plutellae bacovirus (CpBV) was identified in the parasitized Plutella xylostella. The gene, called CpBV-CRP, encodes 189 amino acids with a signal peptide of 20 residues at N-terminus determined by bioinformatic analysis, suggesting a secretory protein. High CpBV-CRP expression in the parasitized P. xylostella was observed at early days after parasitization and decreased with the course of parasitization. Expression of CpBV-CRP was tissue-specific in the fat body/epidermis, but not in hemocyte and gut. Its physiological function was analyzed by transient expression of a CpBV segment containing CpBV-CRP. The treated larvae underwent an immunosuppression in terms of hemocyte-spreading behavior. When the treated larvae were also co-injected with dsRNA against CpBV-CRP, the suppressed hemocyte behavior was significantly recovered. This study reports a cysteine-rich protein encoded in CpBV genome and its physiological function to be an immunosuppressant.
30.
2008.05
구독 인증기관·개인회원 무료
Hemolin is a member of the immunoglobulin (Ig) superfamily and contains four Ig domainsthat are similar to neural cell adhesion molecules. It has been regarded as a recognition molecule at immune challenge in insects. This study showed that hemolin of Plutella xylostella was expressed during pupal and adult stages but absent in all larval instars without any immune challenge. It is, however, strongly induced by the injection of Escherichia coli or its lipopolysaccharide in hemocytes, fat body and gut. A double-stranded RNA (dsRNA) interference experiment revealedits role in activation of prophenoloxidase (PPO) in the hemolymph during bacterial infection. Also its involvement in cellular defense was investigated in its mediation of the adherence of hemocytes to rat blood erythrocytes which was knocked down by its dsRNA. Finally, its physiological significance in pupal stage was confirmed by using dsRNA, which significantly prevented adult development. Therefore, it is concluded that hemolin plays roles in both immune and adult development in P. xylostella.
31.
2008.05
구독 인증기관·개인회원 무료
Phospholipase A2 (PLA2) is the committed catalytic step of eicosanoid biosynthesis, which has been a common molecular target of several entomopathogens to induce insect immunosuppression. Despite critical importance of PLA2 in insect immunity, its gene structure was not known. This study identified insect PLA2 gene associated with immune reactions in the red flour beetle, Tribolium castaneum. Based on a previous study that an immune-associated PLA2 in insect is secretory type of PLA2 (sPLA2), five highly matched cDNA sequences were obtained from T. castaneum genome database using an sPLA2 sequence probe encoded in Drosophila melanogaster. The expressions of these five putative PLA2 were confirmed by reverse transcriptase-polymerase chain reaction. Out of five genes, one PLA2 gene called TcPLA2B was chosen because it showed specific expression in hemocyte and fat body. TcPLA2B was cloned and expressed in Escherichia coli and its protein was purified. The purified TcPLA2B showed PLA2enzyme activity, which was specifically inhibited by bromophenacyl bromide (a specific sPLA2inhibitor) and dithiothreitol (reducing agent of disulfide bond). It was sensitive to pH (optimum at pH 6.0) and reaction temperature (optimum at 10-30°C), and calcium dependency. An immunofluorescence assay indicated that TcPLA2B was localized near to cellular membrane of the cytosol in the hemocytes of T. castaneum at immune chanlenge. Double-stranded RNA (dsRNA) of TcPLA2B-treated larvae showed knockdown of its mRNA expression and did not form hemocyte nodule formation, while control larvae could exhibit time- and bacterial dose-dependent nodule formation in response to bacterial challenge. Addition of arachidonic acid (the catalytic product of PLA2) to the dsRNA-treated larvae rescued the inhibition of nodule formation. These results suggest that TcPLA2B gene is associated with insect immune reaction.
32.
2008.05
구독 인증기관·개인회원 무료
The diamondback moth, Plutella xylostella parasitized by its endoparasitoid Cotesia plutellae undergoes various physiological alterations which involves immunosuppression and developmental arrest. Its symbiotic virus, C. plutellae bracovirus (CpBV) is highly essential for their successful parasitization which possesses more than 136 genes encoded. CpBV15βunique in CpBV genome is expressed at low levels in early and at higher levels during late parasitization period. This gene product alters the hemocyte-spreading behavior through inhibition of protein synthesis under in vitro conditions. In the current study, we investigated its specific involvement in physiological functions in the host by transient expression and RNA interference techniques. The open reading frame of CpBV15βwas cloned into a eukaryotic expression vector and this recombinant CpBV15β was transfected into healthy non-parasitized 3rd instar P. xylostella by microinjection. CpBV15βwas expressed as early as 24 h and was consistent up to 72 h. Due to the expression of this gene, the hemolymph storage protein levels were significantly reduced and the ability of the hemocytes to adhere and spread on extracellular matrix was altered or reduced, wherein CpBV15βwas detectable in the cytoplasm of hemocytes based on indirect immunofluorescence assay. To confirm the role of CpBV15β, its double stranded RNA could efficiently recover the functional efficacy of hemocytes towards non-self and synthesis of storage proteins. Thus these results clearly demonstrate the role of CpBV15βin altering the host physiology by involving in cellular immune response and host protein synthesis.
33.
2008.05
구독 인증기관·개인회원 무료
조명나방(Ostrinia furnacalis, 나비목 명나방과)은 가을철 옥수수 줄기 속에서 노숙유충태로 월동하는데, 수원지방에서는 봄에 월동유충이 발육하기 시작한다. 성페로몬트랩에 의한 표본조사에 의해 6월 초에 1회 성충의 발생피크를 보이고, 이후 7월 중하순에 2회 성충이, 8월말과 9월초 사이 3회 성충이 발생하는 것으로 추정되어 왔다. 9월 중순경부터 포장에서 채집된 유충의 대부분이 이미 휴면에 들어가 있는 것이 기존에 확인되었는데, 그 이전시기에 포장에 존재하는 유충의 휴면 여부에 대한 것은 불투명하였다. 따라서 본 연구에서 5월말부터 9월말까지 5~21일 사이 불규칙한 간격으로 조명나방 유충을 야외에서 인공사료를 먹이면서 사육하면서 조명나방이 휴면에 들어가는 시기를 조사하였다. 휴면에 들어간 것은 이듬해 3월에 말령유충 상태로 남아있는 개체들을 관찰하여 최종적으로 판정하였다. 관찰 결과 6월 29일까지 처리된 유충들은 모두 휴면에 들어가지 않았고, 이후 7월 20일 처리된 유충들의 약 8%가 휴면에 들어갔으며 9월초까지 휴면에 들어가는 개체 비율이 증가하여 일장이 짧아지기 시작한 이후 휴면개체들이 출현하는 현상을 보였다. 한편 9월에 처리된 개체들에서는 우화하는 개체가 없었는데 9월말 처리된 개체들은 60% 이상이 사망하였고, 상대적으로 휴면에 들어간 개체의 비율이 9월초에 비해 감소하였다. 한편 9월 이전까지 처리된 개체들이 우화하기까지 발육하는 기간은 약 23~35일 사이로 나타났는데, 5월말부터 8월초까지 처리한 집단들에서 시기에 따라 짧아지는 경향을 나타냈고 이후 8월 중순 다시 길어지는 것을 보였다. 이상의 결과와 실내 인공사육 집단의 온도의존적 발육 자료를 기반으로 야외에서 월동유충집단을 구성하는 세대를 추정하려고 시도하였다.
34.
2008.05
구독 인증기관·개인회원 무료
애멸구(Laodelphax striatellus)의 내생미생물인 Wolbachia에 의해 발현되는 GroEL이 벼줄무늬잎마름병바이러스(Rice stripe virus, RSV)와 결합 반응함에 따라 GroEL 재조합단백질을 이용한 Immunocapture (IC) RT-PCR 검정법에 의해 RSV 이병벼 및 보독충을 진단하는 i-RSVTM Kit를 개발하였다. i-RSVTM Kit는, 반응 용기 표면에 코팅되어있는 GroEL이 시료 마쇄액에서 RSV를 선택적으로 결합하여 분리하는 isolation kit와 분리된 RSV를 95℃에서 10분간 처리하여 RSV의 유전자를 분리시키고 one step RT-PCR을 수행하는 detection kit로 구성되어있다.
i-RSVTM Kit를 활용한 애멸구 RSV 보독충 발생예찰 기술을 확립하고자 기존의 ELISA 검정법과 상관 관계를 조사하였다. ELISA 검정법은 벼에서 3.1 ㎍ml-1, 애멸구 1마리ml-1이상의 검출 한계를 보였으나 i-RSVTM Kit를 이용한 IC-RT-PCR 검정법은 벼에서 0.2㎍ml-1, 애멸구 0.2마리ml-1의 검출 한계를 나타냈다. 각 지역에서 채집된 애멸구 월동충 7 개체군의 보독충률을 i-RSVTM Kit를 이용한 분자 검정과 ELISA 검정을 동시에 수행한 결과 i-RSVTM Kit 검정법이 ELISA에 비해 충태와 무관하게 높은 민감도를 나타내었으며 두 검정법간에 r2=0.89의 3차원 상관관계식이 도출되었다. 즉 i-RSVTM Kit 검정법으로 검정시 보독충률 10～70%일 때 ELISA는 9～30%로 보독충률 검정의 정확도에 있어서 i-RSVTM Kit 검정법이 우수한 결과를 나타냈다.
본 검정법을 이용하여 2007년 12월～2008년 3월에 전국 20 여 개 시군에서 채집된 애멸구 월동충의 보독충률을 검정한 결과 충남 서천, 태안, 충북 진천, 전북 부안, 익산에서 20% 이상의 높은 보독충률을 나타내었으며 이 중 서천, 태안, 부안 등은 충의 밀도가 10마리ml-1 이상 상대적으로 높아 RSV 대발생 위험이 높을 것으로 우려된다.
35.
2008.05
구독 인증기관·개인회원 무료
Developmental periods of sweet potato whitefly, Bemisia tabaci(Gennaius) Q-biotype, were investigated on three host plants- sweet bell pepper (Capsicum annuum L.), eggplant(Solanum melongena L.) and oriental melon(Cucumis melo L. var. makuwa MAKINO). Egg and nymph development of B. tabaci were studied within temperature ranging of 15℃-35℃ by 2.5℃ under photoperiod 16:8(L:D). Egg period of B. tabaci was the shortest at 32.5℃ and nymphal period was shortest at 27.5℃ on sweet bell pepper. Nymphal period of B. tabaci on eggplant was the shortest at 27.5℃ as well. On the other hand, nymphal period of B. tabaci was shortest at 30℃ and 32.5℃. Lower temperature threshold and effective degree-day for completing egg development on sweet bell pepper were estimated as 13.11, 91.95, respectively. Lower threshold temperature of nymphal stage on sweet bell pepper, eggplant, oriental melon were estimated as 13.01, 13.39, 12.31,respectively. Degree-days required to complete nymphal stage on sweet bell pepper, eggplant, oriental melon were estimated as 191.22, 164.41, 190.34, respectively. The relationships between development rates of egg and nymph were well described by poikilothermal rate function and weibull function. The fitted curves will be used as input for a simulation model of the population dynamics of B. tabaci.
36.
2008.05
구독 인증기관·개인회원 무료
꿀벌을 비롯한 화분매개 곤충의 농업과 자연생태계에 기여하는 공익적 가치는 꿀벌이 생산하는 일차생산물의 약 140여 배에 이른다고 보고하고 있다. 최근 과수 생산 농민들의 고령화로 인한 적화 및 적과에 대한 노동력 부담이 점차 증가함에 따라 적화 및 적과의 생력화 방안으로 화학적 적화제 수요가 증가하고 있다. 석회유황합제는 이의 중요한 대안이다. 이에 사과원 화분매개 곤충 중 꿀벌에 대한 석회유황합제의 실내 독성 평가와, 야외 포장에서 석회유황합제 처리 전후 화분매개 곤충 밀도 및 곤충상 조사를 통해 석회유황합제의 안전성을 평가하였다.
석회유황합제 처리에 의한 꿀벌 실내 독성은 3가지 조합의 lime sulfur를 이용하여 처리 후 3시간, 12시간, 24시간에 평가된 사망률은 추천 농도를 포함한 대부분 농도에서 미국환경청에서 제시한 가이드라인 25%미만으로 꿀벌에 안전하다고 평가된다. 야외 포장에서 석회유황합제의 처리 전후 방화곤충의 밀도를 육안 조사한 결과 처리 전 꿀벌의 밀도는 0.18마리였으며, 처리 후 밀도는 0.34마리로 나타났다. 꿀벌과의 다른 종들은 처리 전 육안 조사가 되지 않았으나, 처리 후의 밀도가 0.05마리였다. 트랩을 이용한 방화곤충상 조사에서 주요 벌목 곤충은 처리 전후 밀도의 통계적 유의차가 없었으나 파리목의 꽃파리과는 처리 이후 더 높은 밀도를 보였다. 또한 트랩에 포획된 방화곤충은 총 6목, 40과, 635개체이었다. 따라서 석회유황합제는 꿀벌 및 화분매개 곤충에 대하여 안전한 것으로 사료된다.
37.
2008.05
구독 인증기관·개인회원 무료
Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) is a gregarious egg parasitoid of Riptortus clavatus Thunberg (Hemiptera: Alydidae) and also attack three other stink bugs in soybean fields. In a previous study the refrigerated R. clavatus eggs were supplemented in soybean fields and found to enhance the parasitism by Gryon japonicum (Hymenoptera: Scelionidae), a sympatric solitary parasitoid of R. clavatus, but not by O. nezarae. Therefore, the R. clavatus eggs refrigerated for 0, 15, 30, 60 and 120 days were evaluated for the parasitization by O. nezarae in the laboratory. The number of parasitized host eggs, number of adult parasitoids emerged, immature mortality, sex ratio, development time, adult longevity, and size of the parasitoids were examined for the parasitoids exposed to or emerged from the refrigerated host eggs. All the attributes examined were not affected by the refrigeration of host eggs for up to 60 days. In addition, refrigeration did not change the reproduction capacity of the emerged adult parasitoids nor the biological attributes of their offsprings. In the evaluation of post-refrigeration period of the host eggs, O. nezarae parasitized the eggs successfully for the first 4 days after the refrigeration at 26.3ºC and 78.7% RH conditions. Since O. nezarae can parasitize the eggs of R. clavatus that were refrigerated up to 60 days, the underlying reason for the no-change in parasitism by O. nezarae in the field supplemented with refrigerated host eggs is in further investigation.
38.
2008.05
구독 인증기관·개인회원 무료
Trissolcus nigripedius Nakagawa and Telenomus gifuensis Ashmead (Hymenoptera: Scelionidae) are solitary egg parasitoids of Dolycoris baccarum L. (Hemiptera: Pentatomidae), a polyphagous seed-sucking bug of agricultural crops. Field examinations revealed that the two parasitoids are the most common species, but only a single species emerge from a host egg mass. To explain this observation we tested two hypotheses of interspecific host discrimination and asymmetry in competitive interaction between the two parasitoids. When provided with host eggs pre-parasitized by each other, both Tr. nigripedius and Te. gifuensis parasitized 94 and 100% of the host eggs without interspecific host discrimination, respectively. Interestingly, from the multiparasitized eggs irrespective of oviposition sequence, progeny of Te. gifuensis always survive better than Tr. nigripedius. Te. gifuensis is superior in immature competition probably due to shorter egg incubation period, hence progeny of Te. gifuensis become first instar faster than that of Tr. nigripedius. However, adult Tr. nigripedius is always superior competitor in possessing and guarding the host eggs even after oviposition against Te. gifuensis. Therefore, the asymmetry in competitive interaction between Tr. nigripedius and Te. gifuensis may explain the emergence of a single species from a host egg mass in the field in spite of no interspecific host discrimination.
39.
2008.05
구독 인증기관·개인회원 무료
Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is economically important pest of various crops causing damage through direct feeding and transmitting tospoviruses. In a previous study differential responses of the thrips to various geometrical patterns of yellow sticky card were found. Therefore, in this study, we compared the behavioral responses of the thrips to visual and olfactory cues in cylindrical black box and Y-tube olfactometer, respectively. Multiple or pair wise choice tests were carried out among/between six geometrical patterns of yellow color paper and artificial flowers. The thrips preferred circular shape to other geometrical patterns in multiple choice test. In pair wise choice test between three geometrical patterns, i.e., circular, rectangle, and modified circular, and artificial strawberry flowers, the thrips showed preference to the yellow artificial flower than any other cues. The thrips resided on the yellow artificial flower almost 4 times more than other patterns. In Y-tube olfactometer test, higher number of the thrips chose the arm with p-anisaldehyde and artificial flower compared to the arm with only the artificial flower. Higher number of the thrips also chose the arm containing both visual and real flower odor as compared to arm with the only real flower odor. The potentials and application of these results in the development of attraction traps for the thrips management have been discussed.
40.
2008.05
구독 인증기관·개인회원 무료
Temperature and humidity are the vital environmental factors influencing the distribution and abundance of ectothermal organisms. Also, these variables often determine the efficacy of biological control of spider mites using phytoseiid mites N. californicus, N. womersleyi and P. persimilis are promising biocontrol agents of spider mites. The combined effects of temperatures (15,20,25,30 & 35oC) and relative humidity (33,51,75 & 95%) on egg hatch, incubation period from single egg and cannibalism from five eggs experiment were tested for three phytoseiid mites. Photoperiod was set to 16L:8D and neither water nor diet was provided. The result showed that higher temperatures (30&35oC) and lower relative humidity (33&51%) caused increased egg mortality by shrinking and desiccation. The egg hatch of N. californicus and P. persimilis were higher than N. womersleyi in all conditions with the exception of 35oC and 95% RH treatment where P. persimilis did not hatch at all. The incubation periods of egg decreased as the humidity level increased even under the same temperature. The cannibalism, habit of feeding the same species was found from protonymphal and deutonymphal stages under higher humidity levels (75&95%) in the three phytoseiid species. This tendency was higher in N. californicus and N. womersleyi than in P. persimilis. The results partially explain the lower predator performance during hot summer by P. persimilis and the possibility to sustain the predator population when the prey population is low.
