2010년대 들어 화학물 기반의 작물보호제에대한 환경독성 및 잔류 문제의 대두, 병해충에 대한 저항성 증대와 이에 따른 신규 작물보호제 개발 비용의 증가 등은 바이오 작물보호제에 대한 관심을 증가시키고 있다. 특히 Bayer의 AgraQuest 인수, BASF의 Becker Underwood인수, 신젠타의Pasteuria Bioscience 인수나 Monsanto와 Novozyme의 BioAg., FMC와 Chr. Hansen 등의 기술 및 제품개발 협력관계 구축 등은 바이오 작물보호제에 대한 다국적 작물보호제 기업의 높은 관심을 보여주는 것이다. 본 발표에서는 미생물을 활용한 글로벌 바이오 작물보호제 개발 동향 및 팜한농에서 개발한 바이오 작물보호제 개발 사례를 소개하고 향후 바이오 작물보호제 산업화를 위해 요구되는 사항들을 정리하여 논의하고자 한다.

The pea aphid, Acyrthosiphon pisum, requires the nutritional endosymbiont, Buchnera, for the production of essential amino acids. However, it is unclear if host plant diet that varies in essential amino acids influences aphid regulation of its nutritional symbioses. We hypothesized that aphid genes respond to host plant diet when aphids feed on their specialized (alfalfa) compared to universal host plant diet (fava), which vary in essential amino acid concentrations. Using RNA-Seq and whole genome bisulfite sequencing, we compared the gene expression profiles and DNA methylation distributions of specialized aphid cells that harbor Buchnera (bacteriocytes) when aphids feed on their specialized compared to their universal host plant diets. Our results show that bacteriocyte transcription and methylation patterns differ between host plant diets. When aphids feed on their specialized host plant, they significantly up-regulate and/or hypo-methylate key aphid genes in bacteriocytes related to the amino acid metabolism, including glutamine synthetase (GS) and the glutamine transporter ApGLNT1. Moreover, regardless of which host plant aphids feed on, we observed significant up-regulation and differential methylation of the key genes in the amino acid metabolism and the glycine/serine metabolism in aphid bacteriocytes. We suggest that the regulatory response of key symbiosis genes in bacteriocytes allows aphids to feed on a specialized host plant diet with suboptimal nitrogen concentrations.

To identify the venom components and their expression patterns of some Aculeata bees/wasps, venom gland-specific transcriptome analysis was conducted. FPKM values were normalized with the average of the transcription level of reference gene (a-tubulin). Common components in both solitary and social wasp venoms include hyaluronidase, phospholipase A2, metalloendopeptidase, etc. Although it has been expected that more diverse bioactive components with the functions of prey inactivation and physiology manipulation are present in solitary wasps, the information on venom compositions of solitary wasps obtained in this study was not sufficient to generalizae this notion. Nevertheless, some neurotoxic peptides (e.g., pompilidotoxin and dendrotoxin-like peptide) and proteins (e.g., insuline-like peptide binding protein) appear to be specific to solitary wasp venom. In contrast, several proteins, such as venom allergen 5 protein, venom acid phosphatase, and various phospholipases, appear to be relatively more abundant in social wasp venom. In the venom gland trancsriptome of bumblebees, major allergens or pain producing factors were barely identified, implying that bumblebee venoms are relatively less toxic than those of social or solitary wasps.

Insect cuticle tanning (pigmentation and sclerotization) is a complex and vital process, which includes hydroxylation of initial amino acid, tyrosine, to DOPA and decarboxylation of DOPA to dopamine. In the pigmentation process, dopamine further undergoes two N-acylation reactions to yield N-acetyldopamine (NADA) and N-β-alanyldopamine (NBAD). In the former reaction, arylalkylamine N-acetyltransferase (AANAT1) converts dopamine to NADA, and in the later reaction, aspartate 1-decarboxylase (ADC) provides β-alanine, which is conjugated with dopamine catalyzed by NBAD synthase (Ebony) for production of NBAD. In this study, we performed functional genomics of TmAANAT1, TmADC and Tmebony to determine whether they are required for cuticle pigmentation in Tenebrio molitor adults. Loss of function of these genes by RNAi caused the significantly darker body color than that of control animals. Note that, although all phenotypes exhibited dark cuticle pigmentation, RNAi of either TmADC or Tmebony only altered brownish outer region of the cuticle to dark/black. In contrast, RNAi of TmAANAT1 had no effect on the brown hue of the outer cuticle layer, but less or no pigmented inner region of the cuticle became significantly darker than those of control adults. These results suggest that, like that seen in TcAANAT1- or TcADC-deficient Tribolium castaneum adults, NADA produced by a reaction by TmAANAT1 contributes the lighter inner cuticle layer(s), whereas NBAD appears to do the highly pigmented outer cuticle layer(s) of the cuticle of T. molitor adults. This work was supported by NRFs (NRF-2015R1A6A3A04060323 and NRF-2018R1A2B6005106).

IKK-γ is an essential protein to form IKK complex which regulate NF-κB. We identified TmIKK-γ (or TmKenny) gene which has 1,521 bp of nucleotides encoding 506 amino acid residues. Domain analysis of TmIKK-γ shows that there are one NF-κB essential modulator (NEMO) domain and a leucine zipper domain. Expression of TmIKK-γ gene was gradually increased from egg to 2-day-old pupal stage, dramatically decreased until 7 day-old pupal stage, and then it was gradually increased. TmIKK-γ transcripts were highly expressed in fat body and hemocytes in late instar larvae and integuments, fat body and Malpighian tubules in 5 day-old adult. TmIKK-γ was drastically induced by E. coli after 3 h challenges and by S. aureus at 3 and 12 h-post injection in hemocytes. TmIKK-γ was not induced by C. albicans although it was significantly induced by E. coli (at 3, 6 and 24 h) and S. aureus (at 9 h) in gut. In fat body, expression of TmIKK-γ was drastically induced by E. coli at 3 and 24 h-post injection while it was not significantly induced by S. aureus and C. albicans. To understand the immunological role of TmIKK-γ, gene specific RNAi and mortality assay was performed. larval mortality against microbial challenge was dramatically increased by TmIKK-γ RNAi. Furthermore, we investigate the tissue specific induction patterns of fourteen AMP genes in response TmIKK-γ dsRNA-treatment. In fat body, ten AMP genes out of fourteen was not significantly induced by microbial challenge in TmIKK-γ dsRNA-treated group. Based on these results, TmIKK-γ might play an important role in antimicrobial innate immune responses in Tenebrio molitor.

Pine wood nematode (Bursaphelenchus xylophilus), the pathogen of pine wilt disease (PWD), is transmitted to new host trees through Monochamus spp., vector insects. In Korea, aerial application has been allowed conventionally to eliminate the vectors in their flying season. In this study, thiacloprid was applied to four-year-old Pinus densiflora, which were fed to adult M. alternatus emerged from PWD infected logs for 72 h in the condition of 1 DAT (Days after treatment of thiacloprid) and 15 DAT, respectively. We confirmed the presence of nematodes in each beetle applied to experiment by Baermann funnel method and PCR with species-specific ITS primers. After 72 h of 1 DAT and 15 DAT, thiacloprid residues in pine trees were 0.59-16.32 and 0.043-0.131 mg/kg and the mortalities of the beetle were 100 and 99.2%, respectively. Detection rate of B. xylophilus was 51.3%. The incidence rate of PWD in 1 DAT and 15 DAT showed no mortality and 5.55% compared with 55.5% of control, respectively.

Spotted wing drosophila (SWD), Drosophila suzukii, is a serious pest of berry fruits and grapes in East-Asia and USA. SWD female oviposits eggs into the skin of ripening fruits, and the larvae dig a burrow inside the fruits. Secondary infestation by other insects and pathogens to the oviposition spots cause substantial economic damages worldwide. SWD has recently been spreading to Europe and USA, and it is becoming a global threat in terms of biosecurity. A quite useful paper has been published in Journal of Chemical Ecology in the most recent issue (Vol. 44, #10) which is titled ‘Advances in the chemical ecology of the spotted wing drosophila (Drosophila suzukii) and its applications’ written by Cloona et al. This article introduces chemical constituents from many odor sources such as fermentation, yeast, fruit, and leaf sources, and commercial lures and traps developed using these compounds. Authors said that the current food-based lures and trap technologies are not expected to be specific to SWD and thus capture large numbers of non-target drosophilids. Attractive and aversive compounds are being evaluated for monitoring, mass trapping, and for the development of attract-and-kill and push-pull techniques to manage SWD populations. (Supported by PJ011756022018, RDA)

A combination using phosphine (PH3) and ethyl formate (EF) was performed to compensate for the disadventages (long exposure time and phytotoxicity) of a single substance. P. longisipinus was more susceptible to mixed phosphine and ethyl formate than P. orchidicola in 12 L dessicator. Mortality of mixed treatment was higher than aggregated mortalities that treated individually, so it indicated to have a synergic effect on each other. Ethyl formate was showed higher adsorption rate than phosphine on imported nursery plants and showed differences depending on the plant. P. longispinus and P. orchidicola was showed 100% mortality when phosphine and ethyl formate was treated as 1 g/m3 and 30 g/m3 for 4 hour in 0.5 m3 fumigation chamber and in 10 m3 container. Phytotoxicity was evaluated to mixture of phosphine and ethyl formate at 1 month after treatment.

밤 재배단지에서 갈색날개매미충은 밤바구미, 복숭아명나방, 붉은매미나방과 주요 해충으로 경제적으로 피해를 야기하고 있다. 이에 밤 재배단지에서 2년 동안 갈색날개매미충의 공간적 이동 양상을 분석하기 위해 실험을 수행하였다. 실험은 부여에 위치한 한 밤 재배단지에서 대략 30m 간격으로 임의로 밤나무를 선정, 표지한 후 GPS를 이용 좌표를 구하고 나무당 50cm 가지 2개에 존재하는 갈색날개매미충 알, 약충, 성충의 밀도를 육안 조사하였다. 조사된 결과를 SADIE를 이용해 공간적 상호관계를 분석해 본 결과 알, 약충, 성충 2년 동안 지속적으로 양의 공간적 상호관계를 보였고, 약충 시기를 제외하고는 통계적으로 유의하였다(p < 0.025). 이는 넓은 밤 재배단지에서 갈색날개매미충이 발육단계에 상관없이 특정 지역에서만 집중적으로 발생하고 있다는 것을 의미하며 특정 지역에 집중적인 방제가 필요하다는 것이다. 이러한 결과를 바탕으로 연구된 밤 재배단지에서 갈색날개매미충의 방제 전략이 제안되었다.

쓰름매미의 진동막와 복부 중 어떤 기관이 유인음의 주파수를 결정하는지 확인하였다. 쓰름매미는 유인음 발생시 복부의 모양을 변화시켜 주파수를 변조하는 것으로 관찰되었다. 안동하회마을에 Songmeter를 설치하여 24시간동안 녹음하여 우는 시간을 분석하였다. 양쪽 진동막에서 나온 비명음을 프로브마이크로폰으로 녹음하였다. 비명음 발생시 진동막의 진동을 초고속카메라로 촬영(20,000 fps)하여 평균진동수±불확도를 분석하였다. 연구결과, 쓰름매미는 일출시각이 05:39이었던 날에 05:13부터 울기 시작하여, 일몰시각이 19:23 이후인 19:55까지 울어, 말매미·애매미·참매미와의 경쟁에서 가장 긴 시간동안 울었다. 유인음의 FFT 결과, 중심주파수는 약 6,000Hz인 고주파임을 알 수 있었다. 두 진동막은 비동시적으로 진동하였는데, 진동 주기는 5.45ms이며, 지속시간은 4.75ms으로 양쪽진동막 소리 사이 공백이 0.7ms로 중첩은 없었다. 2,061Hz의 진동은 계속 유지되고 중간에 11,111Hz의 고주파가 합성되었다. 진동막은 3가지 모드로 진동하였고, 1st 모드의 평균진동수±불확도는 1,904±78Hz, 2nd 1,644±49Hz, 3rd 1,019±39Hz로, 불확도 99% 신뢰수준에서 세 가지 모드 모두에서 양쪽 진동막의 진동수는 다르다고 할 수 없으며 또한, 모드별로 같다고 할 수 없는 것으로 나타났다. 결론적으로, 복부 공명 효과가 배제된 진동막의 진동수 범위는 2,000 Hz 미만임에도 유인음과 비명음에서 모두 6,000 Hz 이상의 소리가 관찰되는 것으로 보아 진동막은 비교적 낮은 주파수의 소리 발생하지만 복부의 부피와 모양을 변화시켜 높은 주파수의 소리를 발생하는 것으로 판단된다.

상주는 귀농 도시이자 농업 중심 도시로써 농업기술원을 유치할 만큼 생태학적 연구가치가 있는 친환경 도시이다. 특히 경천섬은 낙동강 본류에 있는 상주보 인근에 위치하고 있어 낙동강 생태 환경 연구의 중요 지역 중 하나이다. 하지만, 아직 경천섬에 대한 생물다양성 연구가 부족한 상태이다. 섬과 산지의 생태환경이 다르기 때문에 생물의 다양성도 다를 것이라 간주하고, 경천섬 주변의 생태학적 가치를 재조명할 기초자료를 조사하고자 한다. 이에 경천섬과 인근에 위치한 청룡사 길목 산지에 서식하는 곤충 채집을 통해 생물다양성을 조사하여 비교분석하는 것을 목적으로 한다. 채집방법은 직접잡기, 쓸어잡기, 함정트랩, 흡충관을 이용하였으며, 함정트랩에 사용된 유인제는 소주1.8ℓ와 빙초산350㎖를 혼합하여 사용하였다. 2018년 4월~8월 중 3회 채집과정을 수행하여 목표개체수를 확보하였고, 채집된 곤충은 에탄올을 채운 conical tube에 넣어 냉동실에 보관하여 보존성을 높였다. 채집과정에서 잡은 곤충들을 건조시키고 유사종끼리 분류하고 동정하는 과정을 거쳐 다양도지수, 우점도지수, 종풍부도지수, 종균등도지수, 유사도지수를 계산할 것이다. 기존에 알려지지 않았던 경천섬 일대의 생물다양성을 세세하게 분석하는 과정을 통해 경천섬의 생태학적 가치를 드러내고, 경천섬 일대의 자연환경관리와 보존에 필요한 정보나 체계적인 관리체계를 구축할 기초자료를 제공하고자 한다.

최근 전세계적으로 건강기능식품에 대한 사람들의 관심이 증가함에 따라 식용곤충에 대한 활발한 연구가 진행되고 있다. 국내에서도 식용곤충에 대한 활발한 연구가 진행되고 있으며, 그 중 흰점박이꽃무지는 동의보감에서 효능을 인정받아 식량자원으로써 연구되고 있다. 이에 근거하여 본 연구에서는 흰점박이꽃무지 성충의 먹이에 대한 선호도 조사와 사육키트 설계를 통해 생산성 증대를 꾀하고자 하였다. 흰점박이꽃무지 성충에 대한 먹이 선호도 조사는 단백질의 함량과 당도, 그리고 알부민의 함량을 달리하며 실험을 수행하였다. 단백질 함량의 실험의 경우 0 %, 1 %, 5 %, 10 %에 대한 연구를 진행하여 이 실험을 통해 단백질의 함량은 흰점박이 꽃무지의 먹이 선호도에 영향을 미치지 않는다는 것을 알 수 있었다. 당도의 경우 과일의 당도범위를 기준으로 하여 15 brix, 20 brix, 25 brix, 30 brix에 대한 실험을 진행한 결과, 20 brix가 흰점박이꽃무지가 가장 선호한다는 결론을 얻을 수 있었다. 또한 계란 흰자의 주요 단백질 성분인 알부민의 경우 0 %, 10 %, 15 %, 20 %에 대한 실험을 진행하여 알부민의 함량이 적을수록 선호도가 더 높다는 것을 알 수 있었다. 먹이에 대한 선호도조사를 사육키트 설계에 반영하여 흰점박이꽃무지 성충의 사육키트는 실제 사육장의 인터뷰를 참고하여 온도 28 °C와 습도 40%로 자동으로 조절되도록 설계하였다. 사육키트의 온도는 사육키트의 바닥에 부착된 전기 매트를 통해 조절하고 습도는 사육키트의 측면에 위치한 팬을 통해 조절된다. 또한 먹이를 간편하게 제공할 수 있도록 먹이배급장치를 별도로 설계하였다. 본 연구의 의의는 흰점박이꽃무지의 성충에 대한 먹이 선호도 조사와 사육키트의 설계를 통해 미래 식량자원으로 이용될 수 있는 흰점박이꽃무지의 생산성에 대한 연구를 제안한다는 점에 있다.

식품 중 곰팡이 이물에 대한 연구를 위하여 식품 제조 및 유통/보관현장에서의 곰팡이 오염수준 및 주요 곰팡이류를 조사하였다. 측정은 식품유형별 총 9장소 (젓갈류, 식초류, 쌀류, 밀가루류, 냉동만두류, 면류, 과자류, 육가공류, 김치류)와 유통/보관현장 총 8장소(물류 창고)에서 진행하였고, 각 생산라인에서 부유곰팡이, 표면 곰팡이 오염도를 조사하였다. 측정결과, 육가공류 생산현장에서 부유곰팡이 오염도가 가장 높게 측정되었으며, 김치류 생산현장에서의 부유곰팡이 오염도가 가장 낮게 측정되었다. 설비 및 벽면에서의 표면 곰팡이 오염도의 경우, 식품 제조 및 유통/보관 현장에 관계없이 거의 검출되지 않았다. 현장에서 검출된 주요곰팡이를 조사한 결과, Penicillium sp., Aspergillus sp., Cladosporium sp., 종이 우점종 곰팡이로 조사되었다.

Phosphine (PH3) resistance in the stored-products insect pests has been reported throughout the world in various insect species, including Rhyzopertha dominica, Tribolium castaneum, and Cryptolestes ferrugineus, leading farmers and fumigators to identify new fumigation tools to control PH3-resistant insect pests in storage facilities. Understanding PH3-resistance mechanisms in insects might contribute to providing clues for the development of new chemicals, including fumigants, to control various PH3-resistant insects. A proteomic study has shown 15 decreased proteins in the PH3-resistant R. dominica (CRD343 strain) in comparison to the PH3-susceptible R. dominica, and among those 15 proteins, dihydrolipoamide dehydrogenase (DLD), a protein involved in the Krebs cycle, was identified (Park et al., 2008). The DLD polymorphisms responsible for genetic resistance have disulfide active sites for PH3 binding and are highly sensitive to arsenic exposure after mutagenesis in insects (R. dominica and T. castaneum) and Caenorhabditis elegans (Schlipalius et al., 2012). Here, two PH3- resistant S. oryzae strains were used to understand the development of PH3 resistance in these insects. Acute toxicity test by PH3 on the two PH3-resistant strains was undertaken followed by ethyl formate inhibition study on cytochrome c oxidase activity. The Lineweaver-Burk plots after inhibition studies showed there were significantly difference in inhibition mode between the resistant strains and the control. The RT-qPCR analysis and the next-generation sequencing of the mitochondrial DNA revealed significant changes in metabolism and energy production. Taken together, the PH3 resistance in S. oryzae was definitely acquired by the overall transformation of biochemical reactions to overcome PH3 toxicity.

Pine wood nematode (PWN), Bursaphelenchus xylophilus causes devastating damage to pines worldwide. To develop new agent for controlling PWN, 43 alkyloxyalcohols were synthesized and nematicidal activity was tested against PWN. As a control, monochamol, which reported to have nematicidal activity was also tested. The nematicidal activity was diffferent according to total carbon chain length in compounds and carbon numbers of diol derivates. The odd numbered carbon diol derivates (ROC5OH, ROC7OH, ROC9OH) showed weak activity. The compounds which had C14H30O2 formula (C11OC3OH, C10OC4OH, C8OC6OH, C6OC8OH) showed the same level nematicital activity as that of monochamol in the term of LC50 value. Thee compounds which had C15H32O2 and C13H28O2 formulas (C12OC3OH, C11OC4OH, C12OC3OH, C10OC3OH, C9OC4OH, C5OC8OH) were followed.

Pine tree, a dominant species in the flora of Korea is the most beloved tree in Korea. However, recent outbreak of pine wilt disease caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus threatens the vegetation of Pinus species seriously. Furthermore, Pinus densiflora and P. thunbergii, the predominant species in Korea forest are highly susceptible to PWN. Therefore, there has been an urgent demand for the development of a new nematocidal compounds to control PWN, which spurred the national research for the development of new compounds. To find novel sources for nematocidal agents, we used various plant resources for the development. In addition to the foreign plant extracts themselves, we also used the extracts of endophytes composed of over 300 endophytic fungi and 1,000 endophytic bacteria from plants which was reported to contain nematocidal activity. Several extracts of endophytes and plant extracts contained strong nematocidal activity, and the resources are analyzed to identify the active nematocidal compounds. These integrated approach of finding effective nematocidal compounds from plants could be a novel way to elucidate the sources for brand-new nematocidal agents.

Pine trees are ecologically important in Korea. They are seriously imperiled by Pine wilt disease (PWD), by pine wood nematode (PWN, Bursaphelenchus xylophilus). Here, we isolated and characterized bacterial endophytes (BEs) from pine trees in Korea for biological control of PWN using BE metabolites. Using culture-dependent approach BE isolates were extracted from three tissues (needles, stems, and roots) of four pine species across 18 sampling sites in Korea. Bacterial isolates were characterized into 389 distinct isolates based on 16S rDNA sequencing. Ethyl acetate crude extracts (CEs) of bacterial liquid cultures were prepared using ethyl acetate and screened for nematicidal activity against PWN. BEs (1,622 isolates) were isolated; their taxonomic binning resulted in 215 operational taxonomic units (OTUs). Analysis of species richness and Shannon’s diversity of the three tissues revealed that BEs colonized the needles more than the stem and root tissues. Furthermore, based on nematicidal activity screening of 389 isolates, 44 BEs were identified, with two isolates exhibiting a significant inhibitory activity against PWN. Taken together, these data revealed numerous nematicidal BEs in pine trees, providing new insights that can serve as an effective and promising alternative approach to combat PWD.

사회성 말벌류의 분류학적 연구는 과거 1960-1980년도까지 1차적으로 한국산 말벌을 정리하여 그 개략적인 윤곽이 나타났으며 90년대 이후 전문 분류학자들에 의해 연구되어 현재 남한지역에서 보고된 사회성 말벌류는 총 2아과 5속 30종이다. 그러나 아직도 분류학적 논의가 필요한 종이 남아 있는 상태이며 특히 각 계급별 및 벌집의 특성은 아직 밝혀지지 않은 종들이 많은 상태이다. 최근 들어서는 외래종 말벌의 침입을 통해 전국으로 확산되고 있는 가운데 공중보건적, 경제적, 생태적 피해가 나타남에 따라 이들의 조절 및 관리에 대한 연구가 일부 진행되고 있다. 또한 기후변화 및 도시화에 의해 전국적으로 말벌류가 증가함에 따라 119 소방서의 벌집제거수가 연간 20만건을 나타내고 있으며 각종 벌쏘임 사고가 빈발하여 연간 10여명의 사망사고가 나타나고 있어 이에 대한 국가적 대책이 필요한 실정이다. 또한 최근 말벌을 이용하여 만든 노봉방주의 수요가 급증하는 가운데 이들의 과학적 검증에 대한 요구가 증가하면서 독성, 타액 등의 효능분석 및 유해성 분석도 일부 진행되고 있다. 그 외 말벌의 공격성분석, 먹이 원분석, 사냥행동 특성, 기생, 천적 등의 생태적 연구도 일부 진행 중에 있다. 이처럼 말벌에 대한 사회적 문제가 커지고 있음에도 불구하고 국내의 말벌 전문 학자 부족으로 인해 가시적인 연구 성과가 미진하며 문제 해결에 대해 제대로 대처하지 못하고 있는 상황이다.

Various symptoms of virus diseases are observed on the cultivated and non-cultivated crops in Myanmar. The virus diseases cause a major limiting factor in the tomato and chili production. During 2018, survey on the virus disease and its vectors in tomato and chili fields were conducted in central regions of Myanmar including Naypyidaw, Mandalay, Magway and Sagaing Divisions. The symptoms observed on tomato and chili were chlorosis, puckering of leaf, upward curling of leaves, reduction in leaf size, vein and stunting. Tomato leaf curl (TLC) disease incidence and severity ranged from 10 to 100% and 37 to 86% respectively. Chili leaf curl (CLC) disease incidence and severity was 30 to 100% and 13 to 100% respectively. The highest incidence and severity of TLC and CLC recorded in Lewe townships, Naypyidaw. Insect vectors observed in those areas were whitefly (Bamisia tabaci), jassid (Emposca sp) and mealy bug, and the white fly was common. Whiteflies are very important vectors for virus in tropical and subtropical regions, but not confirmed to this area. Jassids are also vectors for virus. Both nymphs and adults suck the plant sap and introduce toxin to host plants. Therefore, an infestation may be very damaging and show stunted growth and bushy appearance.

4,4’-dichlorodiphenyltrichloroethane (DDT) has been re-recommended by the World Health Organization for malaria mosquito control in Africa. Previous DDT use has resulted in predisposition of resistance, and with continued use resistance will increase further in terms of level and extent. Drosophila melanogaster is a model dipteran that has many available genetic tools, has been widely used for elucidating insecticide resistance mechanisms, and is related to malaria mosquitoes allowing for extrapolation. The 91-R strain of D. melanogaster is highly resistant to DDT (>1500-fold); however, there is no mechanistic scheme that accounts for this level of resistance. Recently, reduced penetration, increased detoxification, and direct excretion have been identified as resistance mechanisms in the 91-R strain. Their interactions, however, remain unclear. Use of Gal4/UAS-RNAi transgenic lines of D. melanogaster allowed for the targeted knockdown of genes putatively involved in DDT resistance and has identified the role of several cuticular proteins (Cyp4g1 and Lcp1), cytochrome P450 monooxygenases (Cyp6g1 and Cyp12d1), and ATP binding cassette transporters (mdr50, mdr65, and mrp1) in increased sensitivity to DDT. These findings have been further validated in 91-R flies using a nanoparticle-enhanced RNAi strategy, directly implication these genes in DDT resistance in 91-R flies.