The cotton aphid, Aphis gossypii (Glover) (Hemiptera:Aphididae), is a highly polyphagous pest that directly or indirectly damages cultivated plants. Six field-collected populations of cotton aphid, A. gossypii (BY-A, BY-B, YJ-A, YJ-B, CJ-A, and CJ-B) were tested for susceptibility to 14 different insecticides. Most population exhibited high to very high levels of resistance to neonicotinoid. Among them, a strain showing resistance to imidacloprid were selected and showed 1,543-fold in resistance as compared with susceptible strain. Piperonyl butoxide (PBO), diethyl maleate (DEM), and S,S,S tributyl-phosphorothiolate (DEF) failed to synergize imidacloprid in this resistant population. In addition, the activity of detoxification enzymes (P450, EST, GST) were no differences between susceptibility and imidalcoprid resistance strain. However, by analyzing the nicotinic acetylcholine receptor β1 subunit loop D, R81T point mutation was detected in BY-A, BY-B, YJ-A, and YJ-B strain.

The cotton aphid, Aphis gossypii Glover is an important sap-sucking pest of many pant, including cucumber and pepper. The objective of the present study was to determine the effects of sublethal concentrations of two insecticides (imidacloprid and flonicamid) and the action mechanisms on the feeding behavior of A. gossypii. The median lethal concentrations (LC50) of imidacloprid and flonicamid for adult A. gossypii were 2.01 and 1.92 ppm, respectively. The sublethal concentrations of imidacloprid were 0.22 ppm (LC10) and 0.82 ppm (LC30), and those of flonicamid were 0.094 ppm (LC10) and 0.56 ppm (LC30). The developmental period of A. gossypii nymphs at LC30 was 3.6 days for both insecticide which shorter than controls (4.2 days). Adult longevities at LC10 and LC30 of imidacloprid were 15.2 and 13.6 days, respectively. Adult longevity at LC10 and LC30 of flonicamid was 11.1 and 9.9 days, respectively. Control adult longevity was 15.5 days. Total fecundity was decreased at both sublethal concentration of two insecticides. Feeding behavior analysis using an electrical penetration graph showed that sublethal doses of imidacloprid and flonicamid had significant effects on the duration of phloem ingestion. However, higher doses of flonicamid induced starvation by inhibition of phloem ingestion and higher doses of imidacloprid induced contact toxicity rather than inhibition of feeding behavior.

The cotton aphid, Aphis gossypii (Glover), is one of the most serious pest in seed potato and various vegetable cultivation. The imidacloprid-resistant strain (IR) was over 300-fold more resistant to imidacloprid compared to a susceptible strain (S) as judged by LC50 values. A highly imidacloprid-resistant local field population (L) was collected from cucumber at Gangwha island in 4th August 2011. Even though neonicotinoid insecticides especially imidacloprid were sprayed six times during June and July, aphid density was too high to be counted. To identify differentially expressed genes in IR or L, comparative transcriptome analyses based on GS-FLX were conducted using total RNAs extracted from IR, L and S strains. Futhermore, to search the resistance associated proteins in IR or L, comparative proteome analyses based on 2DE were conducted using total proteins extracted from IR, L and S strains. Few common candidate genes detected among IR and L such as ABC genes. Comparison of the nucleotide sequence of six nicotinic acetylcholine receptor (nAChR) subunit (alpha 1-5, beta 1) genes from IR, L and S strain revealed a point mutation in the loop D region of the nAChR beta 1 subunit of the IR, causing an arginine to threonine substitution (R81T). These mechanisms also reported in Myzus persicae and this amino acid change confers a vertebrate-like character to the insect nAChR and results in reduced sensitivity to neonicotinoids.

Many polyphagous herbivore insects considered as a single species are indeed comprised of genetically differentiated host related races that utilize several unrelated plant families. Aphis gossypii Glover, one of the extremely polyphagous aphid species, has more than 100 host plants distributed worldwide. In Korea, it takes holocyclic life cycle, with a number of primary hosts, which is unusual for other aphid species. However, former population genetic studies on A. gossypii have dealt with the populations from only a few agricultural host plants. In this study, we hypothesized that different primary host utilization may be restricted for certain host races and this may play a key role of the genetic differentiation in this species. We collected the cotten aphid populations from 36 different host plants, 5 primary and 31 secondary hosts including various wild and non-cultivated plants. To determine population genetic structure, we analyzed genetic differentiation among those populations using 9 microsatellite loci. As results, four genetically distinct clusters were verified. Of the five primary host populations, there were significant gaps in genetic differences between Rhamnus-associated group and Hibiscus-associated group, and the other populations were affinitive with the Hibiscus-associated group. Overall, primary host populations have a higher level of genetic diversity than secondary host populations. Several populations associated with secondary hosts such as spiderwort, madder, and Korean lettuce were considerably differentiated in the result of principle component analysis, which nearly showed the species level difference similar to Aphis glycines Matsumura and Aphis sp. ex Rhamnus. Thus, there could be reproductively isolated by the loss of primary hosts, and might be already speciated from A. gossypii

The cotton aphid, Aphis gossypii (Glover), is one of the most serious pest in the cultivation of various vegetables. A highly imidacloprid-resistant field population (CA-L) was collected from cucumber at Gangwha island in 4th August 2011. Even though neonicotinoid insecticides especially imidacloprid were sprayed six times during June and July, aphid density was too high to be counted. IEF and 2DE analyses revealed that general esterase isozyme (pI. 5) in CA-L were dramatically overexpressed and more isozyme spots identified in CA-L compared to susceptible (CA-S) strain. To identify differentially expressed genes in CA-L, comparative transcriptome analyses based on GS-FLX were conducted with total RNA extracted from CA-L, which generated ca. 143 Mb reads. Previously reported, comparative transcriptome analyses performed in imidacloprid resistant (CA-IR) and CA-S. The comparative transcriptome analyses re-investigated after all data sets were combined together. As previously reported, seven ATP-binding cassette (ABC) transporter genes were newly identified in A. gossypii, among which only ABCC9 gene was highly expressed in CA-IR and L. These results suggested that ABCC subfamily associated with imidacloprid resistance in A. gossypii.

After pea aphid Acyrthosiphon pisum genome project, hologenome concept was applied to pea aphid and symbioant such as Buchnera aphidicola. Here we screened symbiotic microorganism in four lab strains (two genetically different insecticide susceptible strains, host plant: cucumber and two different host adopted imiacloprid resistance strains, host plants: cucumber and potato) and four field populations (Jeju, Goryeong, Gimjae and Muju, host plant: potato) of cotton aphid based on GS-FLX pyrosequencing which were conducted with universal primer amplified partial fragments of 16S rRNA from total DNA which was extracted from each strain and population. B. aphidicola occupied over 90% of all identified prokaryotic microorganisms which all tested samples. It’s interesting that the ratio of B. aphidicola occupied over 99% in all of the tested lab strains. However, specific enterobacteriaceae occupied six to seven percents of all field populations which closely related endosymbiont of Glycaspis brimblecombei. That means B. aphidicola occupied only 91~92% of all identified prokaryotic microorganisms. Futhermore, other actinobacteridae and bacillaceae also were detected in field populations. The results obtained for these ratios suggested that there has some interaction between symbioant and environment NOT in imidacloprid resistance.

The cotton aphid, Aphis gossypii (Glover), is one of the most serious pest in seed potato and various vegetable cultivation. The imidacloprid-resistant strain (IR) was over 200-fold more resistant to imidacloprid compared to a susceptible strain (S) as judged by LC50 values. The IR showed cross resistances to other neonicotinoid insecticides. IEF and 2DE analyses revealed that general esterase isozyme patterns in IR were almost identical to those of S. Nevertheless, a significantly overexpressed protein spot was detected in IR. To identify differentially expressed genes in IR, comparative transcriptome analyses based on GS-FLX were conducted using total RNAs extracted from both IR and S strains, which generated ca. 290 Mb reads for each strain. Generally, most nicotinic acetylcholine receptor subunit genes, such as alpha 2 and beta 1, were more transcribed in S than in IR. In contrast, only alpha 5 subunit gene was 1.8 fold more expressed in IR. Seven ATP-binding cassette (ABC) transporter genes were newly identified in A. gossypii, among which only ABCC9 gene was highly expressed in IR. Therefore, this ABCC subfamily, a member of the MRP subfamily which is involved in multi-drug resistance, could be one of the main factors associated with imidacloprid resistance in A. gossypii.

The possibility of commercializing the controlled release of chitosan carrier nano formulation was examined with mortalities and population increase rates of Aphis gossypii and Myzus persicae after treatment of 2 α-cypermethrin nano type formulations of different chitosan carrier molecular weight (M.W. 3,000 and 30,000) and 2 etofenprox nano types of chitosan content (70% and 80%). After 14 days of treatment, α-cypermethrin nano formulation showed over 40% mortality against A. gossypii. Therefore, it was confirmed that the insecticide release was controlled through chitosan carrier. Results of the investigation of insecticidal activity of α-cypermethrin nano formulation showed there were no differences between nano types at 4 days after treatment. However, after 14 days, the population increase rate treated with chitosan M.W. 30,000 formulation was -0.037, much lower than that of M.W. 3,000 formulation with 0.231. The result exhibits that chitosan M.W. 30,000 formulation would be a suitable controlled release formulation. On the other hand, etofenprox formulations didn’t show any significant insecticidal effect or persistency difference against both aphid species.

The cotton aphid, Aphis gossypii (Glover), is one of the most serious pest in seed potato and various vegetable cultivation. The imidacloprid resistant strain (IR) was over 200 fold more resistant to imidacloprid compared to the susceptible strain (S) as judged by the LC50 values and IR showed cross resistant to acetamiprid, thiamethoxam, thiacloprid, clothianidin. By using the suppression subtractive hybridization method, a imidacloprid resistant associated cDNA library was constructed in adult cotton aphid. In total 115 differentially expressed cDNA clones were obtained. Any point mutation detected in nicotinic acetylcholine receptor alpha 1~5 and beta 1 subunits in the IR. Based on IEF, the IR general esterase isozyme banding patterns were identical with that of S.

For the physiological study on environmental impact of genetically modified (GM) pepper plant on non-target but three-trophically related insect species, we investigated behavioral responses of Aphis gossypii and Aphidius colemani in Y-tube olfactometer to the cucumber mosaic virus (CMV)-resistant transgenic pepper plant (H15 GM line) expressing coat protein gene of CMV and its wild type pepper plant (untransformed, susceptible to CMV pathotype II, P2377 inbred line) in relation to CMV infection. CMV-infected plants were prepared with the 30 min of inoculation by the winged A. gossypii viruliferous or mechanical inoculation using CMV-Fny, and with molecular diagnosis using reverse transcriptase-polymerase chain reaction (RT-PCR) over 2 weeks after inoculation. In this study, time for attraction responses (attraction time) of A. gossypii were not significantly different in the pepper strain, and the virus infection of plant. However, the attraction time of A. colemani was significantly different between the GM plant and the non-GM plant. In addition, the attraction time of A. colemani to the GM plant was significantly decreased according to the CMV infection. For further study, the volatile organic compounds (VOCs) emitted by these plants were collected with an entrainment kit and analyzed by Gas Chromatography (GC) on HP-1 column. The specific VOCs related to CMV infection were detected in the GM plant over 4 weeks after inoculation of CMV in this study. Thus, it is suggested that VOCs of the GM plant in this study may be produced more as a signal attracting A. colemani in relation to CMV infection.

오이모자이크바이러스(Cucumber Mosaic Virus, CMV)에 이병된 착색단고추(Capsicum annuum var. grossum) 의 휘발성 물질(Volatile organic chemicals, VOCs)에 대해 식물바이러스 매개충인 목화진딧물(Aphis gossypii)의 유인반응을 조사하였다. 착색단고추에 CMV를 즙액 접종, 진딧물 보독충을 이용한 접종 및 대조군으로 완충용액만 접종한 처리구와 진딧물 비보독충을 접종한 처리구를 배치하였다. 접종한 CMV와 중복 감염 여부를 우려하여 접종하지 않은 PepMoV를 RT-PCR로 각 단계에서 검정하였다. 분자검정은 상처효과(wounding effect)를 우려하여 유인반응 24시간 이전에 수행하였다. Gas chromatography 분석에 의해 CMV에 이병된 착색단고추는 접종 후 2주 또는 4주에 바이러스 감염에 따른 특이적인 VOCs를 확인할 수 있었다. 특히 접종 후 2주차에 즙액접종과 보독충 진딧물 접종 간에는 발병 특이적인 VOCs의 방출 패턴이 유의적으로 차이를 보였다. 이에 따라 이들 VOCs에 대한 진딧물의 유인 반응을 검정하고자 CMV 이병 식물과 건전 식물에 대한 목화진딧물 유시충의 Y-tube 유인 수를 조사하였다. 그러나 CMV 이병주의 VOCs에 대하여 목화진딧물의 특이적인 유인효과는 나타나지 않았으며, 다만 식물의 생장에 따른 유인수의 증가만 확인 되었다.

Temperature-dependent development studies of two aphid species, A. egomae and A. gossypii occurring in green perilla greenhouse were conducted at 15~35℃, and 16:8 (L:D h) of light period in the laboratory. The mortality of two aphid species was high in young stages (1st and 2nd). In A. egomae, the mortalitiy increased with increasing and decreasing temperature: the mortalitie at 15℃ and 35℃ were 22.3% and 15.6%, respectively. While the mortalities of A. gossypii increased with increasing temperature: the mortality at 35℃ was 50.0%. The developmental periods of A. egomae and A. gossypii ranged from 20.8days to 5.4days and from 22.6days to 9.1days at 15℃ to 30℃ of temperature resion, respectively, and were 7.2days and 10.7days at 35℃ for each species. The lower developmental threshold temperatures for total nymphs of A. egoame and A. gossypii were 9.9℃ and 4.9℃, respectively and an effective degree-days (DD) for the developmental completion of total nymph were 108.0 DD for A. egomae and 221.2DD for A. gossypii. In green perilla greenhouse, the occurrence period of A. gossypii was earlier about 15 days than that of A. egomae. When the occurrence period of two aphid species was estimated by degree-days based on lower threshold temperatures, A. gossypii occurred earlier than A. egomae in the field. A. gossypii occurred from early April and showed dominant position to late May compared with A. egomae. Whereas, A egomae started to occur from mid April and then were abundant after late May followed by abrupt population crash around late July.

In organic agriculture, choose of effective and cheap bio-pesticide is very important. The authors developed an insecticidal extract from neem cake, waste of neem oil from kernel, and applied as a bio-pesticide. Bio-pesticide neem cake extracts experiment

진디혹파리(Aphidoletes aphidimyza Rondani 1847)의 발육실험 조건은 RH, 광조건은 16L:8D이었다. 알에서 번데기 기간까지 종합한 발육기간은 에서 43.9, 44.5일이였고, 에서 14.3, 15.8일이였으며, 발육영점온도는 10.7, 이고, 유효적산온도는 210.8, 245.5일도였다. 두 종의 진딧물을 먹이로 한 온도별 발육율은 변형된 Sharpe와 DeMichele의 비선형모형에 잘 적합되었다. 진디혹파리의 발육 단계별 발육완료 시기 분포 모형을 생리적 연령을 이용하여 Weibull function으로 보았을 때 알유충번데기 순으로 점차 발육 완료가 짧은 기간에 이루어지는 것을 볼 수 있었고 적합도를 나타내는 은 0.86-0.93, 0.85-0.94로 누적 발육율을 비교적 잘 보여주고 있다. 성충 수명은 에서 8.7, 9.2일이였고 에서 3.1, 2.7일이였다. 이들 결과를 종합해 보면 알 기간에서 의 경우 발육기간은 짧았으나 부화율이 미만으로 낮았고, 유충은 에서 번데기에 이르지 못하고 모두 사망하였고 에서는 발육기간이 길어져 이상에서는 유충과 번데기가 부의 영향을 받아 기존의 보고와 상이하였다. 또한 성충수명에서 의 경우 성충수명은 길었으나 케이지 내에서 움직임이 전혀 없었고, 산란 또한 하지 않았으며 에서도 성충기간이 짧아 산란 수가 아주 적거나 없을 것으로 생각된다. 따라서 진디혹파리를 진딧물 방제에 이용할 경우 성충이 자유롭게 움직이며 산란할 수 있는 이상 미만의 온도가 좋을 것으로 생각한다.

목화진딧물(Aphis gossypii Glover)의 성충수명, 산자수는 15-32.5, 습도는 , 광주기는 16L: 8D조건에서 조사하였고 이를 이용하여 생명표를 작성하였다. 를 기준으로 온도가 내려감에 따라서 수명이 길어지고 산자수가 증가하였다. 특히 에서 산자수가 61.8마리로 가장 많았다. 이와 다르게 성충의 일일 출산 수는 까지 온도가 올라감에 따라 증가하였고(일일평균 5.6마리) 이후 감소하였다. 온실에서 성충수명은 20.0일, 산자수는 59.6마리로 의 항온조건보다 수명은 길고 산자수는 더 많았다. 목화진딧물의 생명표를 작성한 결과 순증가률(Ro)은 에서 54.9이였고, 내적자연증가률()과 기간증가률()은 에서 0.5와 1.6으로 최고 값이었고, 배수기간(DT)과 평균세대기간(T)은 에서 1.4와 6.8로 가장 작았다. 따라서 이들 수치를 통해 보았을 때 목화진딧물이 생활사를 완성하는데 최적 조건은 라 생각한다.

목화진딧물 발육실험은 15-35, 습도는 60-70%, 광주기는 16：8 (L：D h)에서 수행 하였다. 진딧물 약충 사망률은 초기 1-2령의 사망률이 대부분을 차지하고, 온도의 상승에 따라 사망률이 높아져 32.5에서 36%였으며, 35에서는 1-2령의 사망률이 44%, 3-4령이 56%로 이 온도에서는 진딧물의 발육이 이루어지지 많았고, 3-4령의 사망률이 1-2령의 사망률보다 높게 나타난다. 전체약충의 온도별 발육기간을 보면 15-3까지 온도의 상승에 따라 발육기간이 11.5에서 4.6일로 짧아지는 경향을 보였고, 고온의 영 향을 받은 것으로 생각되는 32.5에서는 오히려 발육기간이 5.5일로 길어졌다. 발육영 점 온도는 5.이였고, 유효적 산온도는 106.8일도였다. 온도별 발육율은 변형된 Sharpe와 DeMichele의 비 선형 모형 에 잘 적합되었다. 발육단계별 발육기간을 표준화하여 누적시킨 값들은 3개의 변수를 갖는 Weibull function에 적합되었다.