Woolly apple aphid, Eriosoma lanigerum, one of the pests occurring in apple do damages on the branch and bastard slip nearby ground roots by sucking sap. Recently, seasonal population of this pest steadily increased but has scarcity the basic data relating to its ecology. This study was conducted to investigate the infested orchard ratio, environmental analysis of occurred orchard, seasonal population and parasite rate by Aphelinus mali, a natural enemy for woolly apple aphid, from 30 to 34 apple orchards, at 11 to 13 major apple producing areas in Gyeongsang-namdo and Gyeongsang-bukdo, Geolla-bukdo, and Chungchung-bukdo, during 2012 to 2013. It showed infested orchard ratio as about 35% and population density started to increase from mid-May, with its optimal density in late-June and increased again in late-September. This pest found in various rootstocks where infested orchards and could not found any significant pattern. The damage appeared in 9 to 35 year-old trees, severed rather old trees than younger trees. Also, orchards that did not eliminate bastard slip were showed high occurrence pattern. Parasite rates of Aphelinus mali showed the difference among investigated orchards but the rates showed generally increased pattern since early- July.

The genus of Stomaphis (Aphididae: Lachninae) is stem or root feeding aphid on trees and can easily be distinguished in having the very long rostrum which extends beyond the length of body. Most of species are monoecious holocyclic without host alternation and attended by ants. Stomaphis sinisalicis Zhang & Zhong, 1982 (Aphididae: Lachninae) is recognized for the first time in Korea, on Salix babylonica L., S. koreensis Anderss. and S. hulteni Floderus (Salicaceae).

본 실험은 오이재배시 사용되는 살충제 47종이 진딧물 포식성 천적인 진디혹파리(Aphidoletes aphidimyza Rondani)의 모든 발육단계에 얼마나 영향을 주는가를 평가하였다. 진디혹파리 알에 대한 살충제의 독성평가 결과 emamectin benzoate 등 22종의 살충제가 낮은 독성을 보였다. 알에 독성이 낮은 22종 살충제 중 flonicamid를 포함하는 12종 살충제가 진디혹파리 유충에 대하여 0~27%로 낮은 독성을 보였으나, indoxacarb + teflubenzuron와 chlorantraniliprole의 독성은 각각 35.4%와 64.6%였다. 진디혹파리 유충에 보통독성 이하의 독성을 보인 indoxacarb + teflubenzuron와 chlorantraniliprole을 포함한 14종 살충제는 진디혹파리의 번데기와 성충에도 낮은 독성을 보였다.

본 연구는 나리 인편자구 포장정식 시 재배시설에 따른 바이 러스 감염률 등을 조사하여 포장 구근생산체계를 확립하고자 하 였다. 맹아률은 비가림하우스 및 망실하우스에서 높았으며, 품종 별로는 ‘Yelloween’이 ‘Star Gazer’보다 높았고 ‘Yelloween’ 의 망실하우스에서 맹아률은 90.3%였다. 총생체중 및 구근특성 도 ‘Yelloween’이 ‘Star Gazer’보다 높았으며 ‘Yelloween’ 노 지 정식구에서 총생체중은 15.8g이었으며 구중은 10.7g으로 가장 양호하였다. 진딧물 비래의 최성기는 5월이었고 노지 38마리 에 비해 비가림 및 망실에서 8마리, 2마리로 월등히 낮았으며, 바이러스 이병률은 CMV가 LSV보다 높았으며 노지에서 CMV 이병률은 17.8%로 비가림 및 망실보다 4배 이상 높았다. Pyrethroid처리는 250mg • L-1이상에서 바이러스 방제효과가 있 었다.

The exotic aphid pest, pomegranate aphid, Aphis punicae Parsserini, 1863 (Hemiptera: Aphididae), is newly recognized in the Korean peninsula. This species is originally distributed throughout the Mediterranean regions, the Middle East, Ethiopia, India, Pakistan, Indonesia, and Turkey. In the major producers of pomegranate such as India and the Mediterranean regions, this species is regarded as one of the most serious insect pests inflicting injury on pomegranate, Punica granatum Linnaeus. By sucking plant sap and excreting honeydew, aphids cause various plant diseases and virus infections which are more likely to occur as population size increases. Aphis punicae infests together commonly with Aphis gosspii Glover, and rarely with Aphis craccivora Koch and Aphis spiraecola Patch on P. granatum in Korea. In this study, we first compared two closely related species, A. gossypii and A. punicae, based on morphometric analysis to confirm their morphological relationships. Second molecular identification using mitochondrial COI barcode region was performed for the aphid samples collected from P. granatum.

For replacement of methyl bromide(MB) in Korea, VapormateTM, a gas formulation of ethyl formate(EF) with carbon dioxide, are firslty introduced in import bananas and VivakilTM, a gas formulation of phosphine(PH3) with carbon dioxide, are ready to commercial use in export cut flowers. Their applications are being extended for other import and export commodities. Ethyl formate have been shown to have effectiveness short exposure time(<4hr) but it has a limited application at low temperature for TSM(Two spotted spider mites) due to some phytotoxic to strawberry. Phosphine gas has demonstrated their efficacy to TSM at low temperature but only meets quarantine requirement when applying longer fumigation time(>24hr) to control CA(cotton aphids). We firstly evaluated two MB alternatives, EF and PH3, have enhansive effect within short exposure time(4hr) at low temperature(5℃) for controlling both TSM and CA without any injury to export strawberries.

In terms of aphid species identification, both host plant association and morphological characteristics are crucial factors. However, aphids in the genus Aphis Linnaeus (Hemiptera: Aphididae) often are cryptic in morphology due to their rapid radiation. Moreover, overlapping host plant species can make difficult situation worse. Three cryptic species Aphis gossypii Glover, Aphis glycines Matsumura, and Aphis rhamnicola sp. nov. occur together on the Buckthorn, Rhamnus spp. in the overwintering season in Korea. Due to lacking informative morphological characters and host plant sharing, the new species recently has been recognized as a distinct species. In this study, A. rhamnicola sp. nov. on various host plants was compared with the primary host sharing species, A. gossypii and A. glycines, based on morphological and molecular characteristics. In the results, there were significant genetic differences between three species, despite the high similarities in morphology. Our results provide strong evidence for establishing new species, which seems to be a typical heteroecious species that alternates between only primary host, Rhamnus spp., and various secondary hosts. We describe a new species, A. rhamnicola sp. nov., for apterous and alate vivipara, fundatrix, ovipara, and gynopara, including diagnostic key for host sharing species in genus Aphis.

진딧물 기생봉인 목화면충좀벌과 진디면충좀벌의 기주를 목화진딧물과 복숭아혹진딧물로 하여 15, 20, 25, 30℃에서 사육하면서 기주섭식수, 기생수, 우화율, 성비, 발육기간을 조사하였다. 목화진딧물이 기주일 때 15℃, 25℃에서 목화면충좀벌의 기주섭식수(5.4, 9.7마리)가 진디면충좀벌(2.0, 2.9마리)보다 많았으며 복숭아혹진딧물이 기주일 때 2종 기생봉 간 기주섭식수의 차이는 없었다. 목화진딧물에 기생한 목화면충벌의 기생수가 15℃에서 11.1마리, 30℃에서 21마리로 진디면충좀벌의 기생수(7, 12.3마리)보다 많았으며 복숭아혹진딧물에 기생시켰을 때는 20℃와 25℃에서 목화면충좀벌의 기생수(12.1, 17.1마리)가 진디면충좀벌(6.1, 10마리)보다 더 많았다. 목화진딧물을 기주로 했을 때 30℃에서 목화면충좀벌의 우화율(83.3%)이 진디면충좀벌(69.4%)보다 높았으며 복숭아혹진딧물에서는 우화율 차이가 없었다. 목화진딧물에서 사육했을 때 진디면충좀벌의 암컷비율이 15℃에서 75.2%, 30℃에서 73.9%로 목화면충좀벌의 암컷비율(19.5, 48.6%)보다 높았으며 복숭아혹진딧물에서 사육했을 때는 목화면충좀벌의 암컷비율이 15℃에서 65.3%, 25℃에서 90.0%여서 진디면충좀벌의 암컷비율(34.4, 78.8%)보다 높은 것을 알 수 있었다. 목화진딧물에서 2종 기생봉간 산란에서 우화까지의 발육기간의 차이는 없었고 복숭아혹진딧물에서는 20℃에서 목화면충좀벌의 발육기간(19.9일)이 진디면충좀벌(16.5일)보다 길었다.

복숭아혹진딧물에 기생하는 목화면충좀벌의 발육기간, 머미율, 번데기 사망률, 성비를 20, 25, 30, 25℃ 인큐베이터에서 수행하였다. 실험을 위하여 피망잎이 놓인 콤팩트샤레를 사용하였다. 각각의 4개 온도에서 발육단계별로 복숭아혹진딧물을 사육하였고 기생을 유도하기 위하여 12시간 동안 목화면충좀벌에 제공하였다. 목화면충좀벌의 알에서 성충까지 발육기간은 20℃ 18.3일, 25℃ 14.7일, 30℃ 10.4일, 35℃ 9.3일 이었다. 복숭아혹진딧물에 기생한 목화면충좀벌의 머미율은 20℃와 25℃, 1령과 2령에서 가장 높았으나 30℃와 25℃에서는 3령충에서 84.4~85.0%로 가장 높았다. 목화면충좀벌의 기주섭식률은 20~35℃까지 각각 12.5%, 17.3%, 16.0%, 10.9%였다. 목화면충좀벌 암컷의 성비는 온도별로 각각 49%, 46%, 69%, 60% 였다.

Many previous ecological studies on three major bacterial symbionts and a newly discovered symbiont PAXS (pea aphid X-type symbiont) in the pea aphid Acrythosiphon pisum have shown that these symbionts are associated with the expression of a variety of host phenotypes, including resistance to parasitoid Aphidius ervi and tolerance to heat stress. The principal role of all four symbionts “Candidatus Serratia symbiotica”, “Candidatus Hamiltonella defensa”, “Candidatus Regiella insecticola”, and PAXS is to protect aphids against abiotic stress by preserving the cells in which most of symbionts dwell and by reducing the rate of parasitism. In this experiment, we detected endosymbionts from four aphid clones by means of genomic DNA extraction, PCR with gene specific primer, and restriction enzyme cutting. The patterns of PCR and restriction enzyme cutting were all identical in the four aphid clones. In order to specifically identify the endosymbiont, we searched the sequences using BLAST. The BLAST search revealed that nucleotide sequences of the symbiont were 98% identical to Serratia entomophil. S. entomophil is also known to provide tolerance to heat stress, resistance to parasitoid wasps, and restoration of reproduction in aphids, suggesting its role in host protection.

Terrestrial toxic effects of soil arsenate were studied using a model system consisting of Capsicum annum, Myzus persicae, Aphidus colemani. We investigated the transfer of arsenic from soil to aphid and toxic effect of elevated arsenic on each trophic level. Artificial soil was treated with arsenate at 0, 2 and 6 mg/kg, then arsenic concentration of soil, plant tissues (root, stem, leaf) aphids were measured to observe the arsenic transfer. Toxic effects of elevated arsenic concentrations on each species were investigated at population level. Physiological and biochemical responses of plant and aphid were observed. In addition, enzyme activities against reactive oxygen species (ROS) induced by arsenic stress were also investigated. Host choice capacity and parasitism success of the parasitoids were examined. The results suggest that arsenic concentration in plant tissues and aphids were elevated with increased concentration of arsenic in soils. Physiological responses of plants were not affected by soil arsenic but there was change of biochemical responses. Decreased fecundity and honeydew excretion of aphids were observed, elevated activity of antioxidant enzymes indicated that aphids received the ROS stress induced by arsenic. Decreased eclosion rate of parasitoids were observed with increased arsenic treatment in soil. The results showed low concentration of arsenic in soil can transfer through food chain and can impact on higher trophic level species.

In the current research, the insect pathogenic fungus, Is aria fumosorosea was assessed for its pathogenecity against adults of different aphid species of wheat and Brassica crop i.e. Schizaphis graminum, Rhopalosiphum padi, Brevicoryne brassicae and Lipaphis erysimi. I. fumosorosea (IF-01) was found effective at all concentrations i.e. 1x106, 1x107 and 1x108 spores/ml on all aphid species, but the uppermost concentration (lx108 spores/ml) provided maximum control within short period of time (P < 0.05). The results showed that the effect of I. fumosorosea on different aphid species was dose and time dependent. I. fumosorosea with LC50 value of 9.02 x 105 proved to be lethal to L. erysimi after 3rd day. Mortality of B. brassicae was observed maximum on highest concentration of 1x108 spores/ml with LC50 value of 1.64 x 107 , while the LT50 values were in range of 1.78-4.53 days for different aphid species treated at various concentrations. By checking the field efficacy of I. fumosorosea against aphid species, this entomopathogenic fungus can be used as possible biological control agent for suppressing aphids.

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 green peach aphids, Myzus persicae (Sulzer), feed consistently and regularly throughout all stages of nymphs and adult. That is, honey dew production (HDP), which indicates a state of feeding, occurs at regular intervals within a given stage, and moving (MV), which interrupts feeding, tends to occur scarcely. We used these behaviors to test whether the sound stimuli acted as a stress in this species. We conducted the playback experiment in which acoustic stimuli with a combination of five frequency (100, 500, 1000, 5000, and 10000 Hz) and three intensity levels (66, 78, 90 dB SPL) were presented to all stages of aphids. Under all acoustic stimuli, HDP occurred less often, and MV occurred more often and longer. The results of two-way multivariate ANOVA showed that the stimulus frequency was a significant factor for variation in aphid behaviors in the playback experiment. However, there was no intensity effect on aphid’s behavior. Based on the electrical penetration graph experiment, aphid feeding was frequently stopped and lasted only for short durations under acoustic stimuli. The results of both experiments demonstrated that the acoustic stimuli were effective in inducing feeding suppression in this species. Thus, the acoustic stimuli may be a stressor in the green peach aphid. Furthermore, the behavioral bioassay employed in this study may be used to assess the effect of various stressors on aphids.

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

Aphids (Hemiptera: Aphididae) are well known as micro-insect pests, which are very specific to their host plants, sucking phloem for acquiring nutrients, and most of them have successfully maintained parthenogenetic generations cyclically or permanently. In the world, the approximately 5,000 described aphid species belong to the family Aphididae, which has taxonomically been subdivided into 27 subfamilies in current. The diversification of host plants, especially angiosperms, has played an important role in their evolution. Major questions about aphid evolution include origins of host alternation as well as age and patterns of diversification in relation to host plants. To address these, I did both macroscale (phylogenetics) and microscale (population genetics) researches on aphids. First I reconstructed the phylogeny of the three major aphid groups, Aphidini, Macrosiphini, and Pterocommatinae, which are the most diverse in the world and constitute more than 60% of the total species. These major lineages demonstrate the evolutionary history of aphids interacting with their host plants. I also used molecular dating method to calculate reasonable divergence time on each clade. Based on phylogenetic and dating analyses, most generic divergences in Aphidinae occurred in the Middle Tertiary when primary hosts, mainly Rosaceae, were diverging, whereas species-level divergences were related with diversification of secondary hosts such as Poaceae in the Middle to Late Tertiary. Most generic divergences in Aphidini occurred in the Middle Tertiary, and species-level divergences occurred between the Middle and Late Tertiary. The divergence times of aphid lineages at the generic or subgeneric levels are close to those of their primary hosts. Second I performed population genetics of the polyphagous cotton-melon aphid, Aphis gossypii Glover. I analyzed population genetic structure between 570 aphids collected from 41 plant species of primary and secondary, mostly wild, hosts using 9 microsatellite loci. As results, population structure of A. gossypii revealed that several genetic affinities in common use of some secondary and primary hosts are detected. Host preference in secondary host is higher than that in primary host, and woody plants share same genetic structure. This species might speciated by the related mechanisms such as host alternation and loss of primary host. I will propose macro- and micro-evolutionary patterns of the Aphidini aphids based on integrating phylogenetic and population genetic approaches

 ,  , To investigate host preferencse of Myzus persicae on 15 sweet pepper cultivars grown in Jeonnam Province, EPG (electrical penetration graph) and life table experiments were carried out in the laboratory. Phloem phase times were significantly longer on Ferrari, Jinju, Debla, and Rapido than Orobell and Thialf. Non-penetration times were conversely observed. Life span, reproduction period, total fecundity, and intrinsic rate of increase (r<, SUB>, m<, /SUB>, ) of M. persicae, were higher on Ferrari, Debla, Orange glory, and Jinju than on Purple, GreenAce, Orobell, and Thialf. On the bases of these results, we conclude that M. persicae preferred Ferrari, Jinju, Orange glory, and Debla among the 15 tested sweet pepper varieties. However, we could not show the preference of the aphid for Purple, Orobell, and Thialf.

The green peach aphid, Myzus persicae Sulzer, is one of the most important pests affecting protected and open-grown crops, because they cause direct damage by feeding on crops and indirect damage as virus vectors. It has recently become a serious problem because of the continuous use of insecticide resulting in resistance among green peach aphid population. Thus, the development of entomopathogenic fungi as aphid biocontrol agents has received increasing interest as part of integrated control strategies. In this study, we report the screening result of pathogenic fungi for the control of green peach aphid. Initial screenings were performed using 347 isolates of putative pathogenic fungi from Korea soils. As results, 20 isolates of entomopathogenic fungi were isolated from cadavers of green peach aphid supporting fungal conidiation. These isolates were identified as three strains of Lecanicillium attenuatum, nine strains of Beauveria bassiana, one strain of Metarhizium anisopliae, one strain of Metarhizium flavoviride, five strains of Paecilomyces lilacinus, one strain of Aspergillus sp. by microscopic examination, genetic sequencing of the ITS region and Universally Primed PCR (UP-PCR). Based on the screening results, twenty isolates were tested for their pathogenicity against adult green peach aphid. All fungal isolates were pathogenic to green peach aphid but mortality varied with isolates. These entomopathogenic fungi may be useful to develop eco-friendly insecticide to control green peach aphid.

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.