Aphid Research Articles

Serological and Molecular Typing of Plum pox Virus Isolates in the Transylvania, Romania

Plum pox virus (PPV) is considered the most destructive viral pathogen of stone fruits. Although PPV is widespread in all plum growing areas from Romania and causes serious yield losses, little is known about the virus variability. For this reason we investigated 100 PPV isolates collected from 13 different plum orchards in the Transylvania - Romania. PPV detection was made by DAS-ELISA and by IC-RT-PCR. PPV strains were serologically determined by TAS-ELISA using PPV-D and PPV-M specific monoclonal antibodies. Molecular strain typing was done by RT-PCR targeting three different genomic segments corresponding to (Cter)CP, (Cter)NIb/(Nter)CP and CI. RFLP analysis was used to distinguish the two major strains, D and M based on a RsaI polymorphism located in (Cter)CP. All PCR products targeting (Cter)CP and 10 PCR products spanning the (Cter)NIb/(Nter)CP were sequenced. All PPV isolates typed as PPV-M by serological analysis and by molecular differentiation in the genomic region corresponding to (C-ter)CP proved to be PPV recombinant (PPV-Rec) when the molecular analysis were performed in the region corresponding to NIb/CP. Sequencing confirmed a high similarity with different sequences of PPV-Rec previously reported. All these recombinant isolates share the same recombination breakpoint and conserve the DAG motif, which is considered essential for aphid transmission. Overall results provided that in Transylvania the predominant strain is PPV-D, followed by PPV-Rec which shares the CP gene with M strain and, therefore, it is serologically detected as PPV-M with M-specific monoclonal antibodies. In this big plum growing area, mixed infections (PPV-D+PPV-Rec), which might generate additional variation by recombination, are also frequent.

CHARACTERIZATION OF PLUM POX STRAINS FROM REGHIN AREA -RFLP METHOD

SUMMARY Plum Pox virus is the causal agent of the sharka d isease, considered the most pathogen viral of stone fruit crops in Europe. The impact of the disease makes a strong limiting factor for propagation material movement. Infected Prunus trees are the major source of inoculum. The virus is transmitted from them either by grafti ng or non-persistently by the aphid vectors Aphis spiraecola and Myzus persicae. The number of trees becoming infected in an orchar d is directly related, in a given season, to numbers of winged aphids. These aphids probe or feed on infected leaves, then fly to other trees where they again probe or feed. Symptoms may appear on leaves, petals, fruits and stones. They are particularly clear on leaves i n spring: mild light green discoloration, chlorotic spots, bands or rings, vein clearing or y ellowing, or even leaf deformation. In this study I collected twenty PPV isolates from two orchards situated in Reghin County, based on typical symptoms on leaves. Total RNA was extracted from fresh material plant using the RNeasy Plant Minikit. Than the viru s infection was confirmed by molecular methods. For the general detection of PPV, primers located near the 3` end of the coat protein (CP) gene were used to amplify a 243 bp fragment: P1: 5`-3` ACC GAG ACC ACT ACA CTC CC and P2: 5`-3` CAG ACT ACA GCC TCG CCA GA (Wetzel et al., 1991). For RFLP analysis the PCR products was treated with RsaI endonuclease. The primers P1/P2 confirmed the presence of the vir us in all the samples with RT-PCR analysis. Using RFLP method we could distinguish the two strains, D and M. Following the digestion with the restriction enzyme Rsa I we detected fifteen samples infected with PPV-D, two samples with PPV-M and three samples which presented PPV-Rec(PPV-D+PPV-M). Conclusions: All isolates collected present infecti on with PPV; PPV-D stain is most spred that PPV-M

Laboratory and field evaluations of entomopathogenic Lecanicillium attenuatum CNU-23 for control of green peach aphid (Myzus persicae).

An entomopathogenic fungus was isolated from an infected aphid. The isolate conformed most closely to Lecanicillium attenuatum CBS 402.78 (AJ292434) based on the internal transcribed spacer (ITS) region of its 18S rDNA, and thus was designated L. attenuatum CNU-23. Laboratory and field evaluations of CNU-23 blastospores were carried out for the control of green peach aphids. The laboratory evaluations of CNU-23 revealed an aphid mortality of about 80% with an estimated LT50 of 3.72 days after the application of CNU-23 at 1x106 blastospores/ ml. Meanwhile, the field evaluations of CNU-23 performed on greenhouse pepper plants during the rainy season showed an aphid mortality ranging from 72% to 97%. Significant sporulation was observed in the aphids treated with CNU-23. Therefore, the results suggest that L. attenuatum CNU-23 can be used as a biocontrol agent for green peach aphids on greenhouse pepper plants.

Aphids Associated with Lettuce (Lactuca sativa L.) in the Matanuska Valley, Alaska

ABSTRACT Commercial lettuce fields in Alaska were surveyed for aphid infestations and species composition. Sixteen species were collected in green tile trap pans. The majority were Lipaphis erysimi (Kaltenbach), Macrosiphum euphorbiae (Thomas), and Pemphigus spp. Pemphigus populitransversus Riley, Subacyrthosiphon, and Cryptobium Hille Ris Lambers were added to Alaska collection records. Macrosiphum euphorbiae complex were the only aphids to colonize lettuce during the 1994 season. Seedlings were infested with aphids within four days of transplanting and more alates landed on 1–3 week old seedlings than on older plants. During the 1–3 week seedling period, more alates were recorded on head lettuce than leaf lettuce. Percent infested plants averaged 9.2 and 19.3 for leaf and head lettuce, respectively, during that period. Green tile trap pans were not effective indicators of aphid activity in lettuce fields under these test conditions.

Effect of host age on searching and oviposition behaviour of <i>Diaeretiella rapae</i> (MIntosh) (Hymenoptera Aphidiidae)

Diaeretiella rapae is an important biological control agent of cabbage aphid Host searching handling and oviposition behaviour were investigated in relation to host age The parasitoid spent 61 of her foraging time searching for hosts Host handling time of the parasitoid decreased with increased number of host encounters The females were more successful in finding older hosts (7 days old) and spent more time (949 205 s/encounter) and did more stings (99 14/encounter) on them than the younger hosts They preferred to sting the abdomen rather than the thorax head or legs of the host The average number of eggs laid per host was highest (14 02 eggs) in 7dayold hosts When attacking 7dayold hosts they gained 42 success in ovipositing the host compared to 10 18 and 30 success in 1 3 and 5dayold hosts respectively Results suggest that D rapae may have adaptive preference for larger hosts and mass production could be more efficient by using 7dayold aphids

Reservoir weed host for Zucchini yellow mosaic virus in Iran

Corresponding author: M. Safaeizadeh Fax: +98 811 4227012 E-mail: safaeezadehmehdi@gmail.com During the summer of 2006, samples of the weed Alhagi camelorum were collected from cucurbit fi elds in the Markazi province of Iran. Using the double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with specifi c polyclonal antibodies, the samples were tested for Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV), Cucumber mosaic virus (CMV), Melon necrotic spot virus (MNSV), and Zucchini yellow fl eck virus (ZYFV) (Loewe Biochemica GMBH, Sauerlach, Germany). Leaf extracts were inoculated mechanically and they produced chlorotic local lesions on Chenopodium amaranticolor; systemic vein netting, yellowing, mosaic, and leaf deformation on Cucurbita pepo; and chlorotic local lesions, systemic vein clearing, yellowing, mosaic and leaf deformation on Cucumis melo. These symptoms were similar to those described previously for ZYMV (Desbiez and Lecoq, 1997). The ELISA results showed that the original leaf samples and inoculated indicator plants reacted positively with ZYMV antibodies, but not with antibodies from any of the other viruses listed above. Also, the reverse transcription-polymerase chain reaction of total RNA extracted from the leaf samples using specifi c primers for ZYMV (Lecoq et al., 2004) resulted in amplifi cation of one fragment of the expected size, approximately 600 bp. ZYMV, a member of the genus Potyvirus in the family Potyviridae, is transmitted by aphids in a nonpersistent manner (Desbiez and Lecoq, 1997). The virus is geographically widespread with a wide host range comprising 11 plant families including Amarantaceae, Papilionaceae, Ranunculaceae, Scrophulariaceae, Asteraceae, Cucurbitaceae, Solanaceae and Umbelliferae (Desbiez and Lecoq, 1997). A. camelorum, a perennial plant in the Papilionaceae family, was common and widely distributed in the fi elds surveyed. The occurrence of ZYMV-infected weed hosts in cucurbit fi elds may impact disease management strategies. ZYMV was fi rst observed on Cucumis melo in Iran (Ghorbani, 1988). This is the fi rst report of its natural occurrence on weed hosts in Iran.

Tobacco type mediated effects on the development of pink aphid, Myzus nicotianae Blackman and its predator, Chrysoperla carnea (Stephen) (Neuroptera: Chrysopidae).

The present study revealed that fecundity of tobacco aphid, Myzus nicotianae Blackman was highest on Lanka type (37.8 ± 7.5) and lowest on Nicotiana rustica (7.0±2.5). Chrysoperla carnea consumed 71.20 aphids/larva on Flue cured Virginia tobacco and 58 aphids on Burley type. Highest per cent pupation was observed on Beedi type (88%). Fecundity of Chrysoperla was the highest when it fed on aphids on cigar wrapper tobacco (291 eggs/female), followed by Lanka (287 eggs/female). The fecundity was lowest (114 eggs) when aphids on aromatic tobacco were consumed. Fecundity when fed on Corcyra eggs was least (220 eggs). FCV tobacco was most favored for oviposition by Chrysoperla (25 eggs/plant) and beedi and aromatic types were least preferred. On all tobacco types, when the larvae of the predator were released 63 to 92% reduction in aphid population was achieved. The nutritional profile of the aphids on the most favored tobacco type, Lanka , revealed that sugars and proteins/100g dry weight of aphids were 3.6 and 7.20 compared to 2.88 and 6,20, respectively, on aphids on aromatic types, which were less suitable as food. Prospects of utilizing host plant genetic diversity in tritrophic interactions for effective management of sucking pests are discussed.

The Rediscovered Types of the Fossil Aphids Described by GERMAR and BERENDT in 1856

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THE EFFECT OF SOME INSECTICIDES ON THE LADY BUG (Coccinella 7-punctata L.)

In Romania unfortunatly the use of insecticides for controling the pest it’s made without any respect for the beneficial fauna. One of the most known beneficial species encountered in almost any agricultural biotope it’s the lady bug Coccinella 7 punctata. The lady bug Coccinella 7 punctata it’s an predatory species that fed especially on aphids species and play an essential role in the biological control of these species. This paper present the research regarding the effect of some insecticides used for controling the mealy plum aphid Hyalopterus pruni Geoffr., to the lady bug Coccinella 7 punctata in the conditions from central Oltenia, at the Banu Maracine Didactical Station. The experience has been set up during 2005 - 2006, in a plum orchard from the Banu Maracine Didactical Station, of the University of Craiova. In order to study the effect of some insecticides on the lady bug there has been made observation in orchards as well in laboratory conditions.  The direct toxic action of the insecticides on the lady bug has been esatblished in field at 24, 48 and 72 hours after the apply of the treatments, counting the dead larva and adults. The effect of the insecticides through feeding with intoxicated aphids, has been establish in laboratory at 24, 48 and 72 hours.

Secondary and Primary Plant Metabolites as Chemical Markers for Resistance of Bitter Candytuft (Iberis amara) Plant against Insect Attack

A correlation between the levels of secondary and primary plant metabolites and food coefficient parameters with the population density of infested broccoli plants was studied. Cucurbitacins and glucosinolates compounds were good signs of resistance in bitter candytuft plants. On the other hand, lower values or the absence of these markers rendered broccoli susceptible to the pests under study, not during all stages of growth but whenever these values were much lower throughout growth stages. The major cucurbitacins were isolated and purified from bitter candytuft and identified by spectroscopic techniques. Glucosinolates content in bitter candytuft was also studied. The development of cabbage aphid treated with various bitter candytuft extracts as well as isolated cucurbitacins was also evaluated. A field study showed a remarkable reduction (88.9 %) of cabbage aphid induced by spraying the broccoli plants with 4 % water extract after autolysis of bitter candytuft.

COMPORTAMENTO DAS POPULAÇÕES DE Aphidius sp. (BRACONIDE - HYMENOPTERA) E Brevicoryne brassicae (L., 1778) (APHIDIDAE - HOMOPTERA) EM DIFERENTES CULTIVARES DE REPOLHO EM CONDIÇÕES DE CAMPO

The behavior of Aphidius sp. and B. brassicae populations on cabbage cultivars Kobayashi, Roxo, Chato de Quintal, Coracao de Boi and Matsukase were studied in natural field conditions. Monthly samples were collected from August to December 1995. Leaf discs measuring 6.1cm2 were taken from sites showing higher aphid concentration from each most infected leaf. The percentage of parasitized insects was determined by the number of mummified aphids among the total on each leaf disc. Although Roxo and Kobayashi cultivars showed the highest aphid infestation, they were the least parasitized by Aphidius sp. , with 23.3% and 25% parasitism, respectively. Coracao de Boi and Chato de Quintal cultivars were the least infested by the aphid, but showed the highest parasitoid populations, as 51.7% and 67.5% respectively. The lower aphid and parasitoid populations were observed on Matsukase cultivar. Chato de Quintal, Coracao de Boi and Matsukase cultivars presented a high aphid and parasitoid populations in August, which decrease in September and December and rose in October and November. On Kobayashi and Roxo cultivars both populations increased until November and decreased in December. Generally, higher B. brassicae and Aphidius sp. populations were found during August, October and November. The average parasitism in all cultivars was 36%. The highest parasitism level was 55.8, observed in August. KEY-WORDS: Aphidius ; Brevicoryne brassicae ; comportamento; parasitism; behavior.

Nucleotide Sequence Analysis of the Coat Protein Genes of Two Isolates of Sweet potato feathery mottle virus from Central Taiwan

Two potyvirus-like isolates, CY1 and CY2, were collected from sweet potato displaying leaf symptoms of mosaic or vein mottling at Chia-Yi area. Taiwan, by single-lesion isolation on Chenpodium quinoa plants. Using the degenerate primers for potyviruses, a 1.2 kb and a 1.3 kb DNA fragments were amplified from CY1-and CY2-infected tissues of C. quinoa, respectively, by reverse-transcription polymerase chain reaction (RT-PCR). After clotting and sequencing, the two cDNA fragments were found to be of 1205 and 1351 bp. and corresponding to a part of the 3' end of nuclear inclusion (NIb) region and the 5' end of the coat protein (CP) region of potyviruses. For amplification of the region corresponding to the 3' end of CP region, the 3' untranslated region (3'-UTR), and the poly A tail, RT-PCR was conducted with the oligo (dT) primer and the specific Primers designed from the known sequence. The assembled cDNA sequences of 1249 and 1383 bp, respectively, from CY1 and CY2 were elucidated to reflect the 3'-terminal region of nuclear inclusion b (NIb) protein gene [85 nt (28 aa) / 213 nt (71 aa)], the complete CP gene [939 nts (313 aa) /945 nts (315 aa)], and 3'-uTR (both 225 nt) and a poly (A) tail. Sequence analysis indicated that the two viruses were isolates of Sweet potato feathery mottle virus (SPFMV). The two isolates showed 80.6% nucleotide identity and 86.3% amino acid identity in their CP genes. A putative proteolytic cleavage site Q/S was predicted between NIb protein and CP. A DAG triplet for aphid transmissibility of potyviruses was found at the 9-11 residues from the N-terminus of both CP genes. Phylogenetic analysis of CP sequences revealed that SPFMV-CY1 belonged to the group C and is as closely related to the isolates 115/1S, 5, Arua 10a, O and TZ4. The sequence relationships between the two isolates and potyviruses revealed that SPFMV-CY1, SPFMV-CY2 were closely to the sweet potato infecting potyviruses, SPVY, SPVG and SPLV, reflecting a more recent evolutionary relationship.

Cultivar and endophyte effects on a root aphid <i>Aploneura lentisci</i> in perennial ryegrass

In a pot trial fungal endophytes (Neotyphodium spp) with different alkaloid profiles were investigated for their effects on numbers of a root aphid (Aploneura lentisci) in perennial ryegrass Some endophytes were also tested in different cultivars (Nui Samson and Impact) Two endophytes AR37 and AR6 strongly suppressed root aphid numbers Wildtype had fewer aphids than endophytefree plants and AR1 Endophytes producing peramine only (AR1 AR12 AR22) and an endophyte producing peramine and lolitrem B (AR23) did not differ from endophytefree There were no cultivar by endophyte interactions but cultivar affected the strength of aphid response to Wildtype Comparisons of alkaloid profiles suggest that ergovaline (in Wildtype and AR6) and epoxyjanthitrems (in AR37) may affect root aphids whereas peramine and lolitrem B do not Differences in herbage dry weight of plants and a significant relationship between herbage dry weight and root aphid numbers indicated this aphid reduces the growth rate of plants

Aphids on strawberry

EPPO BulletinVolume 37, Issue 1 p. 81-85 Aphids on strawberry First published: 18 April 2007 https://doi.org/10.1111/j.1365-2338.2007.01083.x European and Mediterranean Plant Protection Organization Organisation Européenne et Méditerranéenne pour la Protection des Plantes Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume37, Issue1April 2007Pages 81-85 RelatedInformation

ASM Submits Comments to APHIS on Brucellosis Regulations

ASM Submits Comments to APHIS on Brucellosis Regulations

Aphids on cereals

Aphids on cereals

Buğday yaprakbitleri, Rhopalosiphum padi (L.) ve Sitobion avenae (F.) (Homoptera: Aphididae)'nin buğdayda bazı verim özelliklerine etkileri ve popülasyon gelişmeleri

Population fluctuations of cereal aphids, Rhopalosiphum padi (L.) and Sitobion avenae (F.), (Homoptera: Aphididae) and their impact on crop loss parameters of wheat were revealed in Antakya during the years of 1998–2002. The aphid populations were recorded in infested and aphid-free plots in Reyhanli by seven day intervals from 22 February to 22 April, 1999 on two wheat varieties, “Genc-99” and “Ege-88”. Twenty plants were examined at each sampling date and alive induviduals (adult+nymph) were counted.

Parasitization of aphids on cauliflower seed crop in relation to their population build-up in mid-hills of Himachal Pradesh.

Continuous monitoring of aphid population on cauliflower seed crop from December to April revealed an increase in infested plants (23 to 48%). aphid population (8 to 131/plant) and parasitization (I to 3.8%) during January to mid-March, followed by a decline in aphid infestation and further increase in parasitization (to 7.4%) till April 6, despite prominence of coccinellid activity (0.8-9.5 beetles/plant). There was concomitant occurrence of Brevicoryne brassicae (Linnaeus) and Myzus persica (Sulzer), the former being predominant (65.3%) and their parasitization varied from 0.7-8.3 (av. 3.6 and 8-8.2 per cent (av. 4.4). respectively. Intra-plant distribution indicated that aphid infestation was maximum on inner whorl of leaves. followed by middle and outcr whorls. but number of mummified aphids did not vary significantly in respect of position of leaves. During mid-March to early-April also, H. brassicae outnumbered M. persicae on terminal bolts and thcil' parasitizlltion was 27.4 and 14.5 per cent. From the mummies of aphids collected from the cabbage fields during Decemher. and May-June, the arasitoid Diaeretiella rapae (M'Intosh) (Aphidiidae) and thc hypeqlanlsitoid Pachyneuron aphids (Bouche) (Pteromalidae) emerged. but the emergence was poor (5.6 and 6.3% respectively), The mummics from which the parasitoid emerged were bigger with oval and uniform emergence holes around cornicles than the mummies from which hyperparasitoid emerged, The emergence holes or the lattel was irregular, smaller and often towards anterior side of the body,

Microbial Control of Sucking Pests Using Entomopathogenic Fungi

Sucking pests cause serious damage to several agricultural, horticultural and plantation crops either by direct feeding or by transmitting plant viral diseases. Since sucking pests likc plant and leaf hoppers, aphids, whiteflies, scale insects, thrips and mites to have developed resistance to insecticides, biological control using microbial pathogens, particularly funga1 pathogens like Beauveria bassiana, Metarhizium anisopliae , and Verticillium lecanil , has been explored for a number of pests. Several commercial formulations based on entomopathogenic fungi were developed for the control of sucking pests in different countries. Mycotrol and Botanigard based on B. bassiana, Mycotal based on V. lecanii and PFR-97 and Pae-Sin based on Paecilomyces fumosoroseus were developed for the control of whiteflies, aphids and thrips in USA, Europe and Brazil. In India, Fusarium pallidoroseum was found effective in controlling cowpea aphid ( Aphis craccivora ) in Kerala. Hirsllte thompsinii has been tried against the coconut eriophyid mite, but not found very promising. The wetland ecosystems like the rice fields as well as the sugarcane ecosystem have been found ideal for the use of M. anisopliae against sucking pests. M. anisopliae and B. bassiana were found to infect the sugarcane woolly aphid ( Ceratovacuna lanigera ) but these were also pathogenic to potential predators like Dipha aphidivoru and Micromus and hence cannot be recommended. Apart from these fungi, entomophthoralean fungi like Erynia neoaphidis, Neozygifes fresenii and Zoophthora radicans are reported to cause epizootics in several aphid species in nature. Fungal pathogens occur very widely in nature and there is a wide scope for isolating strains of fungal pathogens with enhanced virulence as well as desired cultural characteristics. Fungal formulations developed as microbial insecticides should possess good fluid stability and shelf life. Oil formulations have been found to be more effective against target pests even under low RH and aso possess a good shelf life. Since the muscardine fungi are pathogenic to beneficial insects like silk worms, honey bees, pollinators, as well as predators like coccinellids, utmost care should be exercised. Other pathogens like entomopathogenic nematodes (EPN) have been considered for the management of sucking pests but not with much success. The chance of acquisition of bacterial and viral pathogens into the gut of the sucking pests is limited and hence these pathogens have not been considered for the manllgement of sucking pests. Infectivity of protozoans to sucking pests has been rarely reported. The current status of microbial control of sucking pests and the future prospects are reviewed in this paper.

Feeding potential of Ischiodon scutellaris (Fabricius) (Diptera: Syrphidae) on green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae).

Studies carried out on the feeding potential of Ischiodon scutellaris on green peach aphid, Myzus persicae , revealed that the third instar larvae consumed more aphids as compared to first and second instar. The total number of aphids consumed during November was 581 as compared to 497 aphids during January.