Acyrthosiphon Kondoi Research Articles

Establishment of three species of lucerne aphids on 24 cultivars of lucerne

A field trial involving 24 cultivars of lucerne was naturally infested by three species of aphids, Therioaphis trifolii (Monell) f. maculata, spotted alfalfa aphid, Acyrthosiphon kondoi Shinji, bluegreen aphid and A. pisurn (Harris), pea aphid. Aphid establishment was found to be related to the lucerne aphid resistance ratings of these cultivars. These observations suggest that both antixenosis and antibiosis resistance mechanisms are operating.

Time-related rejection of parasitised hosts in the aphid parasitoid, Aphidius ervi

Time-related changes in the patterns of host discrimination may have a complex form depending on whether or not hosts are marked following first parasitisation, the persistence of chemicals in these marks, and changes in the host as a result of being parasitised. Here we present an experimental design capable of detecting temporal patterns in host discrimination of solitary parasitoids. This method is tested against experimental data from Aphidius ervi attacking the aphid, Acyrthosiphon kondoi. The results demonstrate that there are statistically significant changes in the patterns of egg distribution in aphid hosts held for intervals between 1 and 48 h between parasitisation. These changes appear to be attributable to increasing oviposition restraint by the superparasitising female as the time interval between attacks is increased. The form of this relationship is not significantly different to a sigmoid function and the rate of change of restraint was greatest between 6–8 h after the first oviposition.

Effect of aphids and mites on herbage and seed production of subterranean clover (cv. Daliak) in response to superphosphate and potash

The dry matter production (DM) and seed yield of subterranean clover (Trifolium subterraneum L. cv. Daliak) were reduced by infestations of redlegged earth mite (Halotydeus destructor Tucker) and blue-green aphid (Acyrthosiphon kondoi Shinji) during spring growth, flowering and burr burial. The dominance of these pests varied with season. The effects of spraying with insecticides on the DM and seed yield responses to superphosphate and potassium chloride fertilisers were measured. Responses to superphosphate were described by Mitscherlich functions for each of 3 levels of potassium chloride, except for seed yields with pest sprays. At optimum levels of superphosphate and potassium chloride, controlling pests increased DM by up to 150% (from 4.37 to 6.52 t/ha). For all levels of superphosphate, spraying to control pests where no potassium chloride was applied significantly increased DM over that on unsprayed plots that were fertilised with potassium chloride. The maximum DM response to superphosphate application was achieved at 15-20 kg P/ha. With optimum superphosphate, the value for DM depended on the combination of spraying for pests and amount of potassium chloride applied, generating a series of Mitscherlich response curves for superphosphate application with differing maximum yields. With optimum superphosphate applied, the least DM recorded within a season was 3.47 t/ha (pests not sprayed, nil potassium chloride), and the most was 6.52 t/ha (pests sprayed, 120 kg potassium chloride/ha), an increase of about 180%. At optimum levels of superphosphate and potassium chloride, controlling pests increased seed yield by up to 380% (from 290 to 1100 kg/ha). With optimum superphosphate, seed yield within a season ranged from 210 (pests not sprayed, nil potassium chloride) to 1100 kg/ha (pests sprayed, 120 kg potassium chloride/ha), an increase of 524%. With pests sprayed, seed yield declined with superphosphate applications >20 kg P/ha; the relationship was best described by a quadratic function. With pests not sprayed, seed yield did not decline with increasing amounts of superphosphate, and the relationship fitted a Mitscherlich function.

Registration of UC 195 very Nondormant Alfalfa Germplasm with High Resistance to Blue Alfalfa Aphid and Fusarium Wilt, and Resistance to Phytophthora Root Rot

Crop ScienceVolume 32, Issue 1 cropsci1992.0011183X003200010071x p. 286-286 Registration of Germplasms Registration of UC 195 very Nondormant Alfalfa Germplasm with High Resistance to Blue Alfalfa Aphid and Fusarium Wilt, and Resistance to Phytophthora Root Rot W. F. Lehman, W. F. LehmanSearch for more papers by this authorV. L. Marble, V. L. MarbleSearch for more papers by this authorM. W. Nielson, M. W. NielsonSearch for more papers by this author W. F. Lehman, W. F. LehmanSearch for more papers by this authorV. L. Marble, V. L. MarbleSearch for more papers by this authorM. W. Nielson, M. W. NielsonSearch for more papers by this author First published: 01 January 1992 https://doi.org/10.2135/cropsci1992.0011183X003200010071xAboutPDF 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 No abstract is available for this article. Volume32, Issue1January-February 1992Pages 286-286 RelatedInformation

Registration of UC 222 and UC 263 very Nondormant Alfalfa Germplasms with High Resistance to Blue Alfalfa Aphid

Registration of UC 222 and UC 263 very Nondormant Alfalfa Germplasms with High Resistance to Blue Alfalfa Aphid

Instar-Specific Morphometrics and Linear Discriminant Models for Age-Grading Field Populations of Acyrthosiphon kondoi (Homoptera: Aphididae)

Reliable criteria for age-grading field-collected Acyrthosiphon kondoi Shinji are of critical importance for proper development and interpretations of time-specific life table data. Classification criteria in the form of linear discriminant models were developed for laboratory populations of A. kondoi using measurements of several body structures. These models were further validated using field-collected aphids from 11 locations across Oklahoma over a period of 2 yr. Despite greater variability and generally larger size of aphids in field populations, linear discriminant models provided highly accurate (>99%) criteria for identifying all instars. Misclassification was observed only in the first instar, where 0.9% of nymphs were classified as second instars. To attain this degree of accuracy in classifying individuals from field populations, lengths of cornicles, first flagellar segments, and fore tibiae are required.

Influence of winter treading on lucerne growth and survival

Abstract Lucerne (Medicago sativa L.) is frequently used as a winter run-off in New Zealand. Winter grazing and the associated treading was recommended to reduce weed infestations and reduce over-wintering blue-green aphid (Acyrthosiphon kondoi Shinji) populations. The effect on plant numbers and crown disease was unknown. An experiment was conducted on a free-draining alluvial soil at DSIR, Lincoln, Canterbury, which compared the effects of 1, 2, and 4 weeks' heavy stocking with sheep at a stocking rate of 500/ha and an unstocked control. Treatments were applied for five winters. Treading removed wintering aphids and had no effect on plant numbers, crown vigour, or yield of lucerne at the second spring cut. Severe treading in some years reduced Sitona weevil (Sitona discoideus) larvae numbers and weed growth, but had small effects on lucerne yield at the first spring cut and on crown health. It is concluded that the less severe treading used by farmers can continue to be recommended as the beneficial effects are likely to be considerably greater than the detrimental effects.

Cool-season cover crops in the pecan orchard understory: Effects on coccinellidae (Coleoptera) and pecan aphids (Homoptera: Aphididae)

Abstract In mature pecan orchards under minimal or commercial management, cool-season understory cover crops of hairy vetch, Vicia villosa Roth, and rye, Secale cereale (L.), sustained significantly higher densities of aphidophagous lady beetles than did unmown resident vegetation or mowed grasses and weeds. In cover-cropped understories, mean densities of aphidophagous coccinellids were nearly 6 times greater than in unmown resident vegetation and approximately 87 times greater than in mown grasses and weeds. During late winter and spring, rye harbored abundant bird cherryoat aphid, Rhopalosiphum padi L., whereas hairy vetch sustained pea aphid, Acyrthosiphon pisum (Harris); blue alfalfa aphid, A. kondoi Shinji ; and thrips, Frankliniella spp. The following aphidophagous lady beetles were abundant in cover-cropped understories: (1) convergent lady beetle, Hippodamia convergens GuerinMeneville; (2) Olla v-nigrum (Mulsant); and (3) seven-spotted lady beetle, Coccinella septempunctata L. In the orchard under minimal management, there was evidence that the rye/vetch mixture led to enhanced densities of convergent lady beetle in the pecan trees. However, no other effects on coccinellids were seen. There was no evidence of improved biological control of pecan aphids

Further studies on cucumber mosaic virus infection of narrow‐leafed lupin (Lupinus angustifolius): seed‐borne infection, aphid transmission, spread and effects on grain yield

SUMMARYFour field trials were done with narrow‐leafed lupins (Lupinus angustifolius) in 1988 ‐ 1989, to examine the effect of sowing seed with 5% and 0.5% cucumber mosaic virus (CMV) infection on subsequent virus spread, grain yield and percentage of infection in harvested seed. A proportion of the CM V‐infected seed failed to produce established plants and thus, plots sown with 5% and 0.5% infected seed contained 1.5‐2.9% and 0.2‐0.3% of seed‐infected plants respectively. The rate of virus spread by aphids was faster and resulted in more extensive infection at maturity in plots sown with 5% infected seed than with 0.5% infected seed. In three trials, sowing 5% infected seed resulted in yield losses of 34 ‐ 53% and CMV infection in the seed harvested of 6 ‐ 13%. The spread of CMV infection resulting from sowing 0.5% infected seed did not significantly decrease yield. However, late CMV spread in these plots caused > 1% seed infection. In the fourth trial, which was badly affected by drought, CMV spread only slowly, there was no significant effect of CMV on grain yield and the percentage of infected seed harvested was 3–5 times less than that in the seed sown.When CMV‐infected seed was sown at different depths, target depths of 8 and 11 cm decreased the incidence of seed‐infected plants by c. 15% and c. 50% respectively compared with sowing at 5 cm. However, in glasshouse tests, treatment with the pre‐emergence herbicide simazine failed to selectively cull out seed‐infected plants.The field trials were colonised by green peach (Myzus persicae), blue‐green (Acyrthosiphon kondoi) and cowpea (Aphis craccivora) aphids. When the abilities of these aphid species and of the turnip aphid (Lipaphis erysimi) in transmitting CMV from lupins to lupins were examined in glasshouse tests, short acquisition access times favoured transmission. With 5–10 min acquisition access times, overall transmission efficiencies were 10.8%, 9.4%, 6.1% and 3.9% for the green peach, cowpea, blue‐green and turnip aphids respectively.

DIFFERENTIAL IMPACT OF THE PATHOGEN PANDORA NEOAPHIDIS (R.&H.) HUMBER (ZYGOMYCETES: ENTOMOPHTHORALES) ON THE SPECIES COMPOSITION OF ACYRTHOSIPHON APHIDS IN ALFALFA

AbstractA fungal outbreak of Pandora neoaphidis (Remaudière and Hennebert) Humber (Zygomycetes, Entomophthorales, Entomophthoraceae) caused maximum daily mortality of 6 and 34%, respectively, in sympatric populations of Acyrthosiphon kondoi Shinji and Acyrthosiphon pisum Harris (Homoptera, Aphididae). This epidemic suppressed the A. pisum population but not the A. kondoi population. The results suggest that low level infections in A. kondoi may greatly increase the inoculum available for transmission to the highly susceptible A. pisum.

Transmission of Beet Yellows and Beet Mosaic Viruses by Noncolonizing Aphid Vectors

A late Rhopalosiphum padi (L.), Acyrthosiphon kondoi Shinji, and Diuraphis no:xia (Mordvilko) transmitted beet yellows virus (BYV) and beet mosaic virus (BMV) in laboratory tests. In single probe acquisition tests, A. kondoi! and D. no:xia failed to transmit BMV, but both transmitted the virus successfully in free-choice arena tests. A. kondoi and D. no:xia are new vectors of beet yellows and beet mosaic virus. None of the three aphids colonize sugar beets but may be important in BYV and BMV epidemiology.

Some Aphids of Importance to the Southeastern United States (Homoptera: Aphididae)

Despite their importance as pests of ornamentals and crops and as transmitters of plant viruses, aphids have been poorly studied and collected throughout the United States. Lists are available for only 31 of the 50 states; and of those lists, only 3 have been published since 1970. In the southeastern United States, published lists exist for only Louisiana and North Carolina. Of the aphids discussed, Acyrthosiphon kondoi Shinji, Aphis nerii Boyer de Fonscolombe, Brachycorynella asparagi (Mordvilko), Idiopterus nephrelepidis Davis, Myzus varians Davidson, and Toxoptera aurantii (Boyer de Fonscolombe) are reported to occur in some southeastern states and may occur throughout the area. Toxoptera citricida (Kirkaldy) and Pterochloroides persicae (Cholodkovsky) represent species not known to occur in the United States but which have the potential of becoming serious pests if introduced. For each species there are sections on distribution in the southeastern United States, hosts, taxonomic characteristics of apterous and alate viviparae, and general information.

Time-Specific Life Tables for Acyrthosiphon kondoi (Homoptera: Aphididae) in First Crop Alfalfa in Oklahoma

Time-specific life tables were developed for Acyrthosiphon kondoi Shinji in Oklahoma during growth of the first alfalfa crop in 1985 and 1986. In each year, population densities increased rapidly (from 200 aphids per stem) during a 2–3-wk period between early March and May. In the first interval of population growth each year, the observed rates were equivalent to the intrinsic rate of increase determined in laboratory studies. Although alatae were produced throughout the period of population growth, a rapid increase in the prevalence of this morph resulted in proportions of winged adults exceeding 90% just before population decline. A rapid decrease in numbers of A. kondoi from the peak densities occurred due to emigration of alatae and the resulting decrease in nymphal production. Although predaceous insects (primarily Hippodamia convergens Guerin-Meneville) were present in moderate numbers (up to 0.2 individuals per stem), there was little evidence of limitation imposed on the growth rates of the aphid population. We observed no parasitized or diseased aphids and it appeared that natural controls were not effective in slowing the rapid growth of populations and preventing outbreaks during our study. Except for emigration of alatae, no factors were identified that reduced population densities by detectable amounts.

Alfalfa Weevil and Aphid Control, 1989

Abstract Tests were conducted at 3 locations to determine efficacy of insecticides applied with ground sprayers for control of alfalfa weevil larvae using a randomized-complete block design with 3-4 replications. Treatments for Test 1 (Grady County) were applied on 31 Mar with a spray volume of 20 gal/acre. Efficacy of insecticides against blue alfalfa aphid and the alfalfa weevil was evaluated. Test 2 was located in Stephens County where treatments were applied on 28 Mar with a volume of 14 gal/acre. Treatment date and volume for Test 3 (Tillman County) were 15 Mar and 9 gal/acre, respectively. Pretreatment population levels for the weevil exceeded the economic threshold of about 1.5 larvae/stem in all tests. Efficacy of insecticides was determined from counts made by extraction of weevil larvae and blue aphids with Berlese funnels (Test 1) from stem samples taken at several intervals after spraying. Dry matter yields were estimated in Test 1 by harvesting forage from a 1 × 5 m area from each plot and drying a subsample to determine moisture content.

Host‐dependent association and its implications on the relative abundance of blue alfalfa aphid and pea aphid (Homoptera: Aphididae) on alfalfa in Oklahoma

Field populations of blue alfalfa aphid and pea aphid on alfalfa were sampled during 1985 and 1986 to determine the association of co-occurrence, interspecific interactions and comparative temporal variations in the spatial dispersion patterns of these species in Oklahoma. Relative abundance of these species is discussed in the light of above analyses.Cole's coefficient revealed a high degree of association between these species in terms of their occurrence on the same alfalfa stems in the field. Regression analyses indicated that the species populations tended to increase in concert on the same stems without evidence of competitive displacement. Spatial dispersion patterns of both species were highly aggregated at low population densities early in the season. Over time, both species tended to disperse and became less aggregated as numbers increased. It was concluded that magnitude of interspecific interactions between the blue alfalfa aphid and the pea aphid were not of a nature that they could be termed as competing species. On the contrary, a concept of an “ecospecies” is proposed for practical applications such as sampling plans and economic threshold determinations.

DISPERSION OF ACYRTHOSIPHON KONDOI SHINJI (HEMIPTERA: APHIDIDAE) AND THE DEVELOPMENT OF SEQUENTIAL SAMPLING PLANS FOR CONTROL DECISIONS IN LUCERNE

AbstractThe dispersion of the bluegreen aphid Acyrthosipon kondoi Shinji in lucerne conformed to the negative binomial distribution and a high degree of contagion was evident from aggregation indices. These data were used, together with proposed treatement thresholds, to develop and test sequential sampling plans for this aphid based on a single stem sampling unit. Four plans, accounting for variations in plant growth stage and varietal susceptibility to A. kondoi were computed at 2 treatment threshold levels. One of these plans was tested on 3 lucerne varieties in the field. Treatments made on plan recommendations restricted yield losses to within expected limits.

Release and establishment ofAphidiusspp. (Hymenoptera: Aphidiidae), parasitoids of pea aphid and blue green aphid in New Zealand

Abstract Three Aphidius spp. parasitoids of the lucerne aphids, pea aphid (P A) and blue green aphid (BGA), were introduced into New Zealand from 1977 to 1982. A. eadyi spread rapidly and now occurs in all the main lucerne-growing areas. In comparison, A. ervi was difficult to establish, failing to persist after several initial recoveries, but was eventually established from releases of se:parate strains in the North and South Islands, replacing A. eadyi as the predominant parasitoid in the North Island. Despite large releases, A. smithi has not established. A. ervi shows a preference in the field for BGA, but in the laboratory it demonstrated the ability to adapt from PA to BGA in two generations. Laboratory experiments showed that A. eadyi has a higher fecundity and faster development rate than A. ervi indicating that it competes better for PA. However, the polyphagy of A. ervi may be significant in its increasing predominance in the field. Comparisons are drawn with North American results.

Cultivar and Temperature Influence on Development, Survival, and Fecundity in Four Successive Generations of Acyrthosiphon kondoi (Homoptera: Aphididae)

Total developmental time for Acyrthosiphon kondoi Shinji reared at 20°C was significantly longer on the alfalfa cultivar ‘CUF 101’ than on ‘Moapa 69.’ Mortality rate was more rapid and survival shorter on ‘CUF 101.’ Fecundity, averaged over four generations, was 27% lower on ‘CUF 101’ than on ‘Moapa 69.’ The intrinsic rate of increase was consistently higher on ‘Moapa 69’ in all generations. At 15°C, developmental times and aphid survival were nearly identical. Progeny production was significantly higher on ‘Moapa 69’ in the parental generation but was virtually identical on the two cultivars in F1 through F3. Intrinsic rate of increase values was nearly identical in all generations. Results support the hypothesis that antibiosis is involved in ‘CUF 101’s’ resistance to A. kondoi . Resistance is virtually lost at 15°C, a result consistent with other aphid-alfalfa systems.

The Role of Predators and Parasites in the Natural Regulation of Lucerne Aphids in Eastern Australia

(1) The impact of invertebrate predators on lucerne aphids (Acyrthosiphon kondoi (Shinji), Therioaphis trifolii (Monell) and Acyrthosiphon pisum (Harris) was studied in the Hunter Valley, New South Wales, Australia, using a selective insecticide to suppress predators. Aphid and predator numbers were monitored weekly over 2 years in unsprayed and carbaryl-treated plots. (2) The major predator groups were hemerobiids (Micromus sp.), coccinellids (Coccinella repanda Thunberg), predatory mites (Bdellidae) and syrphid larvae. (3) In 1980-81, predators had a significant effect on aphid numbers in late spring, summer and early autumn but not in late autumn. (4) There was no build-up of aphids in spring or summer of the second year (1981-82). When aphid numbers did increase, in autumn 1982, no significant impact of predators was demonstrated. (5) Parasitism by the braconid parasite Aphidius ervi Haliday became an increasingly important mortality factor for A. kondoi during the 2-year period. The high incidence of parasitism in the winter and spring in 1981 and 1982 was significant in preventing the spring build-up that had characterized populations of A. kondoi since its arrival in the Hunter Valley. (6) A. kondoi appeared to be sensitive to the stage of growth of the host plant, alate production increasing as the plant approached maturity, even when there were few aphids. (7) It was concluded that predators and parasites are capable of making a significant contribution to lucerne aphid control in a pest management programme.

Acyrthosiphon kondoi influences alata production by the pea aphid, A. pisum

Entomologia Experimentalis et ApplicataVolume 45, Issue 2 p. 195-198 Acyrthosiphon kondoi influences alata production by the pea aphid, A. pisum R. J. Lamb, R. J. Lamb Agriculture Canada Research Station and Department of Entomology, University, Manitoba, Winnipeg, Manitoba, CanadaSearch for more papers by this authorP. A. MacKay, P. A. MacKay Agriculture Canada Research Station and Department of Entomology, University, Manitoba, Winnipeg, Manitoba, CanadaSearch for more papers by this author R. J. Lamb, R. J. Lamb Agriculture Canada Research Station and Department of Entomology, University, Manitoba, Winnipeg, Manitoba, CanadaSearch for more papers by this authorP. A. MacKay, P. A. MacKay Agriculture Canada Research Station and Department of Entomology, University, Manitoba, Winnipeg, Manitoba, CanadaSearch for more papers by this author First published: November 1987 https://doi.org/10.1111/j.1570-7458.1987.tb01082.xCitations: 9AboutPDF 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 onFacebookTwitterLinked InRedditWechat Citing Literature Volume45, Issue2November 1987Pages 195-198 RelatedInformation