Showing papers on "Aphididae published in 1988"
TL;DR: A green biotype of the pea aphid, A. pisum, from Lusignan (France), showed very poor performance on the standard Akey and Beck diet, but significant improvement occurred after reduction of the osmotic pressure of the diet and modification of the amino acid component, according to the results of carcass analysis.
Abstract: A green biotype of the pea aphid, A. pisum, from Lusignan (France), showed very poor performance on the standard Akey and Beck diet. Significant improvement occurred after reduction of the osmotic ...
179 citations
TL;DR: This article showed that the ten-chromosome form may be regarded as a single clone of R. maidis recognizable by its karyotype and host-plant relationships, although not completely separable by morphology alone from all other clones of this permanently parthenogenetic species complex.
Abstract: Rhopalosiphum maidis (Fitch) collected on barley in the northern hemisphere usually has a ten-chromosome karyotype, whereas samples from maize, sorghum and Johnson grass (Sorghum halepense) from all parts of the world commonly have 2n = 8. Samples with other karyotypes (2n = 9, 2n = 11 and 2n = 8 heterozygous for an interchange between the X chromosomes) occur less frequently on these and other species of Gramineae. Multivariate morphometric analysis, principally by the method of canonical variates, indicated that the ten-chromosome form may be regarded as a single clone of R. maidis recognizable by its karyotype and host-plant relationships, although not completely separable by morphology alone from all other clones of this permanently parthenogenetic species complex.
62 citations
46 citations
TL;DR: Resistance in four resistant cultivars of cowpea was governed by a single dominant gene and was nonalletic to, and independent of the resistance gene of cultivars ICV11 and ICV12.
Abstract: Aphid (Aphis craccivora Koch) is a major insect pest of cowpea [Vigna unguiculata (L.) Walp.] particularly in Africa and Asia, causing direct damage by removal of plant sap and indirect damage by transmitting mosaic viruses. The objectives of this study were to determine the inheritance of resistance to aphid in four resistant cultivars of cowpea and to determine if the genes for resistance were independent. The parental, F₁, F₂, and BC₁ populations involving resistant × susceptible and resistant × resistant cultivars were evaluated in the screenhouse. Three-day-old seedlings were each infested with 10 apterous adult aphids and injury reactions were recorded 8 to 10 d after infestation by counting dead (susceptible) and surviving (resistant) seedlings in each population. The reactions of F₁, F₂, and BC₁ populations arising from the crosses of four resistant cultivars, ‘ICV10’, ‘ICV12’, and ‘Tvu 310’ with susceptible cultivar ‘ICV1’, revealed that resistance in each of these cultivars was governed by a single dominant gene. Tests for allelism in the F₁ and F₂ populations from crosses between resistant cultivars indicated that the resistance of ICV10 and Tvu 310 is controlled by a common locus as are those of ICV11 and ICV12. The locus of the resistance gene in ICV10 and Tvu 310 is not linked to the locus of the resistance gene in ICV11 and ICV12. Thus, the resistance gene common to ICV10 and Tvu 310 was nonalletic to, and independent of the resistance gene of cultivars ICV11 and ICV12. The gene symbols Rac1 and Rac2 (resistance to A. craccivora were assigned for the nonallelic and independent loci controlling this trait. Contribution from the Crop Pests Res. Programme.
45 citations
TL;DR: The frequency with which the parasitoid attempted to oviposit diminished in aphids inoculated with the fungus 3 days previously, that is within only 24 h of dying of the infection, but not in those infected only 1 or 2 days previously.
Abstract: The oviposition behaviour of the hymenopterous parasitoidAphidius rhopalosiphi onMetopolophium dirhodum nymphs at successive stages of infection with the aphid-pathogenic fungusErynia neoaphidis was compared with that on uninfected nymphs. The frequency with which the parasitoid attempted to oviposit diminished in aphids inoculated with the fungus 3 days previously, that is within only 24 h of dying of the infection, but not in those infected only 1 or 2 days previously. The parasitoid did not attempt to oviposit in aphids killed by the fungus.
44 citations
TL;DR: In a system using soybean plants and soybean mosaic virus, it is found that denser leaf pubescence retards field epidemics of non-persistently transmitted plant viruses.
Abstract: SUMMARY
A study was undertaken to determine the influence of trichome density on the spread of non-persistently transmitted plant viruses by aphid vectors. A system using soybean plants and soybean mosaic virus (SMV) tested the hypothesis that greater leaf trichome density inhibits probing activity of vector species, leading to reduced virus spread and retarded virus epidemics under field conditions.
Probing activity of three important aphid vectors of SMV, Myzus persicae, Rhopalosiphum maidis, and Aphis citricola, was affected by the density of soybean leaf trichomes. Less pubescent and glabrous isolines elicited greater probing activity than did densely pubescent isolines. Among the parameters considered, probe duration was found to be species specific, whereas the following traits were consistent among species for the denser isolines: reduced numbers of probes, greater length of time to first probe, and less time spent probing. Laboratory transmission of soybean mosaic virus was reduced in the more densely pubescent isolines by the vector species tested.
Field spread of SMV was negatively correlated with density of pubescence. In our system, we found that denser leaf pubescence retards field epidemics of non-persistently transmitted plant viruses.
43 citations
TL;DR: Although natural enemy populations showed functional responses to increases in Diuraphis noxia numbers, they did not prevent the latter from attaining and exceeding economic injury levels.
Abstract: The influence of natural enemies on the population growth of Diuraphis noxia (Mordvilko) in wheat fields in eastern South Africa was investigated. Since the natural enemies were not present in the initial stages, the apparent mortality observed must have been due to other causes. During the logarithmic phase of aphid population growth, predators, in particular the coccinellid Hippodamia variegata (Goeze), had a slight inhibitory effect on growth. During the decline phase of the aphid population, the potential population size was reduced by as much as 52% by predation. The most abundant parasitoids, Aphidius colemani Viereck and Diaeretiella rapae (M'Intosh), had a negligible effect. Although natural enemy populations showed functional responses to increases in Diuraphis noxia numbers, they did not prevent the latter from attaining and exceeding economic injury levels.
42 citations
01 Jan 1988
41 citations
TL;DR: The effect of acute ozone exposure of eastern cottonwood on the survivorship, reproduction, and development of the aphid Chaitophorus populicola Thomas was investigated and hypotheses relating aphid leaf preference to stages of leaf development supported.
Abstract: The effect of acute ozone exposure of eastern cottonwood ( Populus deltoides Bartr.) on the survivorship, reproduction, and development of the aphid Chaitophorus populicola Thomas (Homoptera: Aphididae) was investigated. Cottonwoods were exposed to 397 μ g/m3 (0.20 ppm) ozone or charcoal-filtered air and infested with aphids on leaf plastochron index 5, 40 h after fumigation. Aphid performance was not significantly different on plants exposed to ozone compared with charcoal-filtered air-treated control plants. These data do not support the notion that aphid performance will directly increase on air pollution-stressed plants. We also examined settling and feeding preference of aphids for cottonwood leaves of different developmental ages. Aphids significantly preferred leaf plastochron index 5 to all other leaf ages. These data support hypotheses relating aphid leaf preference to stages of leaf development. Reproduction of the cottonwood leaf rust fungus ( Melampsora medusae Thum.) and the imported willow leaf beetle ( Plagiodera versicolora Laicharting) are reduced on ozone-fumigated plants (reported elsewhere). If aphid populations are affected by competition with these cottonwood pests for leaf resources, then aphid pest potential may actually increase in areas characterized by episodic ozone concentrations because of ozone-induced decreases in populations of M. medusae and P. versicolora .
41 citations
TL;DR: The behavior-modifying properties of pyrethroids are extended to A. nasturtii and confirm that nonpyrethroid insecticides can affect the behavior of certain aphid species, but increased dispersal of aphids might decrease the effectiveness of control.
Abstract: From 14 to 26% of apterous green peach aphids, Myzus persicae (Sulzer), placed on leaflets of potato treated with deltamethrin, fenvalerate, pirimicarb, and methamidophos dispersed to untreated leaflets, compared with only 2-6% of aphids placed on control or dimethoate-treated leaflets. Apterous buckthorn aphids, Aphis nasturtii (Kaltenbach), dispersed significantly in greater numbers only from deltamethrin and fenvalerate treatments. Pyrethroids reduced duration of probing for alate and apterous morphs of both species from 33 to 77%. Dimethoate decreased probing of apterous A. nasturtii 24%, while methamidophos did not alter probing times for apterous or alate morphs of either species. Pirimicarb reduced probing times of M. persicae , and the results indicated that the effect on probing may depend on the condition of the leaf material or species of aphid. Colonization of pyrethroid-treated and untreated leaf disks in flight tests suggests no repellent action on M. persicae . Decreased probing on pyrethroid-treated leaves could help control the spread of nonpersistent viruses, but increased dispersal of aphids might decrease the effectiveness of control. These data extend the behavior-modifying properties of pyrethroids to A. nasturtii and confirm that nonpyrethroid insecticides can affect the behavior of certain aphid species.
41 citations
TL;DR: Osmotic stress due to high sucrose concentration was imposed on the potato aphid, Macrosiphum euphorbiae (Thomas), in an artificial diet situation, and significantly higher levels of these oligosaccharides were recovered from the honeydew of this species in response to feeding on increased dietary sucrose concentrations, pointing to an osmoregulatory response.
Abstract: Osmotic stress due to high sucrose concentration was imposed on the potato aphid, Macrosiphum euphorbiae (Thomas), in an artificial diet situation. Thin layer chromatography resolved melezitose and six additional honeydew oligosaccharides. Significantly higher levels of these oligosaccharides were recovered from the honeydew of this species in response to feeding on increased dietary sucrose concentrations, pointing to an osmoregulatory response. In addition, carbohydrase activities from the potato aphid were described. A degree of specificity toward hydrolysis of the sucrose substrate over other α-glucosyl sugars was demonstrated. Also, sucrose was optimal for the formation of the oligosaccharides. A strong α-galactosidase activity was found and transgalactosylation ability was indicated. These major trends in carbohydrase activity were also found in the foxglove aphid, Acyrthosiphon solani (Kaltenbach), and the oleander aphid, Aphis nerii Fonscolombe.
TL;DR: Large colonies of holocyclic Rhopalosiphum padi were sampled in May-June in 1985 and 1986 from the principal host, Prunus padus, in various parts of Britain, mainly in the south-east, and the low level of genetic variability may reflect population bottlenecks which have purged most of the variation and have been imposed by the distribution of P. padus.
Abstract: Large colonies of holocyclic Rhopalosiphum padi (L.) were sampled in May-June in 1985 and 1986 from the principal host, Prunus padus, in various parts of Britain, mainly in the south-east. They were tested electrophoretically using nine enzymes representing 14 putative genetic loci. Only two loci (14%) were polymorphic (GOT, glutamate-oxaloacetate transaminase, and SORDH, sorbitol dehydrogenase), the remainder being monomorphic. Allele and genotype frequencies at each locus were generally similar both spatially and temporally, and genotype frequencies were close to Hardy-Weinberg expectations. The low level of genetic variability may reflect population bottlenecks which have purged most of the variation and which have been imposed by the distribution of P. padus, especially in the south of Britain where the tree is generally scarce. In addition, it is probable that adverse climatic conditions directly affect winter survival of anholocyclic populations of the aphid and thus also reduce variability. In the long term, such bottlenecks would tend to preclude the maintenance of effectively neutral enzyme variants that arise within populations. The similarity of allele and genotype frequencies may reflect the highly migratory behaviour of R. padi. Thus, in southern Britain, where P. padus is generally much rarer in comparison with the north of the country, R. padi inter-population gene flow is still sufficient to alleviate the influences of genetic drift and possible directional selection on the allelic variation that remains.
01 Jan 1988
TL;DR: In a field study of the grain aphid Sitobion avenae (F.) almost all apterous aphids were found to move from the natal ear before reproducing, and alatiform nymphs usually moved between ears during their development.
Abstract: In a field study of the grain aphid Sitobion avenae (F.) almost all apterous aphids were found to move from the natal ear before reproducing, and alatiform nymphs usually moved between ears during their development. Apterae were very mobile, with over 50% staying on one ear for less than 24 h. Movements did not appear to be a response to climatic conditions, predation or colony density.
TL;DR: Derivatives produced by 1,4-cycloaddition reactions between acetylenecarboxylic acid esters and the aphid alarm pheromone, (E)-β-farnesene, and analogues in which other features of the phersomone molecule were modified, were tested for activity against aphid colonisation.
Abstract: Derivatives produced by 1,4-cycloaddition reactions between acetylenecarboxylic acid esters and the aphid alarm pheromone, (E)-β-farnesene, and analogues in which other features of the pheromone molecule were modified, were tested for activity against aphid colonisation. The most active compound, formed from (E)-β-farnesene and diundecyl acetylenedicarboxylate, decreased aphid-transmitted barley yellow dwarf virus infection of autumn-sown barley.
TL;DR: The physiological condition of the plant may be an important environmental (ecological) factor affecting the variation in clone-size and in aphid morphology among galls.
Abstract: Samples of shoots ofPistacia lentiscus carrying galls of the aphid,Aploneura lentisci, were collected at three localities in Israel.
TL;DR: The role of aphid species trapped in the Arava Valley, in the epidemiology of potato virus Y (PVY) and zucchini yellow mosaic virus (ZYMV), is discussed.
Abstract: A survey of aphid species which colonize or reproduce on wild and cultivated plants in the Arava Valley of Israel was carried out at the end of winter 1986. Thirty-three aphid species were collected on wild plants and 23 in green tile or yellow traps exposed in cultivated plots. Aphids were recorded from 77 plant species in 22 botanical families.Myzus persicae, Aphis craccivora, Brachyunguis harmalae, Acyrthosiphon gossypii andAphis gossypii were present on plants in 19 botanical families. M. persicae was the most frequently trapped aphid species in both green tile and yellow traps. The possible origin of the aphid species found in the desert was considered in view of the ecology and geography of the region. The role of aphid species trapped in the Arava Valley, in the epidemiology of potato virus Y (PVY) and zucchini yellow mosaic virus (ZYMV), is discussed.
TL;DR: Several different morphs from over 50 species of aphids were dissected and the number of ovarioles recorded for each, finding certain trends in variability of ovariole number appear to be linked with the morph of the aphid, migratory morphs (particularly within the Aphididae) having greater variability than non-migrated morphs.
Abstract: Several different morphs from over 50 species of aphids were dissected and the number of ovarioles recorded for each. By using these results and published data, details of ovariole number in more than 125 species of aphid from seven families were analysed. Variation in ovariole number between generations was found in six of the seven families studied. Variation within a generation appeared to be restricted to certain subfamilies. Certain trends in variability of ovariole number appear to be linked with the morph of the aphid, migratory morphs (particularly within the Aphididae) having greater variability than non-migratory morphs. Heteroecious aphids tend to show greater variability than autoecious aphids which, in turn, show greater variability than anholocyclic aphids.
TL;DR: In Davis, Calif., cabbage aphids, Brevicoryne brassicae (L.), and green peach aphids were sampled from collards planted October 1982 and March 1983 in replicated plots where weeds were subjected to one of three treatments—mowed, tilled, or unmanaged.
Abstract: In Davis, Calif., cabbage aphids, Brevicoryne brassicae (L.), and green peach aphids, Myzus persicae (Sulzer), were sampled from collards planted October 1982 and March 1983 in replicated plots (3 by 7 m) where weeds were subjected to one of three treatments—mowed, tilled, or unmanaged. In the October planting, collards and weeds began growth simultaneously, and weeds had no apparent impact on collard growth or on colonization by either aphid species. Parasitism of aphids by Diaeretiella rapae (McIntosh) was significantly higher in plots containing unmanaged weeds only once (6 December), and during early November secondary parasitism, mostly by Alloxysta fuscicomis (Hartig), was greater in tilled and mowed plots (18–38%) than where weeds were unmanaged (0–5%). In the March planting, collards were planted among preexisting weeds; collard growth among weeds was retarded as was the development of aphid populations. Primary parasitism was negligible (as were aphids) in unmanaged weedy plots and greater in mowed (7.2%) than in tilled plots (3.6%). The overall impact of parasitism on aphid populations was minimal. Secondary parasitism (again mostly by A. fuscicornis) averaged 40.8% in tilled, 7.5% in mowed, and none in weedy plots.
TL;DR: Stability of green peach aphid resistance was consistent across test locations and GPA populations, and apparently, if GPA-resistant breeding lines were developed, they could be used widely and this resistance would prove stable.
Abstract: In a series of 39 field and laboratory experiments, relative resistance to green peach aphid (GPA), Myzus persicae (Sulzer), was determined for 82 potato accessions representing 42 wild species. Field experiments were done at two locations in Minnesota and one location each in New York and Peru; laboratory experiments were done in Minnesota, England, and Peru. Aphid populations used were of five origins: Minnesota, New York, England, Puerto Rico, and Peru. Stability of green peach aphid resistance was consistent across test locations and GPA populations. No accession differed significantly from its overall mean resistance index in more than one test environment. Most significant deviations occurred in experiments with Peruvian and Puerto Rican GPA populations, although there was little evidence that either population represented biotypes different from the GPA populations of Minnesota, New York, or England. Apparently, if GPA-resistant breeding lines were developed, they could be used widely and this resistance would prove stable.
TL;DR: It is suggested that aphid population regulation by predators and parasitoids in the wider habitat of Canterbury, New Zealand, is suggested, because the decline in aphid numbers during the study period was apparently not related to disease incidence.
Abstract: Spring populations of Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) on barley, at Lincoln and elsewhere in Canterbury, New Zealand, declined markedly during 1984–87. Spring suction-trap ca...
TL;DR: Of the three aphid strains, those from Minnesota had the lowest susceptibility to permethrin, pirimicarb and azinophos-methyl, and no mortality was observed in this GPA strain when tested with azinphosmethyl.
TL;DR: Four methods of analysis based on a simple population model and applicable to aphid and predator field density data are described, determining the extent to which predators accounted for an observed change in aphid densities and how much the aphid population would have increased if the predators had not been present.
Abstract: Four methods of analysis based on a simple population model and applicable to aphid and predator field density data are described. Two of the analyses determine the extent to which predators accounted for an observed change in aphid densities, and the other two estimate by how much the aphid population would have increased if the predators had not been present. The methods are illustrated with examples taken from cereal aphid research, and their advantages and limitations are discussed.
TL;DR: Growth of asparagus plants during a growing season had a weak, inverse relationship to aphid numbers, and predicted time of egg hatch based on degree days was within 1 d of observed hatch.
Abstract: Dynamics of the asparagus aphid, Brachycorynella asparagi (Mordvilko), were studied in two mature asparagus fields and one immature field for a minimum of two seasons. To minimize disturbance to the asparagus, no harvesting, spraying, or cultivation was done. Numbers of B. asparagi were low early in the spring and increased to a peak in late June or July or in September to early October. No midseason peak was observed. Fields with an early summer peak had a midsummer low point and usually a late summer peak. Decline of aphid numbers in the fall coincided with egg laying that started during the last week of September when day length was about 12 h. Production of winged aphids and parasitism by Diaeretiella rapae (McIntosh) were density-dependent on some plots. These mortality factors undercompensated for changes in aphid density and failed to keep aphid numbers at acceptable levels. No consistent, significant correlations between temperature or rainfall and aphid numbers were found. Egg hatch occurred shortly after the first asparagus spears emerged in the spring. Predicted time of egg hatch based on degree days was within 1 d of observed hatch. Growth of asparagus plants during a growing season had a weak, inverse relationship to aphid numbers.
DOI•
01 Jan 1988
TL;DR: Türkiye yaprakbitleri faunistik listesinin bu üçüncü kısmında Macropsophini tri— busundan 13 cinse ait 38 tür yer almaktadır yanında ekonomik zarar durumları da belirtilmiştir.
Abstract: Türkiye yaprakbitleri faunistik listesinin bu üçüncü kısmında Macropsophini tri— busundan 13 cinse ait 38 tür yer almaktadır. Bu makalede yer alan cinslerden NeoamphorophoraMsson ve Rhopafos/phon/nusBsker ve Myzus (Nectarosiphon)iigusfry(Mosley), Neoamphorophora sp., Rhopalosiphoninus iatysiphon {Ds>j\dsor\), Uroleucon /nui/coia {H\\\e Ris Lambers) ve U. (Belochilum) inulae(Ferrari) türleri yurdumuz için yeni kayıttır. Herbir türün Dünya'da ve yurdumuzdayayıl ışı , konukçu bitkileri yanında ekonomik zarar durumları da belirtilmiştir.
TL;DR: The probing and feeding behavior of an important vector of barley yellow dwarf virus, the bird cherry-oat aphid, Rhopalosiphum padi was electronically monitored and showed that this aphid should be highly efficient in acquiring and transmitting the phloem-delimited BYDV to ‘California Mariout’ barley, with or without the Yd2 gene.
Abstract: The probing and feeding behavior of an important vector of barley yellow dwarf virus (BYDV), the bird cherry-oat aphid, Rhopalosiphum padi was electronically monitored on barley varieties with and without the Yd2 gene, a gene that imparts BYDV resistance to certain cereal cultivars. The presence of the Yd2 gene was shown to have no significant effect on the time elapsed to the first sieve element contact, total number of sieve element contacts, or duration of phloem sieve element ingestion by R. padi . Furthermore, aphid probing and feeding was not greatly affected by BYDV infection in susceptible plants. These data demonstrate that the mechanisms underlying BYDV resistance in plants with the Yd2 gene do not involve factors significantly influencing plant-aphid interactions that invoke alterations in aphid probing or feeding behavior. In addition, the number of sieve element contacts and duration of ingestion from sieve element cells by R. padi indicate that this aphid should be highly efficient in acquiring and transmitting the phloem-delimited BYDV to ‘California Mariout’ barley, with or without the Yd2 gene.