Alate Aphids Research Articles

On the fluctuation of captured alate aphids concerned with virus disease of tomato

On the fluctuation of captured alate aphids concerned with virus disease of tomato

Epidemiology of potato leaf roll virus in the Fraser River delta of British Columbia

The spread of potato leaf roll virus (PLRV) and the resulting phloem necrosis in the tubers has been a limiting factor in the production of the Netted Gem (Russet Burbank) variety in southwestern British Columbia, Canada. Steckling sugar beets are an important overwintering host for nymphs and adults of the green peach aphid,Myzus persicae (Sulzer). By June, aphids are widely disseminated to the florets and new leaves of sugar beet and other hosts, including potato. Colonies with alates are produced on summer hosts which are not treated with insecticides. The peak of the flight of alates from the colonies on the summer hosts occurs during the first half of August. Those alates that were produced on PLRV-infected potato and which travel to other potatoes transmit the virus as soon as they feed. By the end of August, the sugar beet seed crops and the early and mid-season potato crops have been defoliated or harvested. Thus many colonies ofM. persicae are destroyed and the threat of PLRV spread diminishes. Crop and weed plants which serve as overwintering hosts become infested during late summer with alate aphids. Their offspring survive the winter in numbers which are determined by the weather and survival of host plants.

Effects of Temperature and Light on Dispersal of the Pea Aphid, Acyrthosiphon pisum,1 and a Braconid Parasite, Aphidius pisivorus,2 in the Field3

Alate pea aphids, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), and braconid parasites, Aphidius pisivorus C. F. Smith (Hymenoptera: Braconidae), were collected at 30-min intervals from 28 April to 17 May 1967 with Johnson-Taylor segregating suction traps placed level with the tops of alfalfa. Simultaneous records of air temperature and light intensity were taken at crop level. Data indicate the parasites were in flight 1 hr earlier in the morning and 21 min later in the evening than alate aphids. Temperatures below 0°C did not noticeably reduce populations of the pea aphid or parasite, but flight of both species was inhibited below about 6°C. The median temperature thresholds for parasite and aphid flight were 19.8 and 21.8°C, respectively. Parasites were in flight at lower light intensities in the morning and evening than alate aphids. The median light intensity thresholds for parasite and aphid flight were 2800 and 4300 foot-candles, respectively.

Preference of Green Peach Aphids for Virus-Infected Sugar beet Leaves12

In detached-leaf experiments, apterous Myzus persicae (Sulzer) preferred yellows-infected leaves to symptom less, mosaic-infected, or curly-top-infected leaves. However, apterous aphids appeared to move at random to healthy, mosaic-infected, or yellows-infected whole plants. Twice as many alate aphids were found on yellows-infected whole plants 24 hours after release as on healthy or mosaic-infected plants, but no marked differences were found in numbers of alate aphids on healthy, mosaic-infected, and yellows-infected whole plants 48–96 hours after release. In all tests aphids appeared to avoid curly top-infected leaves or plants.

Migration in aphids: response to current adversity.

Johnson1–3, Kennedy4 and Southwood5 state that migration occurs in alate aphids whether the alate population is large or small, and this behaviour of the alatae is not due to population pressure or to current lack of food; in other words, the migration of alatae is an evolved adaptation rather than a response to current adversity. This hypothesis does not apply to the sycamore aphid, Drepanosiphum platanoides (Schr.), in which migration is more marked in conditions of over-population (unpublished results of A. F. G. D.). The sycamore aphid, however, which is a tree dwelling aphid and therefore occupies a permanent habitat5, does not show the same degree of polymorphism as polyphagous aphids. It could be regarded as an exception to this hypothesis, which has been developed to explain migratory activity in aphids occupying temporary habitats.

Alate aphids trapped over 8 years at two sites in Canterbury, New Zealand

Abstract Trapping of alate aphids at two sites with grease traps over 8 years yielded a total of 51 species, 9 of which flew regularly in high numbers and are referred to as primary species. Six others occasionally occurred in high numbers The validity of likely inferences from information collected by this method is discussed, as is also the application of the knowledge of flights to problems of aphid control.

Aphid Vectors of Barley Yellow Dwarf Virus in Blacklight Traps in Eastern United States1

Alate aphids were captured in blacklight traps at 8 locations from Clemson, South Carolina, northward to Ithaca, New York. Four aphid species which vector barley yellow dwarf virus of small grains are reported: English grain aphid, Macrosiphum avenae (F.); oat bird-cherry aphid, Rhopalosiphum padi (L.); corn leaf aphid, R. maidis (Fitch); and greenbug, Schizaphis graminum (Rondani). These 4 species comprised 30% of all aphids captured. The number of each species taken during the season and periods of maximum flight varied greatly at the different locations. The 8 collections contained 20% English grain aphids, 6% oat bird-cherry aphids, 3% corn leaf aphids, and 1% greenbugs, with percentages at each location varying greatly. Earliest aphid capture ranged from April 13 at Clemson to May 13 at Mt. Carmel, Connecticut. Last capture ranged from May 30 at Clemson to December 2 at Mt. Carmel. The days from first to last capture varied from 4 days for the corn leaf aphid at Clemson to 203 days for the English grain aphid at Mt. Carmel.

Alate Aphids Captured in Air Traps Arranged at Different Heights1

Journal Article Alate Aphids Captured in Air Traps Arranged at Different Heights Get access B. F. Coon, B. F. Coon Department of Entomology, Pennsylvania State University, University Park 16802 Search for other works by this author on: Oxford Academic PubMed Google Scholar J. O. Pepper J. O. Pepper Department of Entomology, Pennsylvania State University, University Park 16802 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 61, Issue 5, 1 October 1968, Pages 1473–1474, https://doi.org/10.1093/jee/61.5.1473 Published: 01 October 1968 Article history Accepted: 31 May 1968 Published: 01 October 1968

Alate Aphid Species Captured in Yellow Pans1

Alate Aphid Species Captured in Yellow Pans1

Aphid Sampling Efficiency of Möericke Traps Affected by Height and Background12

Alate aphids were trapped in studies of the field spread of lettuce mosaic virus. The effectiveness of yellow-painted water pans (MOericke traps) at different heights and backgrounds was compared in determining the seasonal abundance of alate aphid populations. Pans 15 inches above bare soil were most effective; pans at the same height surrounded by plants were less effective; and pans 8 feet above bare soil were least effective. Sixty-eight species of aphids in 37 genera were identified. Myzus persicae (Sulzer), green peach aphid, comprised 28% of the total. Brevicoryne brassicae (L.), cabbage aphid; Rhopalosiphum maidis (Fitch), corn leaf aphid; and Hyalopterus atriplicis (L.) contributed 37% of the total.

Aphids and the Increase of Potato Leaf Roll Virus in Seed Potatoes on the Wolds of the East Riding of Yorkshire

SUMMARYIt is shown that aphid infestation in seed potato crops in the East Riding Wolds can be assessed by reference to five sites indicated as representative of the area as a whole.The concept of virus multiplication in seed potato stocks is shown not to be related to aphid infestations expressed as Angles of Colonization for the East Riding Wolds in the seasons 1962 to 1964.It is suggested that most of the observed increase in leaf roll virus can be accounted for as additions to the virus content of the parent stock attributed to introduction by migrant alate aphids from ware potato areas.

Studies of the ecology of the cabbage aphid (Brevicoryne brassicae(L.)) on brassica field crops in Canterbury, New Zealand

Abstract Results are presented from a second year of replicated trials dealing wilh field population studies of the cabbage aphid (Brevicoryne hrassicae (L.)) on five varieties of brassica crops at three sites in Canterbury, New Zealand. Total aphids and total alates on plants were counted throughout the year at weekly or fortnightly intervals, and plants and leaves were weighed. Alate aphids were trapped at crop height. Plant survival against combined aphid-virus attack was tested in counts taken at the peak of growth. Three resistant varieties were colonised by aphids at a lower rate than two susceptible varieties, and these differences were consistent at all sites. Plant survival at the end of six months differed significantly between sites. During the vegetative stage, aphid numbers per site were approximately proportional to leaf weight, but this relationship was not maintained during the flowering and seeding stage. Once aphids entered the crop, alate production on plants and alate numbers on traps ...

Reflective Surfaces Used to Repel Dispersing Aphids and Reduce Spread of Aphid-Borne Cucumber Mosaic Virus in Gladiolus Plantings

Field experiments were conducted in 1965 at Farmingdale, New York, to evaluate reflective materials used as soil mulches to repel dispersing alate aphids and thus reduce the spread of cucumber mosaic virus (CMV) in gladiolus plantings. Mulching with aluminum foil laminated to paper and asphalt showered with small pieces of aluminum foil reduced catches of winged aphids in yellow-pan water traps by 87-97%. White polyethylene reduced catches 88%. Strips of reflective material 2 feet wide were more effective than strips 1 foot wide. Mulching on both sides of the rows opposed to mulching on 1 side was necessary for maximum protection. Reduction in spread of CMV in the gladiolus plantings was proportional to the effectiveness of the materials as repellents of aphids.

Effects of a Nitrogen-Deficient Host and Crowding on the Corn Leaf Aphid1

Corn leaf aphids, Rhopalosiphum maidis (Fitch), were allowed to feed on sorghum plants grown under high and low levels of nitrogen. Results showed that more than twice as many aphids were found on plants receiving nitrogen than on nitrogen-deficient plants. Other tests indicated that the reduction in aphid fecundity was due to a crowding response rather than to nitrogen deficiency. Aphid densities (number of aphids per gram of green plant weight) were more than double on nitrogen-deficient plants than on plants receiving nitrogen. The percentage of alate aphids on nitrogen-deficient plants was twice that on plants that were not deficient. The higher percentage of alate aphids appeared to be due to nitrogen deficiency and not to overcrowding.

On the use of gut characters to determine the origin of migrating aphids

SUMMARYA survey of plant metabolites recoverable from aphids indicated that amino acids, sugars, and phenolic compounds do not provide criteria for associating aphids with their original host plant.An insoluble polysaccharide accumulates in the crop of aphids fed on members of the family Chenopodiaceae, and distinguishes Myzus persicae alatae reared on chenopods from those reared on other host plants. The polysaccharide causes swelling of the crop in alate and apterous aphids transferred to beet from cabbage and persists in the crops of these aphids after subsequent transfer from beet to non‐chenopod hosts, or in aphids removed from beet and starved to death.Migrants from chenopods can be recognized by the intensely positive periodic acid‐Schiff reaction of the crop contents, and the increased cross‐sectional area of the crop, caused by the accumulation of polysaccharide.

Occurrence of Alate and Apterous Green Peach Aphids on Burley Tobacco in Kentucky1

General observations in prior years have shown that heavy colonizations of the green peach aphid, Myaus persicae (Sulzer), usually do not appear on burley tobacco in Kentucky until the latter part of the growing season. Aphids are occasionally found on tobacco in the early part of the growing season, but the large populations almost invariably occur late in the season. The same situation also exists in southern Maryland, where aphids do not become a problem until late in the summer after the tobacco plants have attained some size (Savage and Harrison 1962).

Transmission of beet yellows virus by alate and apterous aphids

SUMMARY Myxus pusicae alatae and apterae were consistently better vectors than Aphis fabae of beet yellows virus, but there was little difference between the ability of alatae and apterae of each species to transmit.Alatae born and reared on infected plants transmitted no more readily than alatae that had fed on infected plants for only one day. No individual became infective after feeding on the plants for only 5 min., and few were infective after feeding for 30–60 min. Alatae and apterae were about equally infective after similar feeding times on infected plants.Apterae kept from feeding and at various temperatures up to 30°C. for 4 hr. after their infection feed, all transmitted equally often. Alatae transmitted as readily after a 4 hr. flight as after a 15 min. one. Some alatae of M. persicae remained infective longer than apterae, but most individuals of both ceased to be infective within 2 days of leaving infected plants. Most alatae ceased to fly 3–5 days after the final ecdysis because their flight muscles autolysed. A. fabae and Rhopalosiphoninus staphyleae transmitted BYV rather less than half as often as did M. persicae. Macrosiphum euphorbiae and Aulacorthum solani transmitted only rarely and transmissions were not obtained with Megoura viciae, Metopolophium festucae and Rhopalosiphoninus latysiphon.

THE ROLE OF INSECTS IN THE SPREAD OF CUCUMBER MOSAIC VIRUS

Entomological aspects of the epidemiology of cucumber mosaic virus (CMV) were studied in Michigan. Myzus persicae (Sulzer) and Aphis gossypii Glover were efficient vectors of CMV between various hosts in the laboratory. Macrosiphum euphorbiae (Thomas) transmitted CMV between cucumber and Echinocystis lobata (Michx.) T. & G. Myzocallis asclepiadis (Monell) was shown to be a new vector of CMV between Asclepias syriaca L. Neither Melanoplus differentialis (Thomas) nor Acalymma vittata (Fabricius) transmitted the virus in limited trials.There was a small proportion of cucumber plants infected early in July, when alate M. persicae were present. In August the incidence of infection rose rapidly after a period of activity of alate A. gossypii. Alate aphids were trapped in yellow water pans situated in and around cucumbers. Seven known vectors of CMV were caught.

The Spatial Pattern of the Pea Aphid in Alfalfa Fields

The terminal 6 inches of a vigorously growing, nonblooming alfalfa stem were used as the sampling unit in a study of the spatial pattern of the pea aphid, Macrosiphum pisi (Harris). Samples of 100 stems each were taken in four New York alfalfa fields at various intervals throughout the 1961 growing season, and the number of aphids per stem was counted. The counts of the total number of aphids and the counts of the total number less the first instar nymphs were fitted to the Poisson and negative binomial series. There was a very low probability of a greater chi-square when the samples taken in the spring and in the late summer were fitted to the Poisson series. The samples taken in midsummer showed a very low population of pea aphids and a close agreement to the Poisson series. as indicated by the very nearly equal mean and variance of each sample. The spring- and late-summer samples, and a midnight sample, generally gave good fits to the negative binomial series, although there were a few that did not fit the contagious distribution very well. When one or two stems with unusually high numbers of aphids were omitted from some of these samples. there was a decided improvement of the fit to the negative binomial. Extremes in daily weather conditions and the presence of parasitized and alate aphids had little apparent effect on the spatial pattern form.

VARIATION AND COVARIATION OF CHARACTERS OF ALATEPEMPHIGUS POPULI-TRANSVERSUSIN EASTERN NORTH AMERICA,

This paper is based on a study of the variation and covariation of 18 morphological characters of the aphid, Pemphigus populi-transversus Riley, from 23 localities in eastern North America. The variation and covariation of these characters are separately studied within galls, among galls within localities, and among localities. By means of factor analysis, covariation is restated in terms of fewer dimensions (factors). The factors are compared at the different levels of variation. This paper continues an earlier study (Sokal, 1952) in which the author examined 21 characters of a single population of this gall-forming aphid from Ripley, Ohio. Of this local population, 28 galls containing four alate aphids each were studied. Since the alates within any one gall are isogenic and the different galls presumably represent different genotypes, the variance of the characters could be partitioned into a non-hereditary, intragall portion and an intergall portion which is assumed to be partly genetic and partly environmental in origin. Several characters, representing independent dimensions of intergall variation, were chosen by analysis of covariance. The purpose behind this procedure was the recognition of fewer than the original number of characters for a further study of intraspecific variation. Three problems emerged concerning the use of the characters chosen by the previous analysis. The first is the possibility, suggested by Clark's (1941) findings on Peromyscus, that the intergall correlations on which the former study is based might vary geographically, thus presenting a different pattern of significant characters in other areas. Average intergall correlations for many localities are therefore computed below. The second problem is whether some characters lacking intergall variance in the Ripley population might yet possess significant interlocality variance. As will be seen below, this proved to be the case for several meristic characters. Thirdly, and most important, are the characters representing genetic and environmental differences among galls necessarily the same as those describing genetic and environmental differences among localities? This study will show that there are real differences between interlocality and intergall factor patterns. As the study progressed a number of other objectives came into view, and assumed progressively increasing importance. The unusual hierarchic structure of the data at hand (isogenic alate aphids descended from a single stem mother, morphologically distinct but genetically identical, all contained within an individual gall; galls putatively representing different genotypes found within one locality; and finally localities presumed to differ genetically from each other) permitted a detailed and quantitative separation of sources of variation in this study. Since correlations can be computed at each of these levels of covariation, the differences between these correlation matrices and between the factors into which they were resolved eventually, provide a novel Part 2 of a study of variation in the aphid genus Pemphigus. Part 1 is Sokal (1952), part 3 is Sokal and Rinkel (1962). 2 Contribution No. 1125 from the Department of Entomology of The University of Kansas, Lawrence, Kansas.