scholarly journals Population dynamics of Chaetocnema tibialis Illiger and Phyllotreta vittula (Redtenbacher) on the weed Amaranthus retroflexus L. and cultivated Amaranthus caudatus L.

2010 ◽  
Vol 42 (No. 2) ◽  
pp. 72-80
Author(s):  
Ľ. Cagáň ◽  
P. Tóth ◽  
M. Tóthová
Keyword(s):  
Population Dynamics ◽  
Wild Species ◽  
Low Temperatures ◽  
Flea Beetle ◽  
Amaranthus Retroflexus ◽  
Amaranthus Caudatus ◽  
Flea Beetles ◽  
Amaranth Species ◽  
Negative Effect ◽  
Cultivated Species

In 1995–1997, the population dynamics of the flea beetles <i>Chaetocnema tibialis and <i>Phyllotreta vittula</i>, associated with <i>Amaranthus retroflexus</i> (wild species) and <i>Amaranthus caudatus</i> (cultivated species), were studied at the locality Nitra-Malanta (48°19'N, 18°09'E) in south-western Slovakia. On both plant species, the number of <i>C. tibialis</i> adults was usually very low until the beginning of July. During July the number of <i>C. tibialis</i> increased, but sooner on cultivated amaranth. An increased number of <i>C. tibialis</i> adults was observed on both amaranth species until the middle of September. The results showed that amaranth plants are a very important reservoir of <i>C. tibialis</i> during summer. <i>P. vittula</i> was a common flea beetle on amaranth during the whole summer, but its numbers never exceeded more than 10 adults per 25 plants. Low temperatures in winter had a negative effect on populations of <i>C. tibialis</i> on both amaranth species and also on populations of <i>P. vittula</i> on <i>A. retroflexus</i>. The lower the precipitation was in July, the higher were the populations of <i>C. tibialis</i> on both amaranth species and the populations of <i>P. vittula</i> on <i>A. retroflexus</i>.

scholarly journals Population parameters and the relationships between environmental factors and abundance of the Acetes americanus shrimp (Dendrobranchiata: Sergestidae) near a coastal upwelling region of Brazil

2015 ◽  
Vol 63 (3) ◽  
pp. 229-238
Author(s):  
Ana Paula Freitas dos Santos ◽  
Sabrina Morilhas Simões ◽  
Gabriel Lucas Bochini ◽  
Cinthia Helena Costa ◽  
Rogerio Caetano da Costa
Keyword(s):  
Population Dynamics ◽  
Sexual Dimorphism ◽  
Environmental Factors ◽  
Primary Productivity ◽  
Low Temperatures ◽  
Coastal Upwelling ◽  
Statistical Correlation ◽  
Individual Growth ◽  
Otter Trawl ◽  
Population Parameters

AbstractThe population dynamics of Acetes americanus was investigated, focusing on the sex ratio, individual growth, longevity, recruitment and relationship between abundance and environmental factors in the region of Macaé, strongly influenced by coastal upwelling. Otter trawl net samplings were performed from July 2010 to June 2011 at two points (5 m and 15 m). Nearly 19,500 specimens, predominantly females (77.15%), were captured. Their sizes, larger than that of males, indicated sexual dimorphism. Shrimps at lower latitudes present larger sizes and longer longevity than those from higher latitudes. This difference is probably due to low temperatures and high primary productivity. Though no statistical correlation was found between abundance and environmental factors, the species was more abundant in temperatures closer to 20.0º C and in months with high chlorophyll-a levels. Due to the peculiar characteristics of this region, A. americanusshowed greater differences in size and longevity than individuals sampled in other studies undertaken in the continental shelf of Southeast Brazil.

scholarly journals Relationship of Cultivated Grain Amaranth Species and Wild Relative Accessions

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1849
Author(s):  
Ranjita Thapa ◽  
Matthew Edwards ◽  
Matthew W. Blair
Keyword(s):  
Wild Species ◽  
Germplasm Conservation ◽  
Conservation Strategies ◽  
South American Species ◽  
Amaranthus Cruentus ◽  
Amaranthus Hypochondriacus ◽  
Major Allele Frequency ◽  
Population Structure Analysis ◽  
Amaranth Species ◽  
Relationship Of

Amaranthus is a genus of C4 dicotyledonous herbaceous plants, and three New World species have been domesticated to produce grain crops with light colored seed which are classified as pseudo-cereals rich in protein and minerals. A core collection of grain amaranths and immediate precursor species has been established, representing the closest related species. The goal of this study was to evaluate the genetic diversity in that collection of cultivated and wild species, using competitive allele single nucleotide polymorphism markers. A secondary objective was to determine the relationships among the three cultivated species and non-domesticated Amaranthus, while a third objective was to evaluate the utility of the markers in detecting diversity in the 276 genotypes. The markers were found to be highly variable with an average polymorphism information content of 0.365. All markers were bi-allelic; and the major allele frequency ranged from 0.388 to 0.871. Population structure analysis of the cultigens revealed the presence of two sub populations. Phylogeny confirmed that the two Mesoamerican species, Amaranthus cruentus and Amaranthus hypochondriacus, were related and distant from the South American species Amaranthus caudatus, which in turn was very closely clustered with Amaranthus quitensis, even though this is considered a weedy relative. The first pair of species were likely to have inter-crossed, while the latter two likely exist in a wild-cultivated hybrid state. In conclusion, the results of this SNP study provided insights on amaranth cultivars and their relationship to wild species, the probable domestication events leading to the cultivars, and possible crop breeding or germplasm conservation strategies.

A search for diagnostic AFLP markers in Cichorium species with emphasis on endive and chicory cultivar groups

Genome ◽  
2000 ◽  
Vol 43 (3) ◽  
pp. 470-476 ◽  
Author(s):  
A M Kiers ◽  
T HM Mes ◽  
R van der Meijden ◽  
K Bachmann
Keyword(s):  
Wild Species ◽  
Genetic Relationships ◽  
Group Method ◽  
Specific Marker ◽  
Pair Group ◽  
Cultivar Groups ◽  
Average Analysis ◽  
Species Analysis ◽  
Cultivated Species ◽  
Unique Markers

The genus Cichorium consists of two widely cultivated species C. intybus (chicory) and C. endivia (endive) and four wild species, C. bottae, C. spinosum, C. calvum, and C. pumilum. A multivariate and an UPGMA (unweighted pair group method average) analysis based on AFLP (amplified fragment length polymorphism) markers were used to establish the genetic relationships among the species and cultivar groups of C. intybus and C. endivia. At the species level, the results correspond with previously obtained phylogenetic relationships in that C. bottae is the most divergent species, and C. intybus and C. spinosum, as well as C. endivia, C. pumilum, and C. calvum formed clusters. Based on the congruence between phylogenetic and genetic analyses, unique markers were expected for all species, however, hardly any specific marker was found except for C. bottae. The analysis of cultivar groups of C. intybus resembled the species analysis in two respects: (i) grouping of cultivars according to cultivar groups, and (ii) lack of markers unique to cultivar groups. In contrast to C. intybus, the cultivar series of C. endivia do not form distinct groups, which would reflect that crosses have been made among the various cultivar groups. The relationships among Cichorium species and cultivars will be useful for setting up a core collection of Cichorium, and stress the importance of inclusion of the wild species in the collection.Key words: Cichorium, AFLP, diagnostic markers, cultivar relationships, genetic resources.

scholarly journals Quantifying the Feeding Periods Required by Corn Flea Beetles to Acquire and Transmit Pantoea stewartii

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 319-324 ◽  
Author(s):  
B. Menelas ◽  
C. C. Block ◽  
P. D. Esker ◽  
F. W. Nutter
Keyword(s):  
Nalidixic Acid ◽  
Growth Models ◽  
Flea Beetle ◽  
Feeding Time ◽  
Feeding Period ◽  
Selective Media ◽  
Pantoea Stewartii ◽  
Flea Beetles ◽  
Time Required ◽  
The Relationship

The feeding periods required by corn flea beetles to acquire and transmit Pantoea stewartii were investigated in the Stewart's disease of corn pathosystem. To quantify the effect of acquisition feeding period on percentage of acquisition, field-collected corn beetles were allowed to feed for 6, 12, 24 36, 48, and 72 h on corn seedlings previously inoculated with a rifampicin- and nalidixic acid-restraint strain of P. stewartii. Acquisition of P. stewartii by corn flea beetles was considered positive if the rifampicin- and nalidixic acid-marked strain was recovered on selective media. To quantity the effect of transmission feeding period on percent transmission of P. stewartii by corn flea beetles, P. stewartii- infested corn flea beetles were allowed to feed on healthy corn seedlings for periods of 3, 6, 12, 24, 36, 48, and 72 h. After the appropriate transmission feeding period, leaf tissues surrounding the sites of feeding scars were cultured for the presence of the P. stewartii-marked strain. Transmission of P. stewartii was considered positive if the marked strain was recovered on selective media. Acquisition of P. stewartii occurred within 6 h and the percentage of corn flea beetles that had acquired P. stewartii after 72 h ranged from 68 to 94%. The change in P. stewartii acquisition by corn flea beetles (Y) with respect to acquisition feeding period (X) was best described by the Gompertz model, with R2 values ranging from 91 to 99%. The mean time for acquisition by 50% of the corn flea beetles was 36.5 ± 11.6 h. The minimum transmission feeding time required for corn flea beetles to transmit P. stewartii following a 48-h acquisition feeding period was less than 3 h. The percent transmission of P. stewartii by corn flea beetles was nearly 100% after a 48-h transmission feeding period and was 100% by 72 h. Among population growth models evaluated, the monomolecular model best described the relationship between percent transmission (Y) and transmission feeding periods (X), with R 2 values of up to 84%. However, a nonlinear form of the monomolecular model better quantified the relationship between percent transmission and transmission feeding period, because pseudo-R2 values ranged between 98.1 and 99.5%. The predicted transmission feeding time required for 50% of P. stewartii-infested corn flea beetles to transmit the pathogen was 7.6 ± 0.87 h. These results suggest that the corn flea beetle is a highly efficient vector that can quickly acquire and transmit P. stewartii, thereby requiring insecticide seed treatments and foliar insecticides that act quickly to prevent corn flea beetles from acquiring and transmitting P. stewartii to corn plants.

Ballistics and visual targeting in flea-beetles (Alticinae)

1995 ◽  
Vol 198 (9) ◽  
pp. 1931-1942 ◽  
Author(s):  
J Brackenbury ◽  
R Wang
Keyword(s):  
Flea Beetle ◽  
Rotational Energy ◽  
The Body ◽  
Translational Energy ◽  
High Contrast ◽  
Significant Preference ◽  
Flea Beetles ◽  
Mode 2 ◽  
Optical Grid ◽  
Targeting Accuracy

The kinematics of jumping was measured in seven species of flea-beetle (Alticinae). The accuracy of two species during targeted jumping was also investigated. Take-off accelerations ranged from 15 to 270 times gravity. Rotational energy accounted for 4&shy;21 % of the total translational energy. Two species were able to control jump direction and landing. When presented with a high-contrast optical grid, Chalcoides aurata exhibited two alternative jump modes. In mode 1 or wingless jumping, the body rotated continuously, the insect rarely landed on its feet and no discrimination was shown between landing on the black or white stripes of the grid. In mode 2 jumping, recruitment of the wings eliminated rotation and virtually ensured a feet-first landing; there was also a significant preference for jumping towards the black stripes. Aphthona atrocaerulea could alter take-off angle in order to strike targets at inclinations of 0&shy;90 &deg; to the horizontal. Targets consisting of a white illuminated cross on a black background were struck with equal accuracy, regardless of distance (within the normal jumping range). The beetle aimed specifically for the centre of the target and not for the high-contrast boundary. The distribution of hits about the target centre was radially symmetrical. Although take-off was wingless, rotation could be abolished in mid jump, within 10 ms, by extending the wings. This virtually guaranteed a feet-first landing. Targeting accuracy is discussed in the context of biomechanical steering mechanisms and visual control.

When is fall feeding by flea beetles (Phyllotreta spp., Coleoptera: Chrysomelidae) on canola (Brassica napus L.) a problem?

2012 ◽  
Vol 92 (1) ◽  
pp. 97-107
Author(s):  
Juliana J. Soroka ◽  
Larry F. Grenkow
Keyword(s):  
Brassica Napus ◽  
Field Experiments ◽  
Flea Beetle ◽  
Brassica Napus L ◽  
Late Season ◽  
The Third ◽  
Flea Beetles ◽  
Seeding Date ◽  
Seed Yields

Soroka, J. J. and L. F. Grenkow. 2012. When is fall feeding by flea beetles ( Phyllotreta spp., Coleoptera: Chrysomelidae) on canola ( Brassica napus L.) a problem? Can. J. Plant Sci. 92: 97–107. Two cultivars of Brassica napus canola were seeded in mid-May and early June in three field experiments in each of 3 yr near Saskatoon, Saskatchewan, to determine the effects of late-season flea beetle feeding on seed yields. In the first experiment, canola was sprayed with insecticide late in the summer to eliminate naturally-infesting flea beetles. In the second, 1×1×1.5 m screen cages were placed over early- and late-seeded canola at flowering and infested with flea beetles as canola matured. In the third investigation, sleeve cages were placed over individual plants and infested with 100 flea beetles. Flea beetles had no detrimental effects on early-seeded canola in any experiment, but did affect seed yields of late-seeded plots in some trials. Over two cultivars in 1 year, late-seeded plants in cube cages infested with about 350 flea beetles per plant when lower pods were turning from translucent to green in colour reduced yield by 241 kg ha−1 over control yields. Seed weights in these late-seeded plots were decreased from 2.68 g per 1000 seeds in uninfested cages to 2.44 g per 1000 seeds in infested cages. Populations of 100 flea beetles per plant in sleeve cages had no effect on harvest parameters in any seeding date or year.

Effects of seed size and seed weight on seedling establishment, seedling vigour and tolerance of summer turnip rape (Brassica rapa) to flea beetles, Phyllotreta spp.

2007 ◽  
Vol 87 (2) ◽  
pp. 385-393 ◽  
Author(s):  
R. H. Elliott ◽  
L. W. Mann ◽  
O. O. Olfert
Keyword(s):  
Seed Size ◽  
Brassica Rapa ◽  
Seedling Establishment ◽  
Seed Weight ◽  
Flea Beetle ◽  
Dry Weight ◽  
Seedling Vigour ◽  
Shoot Dry Weight ◽  
Flea Beetles ◽  
Beetle Damage

A 3-yr study was conducted on three synthetic Brassica rapa L. cultivars to determine the effects of seed size and seed weight on seedling establishment, seedling growth and susceptibility to feeding damage by flea beetles, Phyllotreta spp. (Coleoptera: Chrysomelidae). Seed lots of AC Boreal, Fairview and Hysyn 110 were sieved to obtain small, medium and large seeds (1.4–1.6, 1.6–1.8 and 1.8–2.0 mm, respectively). In the laboratory, seedlings grown from large seeds had the largest cotyledons, highest shoot dry weight and highest biomass. Shoot weights increased as seed size increased. Sized seeds of the three cultivars were grown in the field without insecticides in 1998–2000. Seedlings of small seeds had the highest flea beetle damage and poorest seedling establishment. Shoot dry weight and biomass 14–35 d after planting increased as seed size and seed weight increased. Compared with small seeds, large seeds improved shoot dry weight, biomass and seed yield by 13–43, 25–57 and 12%, respectively. Results indicated that seedlings of medium and large seeds are more vigorous and tolerant to flea beetle damage than seedlings of small seeds. Tolerance was due to a higher initial seedling weight rather than higher relative growth rate. Shoot dry weights, biomass and yield of the three cultivars were more strongly correlated with 1000-seed weight than with seed diameter. Key words: Canola, flea beetles, seed size, seedling vigour, tolerance, seed weight

scholarly journals The consequences of polyandry for population viability, extinction risk and conservation

2013 ◽  
Vol 368 (1613) ◽  
pp. 20120053 ◽  
Author(s):  
Luke Holman ◽  
Hanna Kokko
Keyword(s):  
Population Dynamics ◽  
Extinction Risk ◽  
Population Level ◽  
Female Fitness ◽  
Male Care ◽  
Negative Effect ◽  
Adverse Environmental Conditions ◽  
The Cost ◽  
Cost Of Sex ◽  
Population Fitness

Polyandry, by elevating sexual conflict and selecting for reduced male care relative to monandry, may exacerbate the cost of sex and thereby seriously impact population fitness. On the other hand, polyandry has a number of possible population-level benefits over monandry, such as increased sexual selection leading to faster adaptation and a reduced mutation load. Here, we review existing information on how female fitness evolves under polyandry and how this influences population dynamics. In balance, it is far from clear whether polyandry has a net positive or negative effect on female fitness, but we also stress that its effects on individuals may not have visible demographic consequences. In populations that produce many more offspring than can possibly survive and breed, offspring gained or lost as a result of polyandry may not affect population size. Such ecological ‘masking’ of changes in population fitness could hide a response that only manifests under adverse environmental conditions (e.g. anthropogenic change). Surprisingly few studies have attempted to link mating system variation to population dynamics, and in general we urge researchers to consider the ecological consequences of evolutionary processes.

scholarly journals Population dynamics and biting rhythm of the anthropophilic sandfly Lutzomyia cruciata (Diptera: Psychdidae) in Southeast, Mexico

1996 ◽  
Vol 38 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Eduardo A. Rebollar-Tellez ◽  
Filiberto Reyes-Villanueva ◽  
Ildefonso Fernandez-Salas ◽  
Fernando J. Andrade-Narvaez
Keyword(s):  
Population Dynamics ◽  
High Temperature ◽  
The State ◽  
Endemic Focus ◽  
Host Seeking ◽  
Biting Rate ◽  
Population Peak ◽  
Negative Effect ◽  
Southeast Mexico

Sandflies attracted by human bait were caught in an endemic focus of localized cutaneous leishmaniasis in the state of Campeche, Mexico. Catches were carried out monthly from February 1994 to January 1995 between 18:00 and 22:00 h. Lutzomyia cruciata was the only species caught. The highest population peak of Lu. cruciata was found in March with lesser peaks in February, December 1994, and January 1995. Maximum biting rate of Lu. cruciata was found between 18:00 and 19:00 h. The host-seeking females of Lu. cruciata were directly related to levels of humidity between 88 and 100%. Low and high temperature had a negative effect upon Lu. cruciata activity. The possible role of Lu. cruciata as vector of leishmaniasis in the state of Campeche, Mexico is discussed.

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