scholarly journals Comparisons Between Alate Aphids Caught in Υellow Water Traps and Aphid Populations on Tomato Plants

2017 ◽  
Vol 11 ◽  
pp. 29 ◽  
Author(s):  
P. Lykouressis ◽  
D. CH. Perdikis ◽  
CH.A. Chalkia ◽  
S. C. Vardaki
Keyword(s):  
Total Population ◽  
Macrosiphum Euphorbiae ◽  
Aphid Population ◽  
Tomato Plants ◽  
Growing Seasons ◽  
Significant Relationships ◽  
Water Traps ◽  
Plant Sampling ◽  
Trap Catches ◽  
Aphid Populations

Aphid monitoring was conducted by means of yellow Moericke water traps placed in tomato fields in two different localities in Co Boiotia during the growing seasons in 1992 and 1993. Additionally, aphid population densities were estimated by plant sampling. Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer) were the only species which developed populations on plants. Regression analysis between the number of alates from traps with either the number of alates or the total aphid population on plants showed that there was no correlation in the case of M. persicae for both localities and years. However, there were significant relationships between the number of alates in traps and either the number of alates on plants (r2=0.83) or the total aphid population on plants (r2=0.69) for M. euphorbiae in 1992. In 1993, such significant relationships were not found for the latter species, most probably due to extremely low trap catches. Significant relationships were also found between alates in traps, during their immigration period, with either alates on plants (r2=0.93) or the total population on plants (r2=0.80) in M. euphorbiae in 1992.

scholarly journals The Effects of Νatural Enemies on Aphid Populations on Processing Tomato in Central Greece

2017 ◽  
Vol 13 ◽  
pp. 35 ◽  
Author(s):  
Ρ. Lykouressis ◽  
D. CH. Perdikis ◽  
CH. Α. Chalkia
Keyword(s):  
Growing Season ◽  
Aphid Population ◽  
Parasitoid Species ◽  
Tomato Plants ◽  
Central Greece ◽  
Processing Tomato ◽  
Vegetable Products ◽  
Population Peak ◽  
Population Suppression ◽  
Aphid Populations

Two species of aphids, Macrosiphion euphorbiae (Thomas) and Myzus persicae cae (Sulzer) (Homoptera: Aphididae) were the only ones which developed populations on processing tomato in a two year study conducted in central Greece. The aphid population structure showed that M. euphorbiae was much more abundant than M. persicae in both years. The former species peaked in August whilst the latter did not show any particular peak over the two successive years. Some species of natural enemies were recorded. Orius niger Wolff was found in low numbers scattered over a long period but mainly towards the end of the growing season, and it did not correlate with the aphid population. The rate of parasitism of M. euphorbiae by Aphelinus abdominalis Dalman and Praon volucre (Haliday) was very low and it seemed that these two parasitoid species did not have any particular effect on the aphid population suppression. Macrolophus pygmaeus Rambur was the key natural enemy and the most abundant and effective among the predators found. Its highest numbers occurred towards the end of the growing season following the aphid population peak, suggesting a numerical response of this species to its prey. A proportion of the population of M. pygmaeus occurring on tomato plants after fruit harvesting, might he collected and subsequently released in crops such as tomato, pepper and eggplant to biologically control pests in greenhouses, like aphids and whiteflies, thus contributing to the production of healthy vegetable products.

scholarly journals Weather Variables Associated with Infection of Tomato Fruit by Colletotrichum coccodes

Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 753-756 ◽  
Author(s):  
S. Sanogo ◽  
S. P. Pennypacker ◽  
R. E. Stevenson ◽  
A. A. MacNab
Keyword(s):  
Field Experiments ◽  
Tomato Fruit ◽  
Field Conditions ◽  
Colletotrichum Coccodes ◽  
Weather Variables ◽  
Tomato Plants ◽  
Growing Seasons ◽  
Central Pennsylvania ◽  
Best Fitting ◽  
Relationship Of

Field experiments were conducted to determine the relationship of tomato anthracnose to weather variables. Sixteen potted tomato plants were exposed to field conditions within rows of tomato plants for 4 consecutive days at various time periods during the 1993 and 1994 summer growing seasons. Incidence of fruit infection by Colletotrichum coccodes was correlated with rain variables (amount and duration of rain) alone and in combination with other meteorological factors. The best fitting regression equation, accounting for 72% of the variation in anthracnose incidence (arcsine-square root transformed), was Y = 111.77 - 1.16 HNRo, in which HNRo is the numbers of hours during which no rainfall occurs within 4-day intervals that tomato fruit were exposed to field conditions in central Pennsylvania.

scholarly journals Seasonal dynamics and entomophthoralean infection of the pea aphid, Acyrthosiphon pisum Harris

2001 ◽  
Vol 37 (No. 1) ◽  
pp. 17-24 ◽  
Author(s):  
Ľ. Cagáň ◽  
M. Barta
Keyword(s):  
Entomopathogenic Fungi ◽  
Seasonal Dynamics ◽  
Positive Relationship ◽  
Acyrthosiphon Pisum ◽  
Correlation Coefficients ◽  
Pea Aphid ◽  
Infestation Level ◽  
Erynia Neoaphidis ◽  
Growing Seasons ◽  
Aphid Populations

The seasonal dynamics of the pea aphid, Acyrthosiphon pisum Harris, and entomopathogenic fungi from the order Entomophthorales attacking the aphid were analysed in alfalfa and field pea crops during the growing seasons of 1998 and 1999 at Nitra-Malanta. In both years, pea aphid populations on pea showed a pattern with one peak, culminated at flowering and pod formation. The infestation level on alfalfa was low in both years. Entomopathogenic fungi attacking the pea aphid were identified as Erynia neoaphidis Remaudičre and Hennebert and Conidiobolus obscurus (Hall and Dunn) Remaudičre and Keller. Both pathogens infected the aphid on pea, but only E. neoaphidis was found in the alfalfa plots. Infected aphids were not found on alfalfa during 1999. The maximum levels of infected aphids on pea were 10.30% and 48.39% in 1998 and 1999, respectively. During both years alate aphids were more frequently attacked than apteral ones. Correlation coefficients indicated a positive relationship between the number of infected aphids and precipitation, but this relationship was weak or moderately strong. A strong correlation was found between the number of dead aphids and number of alate aphids counted 5 to 10 days earlier.

SEASONAL ABUNDANCE OF RED AND GREEN MORPHS OF THE TOBACCO APHID (HOMOPTERA: APHIDIDAE) ON FLUE-CURED TOBACCO IN GEORGIA

1989 ◽  
Vol 24 (4) ◽  
pp. 531-538 ◽  
Author(s):  
Robert M. McPherson
Keyword(s):  
High Temperatures ◽  
Field Experiments ◽  
Aphid Population ◽  
Seasonal Abundance ◽  
Population Increase ◽  
Population Densities ◽  
Early Season ◽  
Myzus Nicotianae ◽  
Aphid Populations ◽  
Tobacco Aphid

The seasonal abundance of red and green morphs of the tobacco aphid, Myzus nicotianae Blackman, was investigated on flue-cured tobacco in Georgia during 1987–1988. The effect of tobacco transplantation date also was examined in 1988. Aphid populations peaked on tobacco in mid-June 1987, then rapidly declined following the removal of the terminal floral branch (topping). Early season samples contained both green and red morphs; however, by early June, and throughout the remainder of the season, the aphid population was almost exclusively comprised of the red morph. Similar results were obtained in 1988, although population densities were higher and peaked earlier in the early transplanting (30 March) compared to the 14 April and 28 April transplantings. Regardless of transplanting date, the red morphs began a rapid population increase about 45 days after transplantation, and this increase continued until plants were topped. Daily high temperatures exceeding 35°C did not appear detrimental to the red morphs in these field experiments.

MATING DISRUPTION FOR CONTROLLING THE CODLING MOTH, CYDIA POMONELLA (L.) (LEPIDOPTERA: TORTRICIDAE), IN ORGANIC APPLE PRODUCTION IN SOUTHWESTERN ONTARIO

1995 ◽  
Vol 127 (4) ◽  
pp. 493-505 ◽  
Author(s):  
R.M. Trimble
Keyword(s):  
Adult Male ◽  
Mating Disruption ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
The Other ◽  
Growing Seasons ◽  
Apple Production ◽  
First And Second Generation ◽  
Trap Catches ◽  
Pheromone Dispensers

AbstractSex pheromone-mediated mating disruption using Isomate-C® pheromone dispensers was evaluated as a means of controlling the codling moth, Cydia pomonella, over three consecutive growing seasons in organically managed blocks of apples at two commercial apple orchards in Ontario. The objective of the study was to determine if mating disruption could be used to stabilize or reduce the amount of damage caused by indigenous codling moth populations. The emission rate of the pheromone dispensers was estimated using volumetric and gravimetric methods. Efficacy of the pheromone treatment was assessed by comparing pheromone-baited trap catches of adult male codling moths in pheromone- and insecticide-treated blocks of apples, and by estimating damage caused by first- and second-generation codling moths in pheromone- and insecticide-treated blocks as well as in small plots of apples where the codling moth was not controlled. The estimated average release rate of pheromone varied from 22.2 to 30.3 mg per ha per h. The seasonal total number of adult male moths trapped in the pheromone-treated blocks was from 3.8 to 25.3% of the number trapped in insecticide-treated blocks; during one season at one farm, no moths were trapped in a pheromone-treated block. Treatment with pheromone did not prevent an increase in codling moth damage. At one farm, damage increased ca. 5-fold during the 3-year study. At the other farm, damage increased ca. 4-fold during two consecutive growing seasons in one block and ca. 4-fold during three consecutive seasons in the other block. At both farms there was a marked increase in the amount of damage between the first and second generations of the pest. Possible reasons for the failure of the pheromone treatment to prevent increases in codling moth damage are discussed.

scholarly journals Evaluating Winter-sown Onion Entries for Iris yellow spot virus Susceptibility

HortScience ◽  
2011 ◽  
Vol 46 (9) ◽  
pp. 1224-1229 ◽  
Author(s):  
Mohsen Mohseni-Moghadam ◽  
Christopher S. Cramer ◽  
Robert L. Steiner ◽  
Rebecca Creamer
Keyword(s):  
Iris Yellow Spot Virus ◽  
Yellow Spot ◽  
Enzyme Linked Immunosorbent Assay ◽  
Strong Positive Correlation ◽  
Spot Virus ◽  
Visual Rating ◽  
Growing Seasons ◽  
Disease Rating ◽  
Cropping Seasons ◽  
Plant Sampling

Iris yellow spot virus (IYSV) causes a foliar disease in onion (Allium cepa L.) that results in a reduction in bulb size. Currently, no IYSV-tolerant or -resistant cultivar exists and a genetic source for tolerance or resistance has not been identified. Because other disease control methods are limited, host plant resistance offers the best hope to combat this disease. In this study, 13 winter-sown onion entries were screened for iris yellow spot (IYS) symptoms during the 2007 and 2008 cropping seasons. Twenty plants from each plot were observed and rated weekly during the growing seasons for straw-colored, necrotic lesions, typical of IYSV infection. Collected plant samples were assayed for IYSV by enzyme-linked immunosorbent assay (ELISA) and reverse-transcription polymerase chain reaction (RT-PCR). Visual rating was done using a scale of 1 to 9 with 1 representing no symptomatic tissue and 9 representing more than 50% tissue damage. Two different plant sampling methods were used in disease rating to determine their effect on mean severity and to correlate disease severity with absorbance values. Of the entries tested, plants of NMSU 05-33-1 exhibited a delay in symptom expression and lower IYSV levels relative to plants of other entries. Plants of ‘Denali’ and ‘Gelma’ appeared to be more susceptible to IYSV than plants of other entries. Plant selection within the plot over time did not influence disease rating values. When the same plants were rated and sampled for IYSV using ELISA, there was a strong, positive correlation between rating and absorbance values.

scholarly journals Mating Disruption of Helicoverpa armigera (Lepidoptera: Noctuidae) on Processing Tomato: First Applications in Northern Italy

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 206 ◽  
Author(s):  
Giovanni Burgio ◽  
Fabio Ravaglia ◽  
Stefano Maini ◽  
Giovanni Giorgio Bazzocchi ◽  
Antonio Masetti ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Mating Disruption ◽  
Northern Italy ◽  
Processing Tomato ◽  
Growing Seasons ◽  
Helicoverpa Armígera ◽  
Weak Points ◽  
Fruit Damage ◽  
Trap Catches ◽  
Globally Distributed

Helicoverpa armigera is a polyphagous and globally distributed pest. In Italy, this species causes severe damage on processing tomato. We compared the efficacy of mating disruption with a standard integrated pest management strategy (IPM) in a two-year experiment carried out in Northern Italy. Mating disruption registered a very high suppression of male captures (>95%) in both growing seasons. Geostatistical analysis of trap catches was shown to be a useful tool to estimate the efficacy of the technique through representation of the spatial pattern of captures. Lower fruit damage was recorded in mating disruption than in the untreated control plots, with a variable efficacy depending on season and sampling date. Mating disruption showed a higher efficacy than standard IPM in controlling H. armigera infestation in the second season experiment. Mating disruption showed the potential to optimize the H. armigera control. Geostatistical maps were suitable to draw the pheromone drift out of the pheromone-treated area in order to evaluate the efficacy of the technique and to detect the weak points in a pheromone treated field. Mating disruption and standard IPM against H. armigera were demonstrated to be only partially effective in comparison with the untreated plots because both strategies were not able to fully avoid fruit damage.

Diversity and seasonal density of carabid beetles (Coleoptera: Carabidae) in relation to the soybean aphid in soybean crop in Québec, Canada

2012 ◽  
Vol 144 (4) ◽  
pp. 542-554 ◽  
Author(s):  
Annabelle Firlej ◽  
Annie-Ève Gagnon ◽  
Simon Laurin-Lemay ◽  
Jacques Brodeur
Keyword(s):  
Multivariate Analyses ◽  
Sampling Period ◽  
Soybean Aphid ◽  
Carabid Beetles ◽  
Pitfall Traps ◽  
Activity Density ◽  
Pterostichus Melanarius ◽  
Trap Catches ◽  
Field Location ◽  
Aphid Populations

AbstractWe studied the diversity and summer seasonal activity-density of Carabidae associated with soybean fields infested by the soybean aphid (Aphis glycinesMatsumura; Hemiptera: Aphididae) in Québec, Canada. Carabid beetles were sampled in six to seven fields from June to September 2004 and 2005 using pitfall traps. A total of 33 species from 15 genera were identified, with the exoticPterostichus melanarius(Illiger) (Coleoptera: Carabidae), representing 75.8% and 84.5% of all individuals trapped in 2004 and 2005, respectively. Large variations in species richness and diversity indexes were observed between fields within and between years. Multivariate analyses showed that carabid activity-density varied as a function of field location and sampling period, with individuals belonging to species overwintering as adults being more abundant early in the growing season. There was no relationship between carabid trap catches andA. glycinesdensity, suggesting that carabid beetles do not respond numerically to soybean aphid populations at the spatial scale studied.

Some factors influencing variability in water-trap catches of Tipula spp. (Diptera: Tipulidae)

1983 ◽  
Vol 73 (4) ◽  
pp. 693-699 ◽  
Author(s):  
R. P. Blackshaw
Keyword(s):  
Northern Ireland ◽  
Unit Area ◽  
Colour Preference ◽  
Water Trap ◽  
Factors Influencing ◽  
Water Traps ◽  
The Mean ◽  
Trap Catches

AbstractExperiments were undertaken in July and August 1982 in Northern Ireland to examine the effects of some factors which could influence the number of craneflies caught by water traps. Tipula paludosa Mg. and T. oleracea L. were caught, but the latter only in small numbers. Catches of males of T. paludosa, but not of females, decreased as the height of the trap walls increased. All catches were larger in traps of greater diameter. A significant colour preference was found for males of T. paludosa, in the order green > red > yellow > white > blue > black. Increasing the number of traps per unit area increased the mean catch per trap. It is concluded that the attraction of traps for craneflies, if any, is only slight and that the insects may descend randomly over traps so that greater numbers are caught in wide, low-walled traps. Catch is possibly greatest in green traps because of an inability of craneflies to distinguish them from grass.

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