scholarly journals Cumulative vector intensity and seed potato virus infection in Hungary

Author(s):  
Z. Basky

Aphids were collected by Moericke yellow pan traps placed in the potato fields. The cumulative vector intensity is an index that describes the vector abundance and their propensity to transmit PVY (3). The vector intensity was obtained as the number of known PVY vector species caught and multiplied by their relative vector efficiency value. Cumulative vector intensity for the season was calculated by accumulating species-specific vector intensity values at each trapping date. In those places where the number of PVY vectors caught by yellow pan traps were the highest (1194, 1495 and 663, 570, respectively), the cumulative vector intensity was also the highest (322 and 570, respectively). This high vector intensity resulted in high progeny tuber infection 21 and 31 %, respectively. In those years when the cumulative vector intensity did not reach the value of 10 until the end of June and the beginning of July the proportion of PVY infected progeny tubers met the requirements of the standard, it was less than 5 %. The cumulative vector intensity seems to be a reliable way to forecast virus threat to seed potato. Both seasonal variation and vector abundance is reflected in cumulative vector intensity, above all propensity of different vector species is included in the calculation. As the virus translocation from leaves to tubers takes 12-14 days. Therefore it is imperative that immediately after weekly trap catches cumulative vector intensity values are calculated, as when values reach around ten growers in seed potato growing region will have 12 days to execute killing leaves and stems of seed potatoes.

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Göran Birgersson ◽  
Mark J. Dalusky ◽  
Karl E. Espelie ◽  
C. Wayne Berisford

Hindgut volatiles from attacking, unmated males ofIps avulsus, I. calligraphus, I. grandicollis, andI. piniwere analyzed by combined gas chromatography and mass spectrometry. Based on the quantitative identifications of hindguts and subsequent individual aerations, baits were formulated and a combined species-specific subtractive field bioassay was set up for the four bark beetle species. The bioassays were subtractive for the compounds identified in the hindgut analysis of each species, and volatiles identified in sympatric species were added as potential inhibitors alone and in combination. The trap catches from this bioassay revealed strong interspecific inhibition. The subtractive assays showed thatI. grandicollisandI. calligraphusshare (–)-(4S)-cis-verbenol as one pheromone component, while their second, synergistic pheromone component, (–)-(S)-ipsenol inI. grandicollisand (±)-ipsdienol inI. calligraphus, acts as an interspecific inhibitor to the other species.I. avulsusandI. piniwere found to have very similar production of hindgut volatiles, and both use ipsdienol and lanierone as synergistic pheromone components. No beetle-produced interspecific inhibitor was identified between these two species. Lanierone was found to be an interspecific inhibitor for bothI. calligraphusandI. grandicollis.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1022
Author(s):  
Clarissa D. Guerrero ◽  
Steven Hinojosa ◽  
Diana Vanegas ◽  
Niko Tapangan ◽  
Matthew Guajardo ◽  
...  

From 2016 to 2018, Hidalgo County observed the emergence of Zika virus (ZIKV) infections along with sporadic cases of Dengue virus (DENV) and West Nile virus (WNV). Due to the emergence of ZIKV and the historical presence of other mosquito-borne illnesses, Hidalgo County obtained funding to enhance mosquito surveillance and educate residents on arboviruses and travel risks. During this time period, Hidalgo County mosquito surveillance efforts increased by 1.275%. This increase resulted in >8000 mosquitoes collected, and 28 mosquito species identified. Aedes aegypti, Ae albopictus and Culex quinquefasciatus made up approximately two-thirds of the mosquitoes collected in 2018 (4122/6171). Spatiotemporal shifts in vector species composition were observed as the collection period progressed. Significantly, temperature variations (p < 0.05) accounted for associated variations in vector abundance, whereas all other climate variables were not significant.


1982 ◽  
Vol 114 (2) ◽  
pp. 145-154 ◽  
Author(s):  
G. L. Ayre ◽  
W. J. Turnock ◽  
D. L. Struble

AbstractTests of intertrap variability in catches of moths of the clover cutworm, Scotogramma trifolii (Rottenberg), were conducted by placing two traps baited with an artifical sex attractant at 1 mi (1.6 km) intervals to form a grid covering 25 mi2 (64 km2) near Domain, Manitoba. The 50 traps (2/location) placed near the intersects of the grid were baited with a blend of Z-11-hexadecen-1-yl acetate and Z-11-hexadecen-1-ol. This blend was 98.6% species-specific for S. trifolii. Moth catches varied between traps and flights, but the ranking of the traps by catch was consistent during any given flight period. Up to 35 traps would be required within an area of 64 km2 (1 trap/1.8 km2) to give a population estimate within 20% of the true mean. Temperature influenced both the initiation of the flights and the number of moths caught at any given time, but there were no correlations between flights and precipitation or wind. Crop type influenced catches of S. trifolii only when moth populations were large. The catch of second generation moths averaged 9.8× the catch of first generation moths. The consistency of this relationship indicates that the annual differences in population density are controlled by variations in winter survival. The latter was linked to the induction of diapause which is governed by daylength during the larval development of the second generation.


1999 ◽  
Vol 89 (3) ◽  
pp. 218-225 ◽  
Author(s):  
C. M. Stiles ◽  
P. V. Oudemans

A survey was conducted over a 3-year period to determine the frequencies and distributions of fruit-rotting fungi in New Jersey cranberry beds. In the first 2 years of the study, Physalospora vaccinii and Glomerella cingulata were the most prevalent and widespread field-rotting fungi. In the third year, the frequency of G. cingulata declined markedly. Other species such as Coleophoma empetri, Phyllosticta vaccinii, and Phomopsis vaccinii were isolated at high frequencies from a limited number of locations. Storage-rotting fungi including Allantophomopsis cytisporea and A. lycopodina were isolated at low frequencies, but were widely distributed within the growing region. On sound fruit, a somewhat different profile emerged. Fungi such as Phyllosticta elongata, Alternaria spp., and Physalospora vaccinii were commonly isolated. In comparisons among different cranberry cultivars, no differences in the fungal profiles were seen. This was interpreted to indicate that if differences in fruit-rot resistance exist, they are likely to be general forms of resistance rather than fungal species-specific mechanisms.


1982 ◽  
Vol 114 (11) ◽  
pp. 993-1001 ◽  
Author(s):  
G. L. Ayre ◽  
W. J. Turnock ◽  
D. L. Struble

AbstractTests of intertrap variability in catches of moths of the darksided and redbacked cutworms, Euxoa messoria (Harris) and E. ochrogaster (Guenée), were conducted by placing two traps for each species baited with synthetic sex attractants at 1.6 km (1 mi) intervals to form a grid covering 64 km2 (25 mi2) near Domain, Manitoba. These sex attractants were 93 and 99.6% species specific for E. messoria and E. ochrogaster respectively. Moth catches varied between traps and flights, but the ranking of the traps by catch for each species was consistent during any given flight period. Variability in intertrap catches of E. messoria indicated the moths were not evenly distributed throughout the test area and consequently a sex-attractant trap system with 1.6 km trap spacing is not suitable for monitoring population levels. For E. ochrogaster four traps within an area of 64 km2 would be required to give a population estimate within 20% of the true mean. The flights of E. messoria are not related to degree days and started abruptly and at the same time each year suggesting that development may be synchronized by the summer diapause of the prepupae. The flights of E. ochrogaster were related to degree day accumulations above a threshold temperature of 12.5 °C. Crops had no apparent influence on the distribution of moth catches for either species.


2017 ◽  
Vol 150 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Robert J. Lamb ◽  
Guy Boivin

AbstractLong-term trap catches of seedcorn maggot, Delia platura (Meigen), onion maggot, Delia antiqua (Meigen), and cabbage maggot, Delia radicum (Linnaeus) (Diptera: Anthomyiidae), were used to test the hypothesis that related species have more similar population variability than unrelated ones. Annual abundance was estimated from trap catches for 32 years (two species) or 17 years (one species). Population variability was quantified as PV, a proportion between 0 and 1. The three Delia Robineau-Desvoidy species had PV values of 0.51–0.55 that did not differ significantly. These PV values were found to differ significantly from two unrelated species studied over the same time period in the same habitat, which had PV values of 0.39 and 0.67. The hypothesis that related species have more similar population variabilities than unrelated species in the same habitat was supported. These data strengthen the view that PV is a species-specific trait reflecting the adaptation of life histories to their habitat, with related species showing more similar adaptations than unrelated species. The polyphagous and saprophagous seedcorn maggot had PV similar to the two oligophagous herbivores, casting doubt on the hypothesis that more generalist feeders have less variable populations than more specialised feeders.


2020 ◽  
Vol 50 (12) ◽  
pp. 1399-1404 ◽  
Author(s):  
Delaney R. Brooks ◽  
Joseph J. Nocera

Bumble bees (species of Bombus Latreille, 1802) are important pollinators that are generally in population decline, but species presence and relative abundance are unknown in forested wetlands of the Acadian forest. To address this knowledge gap, we sampled bumble bees in forested wetlands and harvested sites (clearcuts) using vane and pan traps. We collected 617 specimens representing 11 species. We also included observations from iNaturalist (n = 70) in disturbed sites. We found that species-specific abundance in Acadian forested wetlands differed significantly from that in harvested sites. Wet coniferous forests with moderate to high herbaceous cover had greater overall bumble bee abundance than harvest sites. Species interactions may also influence community structure: sites with higher abundance of Bombus borealis Kirby, 1837 and B. ternarius Say, 1837 had fewer B. fervidus (Fabricius, 1798); B. flavidus Eversmann, 1852; and B. terricola Kirby, 1837. Differences in presence and abundance of bumble bee species may be explained by forested wetlands having a greater variety of flowering plants than forest harvest sites.


Parasitology ◽  
1992 ◽  
Vol 104 (2) ◽  
pp. 273-281 ◽  
Author(s):  
M. Koskivaara ◽  
E. T. Valtonen ◽  
K.-M. Vuori

SUMMARYThe Dactylogyrus fauna was studied from the gills of 293 roach between February 1988 and April 1989. Roach were caught from three interconnected lakes in Central Finland. Nine Dactylogyrus species were found. Of these the seven most abundant were used for studying the abundance of species on different gill-arches, niche breadth and niche overlap between the species. It was found that all species had a species-specific preference for certain gill-arches. The total abundances of all the species went through distinct seasonal changes, peaking during the spring and early summer. Some seasonal variation was also exhibited in gill-arch preferences. Niche breadth and species overlap were mostly higher during the period of peak occurrence of the various species, but in the case of some species they appeared to be unrelated to abundance, indicating possible niche restriction by other species. Most significant was the restriction of D. micracanthus to the fourth gill-arch during the period of peak occurrence of D. similis. Experimental work is needed to verify the reasons for variations in the microhabitat distribution of certain Dactylogyrus species.


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