Relations between Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae) and Phytophagous Mites in Ontario Peach Orchards

1964 ◽  
Vol 96 (7) ◽  
pp. 925-943 ◽  
Author(s):  
Wm. L. Putman ◽  
D. H. G. Herne

AbstractIn peach orchards undisturbed by pesticides and where phytophagous mites were at endemic densities, spring populations of Typhlodromus caudiglans were small and remained so during early summer until phytophagous mites, especially Aculus cornutus, began to increase. T. caudiglans reached maximal densities in September. In such orchards T. caudiglans appears to be an important factor in maintaining Panonychus ulmi at low density levels. On trees where DDT applied the previous year had caused P. ulmi to build up and which could be repopulated by T. caudiglans from neighbouring trees, the predator increased very rapidly but appeared to reach an upper limit of density fixed by intrinsic factors, possibly cannibalism. Under these conditions T. caudiglans could not bring P. ulmi to endemic densities in one season, though it appeared to slow the mite’s rate of increase and to reduce its maximal seasonal density.

2011 ◽  
Vol 33 (3) ◽  
pp. 765-773 ◽  
Author(s):  
Carla Rosana Eichelberger ◽  
Liana Johann ◽  
Fernanda Majolo ◽  
Noeli Juarez Ferla

Despite the importance of peach (Prunus persica (L.) Batsch) in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836) and Mononychellus planki (McGregor, 1950) were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904) the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43) when compared to Eldorado (H' 0.53; EqJ 0.40). In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939), T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and January and high predator diversity was observed on associated plants and on peach plants, indicating the existence of species mobility in peach orchard.


1962 ◽  
Vol 94 (11) ◽  
pp. 1222-1227 ◽  
Author(s):  
R. S. Downing

In British Columbia the control of phytophagous mites, especially the European red mite, Panonychus ulmi (Koch), and the McDaniel spider mite, Tetranychus mcdanieli McG., is becoming increasingly difficult, mainly because of the mites' ability to develop resistance to most acaricides in a relatively short time (3). Because of this, methods of control other than strictly chemical are examined at every opportunity.


1960 ◽  
Vol 40 (1) ◽  
pp. 198-201 ◽  
Author(s):  
Wm. L. Putman ◽  
D. C. Herne

Numbers of the European red mite (Panonychus ulmi Koch) increased but those of the brown mite (Bryobia arborea Morgan & Anderson) and the peach silver mite (Vasates cornutus Banks) decreased after sprays of Sevin (N-methyl-1-naphthyl carbamate) were applied to peach trees. Sevin practically eliminated the predacious mite Typhlodromus rhenanus Oudms., and larvae and pupae of Stethorus punctillum Weise, and greatly reduced the numbers of adults of S. punctillum, chrysopid larvae, and spiders.


1973 ◽  
Vol 134 (2) ◽  
pp. 531-537 ◽  
Author(s):  
L. L. Rudel ◽  
J. M. Felts ◽  
M. D. Morris

1. The appearance of exogenous cholesterol in free cholesterol and ester cholesterol of plasma chylomicra, very-low-density (VLD), low-density (LD) and high-density (HD) lipoproteins was studied in unanaesthetized rabbits after ingestion of a meal containing 5% fat and 0.08% [3H]cholesterol. 2. The specific radioactivity of ester cholesterol of VLD lipoproteins reached the highest value of any lipoprotein fraction and for each lipoprotein it increased at a faster rate and reached a higher maximum than that of free cholesterol; the maximum in VLD lipoproteins occurred later than in chylomicra. 3. The pattern of appearance of exogenous cholesterol in chylomicra and VLD lipoproteins of plasma was similar to the pattern previously observed in lymph. The specific radioactivity of ester cholesterol in plasma VLD lipoproteins was higher than that in chylomicra in spite of a larger pool size and dilution of cholesteryl esters from VLD lipoproteins produced by the liver. These results support the concept that during absorption the major portion of exogenous cholesterol is transported in VLD lipoproteins as ester cholesterol. 4. The specific radioactivity of ester cholesterol of chylomicra and VLD lipoproteins increased at a faster rate than that of LD and HD lipoproteins. However, the rate of increase and the absolute values of the specific radioactivity in LD and HD lipoproteins were identical. Since cholesteryl esters are thought not to exchange between lipoproteins, this observation supports the hypothesis that a result of VLD lipoprotein and chylomicron metabolism is the formation of LD and HD lipoproteins. 5. Results in vivo showed that the free cholesterol of individual plasma lipoproteins does not equilibrate within a period of 24h.


Plant Disease ◽  
2015 ◽  
Vol 99 (4) ◽  
pp. 467-473 ◽  
Author(s):  
N. Lalancette ◽  
K. A. McFarland ◽  
A. L. Burnett

The ability of the QoI fungicide trifloxystrobin to reduce production of conidia by Fusicladium carpophilum on twig lesions was quantitatively assessed over a 3-year period from 2005 through 2007. Four annual treatment programs, consisting of two consecutive trifloxystrobin applications at pink + bloom, bloom + petal fall, and petal fall + shuck-split, plus a single application timing at petal fall, were examined in a ‘Redgold’ nectarine orchard harboring high levels of overwintering scab lesions. Sporulation potential, the ability of twig lesions to produce conidia under optimum environmental conditions, was subsequently assessed five to six times during each spring and early summer. In each year of the study, all four treatments significantly reduced the area under the sporulation curve or peak sporulation. The petal fall + shuck-split program provided the greatest antisporulant activity, reducing conidia production at peak sporulation by 82 to 92%. Furthermore, examination of results over the 3-year period showed that the programs significantly slowed the annual rate of increase in peak sporulation; however, none of the programs completely halted or caused a decline in the annual rate. Although no fungicide was applied after the treatment programs, results from fruit disease assessments showed that these programs, applied as much as 3 months earlier, significantly reduced disease incidence and, in particular, disease severity. A comparison of four QoI fungicides in 2008 indicated that trifloxystrobin and azoxystrobin provided the most control of fruit scab, while pyraclostrobin + boscalid and fluoxastrobin yielded minimal or no benefit. Results of this study demonstrate that certain QoI fungicides, in particular trifloxystrobin and azoxystrobin, can probably improve the efficacy of current protectant programs used for peach scab control by providing season-long control of F. carpophilum sporulation on twig lesions. Such program enhancement may be critical when orchards have high inoculum levels and/or environmental conditions are very favorable to disease development.


1970 ◽  
Vol 102 (5) ◽  
pp. 592-601 ◽  
Author(s):  
K. H. Sanford ◽  
H. J. Herbert

AbstractUtilizing the knowledge of their direct effects, the materials ryania, carbaryl, and Animert V-101 applied to a uniformly distributed population of the European red mite, Panonychus ulmi (Koch), altered the populations in plots in an apple orchard. Trends after treatment in both host mite and predator populations were assessed. Supplementary applications of the acaricides Animert V-101 or dicofol directed against certain generations of P. ulmi controlled outbreaks and altered the faunal levels during the following season. Ryania was largely innocuous to most species of predators with the exception of Atractotomus mali (Meyer) and Diaphnocoris spp., carbaryl was detrimental to most predacious species, and Animert V-101, while selectively toxic to phytophagous mites, was innocuous to all predacious insects and Typhlodromus pyri Scheuten.Phytophagous mite populations may be altered to almost prescribed levels with pesticides when the predator populations are known. This allows selective chemicals to be used to complement the predator effect and maintain red mites below the threshold of damage.


1973 ◽  
Vol 105 (2) ◽  
pp. 271-276 ◽  
Author(s):  
H. J. Herbert ◽  
K. P. Butler

AbstractThe relative densities of phytophagous and predacious mites within mature apple trees were examined. The eggs of phytophagous mites Aculus schlechtendali (Nal.) and Panonychus ulmi (Koch) were more numerous in the lower position of the tree while the reverse was true for the predacious mite Zetzellia mali (Ewing) and its eggs.


1961 ◽  
Vol 93 (5) ◽  
pp. 380-384 ◽  
Author(s):  
H. J. Herbert

The predacious mites of the subfamily Phytoseiinae are common predators of the phytophagous mites in apple orchards in Nova Scotia. There is little information in the literature on the value of these predators in the control of phytophagous mites or on the food necessary for their development and reproduction. Ballard (1953) found that at 78°F. at least two males of Tetranychus bimaculatus Har. were required daily by Typhlodroms fallacis (Garm.) to complete the protonymphal or the deutonymphal instar. The males and mated females consumed daily an average of 3.9 and 7.5 males respectively from the larva1 to the adult stage. Chant (1960) found that T. pyri required 25 larvae of Panonychus ulmi (Koch), during 26 days to complete development at 64°F. in the absence of plant material or free water. These authors did not study the effects of different amounts of food on the development of these two species of phytoseiids.


1967 ◽  
Vol 99 (7) ◽  
pp. 771-778 ◽  
Author(s):  
B. Parent

AbstractEcological studies, undertaken to determine the fluctuations of phytophagous mites and predators in apple orchards, were conducted in 1955, 1956, and 1957 at Rougemont, Que., in two plots sprayed only with fungicides for the control of apple scab, Venturia inaequalis (Cke) Wint., and in a third one sprayed, in addition to fungicides, with all insecticides needed for the control of destructive insects. Phytophagous mites were more numerous in the plot sprayed with insecticides than in plots sprayed only with fungicides, and densities of the mites in the latter plots were inversely proportional to densities of predators. A similar relationship existed in the insecticide plot between the amount of chemicals used and numbers of predators present. The principal mite predators were Typhlodromus rhenanus (Oudms.), most effective against the two-spotted spider mite, Tetranychus urticae Koch, and Mediolata mali (Ewing), most effective against the European red mite, Panonychus ulmi (Koch).


Author(s):  
R. V. Borovskaya ◽  
S. S. Zhugaylo ◽  
D. O. Krivoguz ◽  
V. A. Shlyakhov ◽  
◽  
...  

The paper studies the ecosystem of the Eastern Sivash in the context of natural and anthropogenic influence. The data collected during the expedition of the Azov-Black Sea Branch of the FSBSI “VNIRO” conducted in early summer 2020 were used as original empirical evidence. Specific features of hydrological and hydrochemical conditions, as well as species composition, distribution, and abundance of ichthyoplankton were indicated. It was shown that the values of pH, nitrates, nitrites, and phosphates did not exceed MPCs established for fishery water bodies within the entire water area under study; the range of dissolved oxygen content was wide: 3.63–9.13 mg/dm3 . By comparison of the environmental status of the biocoenoses during early summer 2020 with the data collected during a similar survey in 2019, it was found that the water temperature at site 4 is lower by 1.9–2.7 °C. Further salinization of the Sivash was recorded: the lowest salinity in 2019 ranged within 32–38 ‰ and the highest one ranged within 83–86 ‰; in 2020, these values were 36–43 ‰ and 91–97 ‰, respectively. In terms of spatial distribution, the range of the increase in salinity was 4.36–16.69 ‰, with the highest value being recorded at site 2 (11.51–16.69 ‰) and the eastern part of site 3 (13.22 ‰). To a lesser extent (by 4.36–6.26 ‰), an increase in salinity was recorded at site 4 and the western part (5.27 ‰) of site 3. The results of plankton net surveys showed that ichthyoplankton was represented almost exclusively by larvae of big-scale send smelt, which had the densest distribution at site 1 at a salinity of 89 ‰, and on the border between sites 2 and 3 at a salinity of 74 ‰. The upper limit of salinity at which this fish reproduction is possible lies within the range 75–90 ‰. The absence of so-iuy mullet eggs and juveniles at a salinity higher than 32–36 ‰ in May – June of 2019–2020 during the peak of so-iuy mullet spawning does not provide a reason to include the Sivash Bay among the Azov Sea areas important for reproduction of this fish species


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