SEX RATIO OF THE EUROPEAN RED MITE, PANONYCHUS ULMI (ACARINA: TETRANYCHIDAE), IN APPLE ORCHARDS IN NOVA SCOTIA

1975 ◽  
Vol 107 (8) ◽  
pp. 825-828 ◽  
Author(s):  
H. J. Herbert ◽  
K. P. Butler
Keyword(s):  
Nova Scotia ◽  
Population Density ◽  
Sex Ratio ◽  
First Generation ◽  
Panonychus Ulmi ◽  
Apple Orchards ◽  
Male And Female ◽  
Average Percentage ◽  
European Red Mite ◽  
Different Levels

AbstractThe number of male and female first generation Panonychus ulmi (Koch) were recorded from 13 apple orchards representing widely different levels of mite infestation on four different varieties. The average percentage of males was 27.5. Statistically significant differences were found among orchards, varieties, observers, and their interactions. No relationship between sex ratio and population density was evident.

THE INFLUENCE OF SPRAY PROGRAMS ON THE FAUNA OF APPLE ORCHARDS IN NOVA SCOTIA: XX. TRENDS AFTER ALTERING LEVELS OF PHYTOPHAGOUS MITES OR PREDATORS

1970 ◽  
Vol 102 (5) ◽  
pp. 592-601 ◽  
Author(s):  
K. H. Sanford ◽  
H. J. Herbert
Keyword(s):  
Nova Scotia ◽  
Apple Orchard ◽  
Typhlodromus Pyri ◽  
Panonychus Ulmi ◽  
Apple Orchards ◽  
Direct Effects ◽  
Phytophagous Mites ◽  
European Red Mite ◽  
Predacious Species

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.

Effects of Increasing the Nitrogen Level of Apple Leaves on Mite and Predator Populations

1961 ◽  
Vol 93 (10) ◽  
pp. 924-927 ◽  
Author(s):  
F. T. Lord ◽  
D. K. R. Stewart
Keyword(s):  
Nova Scotia ◽  
Population Balance ◽  
Panonychus Ulmi ◽  
Nitrogen Level ◽  
Economic Damage ◽  
Apple Orchards ◽  
Apple Leaves ◽  
European Red Mite ◽  
Major Pest ◽  
Predacious Species

Prior to 1950 the European red mite, Panonychus ulmi Koch, was a major pest in Nova Scotia apple orchards, and brown mite, Bryobia arborea M. and A., was practically non-existent. Lord (1949), showed that the sulphur fungicides, commonly in use up to that time, were detrimental to some of the predacious species and toxic to the brown mite. After 1950 red mite populations became negligible and, although the brown mites increased, they did not become sufficiently abundant to cause economic damage. This shift of population balance in Nova kotia orchards has been attributed to the gradual replacement of sulphur and other detrimental materials by pesticides less harmful to predators of the mites (Pickett 1953).

THE INFLUENCE OF SPRAY PROGRAMS ON THE FAUNA OF APPLE ORCHARDS IN NOVA SCOTIA: XIX. APPLE RUST MITE, VASATES SCHLECHTENDALI, A FOOD SOURCE FOR PREDATORS

1969 ◽  
Vol 101 (1) ◽  
pp. 62-67 ◽  
Author(s):  
H. J. Herbert ◽  
K. H. Sanford
Keyword(s):  
Nova Scotia ◽  
Food Source ◽  
Panonychus Ulmi ◽  
Apple Orchards ◽  
Common Food ◽  
European Red Mite ◽  
Adequate Food ◽  
Alternate Food ◽  
The Common ◽  
Selective Chemical

AbstractMaintenance of predacious arthropods in apple orchards requires both the judicious use of chemical sprays and the presence of adequate food supplies. When the common food source, the European red mite, Panonychus ulmi (Koch), is depleted by either a selective chemical, such as Animert V-101, or by excessive activity of the predators, the apple rust mite, Vasates schlechtendali (Nal.), if present, provides an alternate food. This enables survival of sufficient numbers of predators to prevent resurgence of the red mite within the same season.

Effects of phytoseiid predators on the sex ratio of the spider mite Panonychus ulmi

1991 ◽  
Vol 69 (1) ◽  
pp. 208-212 ◽  
Author(s):  
Dan L. Johnson ◽  
Heather C. Proctor
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Spider Mite ◽  
Total Population ◽  
Panonychus Ulmi ◽  
Encounter Rate ◽  
Male Mortality ◽  
Adult Sex Ratio ◽  
Biased Sex Ratio ◽  
Male Activity

The effect of predator presence on the adult sex ratio of a spider mite (Panonychus ulmi) was examined in a field experiment. Phytoseiid predators (chiefly Typhlodromus occidentalis) were removed from 32 trees harboring P. ulmi populations, and allowed to remain at natural levels on 32 other trees. Both total population density and proportion of males in the prey population were significantly higher in predator-free trees. Mechanisms that could explain the increase in the proportion of males are examined. The most probable is that greater male activity results in a higher encounter rate between predator and prey, and that subsequent higher male mortality when predators are present exaggerates the female-biased sex ratio. The theoretical effects of sex-biased predation on diplo-diploid and haplo-diploid organisms are discussed.

SAMPLING SYSTEMS FOR EUROPEAN RED MITE, PANONYCHUS ULMI (ACARINA: TETRANYCHIDAE), EGGS ON APPLE IN NOVA SCOTIA

1973 ◽  
Vol 105 (12) ◽  
pp. 1519-1523 ◽  
Author(s):  
H. J. Herbert ◽  
K. P. Butler
Keyword(s):  
Nova Scotia ◽  
Apple Orchard ◽  
Panonychus Ulmi ◽  
Population Estimates ◽  
Population Densities ◽  
European Red Mite ◽  
Tree Population ◽  
Sampling Systems ◽  
Mature Apple ◽  
Whole Tree

AbstractA study was conducted in a mature apple orchard in Nova Scotia to compare the density of eggs of the European red mite, Panonychus ulmi (Koch), over the whole tree to their density on a selected area using a random selection and standard selection technique. Both methods provided nearly equivalent estimates of population densities for generations 2 and 4 but not for generation 3. The population estimates based on sampling from the selected area overestimated the whole tree population.Optimum allocation of sampling resources may be obtained by sampling a small number of clusters from each of a large number of trees.

The Role of Predators and Other Biotic Agents in Regulating the Population Density of Phytophagous Mites in Ontario Peach Orchards

1966 ◽  
Vol 98 (8) ◽  
pp. 808-820 ◽  
Author(s):  
W. L. Putman ◽  
D. H. C. Herne
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Tetranychus Urticae ◽  
Considerable Extent ◽  
Panonychus Ulmi ◽  
Apple Orchards ◽  
Rapid Population Growth ◽  
One Year ◽  
Heavy Mortality

AbstractMore than 40 species of insects and arachnids attack Panonychus ulmi (Koch), Tetranychus urticae Koch, T. canadensis (McGregor), Bryobia arborea Morgan and Anderson, or Aculus cornutus (Banks) in peach orchards of the Niagara Peninsula. The most effective predators attacking P. ulmi are Typhlodromus caudiglans Schuster, Haplothrips faurei Hood, Stethorus punctillum Weise, and Chrysopa spp. Peach orchards lack the predatory mirids characteristic of apple orchards. A condition, presumably disease, caused heavy mortality in one year. Endemic densities of P. ulmi are maintained in that state by predators, chiefly T. caudiglans, that subsist to a considerable extent on other sources of food, whereas epidemics of P. ulmi are reduced largely by other predators, chiefly H. faurei and S. punctillum, that increase in numbers by feeding on the mite during its period of rapid population growth but exert their greatest effect later in the season by destroying the winter eggs.

THE EGG AND OVIPOSITION SITE OF DERAEOCORIS NEBULOSUS (HEMIPTERA: MIRIDAE) ON APPLE TREES

1980 ◽  
Vol 112 (5) ◽  
pp. 527-528 ◽  
Author(s):  
J. P. McCaffrey ◽  
R. L. Horsburgh
Keyword(s):  
Panonychus Ulmi ◽  
Oviposition Site ◽  
Pest Species ◽  
Apple Orchards ◽  
Apple Trees ◽  
European Red Mite ◽  
Important Pest ◽  
Ornamental Trees ◽  
Trees And Shrubs ◽  
Oviposition Sites

The predaceous mirid Deraeocoris nebulosus (Uhler) is found on more than 50 species of ornamental trees and shrubs where it feeds on several important pest species (Wheeler et al. 1975). It is a common mite and aphid predator in commercial apple orchards in Virginia (Parrella et al. 1978). Wheeler et al. (1975) described the nymphal stages and biology, but made no mention of the egg or oviposition site. We describe the egg and oviposition site which we discovered while studying various predators of the European red mite, Panonychus ulmi (Koch), in Virginia apple orchards. Eggs and oviposition sites of other predaceous mirids associated with apple have been described (Kullenberg 1942; Collyer 1952, 1953; Sanford 1964; Horsburgh and Asquith 1968, 1970).

LIMITS OF EACH STAGE IN POPULATIONS OF THE EUROPEAN RED MITE, PANONYCHUS ULMI

1970 ◽  
Vol 102 (1) ◽  
pp. 64-68 ◽  
Author(s):  
H. J. Herbert
Keyword(s):  
Nova Scotia ◽  
Panonychus Ulmi ◽  
European Red Mite ◽  
Seasonal History ◽  
Mite Mortality

AbstractField populations of the European red mite, Panonychus ulmi (Koch), in Nova Scotia were separated into eggs, larvae, protonymphs, deutonymphs, and adults and the length of time each stage was present for each generation was determined in 1967 and 1968. The duration of each generation was similar in both years, although the diapause eggs hatched later in 1967 than in the succeeding year. Detailed information on the seasonal history is necessary in assessing red mite mortality and in timing of chemical controls of this pest.

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