Note on Population Densities of Spiders (Araneae) in Nova Scotia Apple Orchards

1958 ◽  
Vol 90 (2) ◽  
pp. 111-113 ◽  
Author(s):  
C. D. Dondale
Keyword(s):  
Nova Scotia ◽  
Apple Orchards ◽  
Population Densities ◽  
Sampling Device ◽  
Single Tree ◽  
A Minor

Chant (1956) has shown that spiders are common predators in apple orchards in southeast England. Dondale (1956) listed the species of spiders found in Nova Scotia orchards. This is a note on population densities in the latter orchards from 1953 to 1956.The sampling device used in this study was a cloth-covered, yard-square tray (Lord, 1956), supplemented in a minor way by a collecting umbrella. Each tray or umbrella collection represented the spiders jarred from the lower branches of a single tree, or from the lower branches of half of each of two trees.

The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. VII. Effects on Some Beneficial Arthropods

1954 ◽  
Vol 86 (3) ◽  
pp. 128-135 ◽  
Author(s):  
A. W. MacPhee ◽  
K. H. Sanford
Keyword(s):  
Nova Scotia ◽  
Natural Enemies ◽  
Apple Orchards ◽  
Beneficial Arthropods ◽  
Population Densities ◽  
Apple Trees ◽  
Arthropod Pests

The toxicities of a large number of spray chemicals to arthropod pests are well known. In most instances, observations on the effects of such materials on natural enemies have beeen incidental to other studies, and little has been published on experiments designed to determine the direct toxicities of the chemicals to beneficial species. The effects of spray chemicals on the predators and parasites of the major pests of apple trees in Nova Scotia have been investigated as part of a broader project on the factors that influence population densities of orchard arthropods, as outlined by Pickett et al. (31).

The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. VIII. Natural Enemies of the Eye-Spotted Bud Moth, Spilonota ocellana (D. & S.) (Lepidoptera: Olethreutidae)

1955 ◽  
Vol 87 (2) ◽  
pp. 79-85 ◽  
Author(s):  
H. T. Stultz
Keyword(s):  
Nova Scotia ◽  
Natural Enemies ◽  
Population Level ◽  
Apple Orchards ◽  
Large Fluctuations ◽  
Major Pest ◽  
Marked Decline ◽  
Low Levels ◽  
A Minor ◽  
Orchard Pests

The eye-spotted bud moth, Spilonota ocellana (D. & S.), has a long history as a pest in Nova Scotia apple orchards, serious damage by it being reported as early as 1891 (Fletcher, 1892). Its status has fluctuated considerably, the most notable outbreak reaching its peak in 1927. This outbreak occurred when dusts were being used for the control of orchard pests, and (Kelsall 1932) was one of the two main reasons for abandoning the general use of dusts after 1927. The bud moth declined rapidly after 1927 and by 1931 was rated a minor pest (Gilliatt, 1932a). After flutuating at relatively low levels for seven years, it increased in importance and by 1942 was again a major pest. From 1942 to 1952, there was little change in its general status although large fluctuations in population were observed in orchards in which certain insecticides had been used (Stultz, 1950). During 1953, there was a marked decline in the average population level although reductions did not occur in all orchards.

The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. XIV.: Supplement to II. Oystershell Scale, Lepidosaphes ulmi (L.)

1965 ◽  
Vol 97 (8) ◽  
pp. 816-821 ◽  
Author(s):  
A. D. Pickett
Keyword(s):  
Nova Scotia ◽  
Apple Orchards ◽  
Key Factors ◽  
Predacious Mite ◽  
Winter Temperatures

AbstractThis study confirms an earlier finding that the oystershell scale, Lepidosaphes ulmi (L.) is normally controlled in Nova Scotia apple orchards by the aphelinid Aphytis mytilaspidis Le B. and the predacious mite Hemisarcoptes malus (Shimer). The effectiveness of the former may be limited in colder areas by low winter temperatures, and both species are detrimentally affected by some spray chemicals. The evidence presented indicates that either A. mytilaspidis, or H. malus, or the two of them together, may operate as key-factors in regulating the density of oystershell scale populations.

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 Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. XI. Effects of Low Dosages of DDT on Predator Populations

1962 ◽  
Vol 94 (2) ◽  
pp. 204-216 ◽  
Author(s):  
F. T. Lord
Keyword(s):  
Population Dynamics ◽  
Nova Scotia ◽  
Prey Density ◽  
Apple Orchards ◽  
Laboratory Investigations

The varied interpretations by numerous biologists, of the role of predation in population dynamics have been critically reviewed by Holling (1959) and by Huffaker and Kennett (1956). They conclude that the processes of predation may serve to regulate prey density and disagree with generalizations that minimize the role of predation. This role has been a subject of considerable interest in recent years, notable contributions being the laboratory investigations of Collyer (1958) and Huffaker (1958), and the field studics of Holling (1959).

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.

Note on Occurrence of Agathis laticinctus (Cress.) (Hymenoptera: Braconidae) as a Parasite of the Eye-Spotted Bud Moth (Lepidoptera: Tortricidae) in Nova Scotia

1954 ◽  
Vol 86 (2) ◽  
pp. 96-98 ◽  
Author(s):  
H. T. Stultz
Keyword(s):  
Life History ◽  
Nova Scotia ◽  
Minor Importance ◽  
Research Projects ◽  
Population Densities

Agathis laticinctus (Cress.), a parasite of the eye-spotted bud moth, Spilonota ocellana (D. & S.), is of particular interest because it has only recently become the most important one attacking this pest in Nova Scotia. Sanders and Dustan ( 1919) found it of minor importance and Gilliatt (1932) did not find it worthy of mention. An account of its life-history has been given by Dondale (1954).As in most research projects of the Kentville laboratory (Pickett et al., 1946), attention has been given to the influence of spray practices on population densities of A. laticinctus.

PEST DAMAGE AND INSECT FAUNA OF NOVA SCOTIA APPLE ORCHARDS: 1953–1977

1979 ◽  
Vol 111 (9) ◽  
pp. 985-1004 ◽  
Author(s):  
C. R. MacLellan
Keyword(s):  
Nova Scotia ◽  
Insect Pests ◽  
Integrated Control ◽  
Control Program ◽  
Predator Population ◽  
Apple Orchards ◽  
Operophtera Brumata ◽  
Insect Fauna ◽  
Pest Damage ◽  
General Decline

AbstractAnnual assessments from 1953 to 1977 of insect damage to the preharvest crop in apple orchards in Nova Scotia show a general decline in injury, except for 1966–68. Laspeyresia pomonella (L.) and fruit chewing insects (chiefly Operophtera brumata (L.), Alsophila pometaria (L.), Orthosia hibisci Guenee, Lithophane spp., and Xylena spp.) caused the greatest amount of fruit damage. Dysaphis plantaginea (Pass.), Campylomma verbasci (Meyer), and Atractotomus mali (Meyer) were serious in some years. In integrated control program orchards the proportion of fruit damaged was twice that in preventative pesticide orchards. Fruit destined for processing had more injury than fruit destined for the fresh fruit market.Population levels of the major insect pests and their natural enemies were monitored regularly and gave early warning of threatening levels of pests. Generally predator population levels were high during periods of selective insecticide use but were low when widely toxic insecticides were introduced into the integrated control program.

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).

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