The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. VI. Low Temperatures and the Natural Control of the Oystershell Scale, Lepidosaphes ulmi (L.) (Homoptera: Coccidae)

1953 ◽  
Vol 85 (8) ◽  
pp. 282-291 ◽  
Author(s):  
F. T. Lord ◽  
A. W. MacPhee
Keyword(s):  
Nova Scotia ◽  
Low Temperatures ◽  
Marked Effect ◽  
Insect Control ◽  
Control Problems ◽  
Apple Orchards ◽  
Natural Control ◽  
Ecological Principles

Some of the results of an attempt to apply ecological principles in the solution of apple insect control problems in Nova Scotia have been given in previous papers by Pickett et al. (1946), Lord (1947, 1949), Pickett (1952), and MacPhee (1952). Briefly, these studies aim at an understanding of the changes in the interrelations of the species in an orcl-lard when spray materials are added to the environment. The emphasis to date has heen placed on the effects of spray chemicals on the populations of entomophagous species. The results of this work have already had a marked effect on orchard insect control practices in Nova Scotia.

The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. XIII. Effects of Perthane on Predators

1962 ◽  
Vol 94 (9) ◽  
pp. 928-934 ◽  
Author(s):  
K. H. Sanford ◽  
F. T. Lord
Keyword(s):  
Nova Scotia ◽  
Natural Enemies ◽  
Apple Orchards ◽  
Natural Control ◽  
Predator Prey ◽  
Phytophagous Mites ◽  
Ecological Principles ◽  
Apple Pests

In Nova Scotia, a spray program that integrates chemical and natural control of apple pests has been evolved which is both economical and satisfactory. Among the natural enemies of injurious arthropods that have been favoured by this program are a number of general predators. Further investigation of the ecological principles on which integration is based requires a more intensive knowledge of the factors that influence the densities of these predators. Because of the difficulties of investigating these factors in the orchard, methods of simplifying the predator-prey systems have been sought (Lord, 1956, 1962). These attempts assessed the effects of low dosages of DDT on the interrelationships of phytophagous mites and their natural enemies.

The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. V. The Predacious Thrips Haplothrips faurei Hood

1953 ◽  
Vol 85 (1) ◽  
pp. 33-40 ◽  
Author(s):  
A. W. MacPhee
Keyword(s):  
Nova Scotia ◽  
Oriental Fruit Moth ◽  
Minor Importance ◽  
Apple Orchards ◽  
Natural Control ◽  
Grapholitha Molesta ◽  
Economic Significance ◽  
European Red Mite ◽  
History Of ◽  
Mite Eggs

Lord (1949) listed the predators of the European red mite, Metatetranychus ulmi (Koch.), in Nova Scotia and described the effects of a number of chemicals on them. Among the more important predators is the thrips Haplothrips faurei Hood. This thrips, however, does not confine its feeding to European red mite eggs but readily attacks the eggs of many other mites and insects. There is strong evidence that it is one of the most important biotic factors in the natural control of insect and mite pests in Nova Scotia apple orchards. It and another species, Leptothrips mali (Fitch), are the only thrips of economic significance, and H. faurei, because of its greater numbers, is the more important. A description of the life-history of L. mali was given by Bailey (1940), who also (1939) studied the biology of another thrips, Scolothrips sexmaculatus (Perg.), which is of minor importance in Nova Scotia. The only other predacious thrips found is a species bclieved to be Zygothrips minutus Uzel, which occurs only rarely and in small numbers. Haplothrips subtilissimus Hal. (later identified as H. faurei), was found by Putman (1942) in Ontario to be predacious on phytophagons mites and the eggs of oriental fruit moth, Grapholitha molesta Busck.

Cold-Hardiness, Habitat and Winter Survival of Some Orchard Arthropods in Nova Scotia

1964 ◽  
Vol 96 (4) ◽  
pp. 617-625 ◽  
Author(s):  
A. W. MacPhee
Keyword(s):  
Nova Scotia ◽  
Air Temperature ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Winter Survival ◽  
Kings County ◽  
Winter Conditions ◽  
Cold Hardy

AbstractIn Kings County, Nova Scotia, low temperatures in the coldest nights of winter can differ by as much as 10°F. from one area to another. This has an important bearing on winter survival of some arthropods. Overwintering sites of orchard arthropods range from exposed situations which remain at air temperature to well protected ones on the ground where temperatures rarely go below 20°F. The cold-hardiness of each of 24 species of arthropods was measured: seven were sufficiently cold-hardy to survive any winter conditions in Nova Scotia, five were less cold-hardy but overwinter in well protected sites and twelve had marginal cold-hardiness, their mortality varying with the winter and the locality.

NATURAL CONTROL OF THE GREY BANDED LEAF ROLLER EULIA MARIANA FERN, IN NOVA SCOTIA ORCHARDS

1937 ◽  
Vol 69 (7) ◽  
pp. 145-146
Author(s):  
F. C. Gilliatt
Keyword(s):  
Nova Scotia ◽  
Natural Control ◽  
Leaf Roller ◽  
Control Factors ◽  
Annapolis Valley ◽  
Orchard Pests

Eulia mariana Fern. was identified in Annapolis Valley orchards about twelve years ago and since has become one of the major orchard pests. Although outbreaks continue to occur, fruit growers should fully appreciate the value of natural control, which in one form or another is always assisting in keeping this insect in check. The various natural control factors may be recorded as follows:(1) Mortality of pupae. (2) Parasites of larvae and pupae. (3) Parasites of eggs. (4) Predators.

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.

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.

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.

NATURAL CONTROL OF HEMLOCK SAWFLY, NEODIPRION TSUGAE (HYMENOPTERA: DIPRIONIDAE), POPULATIONS IN SOUTHEAST ALASKA

1976 ◽  
Vol 108 (5) ◽  
pp. 485-498 ◽  
Author(s):  
John S. Hard
Keyword(s):  
Food Quality ◽  
Low Temperatures ◽  
Population Trends ◽  
Biotic Factors ◽  
Natural Control ◽  
Parasitoid Species ◽  
Southeast Alaska ◽  
Heat Units ◽  
Large Numbers ◽  
Southern Half

AbstractHemlock sawfly infestations occur most commonly in the warm southern half of southeast Alaska. Biotic factors that limit sawfly populations are a fungus, Entomophthora sphaerosperma, which kills disproportionately large numbers of female larvae; food quality as affected by host site and defoliation; and three ichneumonid parasitoid species, Delomerista japonica diprionis, Oresbius tsugae tsugae, and Itoplectis quadricingulatus, which attack prepupal larvae in cocoons. E. sphaerosperma was the most effective natural control in recent years, especially during wetter than normal summers. Parasites which attack after the fungus has decimated larval populations were most abundant during two dry summers. Parasitization and sawfly emergence were directly related, and both were highly inversely correlated with percentage fungus killed sawflies. Sawflies reared on lightly defoliated trees produced significantly more eggs than those reared on heavily defoliated trees, and fecundity was directly related to cumulative heat units during the summer. Between 1952 and 1974, most negative sawfly population trends south of Frederick Sound occurred when two wet summers occurred consecutively. Apparent widespread collapse of sawfly populations in 1974 was associated with low temperatures in 1973 which delayed sawfly development and reduced opportunities for successful oviposition.

OBSERVATIONS ON THE WHITE APPLE LEAFHOPPER, TYPHLOCYBA POMARIA (HEMIPTERA: CICADELLIDAE), AND ON THE MIRID PREDATOR BLEPHARIDOPTERUS ANGULATUS, AND MEASUREMENTS OF THEIR COLD-HARDINESS

1979 ◽  
Vol 111 (4) ◽  
pp. 487-490 ◽  
Author(s):  
A. W. MacPhee
Keyword(s):  
Nova Scotia ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Second Generation ◽  
Freezing Points ◽  
Two Generations ◽  
Predatory Mirid

AbstractTyphlocyba pomaria McA., with two generations per year, damages the leaves and defaces the fruit of apple. It was reduced in numbers in an experimental orchard by the predatory mirid Blepharidopterus angulatus (Fall.) which attacked the second generation. The cold-hardiness of T. pomaria and B. angulatus overwintering eggs, which had mean freezing points of −35 °C and −34 °C respectively, was sufficient to protect these species from winter low temperatures in Nova Scotia.

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