The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. IX. Studies on Means of Altering Predator Populations

1956 ◽  
Vol 88 (3) ◽  
pp. 129-137 ◽  
Author(s):  
F. T. Lord

It has been established that a complex of predacious arthropods on apple trees in Nova Scotia can control phytophagous mite populations (Lord, 1949). Some of the predators, when sufficiently numerous, may also be important in the control of other pests such as the eye-spotted bud-moth, Spilonota ocellana (D. & S.), and the codling moth, Carpocapsa pomonella (L.). When predation has reduced the mite population to small numbers, the insect predators almost disappear from the orchard. In most orchards in this province, the use of spray materials innocuous to predators has greatly reduced the phytophagous mite populations. The low mite population is an important gain but it is not known whether the attendant small numbers of predators is advantageous in the natural control of pests in general. This will be answered in time by the experience of the growers and, meanwhile, further research is needed on the interrelations of the phytophagous and predacious species and on how they are affected by orchard practices and other factors. This involves studies on the food preferences and behaviour of many species. In addition, means must be found to modify cultural practices to make conditions as favourable as possible for certain species of predators.

1959 ◽  
Vol 91 (11) ◽  
pp. 735-741 ◽  
Author(s):  
Wm. L. Putman

A number of authors who have mentioned phytoseiid mites as predators of tetranychids reported that “Seius” or “Seiulus” spp. hibernated in the bark of trees, but until recently the taxonomy of the Phytoseiidae was so confused that the identity of the species concerned is uncertain. Herbert (1952), in Nova Scotia,was apparently the first to deal with species that can be definitely identified; she reported that a number of species of Typhlodromus, including most of those occurring on peach in Ontario, overwintered on apple trees under bark scales, in empty hibernacula of the eye-spotted bud moth, Spilonota ocellana (D. & S.), in empty oyster-shell scales, Lepidosaphes ulmi (L.), and in cocoons of the codling moth, Carpocapsa pomonella (L.). Chant (1958) found numbers of T. pyri Scheut. hibernating in burlap pads tied to apple trees in England.


1965 ◽  
Vol 97 (12) ◽  
pp. 1303-1318 ◽  
Author(s):  
H. J. Herbert

AbstractIn Nova Scotia one leaf cluster with an adjoining 1 inch of twig taken from the inside of each of 10 apple trees replicated four times is an adequate sample unit to measure the density of the brown mite.The brown mite has one generation with a partial second in some orchards and one with a partial second and partial third in others. The first generation adults in the bivoltine and trivoltine populations lay summer eggs on the leaves and twigs, and diapause eggs on tin twigs. The second generation adults in the bivoltine populations lay only diapause eggs; in the trivoltine populations they lay both summer and diapause eggs. The adults of the third generation lay only diapause eggs.The brown mite is found on both the leaves and woody parts of the tree. In orchards with bivoltine populations the proportion of mites on leaves reached a peak of 80% by mid-July, but thereafter gradually decreased to 10% by the end of August. However, in orchards with trivoltine populations the proportion of mites on leaves reached a peak of 80 to 90% by mid-July, remained constant until mid-August, and thereafter decreased to approximately 40% by the end of August.The number of diapause eggs laid by adults of each generation in both the bivoltine and trivoltine populations varies widely. The eggs are deposited on the trunk as well as on the branches, with the heaviest deposition in the central area of the tree. The diapause eggs laid by adults of the first generation are the last to hatch and those laid by the third generation are the first to hatch the following spring.The factors responsible for the differences in the number of generations and in the number of diapause eggs laid are unknown.


1937 ◽  
Vol 69 (7) ◽  
pp. 145-146
Author(s):  
F. C. Gilliatt

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.


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.


1982 ◽  
Vol 114 (5) ◽  
pp. 431-437 ◽  
Author(s):  
E. A. C. Hagley ◽  
N. J. Holliday ◽  
D. R. Barber

AbstractLaboratory studies of the food preferences of several adult carabids showed that Amara aenea DeG., Anisodactylus sanctaecrucis F., Harpalus affinis Schr., and Stenolophus comma F. were polyphagous and readily fed on the seeds of several weeds as well as on young codling moth larvae and apple maggot pupae. H. affinis also attacked 4th and 5th instar codling moth larvae and pupae more readily than the other species. Pterostichus melanarius III. showed a strong preference for the larger prey such as 5th instar codling moth larvae, earthworms, and scarabaeid larvae. The potential of these species as predators of the codling moth and the apple maggot is discussed.


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.


1950 ◽  
Vol 43 (6) ◽  
pp. 912-914 ◽  
Author(s):  
Charles H. Richardson ◽  
Robert F. Du Chanois
Keyword(s):  

1961 ◽  
Vol 93 (10) ◽  
pp. 924-927 ◽  
Author(s):  
F. T. Lord ◽  
D. K. R. Stewart

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).


1988 ◽  
Vol 120 (10) ◽  
pp. 917-925 ◽  
Author(s):  
Elmer A.C. Hagley ◽  
W.R. Allen

AbstractPterostichus melanarius Ill. was the predominant ground beetle recovered in pitfall traps in three blocks of apple trees at Jordan Station, Ont. In one block, C, the number of mature fifth-instar larvae of Cydia pomonella (L.) seeking overwintering sites was related significantly (r2 = 0.5476, P < 0.05) to the number of P. melanarius caught, but was not related significantly (r2 = 0.1181, P > 0.10) to the proportion of beetles that were serologically positive. The proportion of larvae pupating also was not related significantly (r2 = 0.2014, P > 0.10) to the number of P. melanarius. The total number of all predators caught was related significantly (r2 = 0.4490, P < 0.05) to the number of larvae present, but the proportion of larvae that pupated was not related significantly (r2 = 0.3606, P > 0.05) to the total number of predators.In block A, in 1983–1985, the number of mature larvae of C. pomonella seeking overwintering sites was not related significantly (r2 = 0.3763, 0.3619, and 0.5042, P > 0.05, respectively) to the number of P. melanarius taken in pitfall traps. In both blocks A and B, the number of serologically positive beetles was not related significantly (r2 = 0.3824 and 0.7921, P > 0.10, respectively) to the number of larvae seeking overwintering sites.Amara aenea DeG., Anisodactylus sanctaecrucis F., Bembidion quadrimaculatum oppositum Say, Clivinia impressifrons LeC., Diplochaeila impressicolis (Dej.), Harpalus aeneus F., and Pterostichus chalcites Say also gave positive serological reactions to the antiserum against C. pomonella.The occurrence of other species of Lepidoptera did not affect significantly the results obtained for C. pomonella.


1949 ◽  
Vol 81 (9) ◽  
pp. 217-230 ◽  
Author(s):  
F. T. Lord

Three mirids, Diaphnidia pellucida Uhler, Hyaliodes harti Knight, and Campylomma verbasci (Meyer), are effective predators of the red mite and probably of the clover mite from early in June until the latter part of July. These three species are the only important predacious mirids under the conditions of the present spray practices in Nova Scotia. Gilliatt (2) has given an account of the life-histories of the three specics and discussed their importance in the natural contrnl of the red mite, and his account need not be repeated here. The three mirids are often the only important predacious species in many commercial orchards during the summer months because of the destruction of I. tiliae and H. faurei by the sulphur sprays emploved around the bloom period. Their presence in such orchards is in itself evidence that neither bordeaux mixture nor flotation sulphur reduces their numbers. Observation on a considerable number of occasions showed that iron carbamate has no effect on these mirids. An opportunity to test some of the common spray chemicals on two of the species was presented in the F. Palmer orchard at Berwick in 1947. Two trees were sprayed with each of the materials listed, and the insects were collected as they dropped on two trays, of 32 square feet each, which had been placed beneath the trees.


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