STUDIES ON THE SITKA SPRUCE WEEVIL, PISSODES SITCHENSIS, IN BRITISH COLUMBIA

1968 ◽  
Vol 100 (1) ◽  
pp. 93-110 ◽  
Author(s):  
G. T. Silver
Keyword(s):  
British Columbia ◽  
Life History ◽  
Population Level ◽  
Sitka Spruce ◽  
Natural Control ◽  
Control Factors ◽  
History Of ◽  
Repeated Applications ◽  
Heavy Mortality

AbstractThe life history of the Sitka spruce weevil, Pissodes sitchensis Hopk., is described. Adults overwinter in duff at the base of trees and emerge in April or early May. Oviposition begins in late April on leaders. The larvae hatch and mine downward, eventually girdling and killing the leader. Larvae pupate in chip cocoons under the bark. Newly developed adults start emerging in August and, prior to hibernation, feed on leaders of young trees. Adults have been observed in the field as late as December.Predators caused heavy mortality but the weevil population maintained itself and increased in some years. Parasitism was light. Natural control factors reduced the population level but were incapable of controlling a population. Satisfactory control was obtained by applying DDT and phosphamidon to leaders with a hand-sprayer early in the spring, but repeated applications would be necessary to protect a plantation through the critical years.Damage to Sitka spruce regeneration and plantations in British Columbia is severe. At present, protection of Sitka spruce plantations would require considerable expense.

SURVEY OF PATHOGENS IN THE LARGE ASPEN TORTRIX, CHORISTONEURA CONFLICTANA (LEPIDOPTERA: TORTRICIDAE), IN ONTARIO AND BRITISH COLUMBIA WITH PARTICULAR REFERENCE TO GRANULOSIS VIRUS

1982 ◽  
Vol 114 (5) ◽  
pp. 457-459 ◽  
Author(s):  
John Burke ◽  
Jean Percy
Keyword(s):  
United States ◽  
British Columbia ◽  
Tree Mortality ◽  
Eastern United States ◽  
Natural Control ◽  
Granulosis Virus ◽  
Control Factors ◽  
Principal Effect ◽  
History Of ◽  
Choristoneura Conflictana

The large aspen tortrix, Choristoneura conflictana Wlk., occurs throughout the range of trembling aspen, Populus trernuloides Michx., in Canada and the eastern United States (Baker 1972). Outbreaks of the insect occur over large areas, but these outbreaks generally collapse in 2 to 3 years. The principal effect of this pest is to reduce growth of aspen, but it causes little tree mortality (Batzer 1972). Prentice (1955) reviewed the history of outbreaks of C. conflictana in Canada from 1912 to 1953 and the natural control factors of the insect. He reported an extensive parasite complement. Dead and apparently diseased insects were examined, but the only pathogen noted was infection of overwintering larvae by the fungus, Beauveria bassiana (Bals .) Vuill.

The Life History and Habits of Chrysomela crotchi Brown (Coleoptera: Chrysomelidae) in Northwestern Ontario

1965 ◽  
Vol 97 (5) ◽  
pp. 541-549 ◽  
Author(s):  
E. P. Smereka
Keyword(s):  
Life History ◽  
Adult Stage ◽  
Egg Mass ◽  
Predator Species ◽  
Control Factors ◽  
Northwestern Ontario ◽  
History Of ◽  
Males And Females ◽  
Overwintering Mortality ◽  
Larval Parasites

AbstractThe life history of Chrysomela crotchi, a univoltine species commonly found on trembling aspen, was studied in northwestern Ontario from 1959 to 1962. The most striking feature of its life history was the longevity of adults, which were capable of overwintering two successive years. Overwintered adults became active and began feeding in late May, and oviposition occurred from early June to late July. The incubation period was approximately 10 days and the three larval instars required approximately one month for development to the adult stage.Females laid more eggs during their second season and the highest number laid was 326. The number of eggs in an egg mass averaged 37.6, and the average interval between the deposition of egg masses was 4 days. Males and females mated more than once, but only one mating was necessary for a female to produce viable eggs throughout the season. Males were capable of fertilizing more than one female and remained potent for more than one season.Parasitism was low, and only two species of larval parasites were reared. Several predator species were observed preying on the immature stages. Predation and overwintering mortality appeared to be the most important control factors.

Life-History and Natural Control in British Columbia of Ocnerostoma piniariella Zell. (Lepidoptera: Yponomeutidae), a Needle Miner on White Pine

1958 ◽  
Vol 90 (10) ◽  
pp. 627-631 ◽  
Author(s):  
Peter Harris
Keyword(s):  
New York ◽  
British Columbia ◽  
Life History ◽  
North America ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Swiss Alps ◽  
Natural Control ◽  
Pinus Cembra ◽  
White Pine

Ocnerostoma piniariella Zell. is an unimportant pest of Scots pine, Pinus sylvestris L., in Europe. A variety, copiosella Frey, is found in the Swiss Alps attacking a white pine, Pinus cembra L., and sometimes occurs in sufficient numbers to reduce growth. Both European forms have a life-history similar to that described here for British Columbia.In North America, specimens identified as O. piniariella were collected in 1882 at Ithaca, New York (Forbes, 1924). The first Canadian record was for 1922 at Abbotsford, British Columbia, from white pine (Felt, 1922). The species has since been found in British Columbia at Vancouver, Victoria, Langley, and Aldergrove. Dr. T. N. Freeman (in litt.), Entomology Division, Ottawa, has collected it at Constance Bay, South March, Ottawa, and Bells Corners, Ontario.

Early Ocean Life History of Harrison River Sockeye Salmon and their Contribution to the Biodiversity of Sockeye Salmon in the Fraser River, British Columbia, Canada

2016 ◽  
Vol 145 (2) ◽  
pp. 348-362 ◽  
Author(s):  
Richard J. Beamish ◽  
Chrys M. Neville ◽  
Ruston M. Sweeting ◽  
Terry D. Beacham ◽  
Joy Wade ◽  
...  
Keyword(s):  
British Columbia ◽  
Life History ◽  
Sockeye Salmon ◽  
Fraser River ◽  
History Of

STUDIES IN THE LIFE HISTORY OF TRACHYKELE BLONDELI MARSEUL

1932 ◽  
Vol 64 (8) ◽  
pp. 189-191
Author(s):  
Geo. R. Hopping
Keyword(s):  
British Columbia ◽  
Life History ◽  
Larval Stage ◽  
Red Cedar ◽  
History Of ◽  
Cheese Cloth

In connection with studies on the biology of T. blondeli, condnctec in the years 1926 to 1930 inclusive, at Pender Harbour, British Columbia, red cedar trees were inclosed in cheese-cloth cages with a view to determining the duration of the larval stage. The cages were constructed prior to April 30, 1926, and the emergence of bettles from the trees was recorded.

scholarly journals Environmental change effects on life history traits and population dynamics of anadromous fishes

2019 ◽  
Author(s):  
P. Catalina Chaparro-Pedraza ◽  
André M. de Roos
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Environmental Change ◽  
Population Level ◽  
Fish Population ◽  
Breeding Habitat ◽  
Energetic Cost ◽  
Life History Stages ◽  
History Of ◽  
The Individual

AbstractMigration, the recurring movement of individuals between a breeding and a non-breeding habitat, is a widespread phenomenon in the animal kingdom. Since the life cycle of migratory species involves two habitats, they are particularly vulnerable to environmental change, which may affect either of these habitats as well as the travel between them. In this study, we investigate the consequences of environmental change affecting older life history stages for the population dynamics and the individual life history of a migratory population. In particular, we use a theoretical approach to study how increased energetic cost of the breeding travel and reduced survival and food availability in the non-breeding habitat affect an anadromous fish population. These unfavorable conditions have impacts at individual and population level. First, when conditions deteriorate individuals in the breeding habitat have a higher growth rate as a consequence of reductions in spawning that reduce competition. Second, population abundance decreases, and its dynamics change from stable to oscillations with a period of four years. The oscillations are caused by the density-dependent feedback between individuals within a cohort through the food abundance in the breeding habitat, which results in alternation of a strong and a weak cohort. Our results explain how environmental change, by affecting older life history stages, has multiple consequences for other life stages and for the entire population. We discuss these results in the context of empirical data and highlight the need for mechanistic understanding of the interactions between life history and population dynamics in response to environmental change.

scholarly journals Small-scale spatial variation in population- and individual-level reproductive parameters of the blue-legged hermit crabClibanarius tricolor

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3004 ◽  
Author(s):  
J. Antonio Baeza ◽  
Donald C. Behringer
Keyword(s):  
Life History ◽  
Body Size ◽  
Florida Keys ◽  
Population Level ◽  
Small Scale ◽  
Reproductive Parameters ◽  
Future Studies ◽  
Individual Level ◽  
Female Body Size ◽  
History Of

Management of the few regulated ornamental fisheries relies on inadequate information about the life history of the target species. Herein, we investigated the reproductive biology of the most heavily traded marine invertebrate in the western Atlantic; the blue-legged hermit crabClibanarius tricolor. We report on density, individual-level, and population-level reproductive parameters in 14 populations spanning the Florida Keys. In C. tricolor, abundance, population-level, and individual-level reproductive parameters exhibited substantial small-scale spatial variation in the Florida Keys. For instance, the proportion of brooding females varied between 10–94% across localities. In females, average (±SD) fecundity varied between 184 (±54) and 614 (±301) embryos crab-1 across populations. Fecundity usually increases with female body size in hermit crabs. However, we found no effect of female body size on fecundity in three of the populations. Altogether, our observations suggest that C. tricolor may fit a source-sink metapopulation dynamic in the Florida Keys with low reproductive intensity and absence of a parental body size—fecundity relationship resulting in net reproductive loses at some localities. We argue in favor of additional studies describing population dynamics and other aspects of the natural history of C. tricolor (e.g., development type, larval duration) to reveal ‘source’ populations, capable of exporting larvae to nearby populations. Our observations imply that future studies aimed at assessing standing stocks or describing other aspects of the life history of this hermit crab need to focus on multiple localities simultaneously. This and future studies on the reproductive biology of this species will form the baseline for models aimed at assessing the stock condition and sustainability of this heavily harvested crustacean.

On the Life History of the Douglas-fir Cone Moth, Barbara colfaxiana (Kft.) (Lepidoptera: Olethreutidae), and one of its Parasites, Glypta evetriae Cush. (Hymenoptera: Ichneumonidae)

1960 ◽  
Vol 92 (11) ◽  
pp. 826-834 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
British Columbia ◽  
Life History ◽  
Rocky Mountains ◽  
Pacific Coast ◽  
Douglas Fir ◽  
Lake Area ◽  
Seed Loss ◽  
The Pacific ◽  
History Of ◽  
Loss Range

The Douglas-fir cone moth has been reported causing damage to cones and seeds of Douglas fir for a number of years; reports of seed loss range from light to almost 100 per cent. The insect occurs throughout the range of the host in British Columbia, the Pacific Coast States, and the Rocky Mountains.Observations recorded here were made during 1957 and 1958 in the Cowichan Lake area of Vancouver Island, and 1959 in the interior of British Columbia.

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