BIOLOGY AND LIFE HISTORY OF EPURAEA OBLIQUUS HATCH (COLEOPTERA: NITIDULIDAE) ON WESTERN GALL RUST

1996 ◽  
Vol 128 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Cameron R. Currie ◽  
John R. Spence ◽  
W. Jan A. Volney

AbstractThe life cycle, phenology, and abundance of Epuraea obliquus Hatch was studied near Hinton, Alberta. Most of the life cycle occurs on galls of Endocronartium harknessii (J.P. Moore) Y. Hiratsuka (western gall rust) infecting lodgepole pine (Pinus contorta Dougl. var latifolia Engelm.). Both adults and larvae feed on the spores of the fungus. Individuals of this beetle were found on most galls sampled. Adults overwinter in the soil. They emerge in the spring to seek out and colonize galls. Eggs are laid on the surface of galls, mainly under the periderm, and larvae feed on the fungus, developing through three larval instars. Larvae in the last instar drop from galls to pupate in the soil. Adults leave the soil in late summer and return to feed on inactive galls before overwintering in the soil. The phenology of E. obliquus is closely synchronized with the timing of rust sporulation and the impact of beetle feeding may be an important natural control of western gall rust.

1998 ◽  
Vol 130 (4) ◽  
pp. 387-397 ◽  
Author(s):  
David W. Langor ◽  
Daryl J.M. Williams

AbstractThe seasonal life history and mortality of the lodgepole terminal weevil, Pissodes terminalis Hopping (Coleoptera: Curculionidae), were investigated in young lodgepole pine, Pinus contorta Douglas var. latifolia Engelmann (Pinaceae), at three sites in west-central Alberta. Flight was monitored with traps. Development and mortality of all stages were investigated by dissecting infested leaders biweekly from late spring to early fall. Two years were required for P. terminalis to complete its life cycle, and generations overlapped. Overwintered adults emerged from the duff and commenced flight in late May, with a peak in mid-June. Eggs were present from mid-June to late July. There were four larval instars. The first two instars fed only in the phloem. Third and fourth larval instars eventually entered the pith to continue feeding, overwinter, and complete development the following spring. The new generation of adults emerged between mid-July and early August, fed on new shoots for several weeks, and overwintered in the duff. Adults have an obligatory diapause and did not reproduce until after winter. Fourth larval instars suffered the highest mortality. The major attributable cause of mortality was resinosis among eggs and young larvae and cold temperatures during the winter among mature larvae. Pathogens caused little mortality. Six species of parasitoids were collected.


2009 ◽  
Vol 141 (1) ◽  
pp. 56-69 ◽  
Author(s):  
G.D. Smith ◽  
A.L. Carroll ◽  
B.S. Lindgren

AbstractPseudips mexicanus (Hopkins) is a secondary bark beetle native to western North and Central America that attacks most species of pine (Pinus L. (Pinaceae)) within its range. A pair of life-history studies examined P. mexicanus in other host species, but until now, no work has been conducted on lodgepole pine (Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson). Pseudips mexicanus in lodgepole pine was found to be polygynous. Galleries were shorter, offspring smaller, and the eggs laid per niche and the potential progeny fewer than in populations from California and Guatemala. Development from the time of female attack to emergence of adult offspring took less than 50 days at 26.5 °C, and the accumulated heat required to complete the life cycle was determined to be 889.2 degree days above 8.5 °C, indicating that in the northern portion of its range P. mexicanus is univoltine. Determination of these life-history traits will facilitate study of interactions between P. mexicanus and other bark beetle associates in lodgepole pine.


1971 ◽  
Vol 2 (3) ◽  
pp. 170-190 ◽  
Author(s):  
Ulf Norling

AbstractThe life-history of Aeshna viridis Eversm. has been studied at a peat-pit in southern Sweden by means of regular sampling. Larvae from some samples from late summer to early spring have been experimentally subjected to constant artificial day-lengths of I3, I4.5, I6 and I9.5 hours at a temperature of 20°C. The results of experiments suggest that the rapid transition of photoperiod in autumn and spring is most important in the regulation of the life-cycle, which in the population studied had a duration of 2-3 years. A comparison is made between the seasonal regulation in Aeshna viridis and that in some other species. The causes of the phenological differences between certain types of spring and summer species and the differences in life-history of Aeshna species at different latitudes are discussed.


1936 ◽  
Vol 2 (2) ◽  
pp. 209-221 ◽  
Author(s):  
J. G. Rempel

In lakes of Saskatchewan adults emerge in late May and early June. Eggs, deposited over lake surface, sink to bottom. Larvae in soft bottom ooze (10–20 m. depth) grow rapidly in late summer, but little during rest of year. Four larval instars and two-year life-cycle. Larva and pupa described and additions made to Staeger's description of adult.


2016 ◽  
Vol 13 (10) ◽  
pp. 2945-2958 ◽  
Author(s):  
Yang Liu ◽  
Tongli Wang ◽  
Yousry A. El-Kassaby

Abstract. Environmental signals are important triggers in the life-cycle transitions and play a crucial role in the life-history evolution. Yet very little is known about the leading ecological factors contributing to the variations of life-history traits in perennial plants. This paper explores both the causes and consequences for the evolution of life-history traits (i.e., seed dormancy and size) in lodgepole pine (Pinus contorta Dougl.) across British Columbia (B.C.), Canada. We selected 83 logepole pine populations covering 22 ecosystem zones of B.C. and through their geographic coordinate, 197 climatic variables were generated accordingly for the reference (1961–1990) and future (2041–2070) periods. We found that dynamic climatic variables rather than constant geographic variables are the true environmental driving forces in seed dormancy and size variations and thus provide reliable predictors in response to global climate change. Evapotranspiration and precipitation in the plant-to-seed chronology are the most critical climate variables for seed dormancy and size variations, respectively. Hence, we predicted that levels of seed dormancy in lodgepole pine would increase across large tracts of B.C. in 2050s. Winter-chilling is able to increase the magnitude of life-history plasticity and lower the bet-hedge strategy in the seed-to-plant transition; however, winter-chilling is likely to be insufficient in the north of 49° N in 2050s, which may delay germination while unfavorable conditions during dry summers may result in adverse consequences in the survival of seedlings owing to extended germination span. These findings provide useful information to studies related to assessments of seed transfer and tree adaptation.


2015 ◽  
Vol 12 (16) ◽  
pp. 14105-14138 ◽  
Author(s):  
Y. Liu ◽  
T. Wang ◽  
Y. A. El-Kassaby

Abstract. Environmental signals are important triggers in the life-cycle transitions and play a crucial role in the life-history evolution. Yet, very little is known about the leading ecological factors contributing to the variations of life-history traits in perennial plants. This paper explores both the causes and consequences for the evolution of life-history traits (i.e., seed dormancy and size) in lodgepole pine (Pinus contorta Dougl.) across British Columbia (B.C.), Canada. We selected 83 logepole pine populations covering 22 ecosystem zones of B.C. and through their geographic coordinate, 197 climatic variables were generated accordingly for the reference (1961–1990) and future (2041–2070) periods. We found that dynamic climatic variables rather than constant geographic variables are the true environmental driving forces in seed dormancy and size variations and thus provide reliable predictors in response to global climate change. Evapotranspiration and precipitation in the plant-to-seed chronology are the most critical climate variables for seed dormancy and size variations, respectively. Hence, we predicted that levels of seed dormancy in lodgepole pine would increase across large tracts of B.C. in 2050s. Winter-chilling is able to increase the magnitude of life-history plasticity and lower the bet-hedge strategy in the seed-to-plant transition; however, winter-chilling is likely to be insufficient in the north of 49° N in 2050s, which may delay germination while unfavourable conditions during dry summers may result in adverse consequences in the survival of seedlings owing to extended germination span.


1965 ◽  
Vol 97 (7) ◽  
pp. 684-690 ◽  
Author(s):  
R. W. Stark ◽  
J. H. Borden

AbstractThe life history of a tortricid cone moth Choristoneura lambertiana subretiniana Obraztsov in California is described. The larvae feed primarily on staminatc flowers and cones of lodgepole pine although some needle- and tip-mining occurs. The only other recorded host is ponderosa pine.Eggs are deposited in late July to early August; first-instar larvae migrate from the needles to protected locations on the branches and spin hibernacula. The larvae overwinter predominantly as second-instar larvae in the hibernaculum. They emerge from the hibernacula in April, and mature in four to six weeks. There are six larval instars. The pupal period lasts approximately two weeks; adult emergence begins in mid-July and extends through the end of August.


Author(s):  
J. B. Brown-Gilpin

The wide variety of reproductive patterns and behaviour in the many species of Nereidae already studied clearly justifies further research. But the life history of Nereis fucata (Savigny) is not only of interest from the comparative point of view. Its commensal habit (it occurs within shells occupied by hermit crabs) immediately gives it a special importance. This alone warrants a detailed study, particularly as no commensal polychaete has yet been reared through to metamorphosis and settlement on its host (Davenport, 1955; Davenport & Hickok, 1957). The numerous interesting problems which arise, and the experimental methods needed to study them, are, however, beyond the range of a paper on nereid development. It is therefore proposed to confine the present account to the reproduction and development up to the time when the larvae settle on the bottom. The complete life cycle, the mechanism of host-adoption, and related topics, will be reported in later papers.


1985 ◽  
Vol 63 (5) ◽  
pp. 938-945 ◽  
Author(s):  
Patricia S. Muir ◽  
James E. Lotan

Mature serotinous and nonserotinous trees of Pinus contorta Dougl. var. latifolia Engelm. in the Bitterroot Watershed of western Montana do not differ in most life-history characteristics (reproductive or vegetative). No differences between trees of the two cone types were found in height, basal area, basal area growth rates over the lives of the trees, or crown ratio. Cone number, weights of individual cones and seeds, and estimates of reproductive effort were similar in serotinous and non-serotinous trees. Reproductive characteristics were either independent of tree age, or related similarly in trees of the two cone types. Nonserotinous trees may, however, have more seeds per cone than serotinous trees. This difference in seed numbers may be adaptive if serotinous trees invest relatively heavily in cone materials to protect seeds (which are retained in cones for many years), while nonserotinous trees (which shed seeds each year) invest relatively heavily in seeds. Trees of the two cone types differ mainly in the particular types of disturbance favoring their regeneration, but they often grow in the same stands where there are similar selective pressures on most aspects of their biology. Gene flow between them probably homogenizes all but those differences maintained by strong selective pressures.


1953 ◽  
Vol 31 (4) ◽  
pp. 351-373 ◽  
Author(s):  
Liang-Yu Wu

A cause of swimmer's itch in the lower Ottawa River is Trichobilharzia cameroni sp. nov. Its life cycle has been completed experimentally in laboratory-bred snails and in canaries and ducks, and the various stages are described. The eggs are spindle-shaped. The sporocysts are colorless and tubular. Mother sporocysts become mature in about a week. The younger daughter sporocyst is provided with spines on the anterior end and becomes mature in about three weeks. The development in the snail requires from 28 to 35 days. A few cercariae were found to live for up to 14 days at 50 °C., although their life at 16° to 18 °C. was about four days. Cercariae kept at room temperature for 60 to 72 hr. were found infective. The adults become mature in canaries and pass eggs in about 12 to 14 days. Physa gyrina is the species of snail naturally infected. It was found in one case giving off cercariae for five months after being kept in the laboratory. Domestic ducks were found to become infected until they were at least four months old, with the parasites developing to maturity in due course; no experiments were made with older ducks. Furthermore, miracidia were still recovered from the faeces four months after the duck had been experimentally infected, and it is suggested that migratory birds are the source of the local infection.


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