Parasites and Insect Predators of the Larch Sawfly

1955 ◽  
Vol 87 (3) ◽  
pp. 117-120 ◽  
Author(s):  
J. A. Muldrew
Keyword(s):  
British Columbia ◽  
Host Material ◽  
Larch Sawfly ◽  
Central Canada ◽  
Insect Predators ◽  
Immunity Reaction

Before the introduction of the parasite Mesoleius tenthredinis Morley into Canada in 1910, the larch sawfly had periodically caused devastating outbreaks that eventually resulted in the destruction of nearly all the mature larch east of the Rockies. The parasite at first gave control wherever it became established and, fallowing its release in Central Canada, the larch sawfly caused no serious damage there until 1938, when it again began to flare up, first in central Manitoba and then in Saskatchewan, Alberta, Ontario, Minnesota, and Wisconsin. Associated with the present resurgence is a loss of effectiveness on the part of M. tenthredinis and this appears to be related to the development of an immunity reaction on the part of the host (Muldrew, 1953a). The larch sawfly in British Columbia is, however, still highly susceptible to the parasite and, apparently, parasitism by N. tenthredinis keeps the level of abundance of the larch sawfly so low that at difficulty is experienced in obtaining host material for study purposes.

THE NATURAL IMMUNITY OF THE LARCH SAWFLY (PRISTIPHORA ERICHSONII (HTG.)) TO THE INTRODUCED PARASITE MESOLEIUS TENTHREDINIS MORLEY, IN MANITOBA AND SASKATCHEWAN

1953 ◽  
Vol 31 (4) ◽  
pp. 313-332 ◽  
Author(s):  
J. A. Muldrew
Keyword(s):  
British Columbia ◽  
Embryonic Development ◽  
Incubation Period ◽  
Natural Immunity ◽  
Sawfly Larvae ◽  
Ringer’S Solution ◽  
Pristiphora Erichsonii ◽  
Effective Inhibition ◽  
Larch Sawfly ◽  
Immunity Reaction

By 1945 it was suspected that the larch sawfly in Saskatchewan and Manitoba had developed an immunity to the introduced parasite Mesoleius tenthredinis Morley. Results of subsequent studies showed that embryonic development of M. tenthredinis in sawfly larvae from Manitoba and Saskatchewan was inhibited three to four days after oviposition. No such inhibition occurred in larvae from British Columbia where the parasite is still highly effective. Inhibition seemed to be related to the deposition of phagocytic capsules around parasite embryos, which occurred in host larvae from Manitoba and Saskatchewan but not in larvae from British Columbia. Encapsulated parasite embryos were shown to be viable, for a number of them hatched after being placed in Ringer's solution. Viability decreased with age. Some embryos were viable seven months after oviposition, though the normal incubation period is 7 to 10 days. Unencapsulated embryos developed more rapidly than encapsulated embryos in Ringer's solution. Results obtained indicate that the phagocytes of the larch sawfly from Manitoba and Saskatchewan play an important role in the immunity reaction of this insect to M. tenthredinis.

History of the Larch Sawfly, with Notes on Origin and Biology,

1955 ◽  
Vol 87 (3) ◽  
pp. 103-111 ◽  
Author(s):  
H. C. Coppel ◽  
K. Leius
Keyword(s):  
British Columbia ◽  
North America ◽  
Native Species ◽  
Insect Pest ◽  
Forest Insect ◽  
Larch Sawfly ◽  
History Of ◽  
Biological Characters ◽  
The Difference ◽  
Forest Biology

The larch sawfly, Pristiphora erichronii (Htg.), is currently considered a major forest insect pest in Canada. At the present time within Canada, the sawfly reacts to parasitism by Mesoleius tenthredinis Morley in two ways. In Manitoba and Saslratchewan the sawfly encapsulates approximately 100 per cent of the parasite eggs deposited, whereas in British Columbia encapsulation rarely exceeds four per cent (Muldrew, 1953). The reasons for the difference in degree of encapsulation are apparently unknown; however, since the origin of the sawfly itself is obscure, the possibility exists that a native species, an introduced species, Or a combination of both may he present, or that geographical or ecological units may have arisen. Studies now under way by officers of the Forest Biology and Entomology divisions are attacking the problem of identity and origin following the pattern established for the European spruce sawfly, Diprion hercyniae (Htg.). In this instance, as with the larch sawfly, parasites were introduced on the assumption that the pest had been introduced from Europe. Critical investigations by Reeks (1941) and Balch, Reeks, and Smith (1941), involving morphological, cytological, and other biological characters, showed that the species occurring in North America was one of two species common in Europe, and previously referred to there as Gilpinia polytoma (Htg.). Balch et al. (1941) showed that D. hercyniae had been introduced into North America.

Estimating Breast Height Diameters from Stump Measurements in British Columbia

1982 ◽  
Vol 58 (3) ◽  
pp. 143-145 ◽  
Author(s):  
Julien P. Demaerschalk ◽  
Stephen A. Y. Omule
Keyword(s):  
British Columbia ◽  
Prediction Model ◽  
Tree Species ◽  
Prediction System ◽  
Tree Diameter ◽  
Local Volume ◽  
Breast Height ◽  
Central Canada ◽  
Volume Equation ◽  
Stump Diameter

A means of estimating tree diameter at breast height from stump measurements has many applications. In this paper, metric equations are derived for estimating diameters at breast height from measured stump heights for all commercial tree species in British Columbia by age class and biogeoclimatic zones. The model found best was the same one as used by Alemdag and Honer (1977) for eleven tree species from eastern and central Canada. This prediction system can be incorporated into any local volume equation to derive a tree volume prediction model based on stump diameter and stump height.

Evolution of white-throated sparrow song: regional variation through shift in terminal strophe type and length

Behaviour ◽  
2016 ◽  
Vol 153 (15) ◽  
pp. 1839-1861 ◽  
Author(s):  
Hannah D. Zimmerman ◽  
Scott M. Ramsay ◽  
Veronica Mesias ◽  
Marcelo Mora ◽  
Brent W. Murray ◽  
...  
Keyword(s):  
British Columbia ◽  
Regional Variation ◽  
Central Canada ◽  
Over Time

We investigated the emergence over time of a novel song variant (doublet-ending song) in a western Canadian sub-population of white-throated sparrows; this variant differs from the species-typical, triplet-ending song. By analysing recent (1999–2014) and historic (1950/1960s) recordings, we show that populations west (British Columbia) and immediately east (Alberta) of the Rockies, and from central Canada (Ontario) initially all had triplet-ending songs. The shift to doublet-ending songs first arose west of the Rockies, and has increased immediately east of the Rockies in the last decade. The Ontario population retained predominantly triplet-ending songs. Note lengths have increased over time in all populations, while inter-strophe interval has decreased, allowing doublet-ending birds the ability to have greater strophe repeats for a given song length. We explore whether the emergence and apparent spread of the doublet-ending songs can be explained by cultural drift, or may be under selection by conveying an advantage during counter-singing.

scholarly journals THE INFLUENCE OF LOGGING ON DOUGLAS FIR BEETLE POPULATIONS

1961 ◽  
Vol 37 (4) ◽  
pp. 308-314 ◽  
Author(s):  
R. R. Lejeune ◽  
L. H. McMullen ◽  
M. D. Atkins
Keyword(s):  
British Columbia ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Economic Importance ◽  
Douglas Fir ◽  
Host Material ◽  
Remedial Action ◽  
Fresh Material ◽  
Breeding Grounds ◽  
Wind Throw

All species of bark beetles of economic importance prefer to attack freshly-killed host material. Logging slash, wind-throw, and fire-killed timber provide ideal breeding grounds for bark beetles. A few species, mostly in the Dendroctonus group, are able to attack and kill living trees. When beetles in this group, raised in preferred host material, cannot find any or enough freshly-killed trees, logs, or slash to enter, they may attack living trees. In the interior of British Columbia, infestations of the Douglas fir beetle can often be traced to logging disturbance.The regulation or control of bark beetle populations involves several generally accepted principles:(a) The removal or destruction of beetle broods in infested material in time to prevent the new adult beetles from emerging to attack fresh material.(b) Continuous logging in time and area will tend to keep the beetles in the slash.(c) Keep suitable breeding material to a minimum.(d) The use of trap trees or trap logs for remedial action in trouble areas.

The millipeds of central Canada (Arthropoda: Diplopoda), with reviews of the Canadian fauna and diplopod faunistic studies

2002 ◽  
Vol 80 (11) ◽  
pp. 1863-1875 ◽  
Author(s):  
Rowland M Shelley
Keyword(s):  
British Columbia ◽  
Rocky Mountains ◽  
Native Species ◽  
New Records ◽  
Lake Superior ◽  
James Bay ◽  
Additional Species ◽  
Large Country ◽  
Central Canada ◽  
Oxidus Gracilis

The milliped fauna of central Canada, extending from the Rocky Mountains of Alberta to James Bay and eastern Lake Superior, Ontario, comprises nine species, four Palearctic introductions, Cylindroiulus latestriatus (Curtis), Archiboreoiulus pallidus (Brade-Birks), Nopoiulus kochii (Gervais), and Polydesmus inconstans Latzel, and five native species, Aniulus garius (Chamberlin), Oriulus venustus (Wood), Underwoodia iuloides (Harger), Underwoodia tida Chamberlin, and Brunsonia albertana (Chamberlin). Three additional species, Polyxenus lagurus (L.), Aniulus (Hakiulus)diversifrons diversifrons (Wood), and Oxidus gracilis (C.L. Koch), are potential inhabitants. Aniulus garius is newly recorded from Alberta, Saskatchewan, and Manitoba, and Archiboreoiulus pallidus is newly reported from British Columbia and Illinois, U.S.A.; Zygotyla phana Chamberlin is formally placed in synonymy under Brunsonia atrolineata (Bollman). The total Canadian fauna consists of 6 orders, 20 families, 43 genera, and 62 species/subspecies, nearly one-third of which (20 species in total) are importations from the Palearctic and Asiatic realms. The total indigenous fauna therefore comprises 6 orders, 15 families, 30 genera, and 42 species, and 10 additional species potentially occur in British Columbia, Ontario, Quebec, and New Brunswick. Uroblaniulus idahoanus (Chamberlin) is provisionally recognized as the representative of the tribe Uroblaniulini (Julida: Parajulidae) in British Columbia, and specific localities are reported, which also constitute new records for the province and country. Canada is the first large country in the world whose diplopod fauna is essentially completely known; other countries, islands, and island groups in this category are summarized.

THE CAPSULE AND ITS RELATION TO THE EMBRYOGENESIS OF THE ICHNEUMONID PARASITOID MESOLEIUS TENTHREDINIS MORL. IN THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HTG.) (HYMENOPTERA:TENTHREDINIDAE)

1960 ◽  
Vol 38 (4) ◽  
pp. 769-775 ◽  
Author(s):  
Joan F. Bronskill
Keyword(s):  
British Columbia ◽  
Blood Cells ◽  
Oxygen Supply ◽  
Outer Region ◽  
Germ Band ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Histochemical Tests ◽  
Inner Region ◽  
Host Blood

Eggs of the parasitoid Mesoleius tenthredinis Morl. from British Columbia develop and hatch in approximately 120 hours when reared at 23 ± 0.5 °C and a relative humidity of 72 ± 2% within field-collected larch sawfly (Pristiphora erichsonii (Htg.)) larvae from British Columbia and Newfoundland, and within laboratory-reared P. crichsonii larvae from British Columbia. However, they develop normally for only 70 to 80 hours within field-collected larvae from Manitoba as encapsulation of the developing eggs occurs and development ceases in the late germ band stage. The capsule is formed by an accumulation of host blood cells. During the formation of the capsule the innermost blood cells become flattened, fibrous, and enucleated, and eventually form a mass of concentric sheaths of non-cellular material. Thus, the definitive capsule is both cellular (outer region) and non-cellular (inner region). Histochemical tests indicate the presence of mucopolysaccharide in the capsule. It is suggested that the capsule inhibits the embryonic development of the parasitoid by interfering with its oxygen supply.

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