FACTORS INFLUENCING THE FALL EMERGENCE OF BESSA HARVEYI (TACHINIDAE: DIPTERA)

1973 ◽  
Vol 105 (3) ◽  
pp. 399-409 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
Mortality Factor ◽  
Regression Analyses ◽  
Strong Negative Correlation ◽  
Factors Influencing ◽  
Long Day ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Host Development ◽  
Common Parasite ◽  
Heavy Mortality

AbstractBessa harveyi (Townsend) is a common parasite of the larch sawfly, Pristiphora erichsonii (Hartig), in southeastern Manitoba but it is ineffective in preventing or terminating outbreaks of its host. Bivoltinism acts as a mortality factor in B. harveyi populations because bivoltine individuals do not contribute progeny to the next generation. Heavy mortality due to bivoltinism occurs when the parasite eggs are laid under long-day conditions and the summer is warm and prolonged. Regression analyses show that most of the variation in the incidence of bivoltinism between years and between dates within years can be described by equations involving the incidence of bivoltinism in the previous year, photoperiod, and temperature. The importance of a genetic factor in determining the incidence of bivoltinism was indicated by a strong negative correlation between the incidences in consecutive years. Photoperiod and temperature during development were positively correlated with incidence. The persistence of bivoltinism in Manitoba is postulated to be related to variability in weather and host development plus developmental advantages associated with the bivoltine phenotype.

HEAT TOLERANCE OF LAST-INSTAR LARVAE OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1967 ◽  
Vol 99 (11) ◽  
pp. 1150-1156 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Heat Tolerance ◽  
Free Water ◽  
Temperature Acclimation ◽  
Mortality Factor ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Conditioning Temperature

AbstractLaboratory tests of heat tolerance of last-instar larvae of the larch sawfly, Pristiphora erichsonii (Htg.), were made to provide information for the evaluation of the role of high temperature as a mortality factor in field populations.Test larvae were reared from eggs at 21 ± 1.5 °C and 50 ± 10% relative humidity. LT50's were determined at 37°, 39°, 40°, and 41 °C for larvae conditioned at 30 °C and 75% relative humidity.Larvae were less heat resistant during the first 24 hours after molting than they were 24 to 48 hours after molting. The conditioning temperature and the duration of conditioning had very significant effects on heat tolerance. Differences in acclimation due to heat treatment could not be accounted for by differences in free water content.Temperature acclimation will occur in field populations and must be considered in evaluating the role of high temperature as a natural mortality factor.Larvae may encounter lethal temperatures when wandering on branches or tree trunks or crawling on dry ground in open sunshine.

Pristiphora erichsonii. [Distribution map].

1959 ◽  
Author(s):  
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
Distribution Map ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Pristiphora erichsonii (Htg.) (Hymenopt., Tenthredinoidea) (Larch Sawfly). Hosts: Larix spp. Information is given on the geographical distribution in EUROPE (excl. USSR), Austria, Britain, Czechoslovakia, Denmark, Finland, France, Germany, Ireland, Netherlands, Norway, Poland, Rumania, Sweden, ASIA (excl. USSR), Japan, USSR, NORTH AMERICA, Canada, U.S.A.

The alternative negative constructions in spoken and written Korean: Logistic regression analysis

2019 ◽  
Vol 15 (2) ◽  
pp. 419-442
Author(s):  
Beom-mo Kang
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Logistic Regression Analysis ◽  
Mixed Effects ◽  
Written Language ◽  
Regression Analyses ◽  
Relevant Factor ◽  
Factors Influencing ◽  
Frequency Of Use ◽  
Relevant Factors

AbstractAdopting quantitative corpus-based methods, this paper focuses on the alternative negative constructions in Korean, [anV] and [Vanhda]. Logistic regression analyses for a mixed-effects model were carried out on data drawn from the Sejong Korean Corpus. Certain features of the verb or adjective in negative constructions significantly affect the use of the two negative constructions. A relevant factor is register/medium (spoken or written), among other significant interactions of factors. Furthermore, the fact that frequency is consistent with other relevant factors, together with certain diachronic facts of Korean, supports the claim that frequency of use plays an important role in linguistic changes. Another finding is that, notwithstanding noticeable differences between spoken and written language, the factors influencing the use of the two negative constructions in Korean are largely similar in the spoken and written registers.

Estimation of Parasitism of Larch Sawfly Cocoons by Bessa harveyi Tnsd. in Survey Collections

1959 ◽  
Vol 91 (8) ◽  
pp. 496-500 ◽  
Author(s):  
W. G. H. Ives ◽  
R. M. Prentice
Keyword(s):  
Forest Insect ◽  
Small Areas ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Insect Survey ◽  
Forest Biology ◽  
Biology Laboratory ◽  
Total Parasitism

The Forest Insect Survey at the Forest Biology Laboratory, Winnipeg, has been compiling records for a number of years on the percentage of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), parasitized by the tachinid Bessa harveyi Tnsd. Sawfly cocoons were collected each fall from the soil in infested stands, and those containing living larvae were dissected to determine the percentage of parasitism by B. harveyi. These estimates have been used to provide an index of parasitism (Lejeune and Hildahl, 1954), but are of limited value for a number of reasons: (1) estimates can be expressed only as percentage of sound cocoons parasitized; (2) total parasitism cannot be estimated because a portion of the parasites emerge from the cocoons before collection; and (3) estimates of parasitism may not be representative of the stand because there is a tendency to collect cocoons where they are easiest to find; hence all the cocoons in a collection may be from one or two small areas. If the proportion of cocoons containing B. harveyi varies within a stand such collections may give unreliable estimates of parasitism.

Mortality of Cocoons of the Larch Sawfly, Pristiphora erichsonii (Htg.), in Relation to Distance from Small-Mammal Tunnels

1959 ◽  
Vol 91 (9) ◽  
pp. 535-542 ◽  
Author(s):  
C. H. Buckner
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Natural Mortality ◽  
Mortality Factors ◽  
Forest Reserve ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
The Relationship

The relationship between the fate of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), and distance from small-mammal tunnels was studied during 1958 in the Whiteshell Forest Reserve of eastern Manitoba. The objects were to determine the distance that small mammals can detect cocoons and to observe possible effects of the interactions of small-mammal predation and other natural mortality factors of the insect. Additional analyses of the data provided information on the behaviour of the predators and the ecology of the prey insect.

VITAL DYES AS MARKERS FOR BEHAVIORAL AND POPULATION STUDIES OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1968 ◽  
Vol 100 (5) ◽  
pp. 470-475 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
Rhodamine B ◽  
Population Studies ◽  
Nile Blue ◽  
Larix Laricina ◽  
Vital Dyes ◽  
Flight Range ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Adult Dispersal ◽  
Dye Retention

AbstractLarvae of the larch sawfly, Pristiphora erichsonii (Htg.), were fed foliage of tamarack, Larix laricina (Du Roi) K. Koch, treated with solutions of the vital dyes, Nile blue sulphate, rhodamine B, and coriphosphine O, to determine their suitability as markers. Coriphosphine O was highly toxic at the concentrations administered but successful tagging was obtained with the other two dyes. Optimal dye retention and survival were obtained when larvae were fed for 3 days early in the last stadium using Nile blue sulphate and throughout the last stadium using rhodamine B.Both dyes persisted throughout development and were incorporated in the cocoons and the oviposited eggs. They could be readily seen in all stages except for the cocoons and for eggs that contained rhodamine B. The dyes could be detected in cocoons by treating them with cold KOH followed by ethanol. The presence of rhodamine B in the eggs could be ascertained by its yellow fluorescence in ultraviolet.The dyes incorporated in the cocoons are relatively stable and laboratory tests indicate they probably can withstand weathering under normal field conditions over a 1-year period.The use of these dyes for internal marking should prove useful in studying adult dispersal and flight range and as a technique for use in population studies of the larch sawfly.

THE IDENTIFICATION AND ORIGIN OF THE STRAINS OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE), IN NORTH AMERICA

1974 ◽  
Vol 106 (11) ◽  
pp. 1121-1131 ◽  
Author(s):  
Horne R. Wong
Keyword(s):  
North America ◽  
North American ◽  
Land Bridge ◽  
Bering Land Bridge ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly

AbstractThis study identifies and presents a key to five strains of the larch sawfly, Pristiphora erichsonii (Hartig), which are designated Aweme, Fernie, Ambleside, Thirlmire, and Salzburg.Aweme and Fernie strains occur only in North America and Salzburg strain is confined to Eurasia. Two Eurasian strains, Ambleside and Thirlmire, were accidentally introduced into Canada from England by 1913 among cocoons shipped for the release of the parasite Mesoleius tenthredinis Morley. It is postulated that the ancestors of Aweme-Salzburg strains Fernie–Thirlmire strains dispersed across the Bering Land Bridge into North America some time in the Miocene. These phyletic lines evolved into distinct Eurasian and North American strains. Early infestations in North America apparently consisted of North American strains, while later outbreaks have consisted primarily of the recently introduced Eurasian strains.

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