The Relationship of Spathimeigenia spinigera Townsend (Diptera: Tachinidae) to its Host, Neodiprion swainei Midd. (Hymenoptera: Diprionidae)

1962 ◽  
Vol 94 (8) ◽  
pp. 809-818 ◽  
Author(s):  
H. A. Tripp
Keyword(s):  
Population Dynamics ◽  
Pinus Banksiana ◽  
Jack Pine ◽  
Immature Stages ◽  
Pine Sawfly ◽  
Factors Influencing ◽  
Form Part ◽  
Extensive Program ◽  
Relationship Of ◽  
The Relationship

Studies on the parasites of the Swaine jack pine sawfly, Neodiprion swainei Midd., form part of an extensive program designed to assess the factors influencing population dynamics of this important defoliator of jack pine, Pinus banksiana Lamb. Investigations were carried out in the Province of Quebec between 1955 and 1959 near the headwaters of the Gatineau River, Abitibi County, and continued during 1960 and 1961 near the source of the Vermillion River, County Laviolette. In both areas, one of the principal parasites associated with N. swainei was the tachinid, Spathimeigenia spinigera Townsend. Descriptions of the immature stages of this parasite, and details of its behaviour were published previously (Tripp, 1960).

THE SUPPRESSION OF GROWTH RINGS IN JACK PINE IN RELATION TO DEFOLIATION BY THE SWAINE JACK-PINE SAWFLY

1963 ◽  
Vol 41 (2) ◽  
pp. 227-235 ◽  
Author(s):  
L. C. O'Neil
Keyword(s):  
Pinus Banksiana ◽  
Radial Growth ◽  
Jack Pine ◽  
Growth Rings ◽  
Cross Sectional ◽  
Pine Sawfly ◽  
Young Stand ◽  
The Dead ◽  
Dense Stand

An investigation of the radial growth of jack pine (Pinus banksiana Lamb.) defoliated by the Swaine jack-pine sawfly (Neodiprion swainei Midd.) disclosed that growth rings were discontinuous and missing in cross-sectional disks from severely damaged trees. In young and open-grown trees with dead tops, the incidence of such deficiencies in radial growth was especially high in disks from upper regions of the stems, in the vicinity of the dead tops; radial growth was suspended for 1 year and subsequently resumed in disks from the lower regions of some stems. Cambial inactivity was more generalized in trees from an old and dense stand and it was detected in disks representing major portions of some of the stems sampled; the death of some trees followed 2 to 6 years of cambial inactivity in disks cut at various heights along their entire stems. Growth deficiencies in the young stand were clearly effects of severe sawfly defoliation. Data from the old, dense stand indicated that sawfly defoliation had perhaps merely hastened the gradual deterioration of the stand in which intertree competition was intense.

scholarly journals Understanding the factors influencing rill erosion on roadcuts in the south eastern region of South Africa

Solid Earth ◽  
2015 ◽  
Vol 6 (2) ◽  
pp. 633-641 ◽  
Author(s):  
K. E. Seutloali ◽  
H. R. Beckedahl
Keyword(s):  
South Africa ◽  
Vegetation Cover ◽  
Site Effects ◽  
Eastern Region ◽  
Rill Erosion ◽  
Economic Costs ◽  
Slope Gradient ◽  
Factors Influencing ◽  
Relationship Of ◽  
The Relationship

Abstract. Erosion on roadcuts is a concern due to the potential of causing environmental degradation, which has significant economic costs. It is therefore critical to understand the relationship between roadcut characteristics and soil erosion for designing roadcuts that are less vulnerable to erosion and to help road rehabilitation works. This study investigated the characteristics (i.e. gradient, length, percentage of vegetation cover and soil texture) of degraded (i.e. with rills) and non-degraded roadcuts (i.e. without rills) and explored the relationship of the roadcut characteristics with the dimensions (widths and depths) of the rills. Degraded roadcuts were steep (52.21°), long (10.70 m) and had a low percentage of vegetation cover (24.12) when compared to non-degraded roadcuts which had a gradient of 28.24°, length of 6.38 m and 91.7% of vegetation cover. Moreover, the gradient and percentage of vegetation cover of the roadcut significantly determine the rill dimensions. The widths and depths of the rills increase with the increase in slope gradient and decrease with an increase in percentage of vegetation cover. Moreover, the widths and depths of the rills decreased downslope of the roadcuts. Based on these results, re-vegetation of roadcuts as well as construction of gentle gradients could minimise rill erosion and hence the negative on-site and off-site effects.

Theoretical Perspectives on Listening

1998 ◽  
Vol 18 ◽  
pp. 3-19 ◽  
Author(s):  
Tony Lynch
Keyword(s):  
Language Skills ◽  
Future Research ◽  
Discourse Comprehension ◽  
Complex Dynamic ◽  
The Past ◽  
Factors Influencing ◽  
Theoretical Perspectives ◽  
Relationship Of ◽  
The Relationship

Research into listening over the past three decades has, above all, highlighted the fundamental intricacy of the processes involved. In order to make sense of spoken messages, listeners may need to integrate information from a range of sources: phonetic, phonological, prosodic, lexical, syntactic, semantic, and pragmatic. The fact that we achieve all this in real time as the message unfolds makes listening “complex, dynamic, and fragile” (Celce-Murcia 1995:366). In this review I consider research into four aspects of these complexities: processes (e.g., speech recognition, discourse comprehension, and memory); the role of context; factors influencing listening; and the relationship of listening with other language skills. Finally I suggest likely directions for future research into listening.

POTENTIAL OF ANTIFEEDANTS TO CONTROL LARVAL FEEDING OF SELECTED NEODIPRION SAWFLIES (HYMENOPTERA: DIPRIONIDAE)

1976 ◽  
Vol 108 (11) ◽  
pp. 1137-1144 ◽  
Author(s):  
J. N. All ◽  
D. M. Benjamin
Keyword(s):  
Pinus Banksiana ◽  
Feeding Habits ◽  
Field Tests ◽  
Field Studies ◽  
Jack Pine ◽  
Larval Feeding ◽  
Pine Sawfly ◽  
European Pine Sawfly ◽  
Feeding Development ◽  
Laboratory Bioassays

AbstractAntifeedants for controlling larval feeding of several Neodiprion sawflies were evaluated in laboratory and field studies. Nine commercially available insect antifeedants and a hexane extract of the juvenile foliage of jack pine, Pinus banksiana Lambert, were tested on larvae of six species. In laboratory bioassays larvae exhibited varying sensitivity to antifeedants; generally species with monophagous or restricted oligophagous feeding habits were most sensitive. In the laboratory the Swaine jack pine sawfly, Neodiprion swainei Middleton, had severely restricted feeding, development, survival, and fecundity. Triphenyltin hydroxide was toxic to N. swainei and to European pine sawfly, N. sertifer (Geoffroy). In field tests certain antifeedants disrupted N. swainei feeding and development. The colonial behavior of larvae often was disrupted and solitary larvae fell from trees or wandered on twigs. Colony disruption by most antifeedants was temporary and many larvae resumed feeding.

Notes on Leconte's Sawfly

1952 ◽  
Vol 84 (2) ◽  
pp. 59-61
Author(s):  
A. S. West
Keyword(s):  
Life History ◽  
Pinus Banksiana ◽  
Pinus Resinosa ◽  
Jack Pine ◽  
Red Pine ◽  
Pine Needles ◽  
Pine Sawfly ◽  
Neodiprion Lecontei ◽  
Significant Damage

Leconte's sawfly or the red-headed pine sawfly (Neodiprion lecontei Fitch) is a common insect attacking pines in Ontario. Plantations red pine are almost invariably attacked from the time the trees have reached two to four feet in height. Periodically epidemic populations cause significant damage. The life history and habits of the species have heen described by Middleton (2) who states that this insect attacks practically all species of pine as bell as larch. Schaffner (3) also indicates that the larvae feed on a wide variety of pine and occasionally on other conifers. Red pine (Pinus resinosa Ait.) is undoubtedly the usual host, although in Ontario jack pine (Pinus banksiana Lamb.) is sometimes attacked. In 1946 evidence was secured to show that jack pine needles may be selected for oviposition even in an area where red pine foliage is plentiful. (Figure 1).

scholarly journals A Research on Employee Retention in Sacred Heart College (Autonomous), Tirupattur

2019 ◽  
Vol 9 (2S3) ◽  
pp. 436-439
Keyword(s):  
Random Sampling ◽  
Employee Retention ◽  
Selection Process ◽  
Working Hours ◽  
Sacred Heart ◽  
Factors Influencing ◽  
Retention Initiatives ◽  
Correlation Result ◽  
Relationship Of ◽  
The Relationship

Many colleges experience increase in attrition and it has great impact on the performance of the colleges. Objective of this study is to find why employee are leaving their job and propose retention initiatives. The research instrument used to obtain data was questionnaire. A total 200 employees are there in the college. By using random sampling a total of 140 employees were interviewed using questionnaires. Correlation analysis is used to test the inter correlation between the variable. Correlation result shows that the two variables of motivation and job satisfaction were correlated with employee retention in the college. Same tool has been used to determine the relationship between the variables namely the relationship of the management with the staff and the factors influencing this relationship to grow stronger. Results indicate attrition is associated with compensation provided for the additional working hours to the staff and their selection process. These findings clearly indicate that in order to retain the best talented employees in the college, taking care of the employees by having good relationship with them is a must.

scholarly journals Influences of Cultural Elements on Metaphor

2016 ◽  
Vol 6 (2) ◽  
pp. 126
Author(s):  
Keyu He
Keyword(s):  
Human Mind ◽  
Cultural Factors ◽  
Cultural Elements ◽  
Language And Culture ◽  
Factors Influencing ◽  
The People ◽  
Figure Of Speech ◽  
Relationship Of ◽  
Different Cultures ◽  
The Relationship

<p>Metaphor is not only an important figure of speech, but also a cognitive means of the human mind. The people with different means of thinking have different cultures. The metaphorical language used by people must be fully saturated with culture peculiar to it. Metaphor, as a figure of speech, is unavoidably associated with culture due to the relationship of language and culture. As far as the theme of the thesis is concerned, it tries to analyze the cultural factors influencing the formation of metaphor.</p>

Oviposition of the Red-Headed Pine Sawfly, Neodiprion lecontei (Fitch)

1960 ◽  
Vol 92 (6) ◽  
pp. 430-435 ◽  
Author(s):  
K. J. Griffiths
Keyword(s):  
Pinus Banksiana ◽  
Jack Pine ◽  
Oviposition Behaviour ◽  
Pine Sawfly ◽  
Important Group ◽  
Neodiprion Lecontei ◽  
Cast Doubt ◽  
The Subject ◽  
European Pine Sawfly

The oviposition behaviour of Neodiprion sawflies has been the subject of much investigation in recent years. The impetus for this interest seems to lie in the paper by Atwood and Peck (1943), in which it was suggested that the number and spacing of eggs on needles were a useful tool for the identification of memhers of this important group of conifer defoliators. Ghent (1955) has analysed the egg clusters of N. pratti banksianae Roh., and Ghent and Wallace (1958) have investigated the behaviour responsible for the pairing of eggs on adjacent jack pine (Pinus banksiana Lamb. ) needles by N. swainei Midd. More recently, Ghent (1959) has presented a study of the factors determining the spacing of eggs by the European pine sawfly, N. sertifer (Geoff.). Of these, the 1955 and 1959 papers, in addition to making valuable contributions to our understanding of the behaviour of adults, cast doubt on the usefulness of the number and spacing of eggs as identifying characters in these species.

Notes on the Parasites of Neodiprion nanulus Schedl (Hymenoptera: Tenthredinidae)

1954 ◽  
Vol 86 (4) ◽  
pp. 167-168 ◽  
Author(s):  
H. C. Coppel
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Pinus Banksiana ◽  
Pinus Resinosa ◽  
Jack Pine ◽  
Red Pine ◽  
Pine Sawfly ◽  
Beneficial Insects ◽  
Heavy Infestation

In collecting sawfly eggs, larvae, and cocoons for propagating beneficial insects at the Belleville laboratory, a heavy infestation of a pine sawfly, Neodiprion nanulus Schedl, was discovered in 1942 nine miles north of Belleville, on a 25-year-old plantation of red pine, Pinus resinosa Ait.; Scots pine, Pinus sylvestris L.; and jack pine, Pinus banksiana Lamb.From samples of the eggs collected in the spring of 1943, no parasites emerged.

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