A new standard pupation shelter for sampling pupae and estimating mortality of the hemlock looper (Lepidoptera: Geometridae)

2004 ◽  
Vol 136 (6) ◽  
pp. 879-887 ◽  
Author(s):  
Christian Hébert ◽  
Luc Jobin ◽  
Richard Berthiaume ◽  
Jean-François Mouton ◽  
Alain Dupont ◽  
...  

AbstractA new standard pupation shelter for sampling hemlock looper (Lambdina fiscellaria) pupae is described and compared with the burlap band method developed by Otvos (1974; The Canadian Entomologist106: 329–31). The new pupation shelter is placed on the bole, at breast height or in the crown, to estimate population abundance and mortality. The utilization of two shelters at breast height was as efficient as the use of burlap bands to estimate hemlock looper abundance and more efficient for sampling braconid cocoons. It provided reliable estimates of braconid and tachinid parasitism but overestimated that by ichneumonids. This new pupation shelter is an inexpensive tool that can be used easily by nonspecialized personnel, thus allowing increases in the number of sample plots, which is necessary to improve detection of outbreaks of the hemlock looper. This new shelter could be used to sample other lepidopterans whose late-instar larvae aggregate in concealed pupation sites.

1989 ◽  
Vol 24 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Terry L. Shore

Burlap wrapped around western hemlock, Tsuga heterophylla (Raf.) Sarg., trees at breast height was used to trap pupae of the western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst). The number of pupae in the traps was highly variable and was not related to tree diameter or the surface area of the trap. There was a significant relationship between the number of viable pupae per trap and the number of healthy western hemlock looper eggs subsequently laid on lichen in the trees. Sample size requirements are presented.


2005 ◽  
Vol 82 (2) ◽  
pp. 57-63 ◽  
Author(s):  
C. Hébert ◽  
L. Jobin ◽  
R. Berthiaume ◽  
C. Coulombe ◽  
A. Dupont

The hemlock looper, Lambdina fiscellaria, pupal distribution was studied through a 3-year outbreak cycle near Lac Princeton on Anticosti Island in Quebec. Over the 3 years, 10 balsam fir trees were cut and all pupae were counted on the stem and branches (non-foliated vs foliated parts) of the lower, middle and upper crowns and on the stem below crown. In pre-outbreak conditions, pupae were mostly found on branches of the middle and upper crowns. During the outbreak, pupal density did not increase on these parts of the trees, since pupae were mostly found on the stem, from the ground to the middle crown, and on branches of the lower crown. Few pupae were found on the foliated portion of branches in post-outbreak conditions but most were found on the basal non-foliated part of branches, which appears to be a preferred location for hemlock looper pupation. In order to optimize detection of population increases in monitoring networks, we suggest using pupal traps at breast height on balsam fir trees.


SIMBIOSA ◽  
2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Yarsi Efendi ◽  
Ramses Ramses ◽  
Adil Waraney

The Research have done started from February to June 2013, have purpose to compare the population abudance and difference of morphometric Telescopium telescopium in two different observation places. The sampling point determined by method of random sampling. The sample has taken by plot measurement 10x10 m and the sub plot measurement 1x1 m placed in 5 pieces plot measurement 10x10 m.The research result got 62 individual Telescopium telescopium in research location with the density value 0.155 (ind/m²) at 1st location and 297 individual Telescopium telescopium with the density value 0.7425 (ind/m²) at 2nd location. The average measurement result (length and dimeter) morphometric of Telescopium telescopium found at mangrove habitat in Sungai Bongkok was length 8.94 cm and diameter 4.73 cm. The morphometric average measurement result (length and diameter) Telescopium telescopium found at mangrove habitat around the garbage disposal Punggur was length 4.66 cm and diameter 2.54 cm. Keywords: Population Abundance; Morphometric; Telescopium telescopium. 


2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  

Growth and value production of Douglas-fir under varying stand densities The investigation is focused on the effects of initial tree number and thinning on growth and value performance of Douglas-fir stands. Data base is a coordinated Douglas-fir spacing experiment in South Germany, started 40 years ago and comprising variants of tree numbers with 500, 1,000, 2,000 and 4,000 Douglas-firs per hectare. The treatment was performed according to a standardized experiment program. The results show that at low initial tree numbers, the diameter on breast height (DBH) of (pre)dominant trees at the beginning of the observations (with 12 m top height) is bigger than at higher initial plant numbers. Accordingly, the quotient of height (H) to DBH (as an indicator for tree's static stability) is lower. The further development of DBH and H/DBH quotient is decisively determined by stand treatment, which superimposes the effect of the initial tree number. The total volume growth shows a clear differentiation, too, the variants with initially high tree numbers appearing on top. In the monetary analysis, this ranking is reversed: despite a supposed inferior wood quality, the variants with lower initial tree numbers clearly outperform the ones with higher numbers in terms of value. From these results, the following silvicultural recommendations for Douglas-fir can be derived: the initial tree numbers should be in the range from 1,000 to 2,000 plants per hectare. On technically not accessible sites, even lower tree numbers may come into question. The strong influence of stand treatment on DBH and H/DBH development highlights the problem of postponed thinnings, for this causes growth and stability losses even under favorable starting conditions in terms of competition.


Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 170
Author(s):  
Gladys N. Benitez ◽  
Glenn D. Aguilar ◽  
Dan Blanchon

The spatial distribution of corticolous lichens on the iconic New Zealand pōhutukawa (Metrosideros excelsa) tree was investigated from a survey of urban parks and forests across the city of Auckland in the North Island of New Zealand. Lichens were identified from ten randomly selected trees at 20 sampling sites, with 10 sites classified as coastal and another 10 as inland sites. Lichen data were correlated with distance from sea, distance from major roads, distance from native forests, mean tree DBH (diameter at breast height) and the seven-year average of measured NO2 over the area. A total of 33 lichen species were found with coastal sites harboring significantly higher average lichen species per tree as well as higher site species richness. We found mild hotspots in two sites for average lichen species per tree and another two separate sites for species richness, with all hotspots at the coast. A positive correlation between lichen species richness and DBH was found. Sites in coastal locations were more similar to each other in terms of lichen community composition than they were to adjacent inland sites and some species were only found at coastal sites. The average number of lichen species per tree was negatively correlated with distance from the coast, suggesting that the characteristic lichen flora found on pōhutukawa may be reliant on coastal microclimates. There were no correlations with distance from major roads, and a slight positive correlation between NO2 levels and average lichen species per tree.


2021 ◽  
Vol 13 (8) ◽  
pp. 4167
Author(s):  
David Kombi Kaviriri ◽  
Huan-Zhen Liu ◽  
Xi-Yang Zhao

In order to determine suitable traits for selecting high-wood-yield Korean pine materials, eleven morphological characteristics (tree height, basal diameter, diameter at breast height, diameter at 3 meter height, stem straightness degree, crown breadth, crown height, branch angle, branch number per node, bark thickness, and stem volume) were investigated in a 38-year-old Korean pine clonal trial at Naozhi orchard. A statistical approach combining variance and regression analysis was used to extract appropriate traits for selecting elite clones. Results of variance analysis showed significant difference in variance sources in most of the traits, except for the stem straightness degree, which had a p-value of 0.94. Moderate to high coefficients of variation and clonal repeatability ranged from 10.73% to 35.45% and from 0.06% to 0.78%, respectively. Strong significant correlations on the phenotypic and genotypic levels were observed between the straightness traits and tree volume, but crown breadth was weakly correlated to the volume. Four principal components retaining up to 80% of the total variation were extracted, and stem volume, basal diameter, diameter at breast height, diameter at 3 meter height, tree height, and crown height displayed high correlation to these components (r ranged from 0.76 to 0.98). Based on the Type III sum of squares, tree height, diameter at breast height, and branch number showed significant information to explain the clonal variability based on stem volume. Using the extracted characteristics as the selection index, six clones (PK105, PK59, PK104, PK36, PK28, and K101) displayed the highest Qi values, with a selection rate of 5% corresponding to the genetic gain of 42.96% in stem volume. This study provides beneficial information for the selection of multiple traits for genetically improved genotypes of Korean pine.


2012 ◽  
Vol 93 (1) ◽  
pp. 134-148 ◽  
Author(s):  
Juan L. Celis-Diez ◽  
Jennifer Hetz ◽  
Paula A. Marín-Vial ◽  
Gonzalo Fuster ◽  
Pablo Necochea ◽  
...  

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