Ecological applications of pheromone trapping of Malacosoma disstria and Choristoneura conflictana

2008 ◽  
Vol 140 (5) ◽  
pp. 573-581 ◽  
Author(s):  
Brad C. Jones ◽  
Maya L. Evenden

AbstractThe forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), and large aspen tortrix, Choristoneura conflictana (Walker) (Lepidoptera: Tortricidae), are important pests of trembling aspen, Populus tremuloides Michx. (Salicaceae), in western Canada. Populations of both species can be monitored with sex pheromone-baited traps as part of an integrated pest management program. Moths captured in pheromone traps can also be used for ecological studies. Captured males of each species were examined to test the effect of population density, geographic region, and collection date on moth quality. Moth quality was assessed on the basis of wing area and level of infection with microsporidian parasites. The level of microsporidian infection of M. disstria was strongly dependent on geographic region but not on population density. Male M. disstria from high-density populations had smaller wings than males from endemic populations. Wing area of male M. disstria decreased throughout the flight period. Neither collection date nor microsporidian infection level affected wing area of male C. conflictana. Collection date also did not affect the level of microsporidian infection of C. conflictana. These data support pheromone trapping as a tool to detect microsporidian infections and examine their temporal and density-dependent effects on wing size in M. disstria and C. conflictana populations.

2005 ◽  
Vol 137 (5) ◽  
pp. 615-619 ◽  
Author(s):  
Maya L. Evenden

Trembling aspen, Populus tremuloides Michx. (Salicaceae), is the most widely distributed tree species in North America (Perala 1990) and is considered to be an ecologically (Hogg et al. 2002) and economically important (Brandt et al. 2003) component of the boreal forest. Due to the recently increased economic value of trembling aspen (Brandt et al. 2003), the impact of native insect defoliators on tree growth and mortality has become commercially important. Two of the most significant defoliators of trembling aspen throughout its range in Canada are the forest tent caterpillar (FTC), Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), and the large aspen tortrix (LAT), Choristoneura conflictana Walker (Lepidoptera: Tortricidae).


1955 ◽  
Vol 87 (11) ◽  
pp. 461-473 ◽  
Author(s):  
R. M. Prentice

Periodic outbreaks of the large aspen tortrix, Choristoneura conflictana (Wlkr.) severely defoliate trembling aspen, Populus tremuloides Michx., in parts of Manitoba and Saskatchewan. The inadequacy of information on the insect prompted further investigation of its life history and the factors affecting its abundance. Field studies were conducted in Northern Manitoba and Saskatchewan, where from 1950 to 1954 the insect was found at various population levels.


1997 ◽  
Vol 129 (6) ◽  
pp. 991-999 ◽  
Author(s):  
R.W. Nicol ◽  
J.T. Arnason ◽  
B. Helson ◽  
M.M. Abou-Zaid

AbstractLarval growth and pupal parameters of the forest tent caterpillar (Malacosoma disstria Hübner) reared on the foliage of two host trees (Populus tremuloides Michx. and Acer saccharum Marsh.) and one nonhost tree (Acer rubrum L.) were quantified. This was achieved by undertaking a larval development bioassay under controlled laboratory conditions, but using fresh leaves collected in two field seasons. Larvae fed foliage of P. tremuloides grew exponentially and began to pupate after 3 weeks. Larvae fed with A. saccharum gained significantly less weight and had a reduced number of larvae pupate, and the pupae weighed significantly less than their counterparts fed on P. tremuloides. All larvae that were fed the foliage of A. rubrum died within 2 weeks. A nutritional utilization bioassay with fourth-instar larvae revealed that the foliage of A. saccharum has a growth-inhibitory component, whereas that of A. rubrum is antifeedant. Reasons are discussed for the discrepancy between the many reports of A. saccharum being a food host for M. disstria in the field and the laboratory results.


Author(s):  
Rimantas Tamosiunas ◽  
Laisvune Duchovskiene ◽  
Alma Valiuskaite

The investigation of Hoplocampa minuta (Christ, 1791) (black plum sawfly), Hoplocampa flava (Linné, 1760) (yellow plum sawfly) and Hoplocampa testudinea (Klug, 1816) (apple sawfly) populations using white sticky traps Rebell®bianco was carried out in conventionally and organically managed apple and conventionally managed plum orchards of the Institute of Horticulture of Lithuanian Research Centre for Agriculture and Forestry in 2010 and 2011. Temperature sums for predicting sawfly spring emergence were determined: 120 ± 5 degree-days for apple sawfly, 85 ± 26 degree-days for black plum sawfly and 95 ± 28 degree-days for yellow plum sawfly. However, more years of the study are needed to confirm these temperature sums. The average densities of sawflies during the flight period were: H. minuta - 14.8 ± 7.3 sawfly trap-1 in 2010 and 54.2 ± 35.9 sawfly trap-1 in 2011; H. flava - 13.3 ± 5.2 sawfly trap-1 in 2010,and 16.6 ± 6.9 sawfly trap-1 in 2011; and H. testudinea in organic orchard - 38.3 ± 26.2 sawfly trap-1 in 2010 and 5.0 ± 2.8 sawfly trap-1 in 2011, in conventional orchard - 14.8 ± 8.1 sawfly trap-1 in 2010 and 9.3 ± 4.3 sawfly trap-1 in 2011. Conditions for development of both plum sawfly species were better in 2011, when abundance nearly reached the economic threshold. Population density, cumulative trap catches during the flight period, and damage caused by apple sawfly varied significantly between the study years and apple cultivars. In 2010, apple sawfly was more abundant and caused more serious damage than in 2011. The economic threshold of 30-40 individuals per trap was reached in 2010 due to the better conditions of development. The various apple cultivars suffered different damage levels: cv. ‘Aldas’, ‘Vitos’ and ‘Rubinola’ suffered the highest damage in the organic orchard, but no significant differences were observed. In the conventional garden, cv. ‘Auksis’ had the most damaged fruits.


1979 ◽  
Vol 111 (7) ◽  
pp. 841-846 ◽  
Author(s):  
Arthur Retnakaran ◽  
Larry Smith ◽  
Bill Tomkins ◽  
Jeffrey Granett

AbstractDimilin (25% wettable powder) was mixed in water and sprayed from a Grumman Agcat aircraft equipped with four micronair units at the rate of 70 g (active ingredients) / 4,67 L/ha (1 oz/0.5 U.S. gal per acre) on two stands of trembling aspen, Populus tremuloides Michx., heavily infested with forest tent caterpillar, Malacosoma disstria Hübner. The material was applied when the insects were in the first and second instars and the trees were starting to flush. Spray deposit analysis using a dye, Rhodamine-B, in the spray mix and spray plates in the plots indicated that conditions for spraying in the morning were better than those in the evening as expected. Total control of the forest tent caterpillar with very little defoliation of the trees was achieved.


2020 ◽  
Author(s):  
Young Hwa Lee ◽  
Young June Choe ◽  
Seung-Sik Hwang ◽  
Sung-Il Cho

Abstract Background Varicella is a highly contagious disease caused by the varicella-zoster virus (VZV). Given its tendency to cluster geographically, spatial analyses may provide better understanding of the pattern of varicella transmission. We investigated the spatial characteristics of varicella in Korea and the risk factors for varicella at a national level. Methods Using national surveillance and demographic data, we examined the spatial distribution of incidence rates and their spatial autocorrelation and calculated Moran’s index. Spatial regression analysis was used to identify sociodemographic predictors of varicella incidence at the district level. Results An increasing tendency in the annual incidence of varicella was observed over a 12-year period (2006–2017), with a surge in 2017. There was a clear positive spatial autocorrelation of the varicella incidence rate during the surveillance period. During 2006–2014, High-High (HH) clusters were mostly confined to the northeast region and neighboring districts. Population density and the number of hospitals per 1,000 persons had negative coefficients, and the former was significant. Childhood percentage, percentage of children under 12 years of age among total population, and vaccine coverage rate had positive coefficients, but only the former was significant. Conclusion There was a temporal uptrend in the incidence of varicella in Korea from 2006 to 2017 in the setting of positive spatial associations. The varicella incidence according to geographic region varied with population density, childhood percentage, suggesting the importance of the community-level surveillance and monitoring strategies.


2010 ◽  
Vol 86 (5) ◽  
pp. 636-648
Author(s):  
Imre S. Otvos ◽  
Kangakola Omendja ◽  
Sharene Foord ◽  
Nicholas Conder ◽  
Neil Borecky ◽  
...  

Forest tent caterpillar (Malacosoma disstria Hübner) is a major defoliator of hardwoods throughout North America, including aspen (Populus tremuloides Michx.). M. disstria has been a major concern in many parts of Canada for the last two decades, but until recently in British Columbia it was considered an aesthetic concern only. However, with the increasing interest in the cultivation of hardwoods for fibre, and more recently for fuel, this insect could become a major concern in hardwood management. Records of past M. disstria outbreaks in British Columbia were summarized. The locations and intensity of six outbreaks were overlaid on biogeoclimatic units to determine which biogeoclimatic zones have experienced repeated outbreaks of M. disstria. Between 1944 and 2003, M. disstria outbreaks have become larger in extent and longer in duration. Analysis indicated that aspen stands in the Boreal White and Black Spruce (BWBS), Sub- Boreal Spruce (SBS) and Interior Cedar-Hemlock (ICH) biogeoclimatic zones have been most frequently attacked. In the BWBS zone, most affected areas (93.3%) were defoliated for only one year (lightly). In the SBS and ICH zones, areas attacked by M. disstria tended to be defoliated two or more consecutive years (40.2% and 56.2%, respectively), and had a greater chance of being more severely defoliated than aspen stands in the BWBS zone. Key words: Malacosoma disstria, forest tent caterpillar, damage, outbreaks, hazard rating


2012 ◽  
Vol 35 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Bernard Têtu ◽  
Jean-Paul Fortin ◽  
Marie-Pierre Gagnon ◽  
Said Louahlia

Background: The aim of the Eastern Québec telepathology project is to provide uniform diagnostic telepathology services across a huge geographic region with a low population density. This project is intended to provide surgeons and pathologists with frozen section and second opinion services anywhere and at any time across the entire region in order to avoid unnecessary patient transfer.Methods: The project has been implemented in 21 sites, each equipped with a whole slide scanner, a macroscopy station, two videoconferencing devices and a viewer/case management and collaboration solution. Of the 21 sites, 6 are devoid of a pathology laboratory. Of the remaining 15 sites, two have no pathologists, 6 have one and 7 have two or more.Results: The project has been successful and most appreciated by pathologists and surgeons. We report a number of challenges related to change management that we had to take into account in the course of implementation of this network. The challenges underscore the need for regular visits and active support to participating centers by the project team.Conclusion: The Eastern Québec telepathology network is successful and improves medical care in this region. In the course of implementation, we encountered a number of challenges which required innovative solutions.


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