Sequential Sampling for Larvae of the Winter Moth, Operophtera brumata (Linn.). (Lepidoptera: Geometridae)

1956 ◽  
Vol 88 (6) ◽  
pp. 241-246 ◽  
Author(s):  
W. A. Reeks

The Forest Insect Survey of the Maritime Provinces has been observing an outbreak of the winter moth, Operophtera brumata (Linn.), since its discovery in Nova Scotia in 1949. In addition to noting annual changes in distribution, the Survey has made population counts on 8 to 20 tagged trees of red oak, Quercus rubra L., at each of seven locations along the south shore of the Province. These trees were sampled each year to show the abundance of larvae of the winter moth and the fall cankerworm, Alsophila pometaria (Harr.). Both species are commonly found on the same trees, and their life histories are similar. The collections and subsequent rearings also showed the degree of parasitism by native or introduced species of parasites. The defoliation of the trees was estimated at the time of sampling and again at the end of the feeding period to determine the relationship between larval population and defoliation. Some of the sampling data, which were collected from 1952 to 1955, are used to develap the sequential plan of sampling described herein. Use of the plan at the sampling stations should reduce the number of samples while retaining accuracy within predetermined limits.

1954 ◽  
Vol 86 (10) ◽  
pp. 433-438 ◽  
Author(s):  
R. F. Morris ◽  
W. A. Reeks

The winter moth, Operophtera brumata (Linn.), was not known to occur in North America until 1949, when it was first reported from the south shore of Nova Scotia by Hawholdt and Cuming (2) and Smith (4). By that time this introduced species was well established. It is suspected that the winter moth in association with the fall cankerworm, Alsophila pometaria (Harr.), has been causing considerable defoliation of deciduous tree species in the region since the early 1930's (2). The habits and stages of the winter moth have been described briefly by Smith (S), who also has indicated the important differences between the winter moth and the fall cankerworm (4).


1958 ◽  
Vol 90 (9) ◽  
pp. 538-540 ◽  
Author(s):  
C. C. Smith

The fall cankerworm, Alsophila pometaria (Harr.), and the winter moth, Operophtera brumata (Linn.), both feed to a great extent on the same tree species and prefer apple, Malus spp., red oak, Quercus rubra L., basswood, Tilia spp., white elm, Ulmus americana L., and Norway maple, Acer platanoides L. They also have similar life-histories and habits (Smith 1950 and 1953). Both lay their eggs on the trees in the fall and overwinter in this stage. The eggs hatch about the same time and the larvae of (both species mature about the third week in June. They drop to the ground and form cocoons at a depth of about an inch. The adults emerge about the same time, commencing usually during the last week in October and continuing until early December or until the ground freezes.


1961 ◽  
Vol 93 (2) ◽  
pp. 135-142 ◽  
Author(s):  
F. G. Cuming

In the early 1930's defoliation of red oak, Quercus rubra L., white elm, Ulmus americana L., apple, Malus spp., and other deciduous trees in the South Shore region of Nova Scotia was attributed to the fall cankerworm, Alsophila pometaria (Harr.), and the spring cankerworm, Paleacrita vernata (Peck). The identity of the latter was questioned when adults occurred in the fall. These adults were sutbsequently identified as Operophtera brumata (L.), the winter moth (Hawboldt and Cuming, 1950; Smith, 1950).


1983 ◽  
Vol 115 (3) ◽  
pp. 243-249 ◽  
Author(s):  
N. J. Holliday

AbstractPupae of winter moth, Operophtera brumata (L.) (Lepidoptera: Geometridae), from southwest England were subjected to nine temperature treatments in the laboratory. The pupal period of about 180 days was unaffected by changes in mean temperatures between 9.5 °C and 16.8 °C. Adult emergence was delayed at a mean temperature of 17.7 °C; no pupae survived at mean temperatures above this. These results are compared with conflicting statements in the literature about the relationship of length of the pupal period with temperature.No pupae died when exposed to temperature cycles of 20°–25 °C in the early part of the pupal period. The same temperatures near the time of adult emergence caused increased mortality. The duration of the pupal period was unaffected by exposure of pupae to 12 h (rather than diurnal) temperature cycles.


1990 ◽  
Vol 41 (2) ◽  
pp. 351 ◽  
Author(s):  
PG Allsopp

The dispersion characteristics of root-lesion, root-knot, spiral, stubby-root, stunt and ring nematodes in soil, and root-lesion, root-knot and spiral nematodes in roots in sugarcane fields, were determined in studies in southern Queensland. The Poisson distribution, negative binomial distribution, Iwao's regression model and Taylor's power law analysis were used to determine the relationship between mean and variance of nematode counts. All methods showed that nematodes were aggregated (Iwao's G 1.12-1.65, Taylor's b 1.10-1.76). In general, Taylor's power law gave better fit compared with the other models (R2>0.61). Relationships to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling were developed for all species. There were functional relationships between variance and mean of untransformed population counts for all species, but suitable transformations eliminated significant correlations in most cases.


2016 ◽  
Vol 3 (10) ◽  
pp. 160361 ◽  
Author(s):  
Anne l-M-Arnold ◽  
Maren Grüning ◽  
Judy Simon ◽  
Annett-Barbara Reinhardt ◽  
Norbert Lamersdorf ◽  
...  

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests ( Quercus petraea  L.) that were heavily infested by the leaf herbivores winter moth ( Operophtera brumata  L.) and mottled umber ( Erannis defoliaria  L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha −1 and 319 kg N ha −1 , respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback.


2009 ◽  
pp. 93-112
Author(s):  
Emanuela Confalonieri ◽  
Cristina Giuliani ◽  
Alessandra Bongiana ◽  
Paola Pavesi

- The present study, related to the one published some years ago (Confalonieri et al., 2004), is an investigation on forced prostitution and the related violence's types in immigrant women involved in streetwalking prostitution. Using the social records available by the Ufficio Stranieri (Comune di Milano), the purpose is to identify the presence of 1) childhood maltreatments or violence before the entry in sex exploitation market and 2) subsequent adult sexual revictimization from partners, pimps and clients. Data were analysed using phenomenological descriptive analysis. The relationship between childhood maltreatment and abuse and subsequent involvement in sex work is discussed comparing data and life histories of immigrant prostitutes coming from Nigeria and East Europe. The role played by social and contexual variables in sexual exploitation story are also considered.Key words: immigration, violence, prostitution, infancy, adulthood.Parole chiave: immigrazione, violenza, prostituzione, infanzia, etŕ adulta.


1988 ◽  
Vol 120 (7) ◽  
pp. 697-698 ◽  
Author(s):  
Kenneth A. Pivnick

In a recently completed study involving pheromone trapping of the winter moth, Operophtera brumata (L.), and the Bruce spanworm, O. bruceata (Hulst), on Vancouver Island (Pivnick et al. 1988), I noticed that O. bruceata had wing colouration different from sympatric O. brumata. The west coast O. bruceata has a pale yellow-orange costal margin on the underside of the forewings and this is faint to absent in O. brumata (Fig. 1). It is also absent from O. bruceata in Saskatoon, which is interesting because some authors consider the west coast population of O. bruceata to be a separate species: the western winter moth, O. occidentalis (see Ferguson 1978; Pivnick et al. 1988). Descriptions of O. bruceata (Brown 1962) and O. brumata (Cuming 1961), and a taxonomic key to these two species (Eidt et al. 1966), do not mention any distinctive wing markings that could be used to separate the two species.


2020 ◽  
Vol 77 (2) ◽  
pp. 295-313 ◽  
Author(s):  
Joseph Munyandorero

The recruitment compensation metrics, the stock–recruit steepness (h) and compensation ratio (κ), are difficult to estimate, yet they are integral components of contemporary fishery models. To aid in the estimation of κ and h, a hybrid method to construct their prior distributions for a species is developed. The method is hybrid because it integrates (i) a meta-analysis of the relationship between maximum rates of recruit production (α) and asymptotic lengths obtained across fish species of different life histories and (ii) species-specific unfished spawning biomass per recruit (Φ0). This method is applied to five finfish species found off the East Coast of the United States. Uncertainty is introduced by sampling growth parameters, α, and natural mortality and — through Monte Carlo simulations — propagated into Φ0, κ, and h for the Beverton–Holt and Ricker stock–recruit relationships. Descriptive statistics and parameters from probability density functions of the simulated distributions of κ and h are generated. The method developed requires fewer inputs than the reproductive ecology method while likewise allowing the development of species-specific statistics for κ and h. These statistics, rather than their counterparts generated from classical meta-analyses, are better suited for use in fishery models.


1960 ◽  
Vol 92 (11) ◽  
pp. 862-864 ◽  
Author(s):  
D. G. Embree

Cyzenis albicans (Fall.) has been introduced into Nova Scotia as a control measure against the winter moth, Operophtera brumata (L.). The parasite attacks the late larval stages of the winter moth, pupates within the host in the ground, and emerges in the spring. The first liberations were made at Oak Hill near Bridgewater and the dates of releases as well as the numbers released were reported by Graham (1958) as follows: 1954, 31; 1955, 1008; 1956, 1005; 1957, 250. Graham made recoveries of C. albicans from rearings of larvae collected at Oak Hill in 1956 and 1957 and found that parasitism was less than two per cent both years. While liberations have been made at other locations in the Province since 1957, no further releases have been made at or near Oak Hill.


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