Phenological diversity in the interactions between winter moth (Operophtera brumata) larvae and parasitoid wasps in sub-arctic mountain birch forest

2011 ◽  
Vol 101 (6) ◽  
pp. 705-714 ◽  
Author(s):  
O.P.L. Vindstad ◽  
S.B. Hagen ◽  
J.U. Jepsen ◽  
L. Kapari ◽  
T. Schott ◽  
...  
Keyword(s):  
Larval Period ◽  
Spatiotemporal Variation ◽  
Trophic Levels ◽  
Mountain Birch ◽  
Individual Species ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Parasitism Rates ◽  
Phenological Diversity ◽  
Parasitoid Guild

AbstractPopulation cycles of the winter moth (Operophtera brumata) in sub-arctic coastal birch forests show high spatiotemporal variation in amplitude. Peak larval densities range from levels causing little foliage damage to outbreaks causing spatially extensive defoliation. Moreover, outbreaks typically occur at or near the altitudinal treeline. It has been hypothesized that spatiotemporal variation in O. brumata cycle amplitude results from climate-induced variation in the degree of phenological matching between trophic levels, possibly between moth larvae and parasitoids. The likelihood of mismatching phenologies between larvae and parasitoids is expected to depend on how specialized parasitoids are, both as individual species and as a guild, to attacking specific larval developmental stages (i.e. instars). To investigate the larval instar-specificity of parasitoids, we studied the timing of parasitoid attacks relative to larval phenology. We employed an observational study design, with sequential sampling over the larval period, along an altitudinal gradient harbouring a pronounced treeline outbreak of O. brumata. Within the larval parasitoid guild, containing seven species groups, the timing of attack by different groups followed a successional sequence throughout the moth's larval period and each group attacked 1–2 instars. Such phenological diversity within parasitoid guilds may lower the likelihood of climate-induced trophic mismatches between victim populations and many/all of their enemies. Parasitism rates declined with increasing altitude for most parasitoid groups and for the parasitoid guild as a whole. However, the observed spatiotemporal parasitism patterns provided no clear evidence for or against altitudinal mismatch between larval and parasitoid phenology.

scholarly journals Seasonal and elevational variability in the induction of specialized compounds from mountain birch (Betula pubescens var. pumila) by winter moth larvae (Operophtera brumata)

2021 ◽  
Author(s):  
Ingvild Ryde ◽  
Tao Li ◽  
Jolanta Rieksta ◽  
Bruna Marques dos Santos ◽  
Elizabeth H J Neilson ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Spectrometry ◽  
Insect Herbivory ◽  
Betula Pubescens ◽  
Mountain Birch ◽  
Feeding Period ◽  
Operophtera Brumata ◽  
Voc Emissions ◽  
Winter Moth ◽  
Chromatography Mass Spectrometry

Abstract The mountain birch (Betula pubescens var. pumila (L.)) forest in the Subarctic is periodically exposed to insect outbreaks, which are expected to intensify due to climate change. To mitigate abiotic and biotic stresses, plants have evolved chemical defenses, including volatile organic compounds (VOCs) and non-volatile specialized compounds (NVSCs). Constitutive and induced production of these compounds, however, are poorly studied in Subarctic populations of mountain birch. Here, we assessed the joint effects of insect herbivory, elevation, and season on foliar VOC emissions and NVSC contents of mountain birch. VOCs were sampled in situ by an enclosure technique and analyzed by gas chromatography–mass spectrometry. NVSCs were analyzed by liquid chromatography–mass spectrometry using an untargeted approach. At low elevation, experimental herbivory by winter moth larvae (Operophtera brumata) increased emissions of monoterpenes and homoterpenes over the three-week feeding period, and sesquiterpenes and green leaf volatile in the end of the feeding period. At high elevation, however, herbivory augmented only homoterpene emissions. The more pronounced herbivory effects at low elevation were likely due to higher herbivory intensity. Of the individual compounds, linalool, ocimene, 4,8-dimethylnona-1,3,7-triene, 2-methyl butanenitrile, and benzyl nitrile were among the most responsive compounds in herbivory treatments. Herbivory also altered foliar NVSC profiles at both low and high elevations, with the most responsive compounds likely belonging to fatty acyl glycosides and terpene glycosides. Additionally, VOC emissions from non-infested branches were higher at high than low elevation, particularly during the early season, which was mainly driven by phenological differences. VOC emissions varied substantially over the season, largely reflecting the seasonal variations in temperature and light levels. Our results suggest that if insect herbivory pressure continues to rise in the mountain birch forest with ongoing climate change, it will significantly increase VOC emissions with important consequences for local trophic interactions and climate.

scholarly journals Forest defoliator pests alter carbon and nitrogen cycles

2016 ◽  
Vol 3 (10) ◽  
pp. 160361 ◽  
Author(s):  
Anne l-M-Arnold ◽  
Maren Grüning ◽  
Judy Simon ◽  
Annett-Barbara Reinhardt ◽  
Norbert Lamersdorf ◽  
...  
Keyword(s):  
Climate Change ◽  
Leaf Litter ◽  
Soil Microbial Activity ◽  
Quercus Petraea ◽  
Oak Forests ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Carbon And Nitrogen ◽  
Soil Microbial ◽  
C And N

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.

A Note on the Association of Fall Cankerworm (Alsophila pometaria (Harr.)) with Winter Moth (Operophtera brumata (Linn.)) (Lepidoptera: Geometridae)

1958 ◽  
Vol 90 (9) ◽  
pp. 538-540 ◽  
Author(s):  
C. C. Smith
Keyword(s):  
Tree Species ◽  
Life Histories ◽  
Quercus Rubra ◽  
Acer Platanoides ◽  
Operophtera Brumata ◽  
Ulmus Americana ◽  
Winter Moth ◽  
The Third ◽  
Norway Maple ◽  
Fall Cankerworm

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.

Evaluation of genomic sequence-based growth rate methods for synchronized Synechococcus cultures

2021 ◽  
Author(s):  
Julia Carroll ◽  
Nicolas Van Oostende ◽  
Bess B. Ward
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Dna Replication ◽  
Growth Rates ◽  
Genomic Sequence ◽  
Niche Differentiation ◽  
Trophic Levels ◽  
Individual Species ◽  
Cell Counts

Standard methods for calculating microbial growth rates (μ) through the use of proxies, such as in situ fluorescence, cell cycle, or cell counts, are critical for determining the magnitude of the role bacteria play in marine carbon (C) and nitrogen (N) cycles. Taxon-specific growth rates in mixed assemblages would be useful for attributing biogeochemical processes to individual species and understanding niche differentiation among related clades, such as found in Synechococcus and Prochlorococcus . We tested three novel DNA sequencing-based methods (iRep, bPTR, and GRiD) for evaluating growth of light synchronized Synechococcus cultures under different light intensities and temperatures. In vivo fluorescence and cell cycle analysis were used to obtain standard estimates of growth rate for comparison with the sequence-based methods (SBM). None of the SBM values were correlated with growth rates calculated by standard techniques despite the fact that all three SBM were correlated with percentage of cells in S phase (DNA replication) over the diel cycle. Inaccuracy in determining the time of maximum DNA replication is unlikely to account entirely for the absence of relationship between SBM and growth rate, but the fact that most microbes in the surface ocean exhibit some degree of diel cyclicity is a caution for application of these methods. SBM correlate with DNA replication but cannot be interpreted quantitatively in terms of growth rate. Importance Small but abundant, cyanobacterial strains such as the photosynthetic Synechococcus spp. are essential because they contribute significantly to primary productivity in the ocean. These bacteria generate oxygen and provide biologically-available carbon, which is essential for organisms at higher trophic levels. The small size and diversity of natural microbial assemblages means that taxon-specific activities (e.g., growth rate) are difficult to obtain in the field. It has been suggested that sequence-based methods (SBM) may be able to solve this problem. We find, however, that SBM can detect DNA replication and are correlated with phases of the cell cycle but cannot be interpreted in terms of absolute growth rate for Synechococcus cultures growing under a day-night cycle, like that experienced in the ocean.

WING COLOURATION DIFFERENCE BETWEEN THE BRUCE SPANWORM OPEROPHTERA BRUCEATA (HULST) (LEPIDOPTERA: GEOMETRIDAE) AND THE WINTER MOTH OPEROPHTERA BRUMATA (L.) ON VANCOUVER ISLAND

1988 ◽  
Vol 120 (7) ◽  
pp. 697-698 ◽  
Author(s):  
Kenneth A. Pivnick
Keyword(s):  
West Coast ◽  
Vancouver Island ◽  
Costal Margin ◽  
Operophtera Brumata ◽  
The West ◽  
Separate Species ◽  
Winter Moth ◽  
Pheromone Trapping ◽  
Yellow Orange ◽  
Bruce Spanworm

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.

Observations on the Spread of Cyzenis albicans (Fall.) (Tachinidae: Diptera), an Introduced Parasite of the Winter Moth, Operophtera brumata (L.), (Geometridae: Lepidoptera), in Nova Scotia

1960 ◽  
Vol 92 (11) ◽  
pp. 862-864 ◽  
Author(s):  
D. G. Embree
Keyword(s):  
Nova Scotia ◽  
Control Measure ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Larval Stages

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.

Recoveries of Introduced Species of Parasites of the Winter Moth, Operophtera brumata (L.) (Lepidoptera: Geometridae), in Nova Scotia

1958 ◽  
Vol 90 (10) ◽  
pp. 595-596 ◽  
Author(s):  
A. R. Graham
Keyword(s):  
Nova Scotia ◽  
Introduced Species ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Made In

Five species of parasites reared from European material were released at Oak Hill, near Bridgewater, Nova Scotia from 1954 to 1956 as biotic agents against the winter moth, Operophtera brumata (L.) which had been established in Nova Scotia since before 1950. Recovery collections were made annually from 1955 to 1957. This work is still in progress, and in 1957 releases were made in four additional localities. Results of establishment of parasites from releases from 1954 to 1956 are reported below.

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