Matacil insecticide spraying, pollinator mortality, and plant fecundity in New Brunswick forests

1985 ◽  
Vol 63 (11) ◽  
pp. 2056-2061 ◽  
Author(s):  
James D. Thomson ◽  
R. C. Plowright ◽  
G. R. Thaler

Exposure-cage trials in spruce–fir forest near Doaktown, N.B., Canada, showed that Matacil aminocarb insecticide, applied for control of spruce budworm, increased mortality rates of several types of solitary bees and syrphid flies, although previous studies had found no effect on bumblebees. Of two plant species predominantly pollinated by the sensitive pollinator taxa, one (Maianthemum canadense Desf.) showed significantly reduced fecundity in sprayed areas. The other (Cornus stolonifera Michx.) tended toward reduced fecundity in sprayed areas, although this trend was obscured by great within-treatment variability. Cornus canadensis L., which is visited by bumblebees as well as by the smaller, Matacil-susceptible insects, showed no reduction of fecundity in sprayed areas. This study generally supports the practicality of assessing plant risk a priori by considering (i) the breeding system, (ii) the flowering phenology, (iii) the effective pollinators, and (iv) the known susceptibility of the pollinators to the spray agent in use.

1980 ◽  
Vol 58 (18) ◽  
pp. 2022-2027 ◽  
Author(s):  
G. R. Thaler ◽  
R. C. Plowright

Eight entomophilous plants, Aralia nudicaulis L., Clintonia borealis (Ait.) Raf., Cornus alternifolia L., Cornus canadensis L., Cornus stolonifera Michx., Kalmia angustifolia L., Maianthemum canadense Desf., and Viburnum trilobum Marsh., all of which bloom shortly after forest spray application in New Brunswick, were shown by bagging experiments to be dependent on insect visitation for seed set. All species showed significantly lower fecundity in fenitrothion-treated than in unsprayed areas. No depression of fecundity in Clintonia borealis or Kalmia angustifolia was found associated with aminocarb (Matacil) spraying.


1983 ◽  
Vol 61 (2) ◽  
pp. 452-457 ◽  
Author(s):  
Marguerite A. Flinn ◽  
Joan K. Pringle

Rhizomes of eight understory species: Gaultheria procumbens, Maianthemum canadense, Vaccinium angustifolium, Cornus canadensis, Pteridium aquilinum, Kalmia angustifolia, Chamaedaphne calyculata, and Rhododendron canadense were subjected to treatments of 45, 50, 55 and 60 °C for 5 min in a water bath. Selection of these species for study was based on differences in the depth of the rhizomes, in habitat, and in rhizome morphology. Samples were collected from study sites located near Halifax, in the Nova Scotia Acadian Forest region.Maximum shoot growth occurred at different temperatures for the various species: 45 °C for Cornus canadensis; 50 °C for Chamaedaphne calyculata, R. canadense, and V. angustifolium; 55 °C for G. procumbens and M. canadense. Death occurred at or below 60 °C for most species. For comparative purposes, a temperature tolerance index (TTI) was calculated for each species. The TTI indicated that R. canadense and V. angustifolium showed the greatest tolerance to higher temperatures and that K. angustifolia and P. aquilinum showed the least tolerance. Mean shoot number increased significantly following spring treatments for all species except for Cornus canadensis which showed greater increase following autumn treatments.


1988 ◽  
Vol 66 (9) ◽  
pp. 1877-1882 ◽  
Author(s):  
B. A. Gaber ◽  
T. C. Hutchinson

A field study was carried out in the boreal forest of Ontario to measure the neutralisation response of the leaves of Cornus canadensis, Aralia nudicaulis, Maianthemum canadense, and Acer spicatum to simulated acid rain. Plots of each species were sprayed with pH 5.6, 3.8, or 3.2 rain, and the pH of the raindrops on the leaves and on Parafilm (control) was measured with a microelectrode at 15-min intervals until the leaves dried. Species differed in their ability to neutralise the rain, with C. canadensis consistently neutralising acidic raindrops the most. The neutralisation response varied greatly between pH treatments, with greatest neutralisation occurring at the most acidic pH treatment. Raindrop neutralisation primarily took place within the first few minutes following the spray. For this reason, the dissolution of basic particulates on the leaf surface was probably responsible for the rapid changes in raindrop pH, while slower changes may reflect cation exchange processes with the cell walls. Weather conditions determined the rate of evaporation of the raindrops, and this affected their acidity. High rates of evaporation reduced the time available for leaf surface – raindrop interactions and are probably responsible for the acidification observed in some plots.


Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 512
Author(s):  
Liam M. Crowley ◽  
Jonathan P. Sadler ◽  
Jeremy Pritchard ◽  
Scott A. L. Hayward

The impact of elevated CO2 (eCO2) on plant–pollinator interactions is poorly understood. This study provides the first systematic review of this topic and identifies important knowledge gaps. In addition, we present field data assessing the impact of eCO2 (150 ppm above ambient) on bluebell (Hyacinthoides non-scripta)–pollinator interactions within a mature, deciduous woodland system. Since 1956, only 71 primary papers have investigated eCO2 effects on flowering time, floral traits and pollination, with a mere 3 studies measuring the impact on pollination interactions. Our field experiment documented flowering phenology, flower visitation and seed production, as well as the abundance and phenology of dominant insect pollinators. We show that first and mid-point flowering occurred 6 days earlier under eCO2, but with no change in flowering duration. Syrphid flies and bumble bees were the dominant flower visitors, with peak activity recorded during mid- and late-flowering periods. Whilst no significant difference was recorded in total visitation or seed set between eCO2 and ambient treatments, there were clear patterns of earlier flowering under eCO2 accompanied by lower pollinator activity during this period. This has implications for potential loss of synchrony in pollination systems under future climate scenarios, with associated long-term impacts on abundance and diversity.


1987 ◽  
Vol 65 (10) ◽  
pp. 2047-2056 ◽  
Author(s):  
Kaius Helenurm ◽  
Spencer C. H. Barrett

The flowering and fruiting phenologies of 12 boreal forest herbs were recorded during 1979 (flowering and fruiting) and 1980 (flowering only) in spruce–fir forests of central New Brunswick. The species studied were Aralia nudicaulis, Chimaphila umbellata, Clintonia borealis, Cornus canadensis, Cypripedium acaule, Linnaea borealis, Maianthemum canadense, Medeola virginiana, Oxalis montana, Pyrola secunda, Trientalis borealis, and Trillium undulatum. Flowering in the community occurred from mid-May to the end of July. The order of flowering was maintained in the 2 years, but the degree of synchronization of inflorescences differed in several species. Fruiting in the community began in mid-July and extended beyond the end of September. The percentage of buds that ultimately bore fruit ranged from 0 (Cypripedium acaule) to 61% (Aralia nudicaulis). With the exception of Cypripedium acaule, which received little pollinator service, the self-incompatible species, Cornus canadensis, Maianthemum canadense, and Medeola virginiana, experienced the lowest levels of fruit-set. Pollen limitation and predation of developing fruit appear to be the major factors limiting percentage fruit-set in boreal forest herbs. Fruit production varied with time of flowering of inflorescences in several species, with periods of low fruit-set tending to coincide with lower densities of flowering inflorescences. Significant rates of fruit removal by herbivores occurred in all sarocochorous species. Disappearance of fruits from infructescences ranged from 31 (Medeola virginiana) to 95% (Aralia nudicaulis), with highest removal rates occurring during periods of greatest fruit availability.


Botany ◽  
2018 ◽  
Vol 96 (9) ◽  
pp. 601-620 ◽  
Author(s):  
Phakpoom Auttama ◽  
Doyle McKey ◽  
Aroonrat Kidyoo

Although Ceropegia species are well known for their complex pitfall flowers that temporarily imprison their pollinators, various aspects of their pollination ecology are still unknown. This study investigated flowering phenology, functional floral traits, and insect visitation in a natural population of a rare endemic lithophyte, Ceropegia thaithongiae Kidyoo. Flowering of C. thaithongiae was not synchronous but staggered. Anthesis lasted mostly 1–2 days, but its duration was shorter in flowers with a pollinium inserted into the stigmatic chamber. Several different insects visited flowers, but only chloropid and milichiid flies were effective pollinators. At anthesis, the epithelial osmophores on the corolla lobes emitted a floral scent that was simple in composition. Nectar of high viscosity was exuded from the nectaries hidden behind the guide rails. When transported by an insect, the pollinarium was attached to bristles on the mouthparts. Size and shape of the thin pellucid margin of the pollinium enable it to fit into the stigmatic chamber in a lock-and-key arrangement. The pollen transfer efficiency was 6.8%. The plant’s staggered flowering and pollination-induced ending of anthesis are advantageous in decreasing competition for pollinators when flower-visiting insects are scarce.


1984 ◽  
Vol 116 (3) ◽  
pp. 457-464
Author(s):  
Richard W. Hansen ◽  
Eben A. Osgood

AbstractCounts of four pollinating insect groups were taken in unsprayed forest localities and in areas sprayed with a split application of Sevin-4-oil® (carbaryl) for spruce budworm control. Results indicate a reduction of pollinator populations due to spraying.Fruit set, measured by fecundity ratios (fruits/flower), was determined for Cornus canadensis L., Maianthemum canadense Desf., Clintonia borealis (Ait.) Raf., and Viburnum cassinoides L. in sprayed and unsprayed areas. Fecundity values for C. canadensis and M. canadense were significantly lower in sprayed than in unsprayed areas. Fruit set of C. borealis was apparently unaffected by carbaryl spraying, but the seed/flower ratio was significantly reduced in the sprayed area. V. cassinoides fecundity values were unaffected by carbaryl application. Reductions in native bee populations probably had the greatest impact on fruit set.


2003 ◽  
Vol 60 (5) ◽  
pp. 1075-1085 ◽  
Author(s):  
Robert J. Latour ◽  
John M. Hoenig ◽  
Daniel A. Hepworth ◽  
Stewart D. Frusher

Abstract Multi-year tag-recovery models can be used to derive estimates of age- and year-specific annual survival rates and year-specific instantaneous fishing and natural mortality rates. The latter, which are often of interest to fisheries managers, usually can only be estimated when the tag-reporting rate (λ) and the short-term tag-induced mortality and tag-shedding rate (φ) are known a priori. We present a new multi-year tagging model that permits estimation of instantaneous mortality rates independently of φλ, provided tagged animals from two adjacent size groups are released simultaneously. If the two size groups comprise animals just above and below the minimum harvestable size limit, then it is possible to estimate year-specific instantaneous fishing and natural mortality rates after 2 yr of tagging and tag-recovery. In addition to the standard assumptions of multi-year tag-recovery models, it is necessary to assume that recruited animals have equal selectivity, pre-recruited animals become fully recruited in 1 or 2 yr, and the size groups experience the same natural mortality rate. Applicability of the model to the Tasmania southern rock lobster (Jasus edwardsii) fishery is evaluated using a simulation model and parameters based on data from the lobster fishery; assumptions are likely to be met and precision should be adequate if at least 1000 animals are tagged per year in each size group.


1988 ◽  
Vol 66 (12) ◽  
pp. 2445-2451 ◽  
Author(s):  
Brigitte A. Gaber ◽  
Thomas C. Hutchinson

Simulated raindrops of pH 5.6 or 3.2 were sprayed on four boreal forest plant species in situ, and raindrops were subsequently collected from their leaves for chemical analysis. The purpose was to understand better the changes involved in foliar neutralisation of acidic raindrops. The species used were Cornus canadensis, Aralia nudicaulis, Maianthemum canadense, and Acer spicatum. Samples were analysed for Ca2+, Mg2+, Na+, K+, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], Cl−, and F−, as well as pH. Changes in leaf raindrop ion concentrations were greater when sprayed with the pH 3.2 than with the pH 5.6 rain. Both increases and decreases in ion concentration were found, indicating leaching and (or) dissolution of particulates on the leaf or retention by the canopy, respectively. Rapid changes in ion concentrations suggest surface deposits play an important role in leaf raindrop neutralisation. Increases in [Ca2+] and [Mg2+] in raindrops with greater neutralisation are evidence that cation exchange may also be occurring (r2 = 0.170 and 0.321, respectively, at pH 3.2; p < 0.01). There were significant negative correlations between changes in [H+] and changes in[Formula: see text], [Formula: see text], and [Formula: see text] (r2 = 0.562, 0.525, and 0.297, respectively, at pH 3.2;p < 0.01). Most of the other ions measured also showed significant correlations with changes in [H+], but generally the correlation could account for only a small percentage of the observed results (low r2). Dry deposition was also measured.


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