Podabrus rugosulus (Coleoptera: Cantharidae), an opportunist predator of Mindarus abietinus (Hemiptera: Aphididae) in Christmas tree plantations

2001 ◽  
Vol 133 (1) ◽  
pp. 151-154 ◽  
Author(s):  
Richard Berthiaume ◽  
Christian Hébert ◽  
Conrad Cloutier

The balsam twig aphid, Mindarus abietinus Koch, is a major pest of balsam fir, Abies balsamea (L.) Mill. (Pinaceae), grown as Christmas trees in eastern Canada and the United States (Nettleton and Hain 1982; Kleintjes 1997). This aphid has three or four generations from April to July, and overwinters as eggs on fir shoots. Mature fundatrices deposit progeny on new shoots in late May. Infested shoots develop into pseudogalls characterised by stunting and needle distortion, thus reducing the aesthetic value of trees.

2016 ◽  
Vol 148 (4) ◽  
pp. 466-475 ◽  
Author(s):  
Richard Berthiaume ◽  
Christian Hébert ◽  
Georges Pelletier ◽  
Conrad Cloutier

AbstractThe balsam twig aphid, Mindarus abietinus Koch (Hemiptera: Aphididae), is one of the most important pests of balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae) grown as Christmas trees in eastern North America. Aphid feeding on the current-year shoots results in needle distortion and shoots stunting, which reduces the aesthetic value of balsam fir trees and can have substantial economic impact. Syrphidae (Diptera) fly predators attacking this aphid are poorly known. We identified four species attacking the balsam twig aphid. Syrphus torvus Osten Sacken (Diptera: Syrphidae) was the most abundant species followed by Eupeodes lapponicus (Zetterstedt) (Diptera: Syrphidae) and Eupeodes americanus (Wiedemann) (Diptera: Syrphidae). We described the seasonal natural history of the two most abundant syrphids feeding on this aphid and we studied their synchrony with their prey. Syrphid larval density on balsam fir shoots increased rapidly and closely followed density of the balsam twig aphid. We also reported heavy parasitism of syrphid pupae by two Hymenoptera on tree foliage but lower parasitism on pupae in the soil under trees. Several cases of multiple parasitism and hyperparasitism were observed in syrphid pupae under trees. Abundance of predaceous syrphid species was higher in untreated balsam fir plantations compared with treated plantations. More research is needed to understand the role and the impact of these predators on balsam twig aphid population dynamics.


2017 ◽  
Vol 149 (6) ◽  
pp. 801-812 ◽  
Author(s):  
Jean-François Doherty ◽  
Jean-Frédéric Guay ◽  
Conrad Cloutier

AbstractThe balsam twig aphidMindarus abietinusKoch (Hemiptera: Aphididae) is a major pest of economic importance for the Christmas tree industry. Global warming during the 21st century could potentially increase local population densities and reinforce the pest status of this aphid in commercial fir (AbiesMiller; Pinaceae) plantations in Québec, Canada. During this study, we tested the effects of a warmer environment on colony growth rates ofM. abietinusand aphid morph composition during the second generation of its cycle, which is key to colony size growth and potential damage to Christmas trees. We monitoredM. abietinuspopulations on two host fir species and one host fir variety, in order to understand the early season dynamics of this aphid and its host tree. It was possible to distinguish the two overlapping generations of winged aphids leaving colonies, which led to observing a much higher proportion of wingless daughters, produced by the stem mother, than what had previously been reported. Colony growth rates were significantly higher in a warmer environment than in the nearby plantation, suggesting that warmer temperatures in late spring and early summer may provide the suitable conditions required forM. abietinuscolonies of greater density.


2007 ◽  
Vol 97 (5) ◽  
pp. 551-556 ◽  
Author(s):  
N. L. Dart ◽  
G. A. Chastagner ◽  
T. L. Peever

The population structure of Heterobasidion annosum in the Pacific Northwest (PNW) Christmas tree plantations was estimated at two spatial scales to assess the relative importance of primary and secondary infection, colonization, and spread of the pathogen. Ninety-three isolates from single trees in 27 discrete mortality pockets and 104 isolates from 12 individual root systems of noble and Fraser fir trees were sampled near Mossyrock, Washington. Isolates were genotyped using somatic compatibility assays and microsatellite markers to determine the spatial scale at which dispersal of single genotypes (genets) was occurring. All isolates sampled from different trees in discrete mortality pockets had distinct genotypes, whereas the root systems of single trees were dominated by one or two genotypes. These results suggest that infection of PNW Christmas trees results from frequent primary infection events of adjacent stumps and localized secondary spread within root systems rather than clonal spread of the pathogen between adjacent trees. We hypothesize that mortality pockets may be due to availability of infection courts and/or variation in inoculum levels during selective harvesting of patches of mature trees.


2019 ◽  
Vol 151 (3) ◽  
pp. 350-364 ◽  
Author(s):  
Suzanne Blatt ◽  
Charlane Bishop ◽  
Karen Burgher-MacLellan

AbstractThe occurrence of Bursaphelenchus xylophilus (Steiner and Buhrer) (Nematoda: Aphelenchida: Parasitaphelenchidae) (pinewood nematode) in Canada prevents export of wood products, including Christmas trees (Pinaceae), to Europe. A nationwide survey in 1992 extracted B. xylophilus from mature, dead, or dying balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae), but not young, healthy Christmas trees. Three species known to harbour B. xylophilus are found in Nova Scotia, but incidence of B. xylophilus within these species is unknown. Monochamus Dejean (Coleoptera: Cerambycidae) species were collected from nine and 20 sites, in 2014 and 2015, respectively, using panel traps baited with a Monochamus lure and evaluated for the presence of pinewood nematode using molecular methods after DNA isolation. Beetles were processed for DNA isolation individually in 2014 and in batches (same species and sex from same collection site and date) in 2015. Bursaphelenchus xylophilus was recovered from all three Monochamus species (M. marmorator Kirby, M. notatus (Drury), and M. scutellatus (Say)) captured in Nova Scotia Christmas tree plantations. Percentage of beetles harbouring B. xylophilus varied with species and sex. Fourteen beetle samples were selected and sent for polymerase chain reaction sequencing. Sequencing results indicated that Bursaphelenchus xylophilus found in Nova Scotia are most similar to isolates from Canada (New Brunswick and Québec), the United States of America, and China.


2018 ◽  
Vol 150 (5) ◽  
pp. 632-636 ◽  
Author(s):  
Jean-Frdéric Guay ◽  
Amy Bernier-Desmarais ◽  
Jean-François Doherty ◽  
Conrad Cloutier

AbstractThe pine needle scale, Chionaspis pinifoliae (Fitch) (Hemiptera: Diaspididae), has the status of an emerging pest in Christmas tree (Pinaceae) plantations in Québec, Canada. The scale is not known to cause any significant damage yet and is not generally monitored by growers. However, it can be an obstacle for exportation to Christmas tree markets where scale insects are strictly regulated. In this study, we describe its life cycle in Christmas tree plantations in southern Québec. We confirm the presence of both parthenogenetic and sexual forms of the scale on Fraser fir Abies fraseri (Pursh) Poiret (Pinaceae) grown as Christmas trees, and of parasitoid and Coccinellidae (Coleoptera) specialists that could contribute to its control.


2016 ◽  
Vol 149 (2) ◽  
pp. 191-203 ◽  
Author(s):  
S.E. Blatt ◽  
C. Bishop ◽  
J. Sweeney

AbstractChristmas trees from Nova Scotia, Canada are banned from import into the European Union (EU) because they may be infected with the pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Nematoda: Parasitaphelenchidae). Monochamus Dejean (Coleoptera: Cerambycidae) species known to vector pinewood nematode are present in Nova Scotia but their abundance in Christmas tree plantations and surrounding stands has not been assessed. We conducted trapping surveys and experiments in 2014 and 2015 to determine the species of Monochamus and their relative abundance in Nova Scotia Christmas tree plantations and the surrounding forests. We also compared commercially available traps and lures from Europe (cross-vane traps, Galloprotect lure=monochamol+ipsenol+α-pinene+2-methyl-3-buten-2-ol) and North America (intercept panel traps, North American lure=monochamol+ipsenol+α-pinene+ethanol) for their efficacy at catching Monochamus species in a 2×2 factorial experiment. We captured three Monochamus species (M. scutellatus (Say), M. notatus (Drury), and M. marmorator Kirby) in Nova Scotia Christmas tree plantations. Mean trap catches were greater within the plantations than in the surrounding forests. North American panel traps coated with Fluon® and baited with the European lure caught the most M. notatus and M. scutellatus and would be most suitable for survey and monitoring.


2001 ◽  
Vol 31 (12) ◽  
pp. 2160-2172 ◽  
Author(s):  
Martin Simard ◽  
Serge Payette

Black spruce (Picea mariana (Mill.) BSP) is the dominant tree species of the southernmost (48°N) lichen woodlands in eastern Canada. Most spruce trees in mature lichen woodlands appear to be declining, as shown by the massive invasion of the epiphytic lichen Bryoria on dead branches of dying trees. A dendroecological study was undertaken to identify the main causal factors of the decline. A decline index based on the abundance of Bryoria on spruce trees was used to distinguish healthy from damaged lichen–spruce woodlands and to select sampling sites for tree-ring measurements. Three conifer species (black spruce, balsam fir (Abies balsamea (L.) Mill.), and jack pine (Pinus banksiana Lamb.)) were sampled to compare their growth patterns in time and space. In the late 1970s and mid-1980s, black spruce and balsam fir experienced sharp and synchronous radial-growth reductions, a high frequency of incomplete and missing rings, and mass mortality likely caused by spruce budworm (Choristoneura fumiferana (Clem.)) defoliation. Jack pine, a non-host species, showed no such trend. Because black spruce layers were spared, lichen woodlands will eventually regenerate unless fire occurs in the following years. Black spruce decline can thus be considered as a normal stage in the natural dynamics of the southern lichen woodlands.


2009 ◽  
Vol 85 (4) ◽  
pp. 625-630 ◽  
Author(s):  
Alan J Thomson

Temperature records from weather stations across eastern Canada were used with published data on degree-day requirements for spruce budworm larval emergence and balsam fir bud flush to estimate historical patterns of larval emergence and timing of bud flush. The pattern of association was studied using Response Surface Analysis and was found to vary from west to east. April values of the Pacific/North American (PNA) pattern, Pacific Decadal Oscillation (PDO) and Northern Annular Mode (NAM) climate indices showed the most significant relationship to both emergence and bud flush in the 2 Ontario stations, while May values of the PDO and Eastern Pacific (EP) indices were most significant in the 4 Quebec and New Brunswick locations. Key words: phenology, balsam fir, teleconnections


2007 ◽  
Vol 24 (3) ◽  
pp. 209-217 ◽  
Author(s):  
Robert A. Slesak ◽  
Russell D. Briggs

Abstract The effectiveness of fertilization as a tool to increase growth rate and quality of Christmas trees depends on the ability to identify trees that are limited by nutrition. Foliar analysis is one approach to identify nutrition-limited trees, but it requires pre-established diagnostic criteria for application. The objective of this study was to assess growth response of Christmas trees to N fertilizer, and to develop critical foliar N levels for species commonly grown in New York. We evaluated diameter growth and foliar N concentration response of balsam fir (Abies balsamea [L.] Mill.), Canaan fir (Abies balsamea var. phanerolepis [Fern.]), Fraser fir (Abies fraseri [Pursh] Poir.), concolor fir (Abies concolor [Gord. and Glend.] Lindl.), and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) midrotation Christmas trees to N fertilization on 11 sites distributed across central New York. Two fertilizer treatments were applied: 1 oz N tree−1 as ammonium nitrate (AN) and chicken manure compost (CMC) applied at 0.6 oz N tree−1. Current annual diameter increment (CAI) for Canaan fir, Fraser fir, and Douglas-fir increased in response to AN. Two-year CAI for AN-treated trees was greater than control trees for all species with the exception of Canaan fir. Application of CMC had no effect on CAI the first year after application but did increase 2-year CAI for concolor and Fraser fir. Vector analysis, which simultaneously displays foliar mass, N concentration, and N content, indicated that all species responded positively to AN in more than 50% of the cases (with the exception of Canaan fir). Foliar response to CMC was weak, exhibiting a positive response in only 38% of the cases. Based on the foliar response of trees to AN, the following critical foliar N concentrations are proposed for Christmas trees in New York: balsam fir, 1.65%; concolor fir, 1.75%; Canaan fir, 1.60%; Douglas-fir, 1.45%; and Fraser fir, 1.60%.


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