caa a22 4500 475834712 CHVBK 20180406123850.0 cr unu---uuuuu 170329e20001201xx s 000 0 eng 10.1023/A:1026565013593 doi (NATIONALLICENCE)springer-10.1023/A:1026565013593 Predation on Mindarus abietinus infestingbalsam fir grown as Christmas trees: the impact ofcoccinellid larval predation with emphasis on Anatis mali [Elektronische Daten] [R. Berthiaume, Ch. Hébert, C. Cloutier] The impact of natural coccinellid larvalpredation on the balsam twig aphid was evaluated bysystematically removing coccinellid egg masses in a6-8 year-old balsam fir (Abies balsamea)Christmas tree plantation in southwesternQuebec. Among coccinellid species hunting on firfoliage during development of Mindarus abietinusfundatrices in May, the indigenous Anatis mali was by far the most abundant and themain one to oviposit on trees. Comparison of trees onwhich coccinellid larval predation was excluded withcontrol trees showed that A. mali had a markedimpact both during and after the phase of rapid M. abietinus population growth that followedfundatrix maturation. On trees where coccinellidlarvae were allowed, aphid colonies became inactive(i.e. no live aphids in the colony) about two weeksearlier than on controls. A strong dampening effect onaphid density was also observed in those colonies thatremained active until the end of the aphid life cycle.Predation on aphid colonies reduced sexualsproduction, as the density of M. abietinusoverwintering eggs per shoot subsequently was reducedby 32%. Predation by coccinellid larvae occurred toolate to prevent needle damage to current year shoots,which affects the aesthetic value of Christmas trees.However, current year shoots measured in the mid-crownof trees late in the season were 19% longer on treeswhere aphid predation by coccinellid larvae wasallowed, compared with trees where they were excluded.Rearing all larval stages of A. mali on 4thinstar and adult sexuparae of M. abietinusindicated an average consumption of 269 aphids tocomplete larval development and pupate, which wasequivalent to at least seven colonies of M.abietinus at maximum aphid density at theexperimental site. Anatis mali is an importantnatural control factor of balsam twig aphid inChristmas tree plantations, hence its activity shouldbe protected and possibly stimulated by favourablepest management practices. Kluwer Academic Publishers, 2000 natural predation nationallicence plantations nationallicence predator voracity nationallicence shoot damage nationallicence tree growth nationallicence Aphididae nationallicence Coccinellidae nationallicence Abies balsamea nationallicence Berthiaume R. Département de biologie, UniversitéLaval, Cité Universitaire, Québec, Canada aut Hébert Ch Service canadien des forêts, Sainte-Foy, Québec, Canada aut Cloutier C. Département de biologie, UniversitéLaval, Cité Universitaire, G1K 7P4, Québec, Canada aut BioControl Kluwer Academic Publishers 45/4(2000-12-01), 425-438 1386-6141 45:4<425 2000 45 10526 https://doi.org/10.1023/A:1026565013593 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1026565013593 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Berthiaume R. Département de biologie, UniversitéLaval, Cité Universitaire, Québec, Canada aut NATIONALLICENCE 700 1- Hébert Ch Service canadien des forêts, Sainte-Foy, Québec, Canada aut NATIONALLICENCE 700 1- Cloutier C. Département de biologie, UniversitéLaval, Cité Universitaire, G1K 7P4, Québec, Canada aut NATIONALLICENCE 773 0- BioControl Kluwer Academic Publishers 45/4(2000-12-01), 425-438 1386-6141 45:4<425 2000 45 10526 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer