Browsing by Subject "insect"

Now showing 1 - 4 of 4
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    Data from: Development of an aggressive bark beetle on novel hosts: Implications for outbreaks in an invaded range
    (2017-11-11) Rosenberger, Derek W; Venette, Robert C; Aukema, Brian H; dwrosenberger@olivet.edu; Rosenberger, Derek W
    Mountain pine beetle (Dendroctonus ponderosae Hopkins) is an aggressive bark beetle native to western North America currently expanding its range east. Should it reach northeastern North American pine forests, it is unclear how novel pine hosts might affect traits related to reproduction and development. These data are the result of studies meant to determine how four novel pine hosts might impact mountain pine beetle reproduction and development, relative to two historical hosts.
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    Effects of winter temperatures, spring degree-day accumulation, and insect population source on phenological synchrony between forest tent caterpillar and
    (Elsevier, 2016) Uelmen, Johnny A.; Lindroth, Richard L; Tobin, Patrick C.; Reich, Peter B; Schwartzberg, Ezra G; Raffa, Kenneth F
    Global climate change has the potential to dramatically alter multiple ecosystem processes, including herbivory. The development rates of both plants and insects are highly sensitive to temperature. Although considerable work has examined the effects of temperature on spring phenologies of plants and insects individually, few studies have examined how anticipated warming will influence their phenological synchrony. We applied elevated temperatures of 1.7 and 3.4 °C in a controlled chamberless outdoor experiment in northeastern Minnesota, USA to examine the relative responses in onset of egg eclosion by forest tent caterpillar (Malacosoma disstria Hübner) and budbreak of two of its major host trees (trembling aspen, Populus tremuloides Michaux, and paper birch, Betula papyrifera Marshall). We superimposed four insect population sources and two overwintering regimes onto these treatments, and computed degree-day models. Timing of egg hatch varied among population source, overwintering location, and spring temperature regime. As expected, the development rates of plants and insects advanced under warmer conditions relative to ambient controls. However, budbreak advanced more than egg hatch. The degree of phenological synchrony between M. disstria and each host plant was differentially altered in response to warming. The interval by which birch budbreak preceded egg hatch nearly doubled from ambient to +1.7 °C. In the case of aspen, the sequence changed from egg hatch preceding, to following, budbreak at +3.4 °C. Additionally, under temperature regimes simulating future conditions, some insect populations currently south of our study sites became more synchronous with the manipulated hosts than did currently coexisting insect populations. These findings reveal how climate warming can alter insect-host plant interactions, through changes in phenological synchrony, possibly driving host shifts among tree species and genotypes. They also suggest how herbivore variability, both among populations and within individual egg masses, may provide opportunities for adaptation, especially in species that are highly mobile and polyphagous.
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    Historical and contemporary biological diversity of Minnesota caddisflies: a case study of landscape-level species loss and trophic composition shift
    (University of Chicago Press, 2010) Houghton, David C.; Holzenthal, Ralph W.
    The biological diversity reflected by nearly 300,000 caddisfly specimens collected throughout Minnesota since 1985 was compared with that of 25,000 specimens recorded prior to 1950 and was analyzed based on the 5 caddisfly regions of Minnesota. In the Lake Superior, Northern, and Southeastern regions, .90% of species known historically from each region were recovered and additional species were discovered. In the Northwestern and Southern regions—the most disturbed areas of Minnesota—species recovery ranged from 60 to 70%. Historical and contemporary assemblages were similar to each other in the former 3 regions and markedly different in the latter 2. Prior to 1950, species in all trophic functional groups were widespread in all regions. A similar pattern still exists in the Lake Superior, Northern, and Southeastern regions, whereas the Northwestern and Southern regions are now dominated by filtering collectors in all sizes of lakes and streams. Over 65% of species extirpated from any region were in the long-lived families Limnephilidae and Phryganeidae, and 70% of these same species were in the shredder functional group. Almost 30% of the statewide fauna has been found from ,5 localities since 1950, suggesting a degree of imperilment on par with that of freshwater bivalves, gastropods, and fish. These observed losses of biodiversity and changes in trophic composition have probably occurred as a result of anthropogenic disturbance throughout most of the northcentral US.
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    Tough Buggers
    (2013) Cira, Theresa; Christianson, Lindsay; Hanson, Anthony; Hefty, A.; Morey, Amy; Nail, K.; Rosenberger, D.; Venette, R.C.