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Full-Text Articles in Life Sciences
Predator Functional Responses And The Biocontrol Of Aphids And Mites, John Delong, Stella Uiterwaal
Predator Functional Responses And The Biocontrol Of Aphids And Mites, John Delong, Stella Uiterwaal
School of Biological Sciences: Faculty Publications
Biocontrol with predators is a key tool for controlling agricultural pests and preserving the productive efficiency of crops. Determining which predators to use for biocontrol often involves measuring their functional response—the relationship between foraging rate and prey abundance, yet comparisons of functional responses across predators are complicated by differences in experimental procedures. Here we use a compilation of functional responses standardized for time and space units to illustrate key sources of variation in functional responses for predators being tested for control of aphids and mites. Our results show that arena size (as a proxy for habitat structure) is a crucial …
Functional Response Of Harmonia Axyridis To The Larvae Of Spodoptera Litura: The Combined Effect Of Temperatures And Prey Instars, Yasir Islam, Farhan Mahmood Shah, Ali Güncan, John Paul Delong, Xingmiao Zhou
Functional Response Of Harmonia Axyridis To The Larvae Of Spodoptera Litura: The Combined Effect Of Temperatures And Prey Instars, Yasir Islam, Farhan Mahmood Shah, Ali Güncan, John Paul Delong, Xingmiao Zhou
School of Biological Sciences: Faculty Publications
Functional responses are central to predator–prey dynamics and describe how predation varies with prey abundance. Functional responses often are measured without regard to prey size (i.e., body mass) or the temperature dependence of feeding rates. However, variation in prey size within populations is ubiquitous, and predation rates are often both size and temperature-dependent. Here, we assessed functional responses of larvae and adult Harmonia axyridis on the 1st, 2nd, and 3rd instars of the prey Spodoptera litura across a range of temperatures (i.e., 15, 20, 25, 30, and 35◦C). The type and parameters of the functional responses were determined using logistic …
Priority Resource Access Mediates Competitive Intensity Between An Invasive Weevil And Native Floral Herbivores, Svata M. Louda, Tatyana A. Rand, A. A. R. Kula, A. E. Arnett, N. M. West, Brigitte Tenhumberg
Priority Resource Access Mediates Competitive Intensity Between An Invasive Weevil And Native Floral Herbivores, Svata M. Louda, Tatyana A. Rand, A. A. R. Kula, A. E. Arnett, N. M. West, Brigitte Tenhumberg
School of Biological Sciences: Faculty Publications
Mechanisms underlying invasive species impacts remain incompletely understood. We tested the hypothesis that priority resource access by an invasive biocontrol weevil, Rhinocyllus conicus, intensifies and alters the outcome of competition with native floral herbivores over flower head resources of the non-target, native host plant Cirsium canescens, specifically with the predominant, synchronous tephritid fly Paracantha culta. Four main results emerged. First, we documented strong, asymmetric competition, with R. conicus out-competing P. culta. Second, weevil priority access to floral resources accelerated competitive suppression of P. culta. Evidence for competitive suppression with increased weevil priority included decreases in both the numbers and …
A Nontechnical Introduction To "Biocontrol As Usual": Review Of Ann Hajek, Natural Enemies, Svata M. Louda
A Nontechnical Introduction To "Biocontrol As Usual": Review Of Ann Hajek, Natural Enemies, Svata M. Louda
School of Biological Sciences: Faculty Publications
Increasing recognition of the problems posed by invasive, exotic species has led to a recent upsurge of interest in the potential of biological control as a sustainable management strategy. The idea that ‘‘natural control’’ could be re-established on a species in its new environment is a seductive one, nurtured by a small set of impressive success stories and the belief in a simple solution (‘‘silver bullet’’). Yet, recent serendipitous discoveries also make it clear that attempts to engineer the outcome of species interactions in new systems can lead to undesired direct and indirect effects of unanticipated magnitude on non-targeted native …
Indirect Interaction Between Two Native Thistles Mediated By An Invasive Exotic Floral Herbivore, F. Leland Russell, Svata M. Louda
Indirect Interaction Between Two Native Thistles Mediated By An Invasive Exotic Floral Herbivore, F. Leland Russell, Svata M. Louda
School of Biological Sciences: Faculty Publications
Spatial and temporal variation in insect floral herbivory is common and often important. Yet, the determinants of such variation remain incompletely understood. Using 12 years of flowering data and 4 years of biweekly insect counts, we evaluated four hypotheses to explain variation in damage by the Eurasian flower head weevil, Rhinocyllus conicus, to the native North American wavyleaf thistle, Cirsium undulatum. The four factors hypothesized to influence weevil impact were variations in climate, weevil abundance, phenological synchrony, and number of flower heads available, either on wavyleaf thistle or on the other co-occurring, acquired native host plant (Platte thistle, Cirsium …