535,656 research outputs found
An Entomopathogenic Nematode by Any Other Name
Among the diversity of insect-parasitic nematodes, entomopathogenic nematodes (EPNs) are distinct, cooperating with insect-pathogenic bacteria to kill insect hosts. EPNs have adapted specific mechanisms to associate with and transmit bacteria to insect hosts. New discoveries have expanded this guild of nematodes and refine our understanding of the nature and evolution of insect–nematode associations. Here, we clarify the meaning of “entomopathogenic” in nematology and argue that EPNs must rapidly kill their hosts with the aid of bacterial partners and must pass on the associated bacteria to future generations
Application of the International Centre of Insect Physiology and Ecology (ICIPE) for Inclusion into the CGIAR System
Documents concerning the application of the International Center for Insect Physiology and Ecology (ICIPE) for full CGIAR support and TAC's recommendation against offering such support. Includes are a report of the Technical Advisory Committee transmitted from TAC Chairman Ralph W. Cummings to CGIAR Chairman Warren C. Baum, ICIPE's March 1979 application itself, and 'Report of the TAC Mission to ICIPE,' in April 1980. Agenda document, CGIAR meeting, October 1980. The application was received at the CGIAR meeting in October/November 1979 and discussed at the TAC 23rd and 24th meetings in February and July 1980
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Insect Phylogenetics: A Guided Tour of Insect Evolution
Interview with Dr. Noah Whitema
Herbivory increases diversification across insect clades.
Insects contain more than half of all living species, but the causes of their remarkable diversity remain poorly understood. Many authors have suggested that herbivory has accelerated diversification in many insect clades. However, others have questioned the role of herbivory in insect diversification. Here, we test the relationships between herbivory and insect diversification across multiple scales. We find a strong, positive relationship between herbivory and diversification among insect orders. However, herbivory explains less variation in diversification within some orders (Diptera, Hemiptera) or shows no significant relationship with diversification in others (Coleoptera, Hymenoptera, Orthoptera). Thus, we support the overall importance of herbivory for insect diversification, but also show that its impacts can vary across scales and clades. In summary, our results illuminate the causes of species richness patterns in a group containing most living species, and show the importance of ecological impacts on diversification in explaining the diversity of life
Crop and Livestock Insect Problems facing CGIAR Centres: A Proposal towards their Long-term Solution
Proposal by ICIPE for cooperative programs with CGIAR centers on animal and plant pest control. Revised version of agenda document presented at TAC 11th Meeting. Agenda document at TAC 14th Meeting October 1976
Entomogenic Climate Change
Rapidly expanding insect populations, deforestation, and global climate
change threaten to destabilize key planetary carbon pools, especially the
Earth's forests which link the micro-ecology of insect infestation to climate.
To the extent mean temperature increases, insect populations accelerate
deforestation. This alters climate via the loss of active carbon sequestration
by live trees and increased carbon release from decomposing dead trees. A
positive feedback loop can emerge that is self-sustaining--no longer requiring
independent climate-change drivers. Current research regimes and insect control
strategies are insufficient at present to cope with the present regional scale
of insect-caused deforestation, let alone its likely future global scale.
Extensive field recordings demonstrate that bioacoustic communication plays a
role in infestation dynamics and is likely to be a critical link in the
feedback loop. These results open the way to novel detection and monitoring
strategies and nontoxic control interventions.Comment: 7 pages, 1 figure; http://cse.ucdavis.edu/~chaos/chaos/pubs/ecc.ht
Associated Insects Reared from Galls of Saperda Inornata (Coleoptera: Cerambycidae) on Trembling Aspen in Michigan
The poplar gall Saperda, Saperda inornata Say, is a common pest of trembling aspen, Populus tremuloides Michx, in Michigan forests. Through its egg-laying activities and larval feeding, this insect causes wood defects and tree mortality (Graham et al., 1963). While studying natural populations of this insect (Grimble and Knight, 1970), we collected many galls and found through rearing and dissection that they harbor a large and varied insect fauna
Fast and robust learning by reinforcement signals: explorations in the insect brain
We propose a model for pattern recognition in the insect brain. Departing from a well-known body of knowledge about the insect brain, we investigate which of the potentially present features may be useful to learn input patterns rapidly and in a stable manner. The plasticity underlying pattern recognition is situated in the insect mushroom bodies and requires an error signal to associate the stimulus with a proper response. As a proof of concept, we used our model insect brain to classify the well-known MNIST database of handwritten digits, a popular benchmark for classifiers. We show that the structural organization of the insect brain appears to be suitable for both fast learning of new stimuli and reasonable performance in stationary conditions. Furthermore, it is extremely robust to damage to the brain structures involved in sensory processing. Finally, we suggest that spatiotemporal dynamics can improve the level of confidence in a classification decision. The proposed approach allows testing the effect of hypothesized mechanisms rather than speculating on their benefit for system performance or confidence in its responses
On mathematical modelling of insect flight dynamics in the context of micro air vehicles
This paper discusses several aspects of mathematical modelling relevant to the flight
dynamics of insect flight in the context of insect-like flapping wing micro air vehicles (MAVs).
MAVs are defined as flying vehicles ca six inch in size (hand-held) and are developed to
reconnoitre in confined spaces (inside buildings, tunnels etc). This requires power-efficient,
highly-manoeuvrable, low-speed flight with stable hover. All of these attributes are present in
insect flight and hence the focus of reproducing the functionality of insect flight by engineering
means. This can only be achieved if qualitative insight is accompanied by appropriate
quantitative analysis, especially in the context of flight dynamics, as flight dynamics underpin
the desirable manoeuvrability.
We consider two aspects of mathematical modelling for insect flight dynamics.
The first one is theoretical (computational), as opposed to empirical, generation of the
aerodynamic data required for the six-degrees-of-freedom equations of motion. For these
purposes we first explain insect wing kinematics and the salient features of the corresponding
flow. In this context, we show that aerodynamic modelling is a feasible option for certain flight
regimes, focussing on a successful example of modelling hover. Such modelling progresses
from first principles of fluid mechanics, but relies on simplifications justified by the known
flow phenomenology and/or geometric and kinematic symmetries. In particular, this is relevant
to six types of fundamental manoeuvres, which we define as those steady flight conditions for
which only one component of both the translational and rotational body velocities is non-zero
(and constant).
The second aspect of mathematical modelling for insect flight dynamics addressed here
deals with the periodic character of the aerodynamic force and moment production. This
leads to consideration of the types of solutions of nonlinear equations forced by nonlinear
oscillations. In particular, the existence of non-periodic solutions of equations of motion is of
practical interest, since this allows steady recitilinear flight.
Progress in both aspects of mathematical modelling for insect flight will require further
advances in aerodynamics of insect-like flapping. Improved aerodynamic modelling and
computational fluid dynamics (CFD) calculations are required. These theoretical advances
must be accompanied by further flow visualisation and measurement to validate both the
aerodynamic modelling and CFD predictions
Why Are There So Few Insect Predators of Nuts of American Beech \u3ci\u3e(Fagus Grandifolia)?\u3c/i\u3e
American beech, Fagus grandifolia Ehrh., is a common nut-bearing tree of eastern North America. Compared to other North American nut-bearing tree species of comparable geographic range, the nut-infesting insect fauna of American beech is species-poor: only the filbertworn, Cydia latiferreana (Wlsm.) (Lepidoptera: Tortricidae), infests nuts of American beech. Why are there so few insect predators of nuts of American beech? Using data from published studies, I explore two hypotheses that may help to explain the species-poor nut-infesting insect fauna of American beech. First, might chemical defense of beechnuts, and/ or low nutritional value, restrict the number of insect predators that can exploit this food resource (unprofitable resource hypothesis)? Second, may spatial and temporal variability of beechnut mast crops limit colonization by nut-infesting insects because of the unpredictability of the resource (unpredictable resource hypothesis)? I found no strong evidence to suggest that chemical defense or low nutritional value was associated with the species-poor nut-infesting insect fauna of American beech. Yearly variability in nut crop size alone did not explain the low species richness of American beech compared to other tree species. Instead, I suggest that spatial and temporal unpredictability in production of sound versus incomplete beechnuts was an effective filter that limited colonization of beechnuts by insects. Moreover, the lone insect species able to successfully colonize beechnuts, C. latiferreana, is well adapted to resource unpredictability. Unlike specialist insect species that infest nuts of only 1 or 2 North American tree genera, C. latiferreana has a relatively broad host range and its mobile larvae can relocate to new resources when faced with food shortages
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