Publications by authors named "Fiorella Ramirez-Esquivel"

The honeybee stinger is a powerful defense mechanism that combines painful venom, a subcutaneous delivery system, and the ability to autotomize. It is a complex organ and to function autonomously it must carry with it all the anatomical components required to operate. In this study, we combined high-speed filming, SEM imagery, and micro-CT for volumetric rendering of the stinger with a synthesis of existing literature.

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This article outlines a suite of techniques in light microscopy (LM) and electron microscopy (EM) which can be used to study the internal and external eye anatomy of insects. These include traditional histological techniques optimized for work on ant eyes and adapted to work in concert with other techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM). These techniques, although vastly useful, can be difficult for the novice microscopist, so great emphasis has been placed in this article on troubleshooting and optimization for different specimens.

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Individual differences in response thresholds to task-related stimuli may be one mechanism driving task allocation among social insect workers. These differences may arise at various stages in the nervous system. We investigate variability in the peripheral nervous system as a simple mechanism that can introduce inter-individual differences in sensory information.

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The ability of ants to navigate when the visual landmark information is altered has often been tested by creating large and artificial discrepancies in their visual environment. Here, we had an opportunity to slightly modify the natural visual environment around the nest of the nocturnal bull ant We achieved this by felling three dead trees, two located along the typical route followed by the foragers of that particular nest and one in a direction perpendicular to their foraging direction. An image difference analysis showed that the change in the overall panorama following the removal of these trees was relatively little.

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Ants are unusual among insects in that individuals of the same species within a single colony have different modes of locomotion and tasks. We know from walking ants that vision plays a significant role in guiding this behaviour, but we know surprisingly little about the potential contribution of visual sensory structures for a flying mode of locomotion. Here we investigate the structure of the compound eye and ocelli in pedestrian workers, alate females and alate males of an Australian ant, Camponotus consobrinus, and discuss the trade-offs involved in optical sensitivity and spatial resolution.

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Insects use antennal sensilla to not only detect chemical and mechanical cues but also to sense changes in temperature, humidity and CO(2) levels. Very little is known about the variation in numbers, size and structure of sensilla in ants. Here we describe in detail the array of sensilla on the apical segment of the antennae of the nocturnal Australian bull ant Myrmecia pyriformis.

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