Odorant receptors tuned to isothiocyanates in and their evolutionary expansion in herbivorous relatives.

Plants release complex volatile compounds to attract mutualists, deter herbivores, and deceive pollinators. Here, we used herbivorous specialist flies that feed on mustard plants ( spp.) and microbe-feeding species ( and spp.

Taste adaptations associated with host specialization in the specialist Drosophila sechellia.

Chemosensory-driven host plant specialization is a major force mediating insect ecological adaptation and speciation. Drosophila sechellia, a species endemic to the Seychelles islands, feeds and oviposits on Morinda citrifolia almost exclusively. This fruit is harmless to D.

Fly Cell Atlas: A single-nucleus transcriptomic atlas of the adult fruit fly.

For more than 100 years, the fruit fly has been one of the most studied model organisms. Here, we present a single-cell atlas of the adult fly, Tabula , that includes 580,000 nuclei from 15 individually dissected sexed tissues as well as the entire head and body, annotated to >250 distinct cell types. We provide an in-depth analysis of cell type-related gene signatures and transcription factor markers, as well as sexual dimorphism, across the whole animal.

Phylogenetic diversity of two common Trypanosoma cruzi lineages in the Southwestern United States.

Trypanosoma cruzi is the causative agent of Chagas disease, a devastating parasitic disease endemic to Central and South America, Mexico, and the USA. We characterized the genetic diversity of Trypanosoma cruzi circulating in five triatomine species (Triatoma gerstaeckeri, T. lecticularia, T.

Evolution of Olfactory Receptors Tuned to Mustard Oils in Herbivorous Drosophilidae.

The diversity of herbivorous insects is attributed to their propensity to specialize on toxic plants. In an evolutionary twist, toxins betray the identity of their bearers when herbivores coopt them as cues for host-plant finding, but the evolutionary mechanisms underlying this phenomenon are poorly understood. We focused on Scaptomyza flava, an herbivorous drosophilid specialized on isothiocyanate (ITC)-producing (Brassicales) plants, and identified Or67b paralogs that were triplicated as mustard-specific herbivory evolved.

Food-derived volatiles enhance consumption in .

Insects use multiple sensory modalities when searching for and accepting a food source, in particular odor and taste cues. Food-derived odorants are generally involved in mediating long- and short-range attraction. Taste cues, in contrast, act directly by contact with the food source, promoting the ingestion of nutritious food and the avoidance of toxic substances.

An inside look at the sensory biology of triatomines.

Although kissing bugs (Triatominae: Reduviidae) are perhaps best known as vectors of Chagas disease, they are important experimental models in studies of insect sensory physiology, pioneered by the seminal studies of Wigglesworth and Gillet more than eighty years ago. Since then, many investigations have revealed that the thermal, hygric, visual and olfactory senses play critical roles in the orientation of these blood-sucking insects towards hosts. Here we review the current knowledge about the role of these sensory systems, focussing on relevant stimuli, sensory structures, receptor physiology and the molecular players involved in the complex and cryptic behavioural repertoire of these nocturnal insects.

Neuroethology of Olfactory-Guided Behavior and Its Potential Application in the Control of Harmful Insects.

Harmful insects include pests of crops and storage goods, and vectors of human and animal diseases. Throughout their history, humans have been fighting them using diverse methods. The fairly recent development of synthetic chemical insecticides promised efficient crop and health protection at a relatively low cost.

The neural bases of host plant selection in a Neuroecology framework.

Understanding how animals make use of environmental information to guide behavior is a fundamental problem in the field of neuroscience. Similarly, the field of ecology seeks to understand the role of behavior in shaping interactions between organisms at various levels of organization, including population-, community- and even ecosystem-level scales. Together, the newly emerged field of "Neuroecology" seeks to unravel this fundamental question by studying both the function of neurons at many levels of the sensory pathway and the interactions between organisms and their natural environment.

Hunger is the best spice: effects of starvation in the antennal responses of the blood-sucking bug Rhodnius prolixus.

Blood-sucking insects strongly rely on olfactory cues to find their vertebrate hosts. As in other insects with different lifestyles, it has been shown that endogenous and exogenous factors modulate olfactory responses. The triatomine bug Rhodnius prolixus is an important vector of Chagas disease and a classical model for studies of physiology and behavior.

Glomerular interactions in olfactory processing channels of the antennal lobes.

An open question in olfactory coding is the extent of interglomerular connectivity: do olfactory glomeruli and their neurons regulate the odorant responses of neurons innervating other glomeruli? In the olfactory system of the moth Manduca sexta, the response properties of different types of antennal olfactory receptor cells are known. Likewise, a subset of antennal lobe glomeruli has been functionally characterized and the olfactory tuning of their innervating neurons identified. This provides a unique opportunity to determine functional interactions between glomeruli of known input, specifically, (1) glomeruli processing plant odors and (2) glomeruli activated by antennal stimulation with pheromone components of conspecific females.

Effects of starvation on the olfactory responses of the blood-sucking bug Rhodnius prolixus.

Blood-sucking insects use olfactory cues in a variety of behavioral contexts, including host-seeking and aggregation. In triatomines, which are obligated blood-feeders, it has been shown that the response to CO2, a host-associated olfactory cue used almost universally by blood-sucking insects, is modulated by hunger. Host-finding is a particularly dangerous task for these insects, as their hosts are also their potential predators.

Species-specific effects of herbivory on the oviposition behavior of the moth Manduca sexta.

In Southwestern USA, the jimsonweed Datura wrightii and the nocturnal sphinx moth Manduca sexta form a pollinator-plant and herbivore-plant association. While certain plant volatile organic compounds (VOCs) attract moths for oviposition, it is likely that other host-derived olfactory cues, such as herbivore-induced VOCs, repel moths for oviposition. Here, we studied the oviposition preference of female M.

The distribution and abundance of triatomine insects, potential vectors of Chagas Disease, in a metropolitan area in southern Arizona, United States.

Triatomine insects are a problem for human health in southwestern United States because of the moderate-to-severe allergic reactions their bites can cause and because they are potential vectors of Chagas Disease. Although both infected insects and wild mammalian reservoirs are plentiful in southern U.S.

An insight into the sialotranscriptome of Triatoma rubida (Hemiptera: Heteroptera).

The kissing bug Triatoma rubida (Uhler, 1894) is found in southwestern United States and parts of Mexico where it is found infected with Trypanosoma cruzi, invades human dwellings and causes allergies from their bites. Although the protein salivary composition of several triatomine species is known, not a single salivary protein sequence is known from T. rubida.

Feeding and defecation behavior of Triatoma rubida (Uhler, 1894) (Hemiptera: Reduviidae) under laboratory conditions, and its potential role as a vector of Chagas disease in Arizona, USA.

Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host.

The neurobiology of insect olfaction: sensory processing in a comparative context.

The simplicity and accessibility of the olfactory systems of insects underlie a body of research essential to understanding not only olfactory function but also general principles of sensory processing. As insect olfactory neurobiology takes advantage of a variety of species separated by millions of years of evolution, the field naturally has yielded some conflicting results. Far from impeding progress, the varieties of insect olfactory systems reflect the various natural histories, adaptations to specific environments, and the roles olfaction plays in the life of the species studied.

Spiking patterns and their functional implications in the antennal lobe of the tobacco hornworm Manduca sexta.

Bursting as well as tonic firing patterns have been described in various sensory systems. In the olfactory system, spontaneous bursts have been observed in neurons distributed across several synaptic levels, from the periphery, to the olfactory bulb (OB) and to the olfactory cortex. Several in vitro studies indicate that spontaneous firing patterns may be viewed as "fingerprints" of different types of neurons that exhibit distinct functions in the OB.

Local interneuron diversity in the primary olfactory center of the moth Manduca sexta.

Local interneurons (LNs) play important roles in shaping and modulating the activity of output neurons in primary olfactory centers. Here, we studied the morphological characteristics, odor responses, and neurotransmitter content of LNs in the antennal lobe (AL, the insect primary olfactory center) of the moth Manduca sexta. We found that most LNs are broadly tuned, with all LNs responding to at least one odorant.

Histamine-immunoreactive local neurons in the antennal lobes of the hymenoptera.

Neural networks receive input that is transformed before being sent as output to higher centers of processing. These transformations are often mediated by local interneurons (LNs) that influence output based on activity across the network. In primary olfactory centers, the LNs that mediate these lateral interactions are extremely diverse.

Male moths bearing transplanted female antennae express characteristically female behaviour and central neural activity.

The primary olfactory centres of the sphinx moth Manduca sexta, the antennal lobes, contain a small number of sexually dimorphic glomeruli: the male-specific macroglomerular complex and the large female glomeruli. These glomeruli play important roles in sex-specific behaviours, such as the location of conspecific females and the selection of appropriate host plants for oviposition. The development of sexually dimorphic glomeruli depends strictly on the ingrowth of sex-specific olfactory receptor cell afferents.

Antagonistic effects of floral scent in an insect-plant interaction.

In southwestern USA, the jimsonweed Datura wrightii and the nocturnal moth Manduca sexta form a pollinator-plant and herbivore-plant association. Because the floral scent is probably important in mediating this interaction, we investigated the floral volatiles that might attract M. sexta for feeding and oviposition.

Infection of kissing bugs with Trypanosoma cruzi, Tucson, Arizona, USA.

Triatomine insects (Hemiptera: Reduviidae), commonly known as kissing bugs, are a potential health problem in the southwestern United States as possible vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Although this disease has been traditionally restricted to Latin America, a small number of vector-transmitted autochthonous US cases have been reported. Because triatomine bugs and infected mammalian reservoirs are plentiful in southern Arizona, we collected triatomines inside or around human houses in Tucson and analyzed the insects using molecular techniques to determine whether they were infected with T.

Dimorphic olfactory lobes in the arthropoda.

Specialized olfactory lobe glomeruli relating to sexual or caste differences have been observed in at least five orders of insects, suggesting an early appearance of this trait in insect evolution. Dimorphism is not limited to nocturnal species, but occurs even in insects that are known to use vision for courtship. Other than a single description, there is no evidence for similar structures occurring in the Crustacea, suggesting that the evolution of dimorphic olfactory systems may typify terrestrial arthropods.

Neuroethology of oviposition behavior in the moth Manduca sexta.

Olfactory cues play decisive roles in the lives of most insect species, providing information about biologically relevant resources, such as food, mates, and oviposition sites. The nocturnal moth Manduca sexta feeds on floral nectar from a variety of plants (and thus serves as a pollinator), but females oviposit almost exclusively on solanaceous plants, which they recognize on the basis of olfactory cues. Plants, however, respond to herbivory by releasing blends of volatiles that attract natural enemies of herbivores.