An update and review of arthropod vector sensory systems: Potential targets for behavioural manipulation by parasites and other disease agents.

For over a century, vector ecology has been a mainstay of vector-borne disease control. Much of this research has focused on the sensory ecology of blood-feeding arthropods (black flies, mosquitoes, ticks, etc.) with terrestrial vertebrate hosts. Of particular interest are the cues and sensory systems that drive host seeking and host feeding behaviours as they are critical for a vector to locate and feed from a host. An important yet overlooked component of arthropod vector ecology are the phenotypic changes observed in infected vectors that increase disease transmission. While our fundamental understanding of sensory mechanisms in disease vectors has drastically increased due to recent advances in genome engineering, for example, the advent of CRISPR-Cas9, and high-throughput "big data" approaches (genomics, proteomics, transcriptomics, etc.), we still do not know if and how parasites manipulate vector behaviour. Here, we review the latest research on arthropod vector sensory systems and propose key mechanisms that disease agents may alter to increase transmission.

Automated Egg-Counting Approaches for Aedes aegypti Oviposition Experiments.

Egg-laying preferences of mosquitoes can reveal key neurosensory mechanisms informing the decision-making process for this critical behavior. A single blood meal results in a gravid female Aedes aegypti mosquito laying more than 100 eggs. Therefore, egg counting represents a potentially time-consuming and laborious component to behavioral assays, such as those that measure oviposition preference or fecundity. Automated algorithms that count eggs from images can dramatically reduce the time required for this step of data processing and analysis and increase reproducibility associated with having multiple human observers count the eggs. Here, we present two distinct approaches for counting melanized Ae. aegypti eggs laid on white filter paper.

Evaluating Egg-Laying Preference of Individual Aedes aegypti Mosquitoes.

Egg-laying behavior in insects has a dramatic impact on their fitness, controlling their extent and distribution across ecosystems. Thus, understanding the cues that guide mosquito egg laying is an important goal. Measuring mosquito egg-laying preference is critically important for understanding the sensory and neural mechanisms guiding adaptive breeding decisions. Here, we present a method for ascertaining the egg-laying preference of individual Aedes aegypti mosquitoes in small chambers with two distinct oviposition substrate choices. This assay is best suited for medium- to high-throughput analysis of egg-laying preference to liquids containing distinct contact chemosensory cues, such as differing salinities. We discuss all steps of the process from assay construction and setup to data acquisition and analysis.

Measuring Oviposition Preference in Aedes aegypti Mosquitoes.

The female mosquito is endowed with the responsibility of gene transfer from one generation to another through careful delivery of her eggs to an appropriate environment. To guarantee a successful reproduction process, female mosquitoes use an evaluative approach to select an oviposition site that will ensure that their progeny successfully hatch and develop from larvae to pupa to adult. Specific conditions must be met during oviposition site selection before gravid females deposit eggs, including but not limited to appropriate temperature, salinity, and pH; the presence of nutrition; and a low risk of predation. Mosquito species exhibit a remarkable diversity in their oviposition site selection behaviors. For instance, Aedes aegypti, which is a vector for Zika, dengue, yellow fever, and chikungunya viruses, prefers to lay its eggs in natural depressions (e.g., tree holes) or artificial containers. In contrast, other mosquito species, like Anopheles, gravitate toward more open water bodies. Understanding the oviposition preference behavior of the Ae. aegypti mosquito will facilitate the development of surveillance and control efforts to hinder the successful progression of this vector. Here, we present information on some of the known behaviors and preferences of Ae. aegypti during oviposition site selection, techniques to measure these preferences, and some open questions.

TReND in Africa: Toward a Truly Global (Neuro)science Community.

TReND is a volunteer-scientist run charity dedicated to promoting research and education on the African continent. Focusing on neuroscience, we discuss approaches to address some of the factors that currently stifle Africa's scientific development and our experience in implementing them.

African neuroscience on the global stage: Nigeria as a model.

Of the 572 neuroscience-related studies published in Nigerian from 1996 to 2017, <5% used state-of-the-art techniques, none used transgenic models, and only one study was published in a top-tier journal.