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

Abstract

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. However, the negative effects of those insecticides on human health and the environment, as well as the development of insect resistance, have been fueling the search for alternative control tools. New and promising alternative methods to fight harmful insects include the manipulation of their behavior using synthetic versions of “semiochemicals”, which are natural volatile and non-volatile substances involved in the intra- and/or inter-specific communication between organisms. Synthetic semiochemicals can be used as trap baits to monitor the presence of insects, so that insecticide spraying can be planned rationally (i.e., only when and where insects are actually present). Other methods that use semiochemicals include insect annihilation by mass trapping, attract-and- kill techniques, behavioral disruption, and the use of repellents. In the last decades many investigations focused on the neural bases of insect's responses to semiochemicals. Those studies help understand how the olfactory system detects and processes information about odors, which could lead to the design of efficient control tools, including odor baits, repellents or ways to confound insects. Here we review our current knowledge about the neural mechanisms controlling olfactory responses to semiochemicals in harmful insects. We also discuss how this neuroethology approach can be used to design or improve pest/vector management strategies.

Circuits for integrating learnt and innate valences in the fly brain

“…Many sensory stimuli have innate valences, acquired through evolution: some stimuli are innately attractive and others are innately repulsive (Q. Li & Liberles, 2015;Reisenman et al, 2016). However, to behave adaptively in an ever-changing environment, animals are also able to learn new valences for stimuli (Q.…”

Olfactory co‐receptor Orco stimulated by Rice stripe virus is essential for host seeking behavior in small brown planthopper

“…Somewhat differently, RSV can be transmitted from female adults to their progeny via eggs, while RBSDV has no transovarial transmission . In the process that insect horizontally transmits virus to plant host, it is involved in plant host orientation of insect vector, and the orientation behavior may be driven by olfaction …”

“…4,5 In the process that insect horizontally transmits virus to plant host, it is involved in plant host orientation of insect vector, [6][7][8] and the orientation behavior may be driven by olfaction. 9,10 Like most animals, insects rely on their olfactory systems for finding food, courtship, and avoiding noxious chemicals and predators. 10 The odorant signals are mainly detected by the olfactory sensory neurons (OSNs) on the insect antennae, 11,12 which project their chemoreceptive dendrites into morphologically different types of cuticular hair structures (named the olfactory sensilla).…”

Genetic variation in the odorant receptor gene OR4 and bit habits in natural populations of Aedes aegypti from Antioquia department, Colombia

“…It is often reported that when exposed to a group of hosts (of the same species), mosquitoes seeking hosts express a preference for one individual over others (Knols et al, 1995;Qiu et al, 2006;Takken & Knols, 2018). This preference is probably caused by the natural variation in odorants between individuals, which affects insects even at very low concentrations, and demonstrates the high sensitivity of odorant receptors to semiochemicals (Reisenman et al, 2016;Zwiebel & Takken ,2004). However, the differences between species in the preference of mosquitoes by hosts are generally very robust because they are based on real differences in the composition of the odor (Majeed et al, 2016).…”