Social behavior, ovary size, and population of origin influence cuticular hydrocarbons in the orchid bee, Euglossa dilemma

Environmental decomposition of cuticular hydrocarbons generates a volatile pheromone that guides insect social behavior

10.1101/773937 ◽

2019 ◽

Cited By ~ 2

Author(s):

Eduardo Hatano ◽

Ayako Wada-Katsumata ◽

Coby Schal

Keyword(s):

Water Vapor ◽

Social Behavior ◽

Cuticular Hydrocarbons ◽

Periplaneta Americana ◽

Group Formation ◽

Mate Recognition ◽

Short Chain Fatty Acids ◽

American Cockroach ◽

Environmental Agents ◽

Time Courses

AbstractOnce emitted, semiochemicals are exposed to reactive environmental factors that may alter them, thus disrupting chemical communication. Some species, however, might have adapted to detect environmentally mediated breakdown products of their natural chemicals as semiochemicals. We demonstrate that air, water vapor, and ultraviolet (UV) radiation break down unsaturated cuticular hydrocarbons (CHCs) of Periplaneta americana (American cockroach), resulting in the emission of volatile organic compounds (VOCs). In behavioral assays, nymphs strongly avoided aggregating in shelters exposed to the breakdown VOCs from cuticular alkenes. The three treatments (air, water vapor, UV) produced the same VOCs, but at different time-courses and ratios. Fourteen VOCs from UV-exposed CHCs elicited electrophysiological responses in nymph antennae; 10 were identified as 1-pentanol, 1-octanol, 1-nonanol, tetradecanal, acetic acid, propanoic acid, butanoic acid, pentanoic acid and hexanoic acid. When short-chain fatty acids were tested as a mix and a blend of the alcohols and aldehyde was tested as a second mix, nymphs exhibited no preference for control or treated shelters. However, nymphs avoided shelters that were exposed to VOCs from the complete 10-compound mix. Conditioned shelters (occupied by cockroaches with feces and CHCs deposited on the shelters), which are normally highly attractive to nymphs, were also avoided after UV-exposure, confirming that breakdown products from deposited metabolites, including CHCs, mediate this behavior. Our results demonstrate that common environmental and anthropogenic agents degrade CHCs into volatile semiochemicals that may serve as necromones or epideictic pheromones, mediating group formation and dissolution.Significance StatementCuticular hydrocarbons (CHCs) cover the outer surface of insects, where they prevent water loss and serve as sex pheromones and in nest-mate recognition in social insects. Although CHCs are not volatile, they can be broken into volatile fragments by reacting with environmental agents. We demonstrate that volatile breakdown products of CHCs affect the social behavior of the American cockroach. A synthetic mix of volatiles dispersed cockroaches away from shelters, signaling an unsuitable shelter. These results highlight that some insect species have evolved communication strategies that exploit environmental and anthropogenic agents to produce bioactive compounds that mediate ecological interactions.

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Cuticular Hydrocarbons of Heterotermes tenuis (Isoptera: Rhinotermitidae): Analyses and Electrophysiological Studies

Zeitschrift für Naturforschung C ◽

10.1515/znc-2004-1-226 ◽

2004 ◽

Vol 59 (1-2) ◽

pp. 135-139 ◽

Cited By ~ 7

Author(s):

Luciane G. Batista-Pereira ◽

Márcio G. dos Santos ◽

Arlene G. Corrêa ◽

João B. Fernandes ◽

Alberto Arab ◽

...

Keyword(s):

Social Behavior ◽

Cuticular Hydrocarbons ◽

High Selectivity ◽

Behavioral Test ◽

The Social ◽

Linear Alkanes ◽

Electrophysiological Studies ◽

Important Pest ◽

Chemical Messenger ◽

Species Specific

Termites have become an important pest of Eucalyptus and Pinus reforestations, sugarcane and other cultures. An alternative for the control of this pest would be the use of attractive traps that take in account the social behavior of these insects. Diverse factors are important for the insects in the localization of the habitat and the choice of the food and specific odors can facilitate this. Studies referring to Heterotermes tenuis (Isoptera: Rhinotermitidae) are scarce. The objective of this work was to analyze the tergal cuticular extract of H. tenuis and determine the selectivity and sensitivity of its antennae to the components of this extract by electroantennography (EAG). The composition of the cuticular extract was determined by GC-MS analysis. The hydrocarbons found were restricted to linear alkanes, being most abundant C24 to C27 that comprises ca. 65% of the total. Olefins were not detected. EAG and behavioral test responses to the cuticular hydrocarbons were greater and significantly different from the control and the high selectivity of the antennae to the extract indicates its potential as chemical messenger. Cuticular hydrocarbons mixture is species-specific and can be used to identify a given taxon without the diagnostic castes, soldiers or imagoes. Difference in the composition appears to relate with the type of habitat of specie.

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