Associate Certified Entomologist (ACE) Practice Exam

What type of pheromones are used by insects primarily to find mates?

1. Aggregation pheromones

2. Trail pheromones

3. Sex pheromones

4. Alarm pheromones

The correct answer is: Sex pheromones

Sex pheromones are chemical signals produced by insects to facilitate mate attraction and selection. These pheromones are typically species-specific, allowing individuals of the same species to identify potential mates from a distance. The production of sex pheromones is often linked to behavioral and physiological changes in the individuals emitting them, including the readiness to mate. In many cases, the female insect releases these pheromones, which then attract males, who can detect the pheromones using their highly sensitive olfactory receptors. The presence of these chemical cues plays a critical role in the reproductive success of insect populations, as they help ensure that mating occurs between compatible partners. The other options refer to different types of pheromones used for distinct purposes. Aggregation pheromones are primarily employed to bring individuals together, often for feeding or nesting, rather than specifically for mating. Trail pheromones are used in communication related to foraging, guiding other individuals to food sources, and alarm pheromones serve to warn others of potential threats. Each of these types serves its own ecological function, but sex pheromones are specifically geared toward reproduction and mate selection.