Student Scholarship
Document Type
Article
Abstract
The paper explores the complex systems of chemical communication utilized by insects, with a specific focus on the role of pheromones in the trailmaking behavior of foraging ants. Unlike hormones that act internally, pheromones are secreted externally to influence the behavior or physiology of other members of the same species. These substances are categorized into two functional groups: releaser pheromones, which trigger an immediate behavioral response via the central nervous system, and primer pheromones, which induce slower physiological changes in the recipient.
Foraging in ant colonies typically involves a transition from exploratory scouting to organized trailing. When a scout discovers a food source too large to move alone, it returns to the nest while laying a chemical trail. This trail acts as a guide for recruit workers, who then follow the scent to the food source and reinforce the trail upon their return if the food remains sufficient. This creates a positive feedback loop that effectively manages colony resources; however, once the food is exhausted, workers stop reinforcing the scent, and the trail's high volatility causes it to evaporate, preventing unnecessary labor.
Anatomically, the source of these trail substances varies significantly across different ant subfamilies. Research indicates that while some species utilize the hind gut and anus to dispense pheromones, others rely on specialized structures such as Dufour’s gland, Pavan’s gland, or the true poison gland, often dispensing the substance through a stinger. Experimental efforts to isolate these chemicals are often hindered by their extreme instability and minute quantities. Understanding these mechanisms not only illuminates the social organization of insects but also suggests potential applications for pest control through the use of synthetic attractants or repellents.
Research Highlights
The Problem: The researcher investigates the mechanisms of chemical communication in ants, specifically focusing on how pheromones function in trailmaking and foraging activities.
The Method: The study reviews existing literature on pheromone types and sources before conducting experiments with colonies of Crematogaster and Prenolepis imparis ants collected from the Busch Wildlife Reserve and St. Charles, Missouri.
Quantitative Finding: Solenopsis saevissima pheromones remain biologically active on glass for 85 to 125 seconds at $28^{\circ}$C; fire ant workers can detect trail odors from a distance of over 10 millimeters; Prenolepis imparis maintained foraging trails to fruit sources for up to 12 days at distances of 2.33 to 2.89 yards.
Qualitative Finding: Trail pheromones are produced in diverse anatomical sites depending on the species, including the Dufour’s gland, hind gut, Pavan’s gland, or the true poison gland; these substances act as "releaser" pheromones that affect the central nervous system to trigger immediate behavioral responses.
Finding: Ants utilize a negative feedback system where the recruitment of workers to a trail is directly dependent on pheromone concentration, which diminishes once a food source is depleted.
Publication Date
1966
Recommended Citation
Young, Roxanna, "Pheremones in Trailmaking" (1966). Student Scholarship. 187.
https://digitalcommons.lindenwood.edu/student-research-papers/187
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
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