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2,5-Dichlorophenol (from ingested herbicide?) in defensive secretion of grasshopper
Science (New York, N.Y.)
|April 16, 1971
Summary
The grasshopper Romalea microptera uses 2,5-dichlorophenol, a compound likely from ingested herbicides, as a defense against ants. This represents a novel instance of insects secondarily utilizing human-introduced pesticides.
Area of Science:
- Chemical Ecology
- Entomology
- Environmental Toxicology
Background:
- Insects utilize a variety of chemical defenses against predators.
- The grasshopper Romalea microptera emits a defensive froth containing various compounds.
- Secondary utilization of chemicals by one species, produced by another, is known but rare.
Purpose of the Study:
- To identify the chemical composition of the defensive froth of Romalea microptera.
- To investigate the origin and function of 2,5-dichlorophenol in the grasshopper's defense.
- To document the secondary utilization of a man-made pesticide by an insect.
Main Methods:
- Gas chromatography-mass spectrometry (GC-MS) to analyze the chemical components of the froth.
- Dietary analysis of grasshoppers to identify ingested substances.
- Behavioral assays to test the repellent properties of 2,5-dichlorophenol against ants.
Main Results:
- The defensive froth contains phenols, terpenes, benzoquinone, and notably, 2,5-dichlorophenol.
- 2,5-dichlorophenol was found to be repellent to ants, indicating a defensive role.
- The presence of 2,5-dichlorophenol is strongly correlated with herbicide or herbicide derivative ingestion by the grasshopper.
Conclusions:
- Romalea microptera incorporates 2,5-dichlorophenol, likely from environmental sources like herbicides, into its defensive secretions.
- This chlorinated aromatic compound serves as an effective anti-predator agent against ants.
- This study highlights a unique case of an insect secondarily utilizing a pesticide introduced by humans for its own defense.