Pain and Lethality Induced by Insect Stings: An Exploratory and Correlational Study.

Justin O. Schmidt

doi:10.3390/toxins11070427

Abstract

Pain is a natural bioassay for detecting and quantifying biological activities of venoms. The painfulness of stings delivered by ants, wasps, and bees can be easily measured in the field or lab using the stinging insect pain scale that rates the pain intensity from 1 to 4, with 1 being minor pain, and 4 being extreme, debilitating, excruciating pain. The painfulness of stings of 96 species of stinging insects and the lethalities of the venoms of 90 species was determined and utilized for pinpointing future directions for investigating venoms having pharmaceutically active principles that could benefit humanity. The findings suggest several under- or unexplored insect venoms worthy of future investigations, including: those that have exceedingly painful venoms, yet with extremely low lethality—tarantula hawk wasps (Pepsis) and velvet ants (Mutillidae); those that have extremely lethal venoms, yet induce very little pain—the ants, Daceton and Tetraponera; and those that have venomous stings and are both painful and lethal—the ants Pogonomyrmex, Paraponera, Myrmecia, Neoponera, and the social wasps Synoeca, Agelaia, and Brachygastra. Taken together, and separately, sting pain and venom lethality point to promising directions for mining of pharmaceutically active components derived from insect venoms.

Highlights

Stinging insects in the immense order Hymenoptera display a dazzling array of lifestyles and natural histories
Each of the multitude of independent biological paths followed by stinging ants, social wasps, social bees, and solitary wasps and bees has resulted in evolutionary complex—and often unique—blends of venom constituents
Additional complicating factors contributing to less emphasis on investigations of stinging insect venoms are the difficulties of identifying the insects and obtaining enough venom for study

Summary

Introduction

Stinging insects in the immense order Hymenoptera display a dazzling array of lifestyles and natural histories. Venoms of stinging insects have a variety of biologically important activities including the abilities to induce pain, cause cellular or organ toxicity, be lethal, produce paralysis, plus others [2,3,4,5] These activities are the result of a wide variety of venom components, especially peptides and proteins, and other categories of constituents [6,7,8]. The intensity of the pain caused by an insect sting depends upon several factors, including the size of the stinging insect, the amount of venom it injects and, most importantly, on the chemical properties of the pain-inducing constituent(s) The purpose of this investigation was to explore as wide a diversity of stinging insects as possible to determine their ability to cause pain, and to pinpoint species that hold promise for discovering new pain-producing products that might be of benefit for science or medical investigations. Several new species of stinging insects whose venoms hold promise are highlighted

Pain Ratings of Insect Stings

Lethality of Stinging Insect Venoms

Relationship between Sting Pain Level and Lethality of Stinging Insect Venoms

Insects

Pain Measurement

Physiological Measurements