Question: I know that stingers on wasps, bees, ants, etc., are modified ovipositors, which helps them out in terms of defense […] this got me into thinking. Do other bugs have anything similar?
This question emailed to us is quite intriguing and complex. Do other bugs have anything similar to a hymenopteran’s (e.g., wasps, bees, ants) stinger?
In short, yes. There are bugs with something similar to a stinger. Previous structures tend to be modified for injecting venom. For example, in Hymenoptera, stingers are modified ovipositors.
Many of us are familiar with ants, bees, and wasps. In addition, scorpions are also a commonly referred to Arthropod that can sting. Curiosity and fear surround animals that can inject venom.
Envenomation is the process by which venom is injected by the bite or sting of a venomous animal. Some insects and other arthropods use venom for a variety of reasons, such as capturing prey, defending themselves, facilitating parasitism, or for extra-oral digestion. The use of venom depends on the natural history of the insect in question.
Just as there is a variety of uses for venom, there are different ways in which an insect injects venom. The injection apparatus and where the venom glands are present in the body differ among insects. An injection apparatus can be modified mouthparts (e.g., maxillary stylets/beak, mandibles, etc.), terminal antennal segments, cuticular spines (spins on the outside of a caterpillar’s body), or a modified ovipositor (i.e., a stinger).
Research has shown evidence for 14 groups of insects that have independently evolved the ability to use venom for capturing prey or defense against predators. Here are a few examples of arthropods with structures that inject venom other than Hymenoptera with their stingers:
- The scorpion beetle, Onychocerus albitarsis (Coleoptera: Cerambycidae). My favorite example of another Arthropod that can sting other than a hymenopteran is the longhorn beetle, Onychocerus albitarsis. This beetle stings with its antennae! The terminal (last) antennal segment looks like a scorpion’s stinger and has two pores that injects venom from special antennal glands. In fact, the delivery system of its venom is extremely similar to that of a scorpion – convergent evolution at its finest. Wonder what a sting from a scorpion beetle feels like? It’s reported to feel like a bee sting.
- Assassin bugs (Hemiptera: Heteroptera: Reduviidae). There are many examples of heteropterans that can inject venom with their maxillary stylets of their mouthparts. The salivary glands contain the venom glands. Heteropteran venoms are known to liquify tissue and cause paralysis of their prey. When an assassin bug captures prey with is rostrum (i.e., beak), it injects a venomous saliva to liquefy its prey so that it can suck up the liquefied mush (an assassin bug’s mouth is kind of like a straw). This manner of prey capture and feeding is called extra-oral digestion.
- Caterpillars (Lepidoptera). There are many examples of venomous caterpillars. Ever see a hairy caterpillar and decide that it’s best not to touch it? That’s because of the fear of envenomation, of course. Some caterpillars have cuticular spins (the “hairs”) that can inject painful venom. Its use is purely for defense (these caterpillars eat plants after all). I personally had a painful encounter with a buck moth caterpillar (Lepidoptera: Saturniidae: Hemileucinae) in Nuevo León, Mexico. I was coming down from a climb and accidentally brushed up against one on a bush. OUCH! That was more painful to me than a wasp sting!
- Antlions (Neuroptera: Myrmeleontidae). Larvae of many neuropterans have mandibles which can inject venom into their prey. My favorite example are antlions. The larval stage of antlions are venomous predators of ants or other insects. They dig pits to trap their prey and then capture them with pincher-like jaws. These critters are also referred to as doodlebugs because of the marks they leave in the sand.
Antlions rarely bite humans. However, when their life is threatened, they may bite. It’s reported to feel like a bee sting (big surprise, right?).
There you have it! Some examples of insects other than ants, bees, and wasps that inject venom.
Berkov, A., Rodríguez, N., & Centeno, P. (2008). Convergent evolution in the antennae of a cerambycid beetle, Onychocerus albitarsis, and the sting of a scorpion. Naturwissenschaften, 95(3), 257-261.
Hawkeswood, T. J. (2006). Effects of envenomation to a human finger and arm by the larva of an unidentified species of Myrmeleon (Neuroptera: Myrmeleontidae). Calodema, 7, 32-33.
Marcela Laura Monné, Miguel Angel Monné, and Qiao Wang. “General morphology, classification, and biology of Cerambycidae.” Cerambycidae of the World-Biology and Pest Management (2017).
Sahayaraj, K., Kanna, A. V., & Kumar, S. M. (2010). Gross morphology of feeding canal, salivary apparatus and digestive enzymes of salivary gland of Catamirus brevipennis (Servile)(Hemiptera: Reduviidae). Journal of the Entomological Research Society, 12(2), 37-50.
Walker, A. A., Robinson, S. D., Yeates, D. K., Jin, J., Baumann, K., Dobson, J., … & King, G. F. (2018). Entomo-venomics: The evolution, biology and biochemistry of insect venoms. Toxicon, 154, 15-27.