Updated on February 28th, 2025
Imagine wielding a tool so precise it can slice through leaves, drill into wood or even inject life into another creature. Insects that some might classify as 'weird insects' have evolved to do just that—turning egg-laying into an art of survival.
Join me as we delve into the depths of these specialized structures, unraveling their secrets and exploring the fascinating stories they tell.
What is an ovipositor?
The ovipositor is a specialized organ found in select female insects, such as certain species of spiders and wasps. This structure serves a vital purpose in the reproduction process.
Ovipositors are typically composed of the hardened sclerites of an insect’s exoskeleton —sclerites are the rigid plates that make up the exoskeleton of insects—and can exhibit both external and internal configurations.
In some insect species, the ovipositor is prominently displayed, situated at the rear end of the abdomen, ready for precise egg-laying maneuvers. In other species, however, the ovipositor may be partially or completely internal, hidden within the body for an insect’s reproductive prowess.
What is the purpose of an ovipositor?
An ovipositor plays a crucial role in egg-laying (a process known as ovipositing). This tool allows female insects to deposit their eggs in carefully selected locations. Depending on the species, ovipositors can:
- Pierce plant tissue: Sawflies saw into leaves and stems to deposit eggs
- Drill into wood and soil: Wood-boring wasps carve tunnels for their offspring
- Inject eggs into hosts: Parasitic wasps turn other insects into nurseries
Every species has the same goal—giving their offspring the best possible chance to hatch and survive.
How do sawflies use their ovipositors to slice into plants?
Sawflies are among the weird insects, with ovipositors specially adapted to saw into plant tissue for egg-laying.
Female sawflies have slender and elongated ovipositors that resemble a tiny saw or drill. When a female sawfly locates a suitable host plant for egg-laying, she uses her ovipositor to make precise incisions (or slits) in the plant tissue—a process referred to as "sawing." The female sawfly exerts controlled movements to carefully cut through the outer layers of the plant, creating minute channels or pockets where she can deposit her valuable eggs.
Do wood-boring wasps have built-in drills?
Some insects have evolved extraordinary tools for survival, and wood-boring wasps—also considered among nature’s "weird insects"—are no exception.
A wood-boring wasp, or wood wasp, has an ovipositor that is a long and slender appendage that is typically curved or angled and accompanied by sharp, serrated edges or teeth near the tip. When a female wood-boring wasp is ready to lay her eggs, she locates a suitable wooden surface or soil environment. Positioning her ovipositor against the surface and applying just-so pressure, she uses it as a drilling tool.
With a combination of forward thrust and rotating movements, she gradually bores into the wood or soil. The sharp edges or teeth on the ovipositor aid in cutting through the material, while the curved or angled shape allows the wasp to maneuver and penetrate deeper into the substrate. The female may also secrete substances that soften the wood or soil, making it easier to drill through.
Once the ovipositor has created a suitable tunnel, the female delicately inserts her eggs into the cavity.
How do parasitic wasps turn other insects into nurseries?
Parasitic wasps are among the most unsettling creatures in the insect world—often earning them a spot on lists of 'weird insects.' Their ovipositors serve a chilling purpose: not just laying eggs, but transforming other creatures into living nurseries.
A parasitic wasp has an ovipositor that is typically long and slender. The wasp, upon locating a suitable host, first paralyzes the host. (This paralyzation immobilizes the host—thus preventing it from defending itself or escaping—and ensures that it remains alive but unable to harm the developing wasp larvae. Keeping the host alive provides a fresh food source for the growing larvae—an eerie but effective strategy.)
Then the parasitic wasp injects her eggs into the host using her sharp, needle-like ovipositor. The ovipositor must be sharp and the wasp must be precise in her insertion, as she needs to access the host’s internal tissues or body cavities with minimal damage to maximize the chances of successful parasitism.
Does an ovipositor have other functions?
Ovipositors serve more than just egg-laying—they can also be tools of survival, manipulation and defense. Here are some fascinating ways insects use their ovipositors beyond reproduction:
- Venom injection (parasitic wasps): Some parasitic wasps have venomous ovipositors, which they use to inject eggs into a host while simultaneously paralyzing it.
- Colony control (ants): In certain ant species, the ovipositor secretes pheromones and chemicals that influence the behavior of other ants, helping shape the social dynamics of the colony.
- Defense mechanism: Some insects use their ovipositors as a defensive weapon, either by stinging or releasing substances to deter threats.
What other insects have ovipositors?
Here are a handful of additional examples that highlight the diversity of insects that possess these fascinating ovipositors:
- Strepsipterans (Order Strepsiptera): Female strepsipterans, also known as twisted-wing parasites, possess coiled ovipositors that they use to insert their eggs into the bodies of other insects. The larvae of strepsipterans live as internal parasites, ultimately emerging from the host's body.
- Tachinid flies (Tachinidae family): These flies have specialized ovipositors for injecting their eggs into various hosts, including other insects or arachnids.
- Dragonflies and damselflies (Odonata order): Female dragonflies and damselflies have ovipositors they use to insert their eggs into aquatic plants or other suitable substrates near water bodies.
- Lacewings (Order Neuroptera): Lacewings, known for their delicate and intricate wings, use their ovipositors to attach their eggs to leaves or other suitable surfaces. The eggs hatch into voracious larvae called aphid lions, which feed on aphids and other small insects.
Dr. Killigan's thoughts on ovipositors
I am awestruck by the diversity in the insect kingdom. I am captivated by the means to which these ovipositor-possessing insects will go to ensure the reproductive success of their offspring. I also perceive that understanding insects is vital in effective pest management and control, as we must keep any egg-laying insect (or any insect for that matter) out of our homes. My research and expertise in this field have paved the way for innovative strategies and products designed to ensure the protection of our homes, our well-being and the well-being of our families and pets. After all, who really wants to see a parasitic wasp or a sawfly in their abode?
Understanding ovipositors isn’t just about entomology—it’s about keeping these prolific egg layers out of our homes. That’s where Dr. Killigan’s plant-powered solutions come in.
- Dust to Dust: A safe, toxin-free, people-friendly, and pet-friendly solution against both winged and crawling insects. It effectively rids your home and yard of ants, cockroaches, ticks, fleas, silverfish, and more.
- Six Feet Under: A superb insect killer featuring a lab-proven, proprietary blend of select essential oils—soybean, clove, and cinnamon. It breaks down bugs’ exoskeletons and works synergistically to enhance its effectiveness through absorption.
- Explore our entire product line: Keep insects where they belong—in the great outdoors and far, far away from your home.
