Monitoring Work can Lead to Unexpected Discoveries
Across the Credit River Watershed, we spend many hours in the field monitoring ecosystems, tracking species and collecting data that help us understand how the watershed is changing. This long-term monitoring helps guide restoration, understand biodiversity and inform science-based decision-making. Along the way, it can also lead to remarkable discoveries.
Last year, during routine field work, we encountered a remarkable leaf beetle, called the clavate tortoise beetle. While this species isn’t rare, its incredible camouflage skills make it easy to miss. Learn more about this fascinating insect.
Built for Defence in Every Stage of Life
These beetles have fascinating body forms in both their adult and larval stages that help them survive. To avoid predators, clavate tortoise beetles display physical and behavioural traits reminiscent of tortoises.
As part of a group known as tortoise beetles, they have wide, curved outer body panels that fit together and cover their legs and other body parts, much like the shell of a tortoise. When they feel threatened, they pull in their legs and press themselves tightly against the surface they are on.
When clavate tortoise beetles hatch from their eggs, they start out as grubs. They’re slow-moving, vulnerable, blob-like creatures with small, obscure legs.
A defensive tactic of the larvae is to wield a fecal shield. These shields not only give the tortoise beetle larvae physical protection from predators but may also provide camouflage and chemical deterrence through smell. To make the shield, they extend a tube from their hind end forward like a telescope and at the tip create a jagged mass of frass, or insect feces, and shed skin. This shield can be shifted around at various angles above the grub’s vulnerable back, allowing them to protect themselves from hungry predators.
An Interesting Appetite
These native beetles primarily eat plants of the potato family. In the natural areas of southern Ontario, they can be found feeding on common potato family weeds, especially bittersweet nightshade. Tortoise beetle feeding can be helpful in managing this invasive plant. Fortunately, they are not considered a major agricultural pest of potatoes, tomatoes, peppers and eggplants in Ontario.
Appreciate the Little Things
Small discoveries like the clavate tortoise beetle highlight the rich biodiversity supported within the Credit River Watershed. While much of our monitoring work focuses on long-term ecosystem trends, individual species observations help build a clearer picture of habitat health and ecological change over time.
Documenting species presence contributes to our understanding of how native insects interact with plants, respond to environmental pressures and fit within broader food webs. Each observation, no matter how small, strengthens the science that guides restoration, protection and stewardship efforts across the watershed.
The next time you’re exploring a natural area, look closer at the leaves around you. You may spot an unexpected example of the remarkable adaptations that help species survive and thrive in our local ecosystems.
Learn more about insects in the Credit River Watershed.
Share your interesting finds in nature with us on Instagram, Facebook and X.
By Dan Schuurman, Specialist, Natural Heritage
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