yorkie's picture

Cassida rubiginosa?

Observed: 17th May 2010 By: yorkieyorkie’s reputation in Invertebratesyorkie’s reputation in Invertebratesyorkie’s reputation in Invertebratesyorkie’s reputation in Invertebrates

Small (approx 6mm) green beetle, with rusty line where elytra meet, and also rusty near scutellum. New for me, id'd from field guide.

Species interactions

No interactions present.

Species with which Thistle Tortoise Beetle (Cassida rubiginosa) interacts


robster333's picture


Looking at my field guide i would say its Cassida viridis Green Tortoise Beetle. C.rubiginosa appears more pointed at the rear

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yorkie's picture

Thanks for your comments.

I know being dependent on generalist field guides leaves us unaware of the multitude of alternatives not included in these guides, but in both of my guides C. viridis looks to be entirely green, without the rusty markings, which is why I chose rubiginosa. I opted to go for the colouration rather than the body shape - but I don't know which is more important!


dshubble's picture

Which Cassida?

Hmmm... pretty sure it's not Cassida viridis as this is all green - C. rubiginosa is possible, but there are a couple of others which really need features on the underside to separate (and/or a close look between the pronotum & elytra). I'm not sure I could be really certain beyond genus here,


John Bratton's picture

The fairly sharp hind corners

The fairly sharp hind corners to the pronotum rule out viridis. The foodplant would be a clue. C. rubiginosa is by far the commonest.

To answer your comment above, beetle body shape is usually a better character than colour, which can change with age.