Country diary: The insects turn the air thick with chemical signals

Wenlock Edge, Shropshire: For the shieldbugs, darters and hornets, this rare moment of autumn sunshine is like a jolt of electricityTwo insects turn like compasses on a leaf of traveller's-joy. They look very different from each other, but they are the same species - the common green shieldbug, Palomena prasina. One is more animated and moves quickly across the leaf; its head and antennae stick out of the top of its green, pitted, shield-shaped body that is broad along the pronotum at the top and pointed at its tip below. This is an adult shieldbug, an imago.The other is more sedentary, a circular, pea-green shield with black heraldic markings; this is a nymph shieldbug, in its fifth and final instar - or stage of development - before it sheds its nymph shield to become an imago. Continue reading...