Brimstone (Gonepteryx rhamni)
The skittle-shaped eggs of G. rhamni are laid singly on the undersides of the youngest Buckthorn leaves at all heights on the foodplant. Although several eggs may be found together, as in the image above, this can be either the result of different females using the same leaf, or, as in the case depicted, the same female revisiting the spot on more than one occasion. Freshly laid eggs are a delicate pale green, turning yellow, and eventually grey as the larva develops within. The egg stage lasts between 1 and 2 weeks. The above picture was taken within minutes of observing the eggs being laid.