It seems that this year has been a particularly fruitful one for ladybirds in my area, and I was pleased to see dozens of pupae on my garden fences in recent weeks. It reminded me that I've been meaning to get something drawn of the little bugs that make it all possible: aphids.
Ladybirds and other wildlife eat prodigious amounts of them, earning the respect of gardeners in the process. Life can be a bit precarious for aphids, being slow-moving and short lived, so they have a secret weapon up their sleeves: cloning! They pop out lots of mini copies of themselves that are fully formed, ready to feed and grow. Some are equipped with wings if the local situation seems dicey, so they can seek out somewhere new to colonise. When the days start drawing in they also produce male clones so that they can mate and produce eggs that will hatch when Spring comes around.
They also have a curious mutualism with various ant species. Their diet of plant sap contains more sugar than they can digest, so they excrete a sugary substance that ants feed off. Long before mankind were tending livestock, ants were looking after aphids like cattle, offering them a measure of protection. In some species, the ants even secrete chemicals on their feet to make the aphids more docile ;3
