Social-climber wasps put their feet up

Sometimes it seems that the lower down the ranks we are the harder we work, while our bosses laze about and reap the rewards.

This is not just a human gripe, social insects exploit those lower down the pecking order, too. …

Dr Jeremy Field [UCL Biology] and colleagues … have found that the hairy-faced hover wasp, Liostenogaster flavolineata, has a hierarchical system in which the older wasps near the top work less than the lowly young wasps at the bottom.

This Malaysian species lives in groups of up to 10 females. The queen reproduces and the others gather food to feed her larvae. When the queen dies, the next-oldest female inherits the right to lay eggs.

When Field's team removed the second-in-line female, it had the effect of promoting the female that was third. As predicted she started to work less, as she was now closer in line to reproducing. Before promotion, she would have spent on average 62 per cent of her time foraging. After promotion, she foraged for only 27 per cent of the time. …

Foraging is a tiring and risky activity. "If your future is brighter - you're near the front of the queue - you should take fewer risks," says Field. "You should work less hard." …

"The closer you are to the front of the queue, the more you have to gain from challenging those ahead of you," says Field.

Rowan Hooper, 'New Scientist'