The Hindu

Serrated egg-laying organ gives wasps an edge

Parasitic fig wasps of the genus Apocrypta lay their eggs inside unripe fruits of fig plants. Larvae that emerge from eggs of parasitic fig wasps feed on larvae of another species — the pollinating fig wasps. So, to ensure best nutrition and survival for its own eggs, a parasitic wasp female lays them near larvae of pollinating wasps already developing in the fig fruit.

To lay eggs inside, parasitic wasp females have to dig through the hard and woody skin of unripe figs several times in their lifespan. Evolution has gifted them with a long, flexible and slender egg-laying organ called the ovipositor, which they use to manage this feat. But there is more to an ovipositor that gives the wasps an edge…

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Photo credit: Lakshminath Kundanati

Why octopus arms don’t entangle

An octopus’s arm is covered with hundreds of suckers that give it a strong tendency to attach to everything it encounters but the octopus’s arms. A team of researchers has shown that chemical signals from the skin of octopus protect its arms from attaching to each other or onto themselves, without which the octopus might end up entangled.

The team studied the behaviour of severed octopus arms — which remain active and move for at least an hour following separation — because arms have their own network of neurons that to some extent can work independent of the central control of brain.

Suckers on severed arms — like the ones on intact arms — attached to any surface but avoided the skin. They did attach to another arm but only at points where the skin was damaged or missing, suggesting that the skin, wherever present, might play a role in inhibiting the attachment.

Read the rest in The Hindu.