Advantages of parasitic plants and animals.

By Charles Q. Choi

The irony is that by damaging parasites sometimes help the host. Scientists have discovered that corn wasp pollinated Pleistodontes imperialis and a species of Figs in Australia (Ficus rubiginosa) are interdependent. They cooperate with each other, benefiting from their partners.

The relationship between wasps and figs - has existed for more than 60 million years - including the process of bees flying into figs and pollinating tiny flowers inside. They then lay eggs in flowers, and every born wasps eat the seeds that grow in that flower.

Another character

What is difficult for scientists to say when it comes to supportive theory is how that relationship can hold stability. What prevents a species from taking advantage of this relationship too much? For example, wasps can easily build an entire kingdom for their descendants and destroy all the seeds in a small figs.

'Theory of generosity is ubiquitous in nature but more difficult to understand than other relationships among species,' said researcher James Cook. He is an evolutionary ecologist at the University of Reading, UK.

It turns out that another parasitic insect, once thought to be harmful to the supportive relationship between wasps and figs, can help this relationship stabilize, prevent hornets from benefiting from the fruit. figs.

The researchers looked at a small fig tree growing on a large rock in a rocky hill in Australia. Derek Dunn, the researcher in the group, does most of the practical work, 'having to become a mountain goat to get the samples,' Cook recalls.

Pollinated bees lay eggs on flowers near the center of the fruit. Scientists have found these pollinators to avoid flowers near the outer wall because their offspring are at risk of being attacked there by other species or parasitic insects. This makes the fig tree develop the seeds of the outer flowers.

Pollinated wasps are laying eggs inside figs.Parasitic species are a factor that helps the cooperative relationship between bees and fig species is stable.(Photo: James M. Cook)

Three linkage

Parasitic insects have always been thought to be detrimental to the relationship between pollinated wasps and fig trees - 'they kill wasps,' Cook explains: 'Actually, as we see , they contribute to stabilizing livelihood relationships in the long run by putting pressure on hornets to leave some flowers to grow into seeds'.

Actual empirical relations are often taken advantage of parasites, 'but now we have to question how often parasitic species play an important role in stabilizing supportive relationships. Overall, ' Cook told LiveScience . 'Ba is not always too much. We have to think about reciprocal relations as surrounded by - and sometimes based on - a wide network of species relationships . '

Dunn, Cook and colleagues detailed their findings on March 10 online in PloS Biology.