Insects are inseparable from the life of plants. To attract pollinators that they need for pollen dispersal, some plants produce nectar. Researchers pose the question at what point plants can decrease the quantity of nectar they produce to save resources that they could otherwise invest in their own development without losing their attractiveness to pollinators. Lines of petunias have been especially selected to study this trait and other characteristics that attract bees or moths as pollinators.
On the other hand, plants must also defend themselves against pest insects. The larvae of Diabrotica devour the roots of maize, while Spodoptera caterpillars munch on its leaves. To fight against the problem, maize launches 'odorous calls' that attract the enemies of the pest. As a result, underground, nematodes come to infect the larvae of Diabrotica, while at the leaf level, parasitic wasps deposit their eggs in the herbivorous caterpillar. To exploit these natural defence strategies for crop protection, scientists study the chemical signals that attract beneficial organisms, and select the most effective plant varieties.
