Nectary structure

Defense is a further category in which plants employ food rewards to acquire protection by arthropod mutualists. The provision of food sources allows plants to recruit or sustain predators or parasitoids, which, in turn, can provide protection against herbivory. The plant-derived food structures involved in indirect defensive interaction can be divided in two main groups food bodies and extrafloral nectaries. 

Extrafloral nectaries include a wide range of nectar-excreting structures, which are distinguished from their floral counterparts by the fact that they are not involved in pollination. Extrafloral nectar is typically dominated by sucrose and its hexose components glucose and fructose. The fact that these common sugars are acceptable to the majority of insects, combined with the exposed nature of extrafloral nectaries, makes them suitable food sources for abroad range of insects. Compared with floral nectar, extrafloral nectar often has increased fructose and glucose levels (Tanowitz... 

Extra-floral nectaries) glandular structures outside the flower,... 

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