Table 1.

Invertebrates as key intermediaries between tritrophic defenses and other regulating ESs in multicrop systems. As an illustrative example, a nonexhaustive listing is provided of how invertebrates respond to various attributes of a legume intercrop, thereby acting as SPUs for a broader range of ESs. For example, in cereal systems, a chickpea intercrop not only fixes atmospheric nitrogen, but also harbors aphid species that act as (alternative) host or prey items for omnivorous BCAs, for example, invertebrate predators such as ladybeetles or big-eyed bugs.

Attribute of legume intercrop	SPU	ESs
		Climate mitigation	Pollination	Erosion control	Tritrophic defense	Water quality	Soil health and fertility
Nitrogen-fixing nodules	Symbiotic bacteria	+	+		+	+	++
Leaf pubescence	Predatory mites				+
Repellent/attractant plant volatiles	Invertebrate predators and parasitoids				++
Floral/EFN	Ants	+	+	+	++	+	++
	Spiders		+		++		+
	Nectar yeasts		+		+
	Hoverflies		++		++
	Managed/wild bees		++		+
Alternative prey or hosts	Invertebrate predators and parasitoids				++		+