In-field habitat diversification increases arthropod species richness and abundance in sweet corn

Agricultural intensification and an associated reduction of in-field plant diversity have reduced the availability of essential resources needed by beneficial arthropods. Consequently, this has contributed to declines in insect abundance, diversity, and biological control services while shifting the balance in favor of insect pests. Field studies were conducted to investigate the influence of conservation tillage in concert with an interplanted living mulch and/or cover crop residue on arthropod natural enemy abundance and biological control services in sweet corn (Zea mays L.). Treatments included 1 conventional tillage treatment (1) and 3 no-till treatments with different cover crops (2 to 4): (2) cover crop residue, (3) living mulch + cover crop residue, and (4) living mulch + winter-killed residue. All cover crop diversified sweet corn contained a greater abundance of arthropods than conventional till (bare-ground). However, beneficial arthropod numbers varied according to arthropod community and sampling method. For illustration, a greater number of beneficial arthropods were detected on sticky cards in the living mulch + winter-killed residue treatment compared to the no-till with cover crop residue. Within the epigeal community, more beneficials were captured in pitfall traps within the living mulch + cover crop residue treatment compared to conventional till. Still, herbivore damage to sweet corn ears was similar among treatments each study year. Overall, the living mulch treatments tended to attract a greater abundance of beneficial insects, though this did not result in a reduction in ear-feeding damage by herbivorous pest insects.