Exploring the potential of <i>Delphastus </i><i>davidsoni</i> (Coleoptera: Coccinellidae) in the biological control of <i>Bemisia tabaci</i> MEAM 1 (Hemiptera: Aleyrodidae)

Abstract

Coleopterans within the family Coccinellidae play an important role in the biological control of Bemisia tabaci MEAM1 Gennadius (Hemiptera: Aleyrodidae), a worldwide pest. Here we report an initial assessment of the predatory capacity and biological aspects of a South American coccinellid, Delphastus davidsoni Gordon (Coleoptera: Coccinellidae) to B. tabaci immature stages under laboratory conditions. Within the 24 h after release, D. davidsoni adults were increasingly more attracted to and consumed six times more B. tabaci fourth instar nymphs than the remaining immature stages. Similarly, D. davidsoni larvae also had a greater consumption of B. tabaci fourth instar nymphs within 24 h after release. Within 10 days after larvae release, there were no significant differences in preference between the nymphal stages. Both D. davidsoni adults and larvae presented a better biological performance when fed with B. tabaci fourth instar nymphs. The larval developmental time and pupal survival for D. davidsoni was optimal when fed fourth instar nymphs. These findings highlight the potential for implementing D. davidsoni in integrated pest management (IPM) programs for B. tabaci and warrant further evaluation under greenhouse and semi-field conditions.