Three homopteran pests of citrus as prey for the convergent lady beetle: suitability and preference

The convergent lady beetle, Hippodamia convergens Guérin-Méneville (Coleoptera: Coccinellidae), is an important predator of soft-bodied insect pests in many regions of the United States, but generally uncommon in Florida citrus. Certain citrus producers in Florida recently initiated releases of commercially available H. convergens from California against the Asian citrus psyllid Diaphorina citri Kuwayama, vector of Huanglongbing or citrus greening disease. However, there is little information on potential efficacy of this predator against the psyllid or other pests of citrus. Preference, development, and reproduction by H. convergens was evaluated on freshly collected nymphs of D. citri, brown citrus aphid Toxoptera citricida Kirkaldy, green citrus aphid Aphis spiraecola Patch, and frozen eggs of the flour moth Ephestia kuehniella Zeller. Larvae preferred D. citri over T. citricida in two-way choice tests and consumed more D. citri or A. spiraecola than T. citricida in no-choice tests. Adults consumed equal numbers of all three species in both tests. Development times of larvae at 25.5±0.05°C on A. spiraecola were longer than on the other three diets. Larval survival and pupation times did not differ among diets. Females lived longer than males irrespective of diet, and longevity of both genders was greatly increased on E. kuehniella compared with D. citri and A. spiraecola. Life table analysis indicated that H. convergens should increase on all three species, with a greater potential on psyllids than aphids. Further studies are warranted to assess establishment and persistence of this potential biological control agent in the Florida citrus environment.