Abstract
The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an economically important pest of citrus because it serves as a vector of the causal pathogens of huanglongbing (HLB) also known as citrus greening disease. The increased use of insecticides for control of D. citri negatively impacts several natural enemies including some effective ladybeetle species which are not available commercially. The two-spotted ladybeetle, Adalia bipunctata (Coleoptera: Coccinellidae) is found in some crop and forest ecosystems of Asia, Europe and North America and available commercially. It is known to attack aphids and mealybugs but there are no published records of feeding on psyllids. We evaluated suitability and preference of A. bipunctata for nymphs of D. citri compared to corn leaf aphid Rhopalosiphum maidis (Hemiptera: Aphididae) a global pest of cereal crops and prey for many predaceous insects. We also compared development and reproduction of A. bipunctata on these two species with frozen eggs of the Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) at 25°C. Initially, more D. citri than R. maidis nymphs were consumed in the no-choice tests although final consumption by larva and adult of A. bipunctata did not differ in the choice and no-choice tests. Larval development was prolonged by one day on D. citri compared to R. maidis nymphs but did not differ between either of these diets and E. kuehniella. Larval survival to adult averaged 93–100% and was not impacted by diet. Adult life span did not differ between diets although those on D. citri and R. maidis nymphs weighed less and produced fewer but more fertile eggs than on E. kuehniella eggs. Significant reduction of D. citri nymphs averaging 54% was observed in colonies caged with adult A. bipunctata on field planted citrus. R° (net reproductive rate) was least for beetles fed R. maidis, but otherwise there were no significant differences in demographic parameters. Successful feeding, development and reproductive performance of A. bipunctata suggest its usefulness as biological control agent of D. citri as well as aphid species exemplified by R. maidis.
Highlights
The Asian citrus psyllid [ACP] Diaphorina citri Kuwayama [Hemiptera: Liviidae] serves as a vector of the causal pathogens of huanglongbing [HLB] known as citrus greening disease
Significantly more D. citri nymphs than R. maidis nymphs were consumed by larvae at 6 h after initiation of no-choice test (χ2 = 6.1, df = 1, P = 0.014, Table 1) no differences were seen at 12 h (P > 0.05)
These findings suggest that both D. citri and R. maidis were preferred and suitable as food for A. bipunctata
Summary
The Asian citrus psyllid [ACP] Diaphorina citri Kuwayama [Hemiptera: Liviidae] serves as a vector of the causal pathogens of huanglongbing [HLB] known as citrus greening disease. The use of insecticides has increased tremendously in Florida citrus with some growers using up to 12 sprays to control ACP and reduce incidence and intensity of HLB [13] Such intense use of insecticides may accelerate selection for pest resistance and negatively impact naturally occurring biological control by ladybeetles, other predators and parasitoids reducing control of D. citri and promoting secondary pest outbreaks [14,15,16,17]. Investigations were to evaluate the preference and suitability of larvae and adults of A. bipunctata for nymphs of D. citri compared to a common and available aphid, Rhopalosiphum maidis Fitch (Hemiptera: Aphididae) as well as survival, development and reproduction on these two species and frozen eggs of the Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae). Ephestia kuehniella eggs are commonly used in the laboratory to rear predators and support the development and reproduction of several ladybeetle species [12,18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
