Influence of plant, animal and mixed resources on development of the zoophytophagous plant bug Campylomma verbasci (Hemiptera: Miridae)

Abstract

The mullein bug, Campylomma verbasci (Meyer-Dür) (Hemiptera: Miridae), exploits both plant and animal resources. The aim of this study was (1) to evaluate the quality of different plant, animal and mixed diets (i.e. plant material or prey from the overwintering host, the summer host or the laboratory rearing) for the development and survival of mullein bug, and (2) to evaluate if the suitability of the resource changes according to the nymphal instar of C. verbasci. Mullein bug nymphs were reared individually in Petri dishes containing different diets and observed daily until reaching adulthood or dying. The rearing diet (living potato aphids + potato leaf + Ephestia eggs + apple pollen) was a high-quality diet. The medium-quality diets were apple fruit + apple pollen, Ephestia eggs and Sitotroga eggs. The low-quality diets included mullein leaf, frozen aphids, living aphids + potato leaf and apple fruit + living aphids + potato leaf. Finally, the inappropriate diets (when no nymphs reached adulthood) were agar gel, apple fruit, apple pollen, apple leaf, potato leaf, frozen spider mites and frozen conspecifics. When comparing the value of the diets for different instars, living aphids + potato leaf was a high-quality diet for third instar. Apple pollen and frozen conspecifics were low-quality diets for third instar. ‘Red Delicious’ fruit was a high-quality diet for fifth instar and low-quality for third instar. ‘Honeycrisp’ fruit constituted an inappropriate diet whatever the instar. Thus, a whole mixed diet maximises development and survival of C. verbasci nymphs.