Relative suitability of the common pistachio psyllid, Agonoscena pistaciae (Hemiptera: Aphalaridae), as prey for the two-spotted ladybird, Adalia bipunctata (Coleoptera: Coccinellidae)

- The suitability of Agonoscena pistaciae as a prey for Adalia bipunctata was evaluated.
- Both larval and adult A. bipunctata feed voraciously on A. pistaciae.
- Preference tests showed no differences between aphid or psyllid diets.
- A. bipunctata preferred to oviposit at a height of about 150-200 cm on pistachio trees.
- The results indicated that A. pistaciae constitutes a complete food for A. bipunctata.

The suitability of Agonoscena pistaciae Burckhardt & Lauterer as a prey for Adalia bipunctata (Linnaeus) was evaluated by studying the predator's development and reproduction on this species in comparison to reference diets of nymphs of Myzus persicae (Sulzer) and eggs of Ephestia kuehniella Zeller. Both larval and adult A. bipunctata fed voraciously on A. pistaciae. The development time of the ladybird was shorter when fed on M. persicae and A. pistaciae and longer on E. kuehniella. The survival rate was 87% on M. persicae and 85% on A. pistaciae, both significantly greater than on E. kuehniella eggs (63%). The ladybirds were heaviest at eclosion and their fecundity was higher on M. persicae than on A. pistaciae or E. kuehniella. Both the aphid and psyllid diets yielded higher R0, rm values and lower T and DT values than E. kuehniella eggs. Based on total development time, immature survival and adult fecundity, the relative suitability for A. bipunctata was M. persicae > A. pistaciae > E. kuehniella. When ladybirds were reared on psyllids, they showed no preference between aphid or psyllid diets, but when raised on M. persicae, they preferred an aphid diet. A field experiment showed that A. bipunctata preferred to oviposit on pistachio trees at a height of 150-200 cm, i.e. towards the top. The results indicate that A. pistaciae constitutes a complete food for A. bipunctata, supporting both completed development and successful reproduction.