Franco, J.C., & Marotta, S. 2001 A survey of mealybugs (Hemiptera: Coccoidea: Pseudococcidae) in citrus groves in continental Portugal.. Entomologica 33(1999): 191-196.
Notes: [Special Issue: Proceedings of the ISSIS VIII International Symposium on Scale Insect Studies held at Wye College (U.K.), Aug. 31st - Sept. 6th, 1998.] A survey of mealybugs living in citrus groves was carried out in order to elucidate the identity and relative importance of the species associated with this crop in Continental Portugal. Samples were collected in 76 citrus groves from the districts of Beja, Coimbra, Évora, Faro, Lisboa, Porto, Santarém, Setúbal and Viseu. The presence of mealybugs was detected in 93% of the citrus groves studied. Four species were identified, i.e. Planococcus citri (Risso), Pseudococcus calceolariae (Maskell), P. viburni (Signoret) and P. longispinus (Targioni Tozzetti). P. citri and P. calceolariae were the most frequent species, present in 66% and 63% of the citrus groves, respectively. P. viburni and P. longispinus were identified in 29% and 14% of the sites, respectively. Apparently, P. calceolariae has the widest geographical distribution on citrus in Portugal. The co-existence of at least two species in the same citrus grove was found in 59% of the cases. P. citri and P. calceolariae were found associated in 37% of the citrus groves; P. viburni was always found associated with at least one of the three other species.