Population fluctuations of Pseudaulacaspis pentagona (Hem.: Diaspididae) and its parasitism rate in Kiwi fruit orchards of Guilan province

The mulberry scale pest Pseudoulacaspis pentagona (Targioni) (Hem.: Diaspididae) has entered Kiwi orchards causing worries to gardeners in recent years. The damages of this pest by feeding of both adults and nymphs from host plant sap, which weakens the plant and cause gradual death of the tree. In the current study, three geographical regions of Guilan province (i.e. west, east, and central) where the kiwi fruit is largely planted were selected. During 2015-2016 pest population changes and the rate of pest parasitism were studied. The results indicated variations in pest density in the studied areas. The spatial distribution pattern of nymphs and adults of these regions were aggregated and random. The highest pest density was recorded in 2015 from the east of Guilan (88.4 ± 14.25 adult scales in 10cm) while, 40.4 ± 4.09 and 77.8 ± 3.24 were recorded in 2016 and 2017 respectively. The Temperature fluctuations and parasitism by Encarsia berlesei Howard were found to be the limiting factors for pest activity. The presence of parasite was found to be remarkable in sampled areas. The highest number of parasitized was recorded in the third generation (38.78 parasited adult scales in 10 cm) from east Guilan in 2015. The annual parasitic activity rate of this parasitoid can be considered as one of the most important options in management of mulberry scale pest on the kiwi. The results could be improved and incorporated in management of this important pest.