Pseudaulacaspis pentagona Targioni Tozzetti

Hodgson, Chris J. & Łagowska, Bozena, 2011, New scale insect (Hemiptera: Sternorrhyncha: Coccoidea) records from Fiji: three new species, records of several new invasive species and an updated checklist of Coccoidea, Zootaxa 2766, pp. 1-29 : 15

Pseudaulacaspis pentagona Targioni Tozzetti

Williams and Watson (1988a) indicate that Maskell (1895) described this species (as Aspidiotus vitiensis ) from Fiji and that it was probably well established by that time. P. pentagona is a cosmopolitan and destructive species and has been recorded on a very large number of plant species. At the time of the present visit, several farmers were complaining about a reduction in the growth and yield of their cassava ( Manihot esculenta ) crops. The most obvious symptoms on the affected crops were numerous white patches over the lower stems and these were found to be patches of male tests of a diaspidid scale insect. The adult females of P. pentagona were also found abundantly on the lower stems in affected crops although they were not obvious as they were very similar in colour to the cassava stems. It is almost certain that these were the cause of the reduction in yield. As the white male tests almost certainly belong to this species, its presence can be quickly detected by the white patches on the cassava stems. However, as cassava crops are planted using 12–15 inch long lengths of the stems of the previous crop, it is clear that, once a crop has been infected, it is easily carried over into the following crop on these twigs (particularly as it is likely that the stronger plants in the future crop probably grow from the thicker stems – i.e. the twigs originating from nearest the base of the old plants, the most heavily infected part of each plant!). We suggest that this carryover could be relatively easily prevented if the stems for the next crop were soaked overnight in a suitable pesticide prior to planting.