de Oliveira, C.M., Frizzas, M.R., Fialho, J.F., & Gullan, P.J. 2008 Biology of Protortonia navesi (Hemiptera: Monophlebidae), a new Cassava pest in Brazil, with notes on its behavior in the field.. Annals of the Entomological Society of America 101(4): 779-785

Notes: Protortonia navesi Fonseca (Hemiptera: Monophlebidae) is a scale insect recently reported as a new cassava (Manihot esculenta Crantz) crop pest in central Brazil. The biology P. navesi was studied under controlled and field conditions, and some aspects of its field behavior were recorded. The laboratory experiments were carried out from August to December 2004 under controlled conditions (25 +- 2 C, 70 +- 23% RH, and a photoperiod of 12:12 [L:D] h), and the field experiment from September 2003 to August 2004, at Planaltina, Federal District, Brazil. In the laboratory, P. navesi showed a 69.2-day cycle from oviposition to adult eclosion, going through three nymphal stages in 44.5 d, on average. The females reproduced by thelytokous parthenogenesis, with an average oviposition capacity of 239.6 eggs per female. No males were observed in this species. In the field, P. navesi had a permanent underground population. However, from September to December 2004, the aerial parts of plants were colonized by part of this population, which was controlled by the predator Exoplectra sp. (Coccinellidae). Individuals of P. navesi were observed to be active on cassava roots in the field throughout the year, suggesting that this scale insect may have at least five generations per year in central Brazil.