Alves, V.S. 2006 . Aspectos da biologia de Dysmicoccus texensis (Tinsley) (Hemiptera: Psudococcidae) e seu controle com nematóides entomopatogênicos. Ph.D. Thesis, Universidade Federal de Lavras, Minas Gerais, Brazil Lavras, Minas Gerais, Brazil 110 pp.

Notes: The coffee root mealybug Dysmicoccus texensis (Tinsley) (Hemiptera: Pseudococcidae) is a pest of great importance to this crop. Damage occurs on plant roots where crypts or ?pop corns? are formed due to intense sucking and fixing of insect colonies, preventing water and nutrients absorption, weakening the plants and resulting in losses in yeald. Informations on biology and behavior of the insects, and adequate control methods are scarce, making the aplication of management methods. Thus, this work has the objective of evaluate the insect biology and this susceptibility to the entomomopathogenic nematodes in laboratory, green-house and field condictions. The studies on biological aspects of the imature stage of D. Texensis were carried out in climatic chambers at 27±1?C, 70±10% RH in darkness, using Agata variety potato sprouts as feeding substrate. There were 52 replicates (plots), each one consisting of a dip on an Elisa plate with a potato sprout with two one-day old nymphs, which were daily evaluated. A selection test of EPN isolates, maximum lethal concentratiom (CL99) and pathogenecity to crypts in the field colected was carried out as well as vertical displacement capacity of nematodes in sand and soil columns. Efficiency tests of EPNs were also conducted under semi-field and field conditions. Biology, results demonstrate that mean nymphal phase duration was of 29.45 days, and 31.06 days for the adult phase, totaling aproximately 60 days of life cycle. The highest virulence was found in Heterorhabditis sp. CCA and Heterorhabditis sp. JPM3, reaching maximum mortality values of 100 and 80.9% respectively, on the highest concentration tested (100 infectant juveniles (IJs)/insect). The estimated CL99 was 530 IJs/dish for CCA and 560 IJs/dish for JPM3. For the vertical displacement, no difference was found on sand column for the evaluated isolates, with both reaching 92% mortality. For the soil column test, aquous suspension of JPM3 was the best treatment on almost all depths evaluated. Results of green-house and field tests also demonstrated that the JMP3 isolate applied in aquous suspention was the best treatment, with 70% efficiency in greenhouse and 65% under field conditions.