Radial growth and stand density of 30 loblolly pine stands throughout southeast Texas which had been attacked byDendroctonus frontalisZimmerman were characterized by measurement of annual increment and basal area. Annual increment was found to be significantly reduced in the last 2 cm of growth, but not related to tree diameter classes which indicates the trees were in a declining condition. Stand density was found to be very high in the infestation spots and was suggested to enhance perpetuation of localized infestations. The combination of reduced radial growth and high stand density was suggested to represent an optimal condition, in terms of susceptible host type, for the development ofD. frontalis.