Macrolophus pygmaeus (Hemiptera: Miridae) population parameters and biological characteristics when feeding on...

The population parameters and biological characteristics of the predator Macrolophus pygmaeus Rambur when feeding on eggplant, Solanum melongena L., and tomato, Lycopersicon esculentum (Miller) (both Solanaceae), without access to prey, were investigated at several temperatures. The experiments were conducted at 15, 20, 25, and 30 degrees C, 65 +/- 5% RH, and a photoperiod of 16:8 (L:D) h. Females oviposited on both plant species at all temperatures, with the exception of tomato at 30 degrees C. Fecundity was highest at 20 degrees C (21.55 and 8.28 eggs per female on eggplant and tomato, respectively). Adult longevity on both host plants was greatest at 15 degrees C, reaching 38.72 and 34.20 d for females and 92.88 and 62.80 d for males, on eggplant and tomato, respectively. The estimated values of population parameters showed that this predator increased its numbers on eggplant at all temperatures tested, but the highest intrinsic rate of increase occurred at 25 degrees C (0.0401 d(-1)). On tomato, this predator could not increase in number, although it could survive for a relatively long period. Results demonstrated that M. pygmaeus can survive on both host plants in periods of prey scarcity, particularly on eggplant. Therefore, phytophagy can positively contribute to the effectiveness of this biological control agent. The importance of eggplant as a reservoir for the predator in mixed crops that are less suitable host plants is discussed.