Aphis gossypii (Hemiptera: Aphididae) as a factor inhibiting the survival and population increase of the predator Macrolophus pygmaeus (Hemiptera: Miridae) on cucumber

Abstract

Abstract. The influence of cucumber offered as a host plant either alone or with Aphis gossypii Glover (Hemiptera: Aphididae) was studied on the various life table and biological characteristics of the predatory bug Macrolophus pygmaeus Rambur (Hemiptera: Miridae). The nymphal development was studied at 15, 20, 25, 30 and 35°C while adult performance was assessed at 15, 20, 25 and 30°C, using a 16L : 8D photoperiod and 65 ± 5% r.h. Nymphs completed their development at all temperatures except at 35°C. Nymphal development took significantly longer time in the absence than in the presence of prey at 20 and 25°C, but the reverse was true at 15°C. Nymphal mortality was highest at 15°C in the presence of prey and it was mainly recorded at the first and second stages. Females oviposited a small number of eggs at all temperatures but not at 30°C in the absence of prey. The average number of eggs per female was almost similar with or without prey, being highest at 20°C, and adult longevity was highest at 15°C. The results concerning population parameters clearly showed that cucumber with or without prey can not support a population increase of M. pygmaeus. However, it seems that A. gossypii on cucumber inhibits development of M. pygmaeus more than when this aphid species is not present. This adverse effect on this host plant-prey system possibly results from the particular aphid genotype on cucumber, leading to high nymphal mortality, reduced fecundity and short adult life-span of M.pygmaeus.

Prey‐mediated changes in the selectivity of the predator Macrolophus pygmaeus (Heteroptera: Miridae)

“…These results suggest that the immobile prey would be higher in quality than the two aphid species, and support previous studies having shown that M. persicae is better than A. gossypii as a food resource for the predator’s population increase (Fauvel et al . ; Perdikis & Lykouressis , ). In contrast, however, Koss et al .…”

“…Among the prey nymphs used, A. gossypii has been considered to be lower in quality than M. persicae or T. vaporariorum , based on studies of the development and reproduction of M. pygmaeus (Fauvel et al . ; Perdikis & Lykouressis , ). The voracity of M. pygmaeus fifth‐instar nymphs is higher compared to the other instars when feeding on M. persicae nymphs (Perdikis et al .…”