Effects of plant age, leaf age and virus yellows infection on the population dynamics of Myzus persicae (Homoptera: Aphididae) on sugarbeet in field plots

Abstract

Field experiments in which clip-caged apterae of Myzus persicae (Sulzer) (Homoptera: Aphididae) were monitored on sugarbeet revealed that leaf age, plant age and infection of the host with beet yellows closterovirus (BYV) had very large effects on aphid performance (development, reproduction and survival). On healthy plants performance was much better on young, expanding heart leaves than on older leaves. Performance on senescent leaves was poor. When apterae were kept on young heart leaves all their lives (by moving clip-cages to younger leaves every 4 days) there was a strong negative relationship between aphid performance and plant age (measured as plant leaf number at birth). On plants inoculated with BYV apterae showed large improvements in performance. These occurred so rapidly that nymphs born at the time of virus inoculation could benefit as much as those born later. The sizes and between-leaf distributions of M. persicae populations which developed from standard numbers of colonists on whole plants in cages were consistent with the results of the clip-cage experiments. Alatae were less sensitive than apterae to differences in plant and leaf age. Implications of the results for BYV epidemiology and control are discussed.

Within-Plant Bottom-Up Effects Mediate Non-Consumptive Impacts of Top-Down Control of Soybean Aphids

“…full pod and beginning seed stages), supporting predictions of the plant vigor hypothesis, and previous studies (e.g. [20], [21], [27], [33], [34]). For example, similar effects of young plant leaves have been demonstrated for Myzus persicae (Sulzer) and Aphis fabae Scopoli (Homoptera: Aphididae), resulting in a bottom-up controlled decline in field populations as the season progressed [20], [21].…”

“…In previous studies we demonstrated a shift in the within-plant distribution of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) towards more mature leaves in response to predation [19]. Population increase of other aphid species on slow-growing plant parts is lower than on vigorous-growing plant parts [20]–[22], as predicted by the plant vigor hypothesis [4], although this is unknown for A. glycines . Therefore, we hypothesize that 1) vigorous-growing plant parts support higher A. glycines population growth rates, and 2) predation on vigorous-growing plant parts results in non-consumptive reductions in A. glycines population growth rates by differentially removing individuals with the highest reproductive potential.…”

“…[20], [21], [27], [33], [34]). For example, similar effects of young plant leaves have been demonstrated for Myzus persicae (Sulzer) and Aphis fabae Scopoli (Homoptera: Aphididae), resulting in a bottom-up controlled decline in field populations as the season progressed [20], [21]. At the within-plant level, we found higher rates of increase and proportions of aphids on upper nodes of young plants, whereas no differences were found between nodes of older plants, indicating that within-plant changes in quality varied with plant phenology.…”

The effect of host plant-induced stomach precipitate on the ability of Myzus persicae (Hemiptera: Aphididae) to transmit sugarbeet yellowing viruses

“…Mi/zus persicae reared on BYV-infected sugarbeet accumulated larger quantities of precipitate which consequently increased their stomach size more than aphids reared on BMYV-infected sugarbeet and healthy sugarbeet. This is somewhat surprising as BYV infection of sugarbeet increases the aphids' growth rate, reproduction rate, nymphal survival and adult weight (Baker, 1960;Akers, 1988;Williams, 1995). However, the precipitate is the precursor to the black deposit which is associated with the premature death of the aphids (Kift & Dewar, 1996).…”

“…Williams (1995) has shown that the reproductive rate and longevity of Mi/zus persicae (Sulzer) (Hemiptera: Aphididae) decline on mature plants. Kift & Dewar (1996) have linked the early decline in populations of this species on sugarbeet to the occurrence of a black deposit in the aphid's stomach, which may be the cause of early death.…”