Characteristics and Pest Description

The peach-potato aphid Myzus persicae is a cosmopolitan aphid occurring worldwide. It is associated with primary hosts – peach and sea buckthorn – and secondary hosts – Solanaceae plants, pepper, potato, beet, legumes, and weeds. In greenhouses, it damages tomatoes, eggplants, and peppers, reproducing continuously. Its developmental stages can feed on up to 200 plant species.

Bionomics

• Eggs – small, oval (0.6 × 0.3 mm), laid in bark crevices of the winter host (peach), where they overwinter.
• Larvae (harmful stage) – 1.8–1.9 mm long, oval, delicate, wingless parthenogenetic females (see 1A, 1B) colored green, olive, or pink. They do not form dense colonies, feeding mostly on the underside of leaves individually. Their piercing-sucking mouthparts extract sap and transmit plant viruses. Parthenogenetic development occurs through multiple generations (anholocyclic – incomplete), especially in greenhouse or storage conditions. In the field, on primary and secondary hosts, development is holocyclic (complete) with parthenogenetic females and a sexual generation (laying eggs).
• Adult insect (harmful stage) – winged forms, 1.8–2.5 mm long. Head, antennae, and thorax black; siphunculi slightly swollen – brown; abdomen olive-green or pink with 1–2 bands and a large spot (see 2A, 2B). Most active in summer when migrating from winter to summer hosts – these are migratory individuals.

Life Cycle

The peach-potato aphid is dioecious, reproducing sexually (holocyclic) or viviparously (anholocyclic). Females lay eggs in autumn in bark crevices of the winter host (peach or sea buckthorn), which overwinter. In spring, parthenogenetic females (fundatrices) develop from eggs on peach. By the second generation, winged migrants appear, moving to summer hosts where several generations of wingless and winged individuals (exules) develop. In autumn, winged sexual females return to peach, laying eggs after mating with incoming winged males from secondary hosts. The incomplete cycle (anholocyclic) occurs in greenhouses, where females reproduce only parthenogenetically. Optimal temperatures are 22–26°C. In Poland, incomplete cycles are more common: parthenogenetic females feed and overwinter in greenhouses, and in spring winged aphids migrate to young potato crops. They can fly actively and with the wind, making them highly mobile. Dry, warm weather accelerates colony development in new locations.

Distribution and Damage

The species is widespread in Europe and abundant in Poland during warm, dry, rainless years and where winter hosts (peach, apricot, sea buckthorn) are present. Population peaks in summer, especially in central and southern regions.

Peach-potato aphids are not directly harmful to potatoes. Their damage comes from virus transmission – they are vectors. M. persicae actively transmits PLRV, PVM, and PVY, which is currently the most economically important potato virus in Poland. Vegetative propagation of potatoes via tubers increases virus accumulation year after year, as the virus persists in seed tubers, leading to infected plants next season. Infection reduces yield by 25–80%, so seed tubers must be frequently replaced with certified, virus-free material.

Economic Threshold

The threshold is 20 aphids per 100 leaves. In seed production, a single winged aphid is already a potential threat, as it can transmit PLRV, PVY, or PVM to many healthy plants while moving between infected and healthy plants.

Monitoring requires frequent field inspections after planting and during the summer growing season. Yellow Moericke dishes (for winged aphids) or counting aphids on the underside of middle-tier leaves (100-leaf method) can be used.

Control Methods

The primary control method is seed tuber treatment with a systemic insecticidal dressing in spring at planting. Currently, only one dressing is available – Prestige Forte 370 FS. Most common are foliar insecticide applications (aphicides). The first spray should be applied when aphids appear on leaves or in yellow dishes. Subsequent sprays at 7–14 day intervals, depending on actual threat. Mineral oil sprays do not effectively control aphids but can reduce their numbers and limit virus transmission, making them valuable in seed production.

Avoiding weed infestation is crucial because weeds may host viruses and some aphid species (e.g., beet aphid Aphis fabae). Excessive nitrogen fertilization (>150 kg/ha) causes lush growth favoring aphid development. Essential oils from rosemary, lavender, thyme, and peppermint have repellent or insecticidal effects, though technical application challenges remain.

Other methods to reduce aphid flights include covering ridges with chopped cereal straw or planting trap crops in strips around the field (soy, sorghum, wheat, oats). Both reduce potential vectors and significantly lower PVY infection in tubers.

Eliminating the winter host – sea buckthorn – and avoiding seed potato plantings near peach orchards significantly limits M. persicae populations. In areas without peach or sea buckthorn, aphid populations are generally low.

Compiled by: Dr. Tomasz Erlichowski