Bean aphid

Adult

The body colour varies: brown, black or black-green, with a faint waxy coating.

Damage

Adults and larvae suck sap from the plants: the leaves lose turgor, curl, become deformed and lag behind in growth, and with severe damage they turn yellow and dry out, which reduces plant productivity. The pest transmits beet yellows virus.

When to look

• The leaf aphid is a pest of sugar beet after emergence, that is, after root moulting.
• The aphid colonises sugar beet crops from the second half of May and in June.

No rate and no spray timing here: both come from the label and the register.

Agronomy

Weeds on which the aphid survives are destroyed, and spindle, guelder rose and jasmine (mock orange), on which it overwinters, are removed from field shelterbelts.

Yield loss

Beet root weight falls by up to 30 %, and seed yield by up to 45–70 %.

Harvest quality

The sugar content of beet roots falls by up to 2 %, and seed germination also falls.

Overwintering

The aphid goes into winter on its primary host plants: spindle tree, guelder rose and mock orange.

Migration

After the first 2–3 generations, which develop on the primary host plant (spindle, guelder rose, etc.), winged dispersal females appear. They fly to sugar beet crops or other field crops.

Favourable conditions

• In April, at a mean daily temperature of +7…+9 °C, larvae of the wingless stem mothers (foundress females) hatch from the eggs.
• Favourable overwintering conditions and warm, moderately moist weather in spring and summer can lead to an outbreak of mass aphid reproduction.
• Numbers are reduced by rain, wind and sudden cold snaps. In warm and moderately dry years the pest multiplies on a mass scale.

Natural enemies

• Aphid numbers are limited by predators (ladybird beetles and their larvae, lacewing and hoverfly larvae, predatory trombidiid mites) and also by parasites (small aphidiid parasitic wasps and Aphelinus wasps).
• In years with a wet summer, aphids die from the fungal disease entomophthorosis.

Every fact rests on a quote from its source, and each quote was checked against the page it is printed on.

1. Зайцева І. А., «Сільськогосподарська ентомологія. Курс лекцій», навчальний посібник, 237 с. · Дніпровський державний аграрно-економічний університет, Дніпро, 2021 · p. 128, 135, 136
2. EPPO Global Database · European and Mediterranean Plant Protection Organization
3. Прогноз фітосанітарного стану агроценозів України та рекомендації щодо захисту рослин у 2025 році · Держпродспоживслужба, НААН, НАН · p. 102
4. Photos: Michael Becker, Wikimedia Commons, CC BY-SA 3.0 · Bill Keim, iNaturalist, CC BY 4.0