Aphid

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Aphid

Aphidoidea family

Insect


In a Nutshell

  • Low to moderate numbers are usually not harmful to crops.
  • Severe infestation can cause damage on leaves and shoots and stunted plant growth.
  • Honeydew secreted by the aphids as they feed is a source of additional infections.
  • Aphids can also transmit viruses from plant to plant in a persistent way.

Hosts

Additional

Almond

Apple

Apricot

Avocado

Banana

Barley

Bean

Blackberries

Blueberry

Cabbage

Cacao

Canola

Capsicum & Chili

Carrots

Cashew

Chard

Cherry

Chickpea, Gram

Citrus

Coffee

Cotton

Cucumber

Currant

Eggplant

Fig

Garlic

Gooseberry

Grape

Leek

Lentil

Lettuce

Maize

Mango

Manioc

Melon

Millet

Mung bean

Oat

Okra

Olive

Onion

Papaya

Pea

Peach

Peanut

Pear

Pineapple

Plum

Pomegranate

Potato

Pumpkin

Quince

Radish

Raspberry

Red gram, Pigeonpea

Rice

Rose

Rye

Sorghum

Soybean

Spinach

Strawberry

Sugar beet

Sugarcane

Sweet potato

Tomato

Triticale

Turnip

Wheat

Zucchini

plant_broadbean

plant_broccoli

plant_cauliflower

plant_herb

plant_ornamental

plant_pistachio

plant_sunflower

plant_tumeric

plant_walnut

Symptoms

Low to moderate numbers are usually not harmful to crops. Severe infestation can cause leaves and shoots to curl, wilt or yellow and stunted plant growth. Overall, a general decline in plant vigor will also be noticed. The honeydew secreted by the aphids as they feed on plant tissues causes an additional infection with opportunistic fungi in many cases. The development of mold on the leaves indicates this. The honeydew attracts ants. Even small numbers of aphids can transmit viruses from plant to plant in a persistent way. Optimal conditions for their growth are dry and warm climates.

Trigger

Aphids are small, soft bodied insects with long legs and antennae. Their size ranges from 0.5 to 2 mm and the color of their body can be yellow, brown, red or black, depending on the species. Their aspect ranges from the wingless varieties, that are generally predominant, to the winged, waxy or woolly types. They usually settle and feed in clusters on the underside of well-fed young leaves and shoot tips. They use their long mouthparts to pierce tender plant tissues and suck out fluids. Low to moderate numbers are not damaging to the crops. After an initial invasion in late spring or early summer, the aphid population usually diminishes naturally due to natural enemies. Several species carry plant viruses that can lead to the development of other diseases.

Biological Control

Beneficial insects such as predatory ladybugs, lacewings, soldier beetles and parasitoid wasps are important agents to control populations of aphids. In case of mild infestation, use a simple soft insecticidal soap solution or solutions based on plant oils. Aphids are also very susceptible to fungal diseases when it is humid. A simple spray of water on affected plants can also remove them.

Chemical Control

Always consider a integrated approach with preventive measures together with biological treatments if available. Insecticides containing cypermethrin, imidacloprid, chlorpyrifos can be used as foliar spray against the pest.

Preventive Measures

Hand-pick the aphids manually from the plant or remove infected plant parts. Maintain a high number of different varieties of plants around fields. Do not over-water or over-fertilize. Remove waste from previous cultures. Control insecticide use in order not to affect beneficial insects. Control ant populations that protect aphids with sticky bands. Check weeds in and around the fields. Use reflective mulches to repel invading populations of aphids. If possible use nets to protect the plants