Aphids

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Aphids

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

Banana

Barley

Bean

Black & Green Gram

Cabbage

Canola

Capsicum & Chili

Carrots

Cauliflower

Cherry

Chickpea & Gram

Citrus

Cotton

Cucumber

Currant

Eggplant

Garlic

Grape

Lentil

Lettuce

Maize

Mango

Manioc

Melon

Millet

Okra

Olive

Onion

Ornamental

Papaya

Pea

Peach

Peanut

Pear

Pigeonpea & Red Gram

Pistachio

Plum

Pomegranate

Potato

Pumpkin

Raspberry

Rice

Rose

Rye

Sorghum

Soybean

Strawberry

Sugar Beet

Sugarcane

Sweet Potato

Tomato

Wheat

Zucchini

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. These natural enemies will take care of the sucking insects in field conditions. 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. Stem application with flonicamid and water @ 1:20 ratio at 30,45,60 Days after sowing (DAS) can be planned. Fipronil 2ml or thiamethoxam @ 0.2g or flonicamid @ 0.3g or acetamiprid @0.2g (per liter of water) can also be used.

Preventive Measures

Maintain a high number of different varieties of plants around fields.,Use reflective mulches to repel invading populations of aphids.,Monitor fields regularly to assess the incidence of a disease or pest and determine their severity.,Hand-pick the aphids manually from the plant or remove infected plant parts.,Check weeds in and around the fields.,Do not over-water or over-fertilize.,Control ant populations that protect aphids with sticky bands.,Prune the branches of your trees or remove the bottom leaves or your plants to favor the ventilation of the canopy.,If possible, use nets to protect the plants.,Control insecticide use in order not to affect beneficial insects.,Remove plant debris from previous cultures.