Beginner

Scientific Names
Various species, including Chaetosiphon fragaefolii, Aphis gossypii and Myzus persicae

Identification

• Small (2 mm or 1/12 in. long) , soft bodied, slow moving
  
• Green, yellowish green, pink or gray in colour and variable in shape
  
• Cornicles resemble tailpipes at the base of the abdomen
  
• Adults may or may not have wings
  
• Nymphs resemble the wingless adults
  
• Symptoms include stunted and malformed plants
  
• Black sooty mould forms on the aphids secretions known as honeydew, this can coat leaves and developing fruit
  
• Most damage caused by the transmission of viruses

Often Confused With
Potato leafhopper
Tarnished plant bug

Period of Activity
Generally, aphids overwinter as eggs. Active stages present from early spring through to late summer. Winged forms migrate away from heavy infestations to start new colonies.

Scouting Notes
Aphids can be found on new shoots, the undersides of leaves and on buds while they are still in the crown. Cast skins from previous moults may be present on leaves after aphids have left. The honeydew can be attractive to ants.

Thresholds
None established.

Advanced

Scientific Names
Chaetosiphon fragaefolii, Aphis gossypii, Myzus persicae, and others.

Identification
There are several species of aphids that can be found in strawberries. All are small (2 mm or 1/12 in. long) and soft-bodied. Nymphs resemble the adults; adults can be winged or wingless. They range in colour from green, yellowish-green to pink or grey and are variable in shape. Cornicles at the base of the abdomen are characteristic features of aphids and help to distinguish them from other soft-bodied insect nymphs. Aphids insert stylets to feed on plant juices. They move very slowly.

In large numbers aphids can produce visible symptoms which include stunted and malformed plants. Aphid secretions, known as honeydew, quickly develop a black sooty mould that discolours leaves and fruit. However, the most damage caused by aphids is usually by the transmission of viruses from infected to uninfected plants.

Often Confused With
Potato leafhopper
Tarnished plant bug

Biology
Aphids infestations can develop from overwintering eggs or from winged adults which blow or fly in from other regions. Populations build quite quickly in random areas throughout the field. Succulent growth in early spring appears to be most susceptible to aphids and favours rapid population increases. Multiple generations of wingless aphids develop on the same plant. Eventually winged forms develop and move on to new hosts.

If left untreated, aphids attract many types of predatory insects such as lacewings, syrphids and cecidomiids. These can provide significant biological control of this pest.

Period of Activity
Aphids can be found from spring through to late summer. They have many alternate hosts.

Scouting Notes
Aphids can be found on new shoots, the underside of leaves and on buds while they are still in the crown. Make notes on the presence of winged adults, and increases or decreases in population from week-to-week. Cast skins from previous moults may be present on the leaves after aphids have left. The honeydew can be attractive to ants. The presence of beneficial insect larvae should be recorded. Parasitized aphids should also be noted- these are beige, swollen empty shells of the aphid’s exoskeleton.

Thresholds
None established.

Management Notes

• Aphids thrive on lush, rapidly growing foliage. Avoid excessive nitrogen which causes such growth.
• Many beneficial insects feed on aphids. These beneficials may be harmed by broad-spectrum insecticides. Avoid the use of these types of insecticides where possible.