Cinara Aphids

Cinara aphids are a genus of aphids that belong to the family Aphididae. The aphids in this genus are large and are commonly known as the giant conifer aphids or large bark aphids.

Host Plants

Cinara aphids are generally found on coniferous trees, especially pine, spruce, and fir trees. They feed on the sap of these trees, usually in the branches and stems.

Regions impacted

Cinara aphids have a widespread distribution and can be found in various parts of the world, including North America, Europe, and Asia. They can pose a significant problem in regions where coniferous trees are grown commercially, such as in Christmas tree farms or timber plantations.

Description

Cinara aphids are large aphids, some of the biggest aphid species, with adults often reaching sizes of 1/4 inch (6 mm) in length. Their color can range from black or brown to dull green or grey. They have piercing-sucking mouth parts that feed on the sap in twigs, branches, trunks, and roots. They have long legs and antennae and a pair of tubes, known as cornicles, extending from the rear of their abdomen. They usually form large colonies on the bark of trees, making them easier to spot.

Aphids secrete honeydew as they feed, and other insects, especially ants, bees, and wasps, feed on it. Honeydew is a growth medium for sooty mold.

Life Cycle

Multiple generations of Cinara aphids occur each year. In spring, eggs hatch into small aphids, which molt through several stages, growing larger each time. Females produce live offspring, except for the last summer generation, where eggs are laid on needles or bark.

Damage and Detection

Damage:

Cinara aphids, while not as destructive as some other pest species, can still cause notable damage to coniferous trees. They feed on the sap of these trees, piercing the tree’s tissues with their sharp mouthparts to access the nutrients. This feeding can lead to yellowing or browning of needles, premature needle drop, and overall tree stress.

In severe infestations, the loss of sap can weaken the tree, reducing its vigor and making it more susceptible to other pests and diseases. It can also slow the growth of the tree.

Additionally, Cinara aphids excrete a sticky substance known as honeydew as they feed. This honeydew can drop onto the lower parts of the tree and any undergrowth or structures below it, creating a sticky mess that can attract other insects. It can also promote the growth of a black sooty mold on the tree, which can block light from reaching the tree’s leaves and further weaken it.

Detection:

Cinara aphids are quite large compared to other aphids and tend to form colonies, so they can be visually spotted on the bark or needles of trees, particularly during the warmer months when they are active. Signs to look for include clusters of large, dark aphids on the tree, often associated with the presence of honeydew or sooty mold.

Another sign of aphid activity is the presence of ants, which are attracted to the honeydew. If ants are observed traveling up and down a tree, it could be an indication of an aphid infestation.

Remember, accurate identification is important in controlling any pest, so if an infestation is suspected, it may be worth consulting with an extension service or pest control professional to confirm the identity of the pest and suggest appropriate control measures.

Prevention and Control

Prevention:

• Maintain Tree Health: Keeping trees healthy and stress-free can make them less attractive to pests, including Cinara aphids. Regular watering, proper fertilization, and suitable planting locations can all contribute to overall tree health.
• Choose Resistant Varieties: When possible, choose tree species or varieties less susceptible to aphid infestation.
• Regular Monitoring: Regular inspection of trees for signs of aphids can help catch an infestation early before it becomes a significant problem.

Control:

• Biological Control: Several natural enemies of aphids can help keep their populations in check. These include lady beetles, lacewings, syrphid flies, and certain parasitic wasps. In many cases, these beneficial insects can provide sufficient control of aphid populations.
• Pruning: Pruning out heavily infested branches can help reduce aphid populations and make it easier to treat the tree with insecticides if necessary.
• Insecticidal Soaps or Oils: These are often effective against aphids and have the benefit of being less harmful to beneficial insects. They should be applied directly to the aphids, so thorough tree coverage is necessary.
• Systemic Insecticides: If infestations are severe, systemic insecticides can be applied to the soil around the tree. The tree absorbs the insecticide, which then kills the aphids when they feed on the tree’s sap.

Note: Always consult with a local extension service or pest management professional before applying any pesticides to ensure they are used safely and effectively. Pesticide regulations vary by location, and it’s important to use products that are approved and appropriate for your specific situation.