Angular-winged katydid

The Angular-winged katydid Microcentrum triangulatum is a member of the Tettigoniidae family. This insect is famous for its exceptional camouflage, as its body resembles a broad, green leaf.

The adult katydid features a distinct angular shape with a high, leaf-like pronotum. Its vibrant green color makes it almost invisible when resting among the dense foliage of trees.

The eggs are oval and flat, usually deposited in overlapping rows along the edges of leaves. They are glued with a hardened secretion, often looking like natural leaf growth.

Nymphs go through several instars, appearing as smaller, wingless versions of adults. Their development is gradual, and they adopt the green color of the host plant early on.

The primary identification trait for the presence of these insects is the sound produced by males at night, characterized by a specific rhythmic chirping noise.

Citrus trees, including lemons, oranges, and grapefruit, are the primary hosts for this pest. The katydids feed on the tender tissues of leaves and young succulent shoots.

Beyond citrus, these insects affect various ornamental plants and shrubs. Their presence in home gardens often goes unnoticed until the damage becomes visually apparent.

Feeding results in irregular, jagged notches along the edges of leaves. Severe infestations can reduce the photosynthetic capacity of the plant, leading to stunted growth.

Young nursery stock is especially vulnerable. Damage to the growing tips of these young trees can lead to permanent structural deformations and loss of vitality.

The damaged leaf margins are susceptible to secondary infections from airborne spores or bacteria, which can cause further localized leaf necrosis and stress to the tree.

The life cycle of the katydid is highly dependent on seasonal temperatures. They overwinter in the egg stage, which remains on leaves throughout the winter months.

Nymphs emerge in the spring as soon as temperatures rise, signaling the start of the primary growing season. This is the period when the population is most active.

Summer is the peak season for growth and mating. Adults are highly active during this time, spreading throughout the garden canopy to feed and reproduce.

In tropical and subtropical regions, multiple generations can occur annually. This continuous cycle makes managing them more challenging compared to temperate areas.

As autumn arrives, the adult activity tapers off. Females seek suitable sites for oviposition, laying eggs that will endure the coming winter months to restart the cycle.

The most prominent sign is the presence of distinctive bite marks along the edges of leaves. These look like semi-circular or irregular pieces removed from the leaf blade.

Observing the rows of flat, scale-like eggs along leaf margins is a clear indicator that the garden has been utilized for egg-laying by the katydids.

Hearing the chirping of males during the night is a reliable method for determining the presence of these insects before extensive foliar damage becomes visible.

The presence of frass (droppings) on the ground under the tree canopy indicates that the katydids have been actively feeding in the branches above.

Finding the adult insects is difficult due to their camouflage. However, shaking the branches during the day often reveals their presence as they move to escape.

On a small scale, physical removal is the most effective approach. Regularly inspecting and pruning leaves containing egg clusters significantly reduces the next generation.

Biological control using entomopathogenic fungi or beneficial insects like parasitic wasps can manage populations without resorting to heavy chemical inputs.

For severe infestations, targeted insecticide applications during the nymph stage are most effective. Always apply treatments during dusk to minimize impact on pollinators.

• Regular pruning of dead or infested wood
• Promoting garden biodiversity to attract predators like birds
• Monitoring population levels with light or sticky traps

Integrated Pest Management (IPM) strategies, including early detection and habitat maintenance, are essential for keeping katydid populations below damaging levels.