Mediterranean Katydid Facts: an Invasive Species

The Mediterranean katydid, a captivating insect native to the Mediterranean region, has established itself as an unwelcome guest in the United States. Let’s dive into the fascinating world of this invasive species, exploring its origins, and its impact on the ecosystem.

They look like grasshoppers

The Mediterranean katydid is also known as leaf katydid, false katydid, or southern sickle bush-cricket. Belonging to the family Tettigoniidae, this insect is superficially similar to grasshoppers but can be easily distinguished by its much longer antennae, often exceeding its body length.

These green bugs sport a unique, leaf-like pattern of veins on their wings. Both males and females have a light green body covered in small black spots, and their eyes are a bright orange color. Sometimes, you might see a brown stripe on their back where their front wings meet, but it usually doesn’t go onto the pronotum.

The adult males have a size of about 14 millimeters and females are slightly larger at 17 millimeters. Adult males of this species are typically around 14 millimeters in size, while females are slightly larger, measuring about 17 millimeters. Their hindwings are longer than their forewings, with the forewings usually reaching about three-fourths the length of the hindwings. Sometimes, the forewings can even extend to the tips of their hind legs.

You can tell adult males apart by their curved cerci, which are paired appendages found at the rear of the abdomen. On the other hand, females have a distinct ovipositor, which is a sickle-shaped structure about 5 millimeters (0.20 inches) long. They use this ovipositor for laying eggs.

Habitat

The Mediterranean katydid is an insect that comes from Europe, North Africa, and places near the Mediterranean Sea. But now, it’s causing problems as an invasive species in different parts of the world.

It first showed up in California’s Bay Area back in the 1930s. Since then, it has spread a lot. It now can be found in places like Los Angeles County, the Portland-Vancouver metro area, New York City, and near the Columbia River in Washington state.

This invasive insect isn’t just in North America; it’s also been spotted in South America. Scientists think its movement could be connected to global shipping.

The Mediterranean katydid mostly lives in sunny, dry places, especially in bushes and the lower parts of trees.

Mediterranean katydid Diet

This type of katydid eats a variety of foods. It causes problems in pear orchards by eating unripe pears. It also likes to eat soft parts of plants, such as leaves and flowers. Sometimes it even eats dead insects and the pupae of the European grape moth. Their existence poses a threat to agricultural crops, particularly in regions such as Californian pear orchards.

Reproduction

The Mediterranean katydid has a special way of finding a mate that sets it apart from other similar insects. Male katydids make their own sound to attract females, and what’s really interesting is that the females respond with their own songs. This behavior is unlike anything seen in other katydids, grasshoppers, or crickets.

As a result, the females won’t go to the males who are singing. Instead, they sing back to lure the males to them. This clever tactic lets the females stay in safe places while the males do the risky work of moving around. However, the females are picky and only respond to males who sing longer songs to initiate the interaction.

After mating, females lay eggs by chewing openings in the leaves of plants and shrubs. They then lay their eggs within these leaf structures. These eggs, which are usually about 3 millimeters in size, can hatch at any time of the year, but they mostly hatch during the summer. The lifespan of the Mediterranean katydid lasts less than a year.

Reference: 10000thingsofthepnw.com