Detailed Explanation of Pest and Disease Control Techniques for the Chinese Medicinal Herb Fritillaria thunbergii

The pleonomus canalieulates Falder., commonly known as the "click beetle," is one of the underground pests harming Fritillaria thunbergii.

The pleonomus canalieulates has a flattened, leathery body shaped like a needle, with a forked tail segment that curves slightly upward, and a longitudinal groove running down the middle of its back, hence the name "grooved click beetle." The grooved click beetle damages the bulbs in the soil, and holes about 0.2 cm in size are commonly seen on the scales.

The grooved click beetle has a very long life cycle, requiring about 3 years to complete one generation. The larval stage is the longest, and its activity is greatly affected by soil temperature and humidity. When the winter temperature drops, it burrows into soil below 30 cm or even deeper to overwinter; in spring, it rises to activity and causes damage earlier than other underground pests. Generally, in early spring when the soil temperature at 10 cm reaches 6°C, it begins to rise and become active, harming Fritillaria thunbergii.

Control methods: Change the living conditions of underground pests, turn the pests out onto the soil surface so that they die from the influence of natural enemies and the natural environment. When the click beetle pupates, destroying the pupal chamber can cause mass mortality.