Asparagus beetles

Crioceris asparagi and Crioceris duodecimpunctata

1. Identification

• Common name: Asparagus beetles
• Scientific name: Crioceris asparagi L. and Crioceris duodecimpunctata L.
• Order: Coleoptera
• Family: Chrysomelidae

2. Pest description

• Adults: Small leaf beetles of 5–7 mm; C. asparagi has a metallic-blue body with red elytra and yellow markings, while C. duodecimpunctata is orange-yellow with 12 black spots; both are easily visible on asparagus shoots.
• Larvae: Soft body, whitish to greyish, covered with excrement that gives them a dark appearance; they feed intensely on shoots and foliage.
• Pupae: Formed in the soil, in small earthen chambers.
• Eggs: Laid on the shoots and leaves of asparagus, singly or in small groups.

3. Main hosts

• Asparagus as the main and practically exclusive host, although it may also attack other species of the genus Asparagus present in production areas or growing spontaneously nearby.

4. Symptoms and damage

• Perforations and scrapings on the young shoots caused by the adults, with loss of commercial quality.
• Significant defoliation caused by the larvae, which can consume a large part of the foliage.
• Deformed, scorched or unmarketable shoots.
• Reduction of the plant's photosynthetic capacity, compromising the following year's production.
• In severe infestations, total loss of production may occur.

5. Biological cycle

• Two to three annual generations, depending on temperature.
• Adults emerge in spring and begin feeding on the young shoots.
• Egg-laying on the stems and leaves; larvae feed intensely for about two weeks.
• Pupation in the soil, with the emergence of new adults that may give rise to new generations in the same year.
• Development favoured by mild temperatures and the continuous presence of asparagus.

6. Monitoring

• Direct observation of adults on the young shoots, especially in spring.
• Inspection of leaves and stems to detect larvae covered with excrement.
• Assessment of damage on shoots intended for consumption.
• Reinforced monitoring in fields with a history of the pest or near spontaneous asparagus.

7. Management measures

• Cultural: Manual removal of adults and larvae in small areas; elimination of crop residues; control of spontaneous asparagus in the vicinity.
• Preventive: Rotation of plots; maintenance of clean fields; avoiding excess nitrogen fertilisation that favours very tender shoots.
• Integrated protection: Regular monitoring; intervention only when necessary; collection and destruction of infested stems; practices that reduce the attractiveness of the young shoots.

Bibliographic references

• EPPO Global Database – Crioceris asparagi and Crioceris duodecimpunctata.
• CABI Invasive Species Compendium – Crioceris spp.
• Capinera, J. L. (2001). Handbook of Vegetable Pests.
• USDA – Asparagus beetle management guidelines.