Brachycorynella asparagi (Mordvilko, 1929)

Morphological characters

1.2-1.7 mm.
Apterous: bluey green and slightly greyish.
Alate: elongate, narrow, bluey green, covered with a waxy pruinosity, antennae very short (1/4 length of body), on wing veins smudged.

See identification

Life cycles

Monoecious holocyclic

Host plants

Asparagus officinalis (cultivated asparagus) and Asparagus densiflorus (ornamental asparagus).

Particular characteristics

B. asparagi was first found in France in 1989 amongst the asparagus crops of Languedoc. Since 2005 it has been present in the Centre region.

Agronomic impact

B. asparagi causes direct damage.
Its presence leads to dysfunctions in the plant owing to reactions to the injections the aphid makes when feeding.
The turions of asparagus are deformed into a "witch’s broom" arrangement (photo of damage).
During a strong attack dwarfism is seen in the aerial parts of the plant. This results from depletion of the normal synthesis of sugars.
The base of the weakened plants becomes more sensitive to fungal infection by Fusarium moniliforme, responsible for a rapid deterioration of the crop.

Natural enemies

Regulation of their populations by indigenous predators has proved effective.
In France, the 7-spotted ladybird is valuable as an auxiliary but insufficient.

Predators

• Coccinella septempunctata

Parasitoids

• Aphidius colemani
• Binodoxys brevicornis
• Diaeretiella rapae
• Ephedrus plagiator
• Praon volucre