Description, Biology, Life Cycle, Damage, Common Names, Images
- Host plant: lucerne.
- Average fecundity: 50 eggs.
- Eggs: they are deposited in groups of 2 to 5 in the flower buds before these open out. Embryonic development lasts 2 days at a temperature of 20°C.
- Larvae: gregarious. Development lasts from 10 to 24 days. When fully grown, larvae drop onto the ground and each forms a cocoon in which it pupates 3 to 4 days later, unless it overwinters.
- Pupa: development lasts at least 10 days.
- Depending on the country, 2, 3 or 4 overlapping generations occur from June to September. The first flights occur by the end of May in Italy and at the beginning of June in the Paris region.
- A generation lasts 15 to 20 days. The emergence of the adults is strongly related to soil humidity (optimum 20% to 50%) and spreads over more than a month, the males appearing one day before the females. Mating and egg laying occur a few minutes after the female has emerged.
The eggs are deposited in the closed, entirely green, buds (*) , whose growth, about 10 days later, is seriously affected. There are, on average, 5 larvae per flower (*) .
The larva develops in flowers which do not open out and are transformed into galls (*) : the stamens are hypertrophied and fleshy whereas the ovary remains short and thin. Seed yield is considerably reduced.
Damage occurs at first on the edges of fields and then spreads in circles around the centres of infestation. Damage is significant on lucerne seed crops.
Contarinia medicaginis is a serious pest throughout Europe, excepting northern countries.
DE: Luzernenblütengallmücke ES: Cecidómido de las flores de la alfalfa FR: Cécidomyie des fleurs de la luzerne IT: Cecidomia dei fiori delle Mediche PT: Cecidomídeo das flores da luzerna GB: Lucerne flower midge
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.