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Sitodiplosis mosellana (Gehin)
Insecta, Diptera, Cecidomyiidae .

Orange wheat blossom midge

Description, Biology, Life Cycle, Damage, Common Names, Images

- Adult: 1.5-2.5 mm long; orange-red; slender; legs long, thin and pale brown; antennae brown; female provided with a short and unstretchable ovipositor (*) .
- Larvae: 2.0-2.5 mm long; orange-red; devoid of legs and head capsule; sternal spatula situated on the lower side of 1st thoracic segment; hind tip of larva bearing several serrate appendages; unable to jump.

This species is widely distributed is the northern hemisphere and develops on wheat, rye and barley.
- Duration of pupation: about 2 weeks.
- Number of eggs produced: 30-40 per female.
- Young larvae hatch about 5-10 days after egg-laying. The feeding period lasts about 3-4 weeks.

[R]Life Cycle
- There is 1 generation per year.
Larvae overwinter in a subterranean, round and transparent cocoon, moving directly to the upper layer of the soil to pupate when temperatures rise in the spring.
- Living for only a few days, the midges start flying at approximately the flowering period of wheat (*) . They usually remain in the soil and, after sunset, especially during still nights, fly to the ears to lay their eggs. If the air is humid enough, egg-laying may take place during the day.
- Duration of the flight period: 2-3 weeks, sometimes longer.
- Number of eggs produced per female: 30-40. Eggs are laid singly on ears at the pre-flowering stage. If eggs are laid later, larvae are incapable of developing normally.
Young larvae hatch about 5-10 days after egg-laying and feed for 3-4 weeks.
Once they have reached their final size, larvae leave the ears when the air is humid and enter the upper layers of the soil, spinning a cocoon in which they will remain in a state of diapause for an extended period..
- Larvae usually pupate the following spring but may remain in a state of diapause for several years. In a population, 0-96% of individuals enter a state of diapause, depending on factors such as rainfall, soil humidity and rotation of crops.
Mainly parasites, diapause and phenological factors determine the life of this species. Heavy rainfall during the flight period can cause individuals to fall to the ground and die.

Average infestation on wheat of 15 larvae per ear can lead to yield reductions.
Early infestations hinder the formation of seeds (*) while late infestations cause them to become brittle. Partial attacks distort ears, which become soft to the touch and seem abnormally thin. Ears of rye may exhibit mines.
The envelope of the grain often ruptures and a secondary fungal infection develops. Grain value, the germination power, the speed of germination, the vigour and the weight of grains can be considerably reduced. The baking quality of rye is poor.

[R]Common Names
DE: Orangerote Weizengallmücke ES: Cecidomido naranjo del trigo FR: Cécidomyie orangée du blé IT: Cecidomia rossa del Grano PT: Cecidomídeo laranja do trigo GB: Orange wheat blossom midge

[R] Images

  1. Sitodiplosis mosellana (Gehin) (Coutin R. / OPIE)
    Female and wheat at the favourable stage for egg-laying Female laying eggs on flowering ears of wheat.
  2. Sitodiplosis mosellana (Gehin) (Coutin R. / OPIE)
    Larva on seed of wheat Anterior glumes and lemmae were removed to show the larva.
  3. Sitodiplosis mosellana (Gehin) (Coutin R. / OPIE)
    Damage on harvested wheat grains Dorsal side of grain hollow on the opposite side from the burrow. Larval exuvia in depression (arrowed).
  4. Sitodiplosis mosellana (Gehin) (BASF)
    Affected wheat grains

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HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.

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