Apion pomonae F.: whose larvae develop in pods of vetches
A. loti Kirby: whose larvae eat seeds of sainfoin
A. trifolii L.: whose larvae eat the clover seeds forming in the inflorescence
A. apricans Herbst.: identical to A. trifolii.
Weevils with the frayed rostrum, are Seminivorous insects (whose larvae eats seeds, same as beetles, or weevils from Tychius) genus.
Example of A. trifolii
With annual generation, apions are present from May to end of July They give birth to larvae (in the inflorescence of red clover, when they are still young buds) that feeds on present seeds. Once the cycle is complete, larvae become adults (after pupation) leave the flower heads (faded) in early August.
Larvae feeding on red clover seeds can ingest on average up to 35% of seeds. Each larva eats an average of 4-8 seeds per inflorescence.
Early budding, until the beginning of flowering. Early pre-cuts as well as, wet and cold spring may extend the period of budding, and thus the sensitive phase.
During sensitive phase, we can capture on average hundred adults with 25 sweeps of nets.
Intervention must occur just before the apions lay their eggs in inflorescences. However, treating plants before the appearance of flower heads before is useless. The first treatment should occur about twenty days after the pre-cuts, the second eighteen days after it.
Parathion: 400 g of a.i./ha: before appearance of first flowers
Dialiphos: 600 g de a.i./ha: after appearance of first flowers
Phosalon: 1000 g de a.i./ha: also after first flowers