ONION INSECTS loi 



ONION PESTS 



The onion magCxOt ^^ (Hylemyia anfiqua) 

 Order — Diptera 



The insect passes the winter mostly as puparia 3 

 to 6 inches below the surface of the soil; the flies 

 appear in May and deposit their white eggs on 

 leaves of the plants, or on the stems near the soil, 

 or in cracks of the soil; the egg hatches in 3 to 7 

 days and the maggots feed on the young onion 

 bulb soon ruining it; they obtain their growth in 

 16 to 18 days and then pupate in soil; the pupal 

 stage lasts 2 to 3 weeks; there is evidently time 

 for 2 or 3 generations in a season. 



Control — Scallions should be planted late in 

 September or early October; sometimes of advan- 

 tage to make a small early planting in August as a 

 trap crop ; sow late, that is, in latter part of April 

 or early May and force crops ; rotate and get away 

 from old infested fields ; practice clean culture ; use 

 carbolic acid emulsion on onions in garden; use 

 sweetened poison bait. 



The onion thrips "^ (Thrips fabaci) 

 Order — Thysanoptera 



This is a very small insect that causes a good deal 

 of annual injury to onions in the United States; it 

 is widely distributed all over the country and hard 

 to control. 



It passes the winter as adults and probably also 

 as nymphs ; the eggs are laid in tissues of the leaves 

 just under the epidermis ; they hatch in 3 to 4 days ; 

 larval stage 7 to 9 days ; nymph stage 4 days ; whole 

 life cycle 16 days; many overlapping broods; the 



19 Gibson and Treherne— Canad. Dept. Agr., Ent. Br., Bull. 12, 

 p. 29. 



20 Quaintance— Florida Bull. 46. 



