Liriomyza brassicae (Riley, 1884)
IMPORTANT CHARACTERS
Adults
Wing length: 1.25 - 1.7 mm. Mesonotum bluish shining. Frons yellow with darkened margins. Hind margin of eyes darkish, normally cuticle around both vertical bristles black. However, the color of orbits and the surrounding of inner vertical bristle can vary. Stridulation mechanism hardly visible.
Male terminalia
Compared to other economically important Liriomyza species the tip of distiphallus is stronger pigmented.
Immature stages
Posterior spiracles with three bulbs each.
BIONOMICS
The larva feeds as a leaf miner either on the upper or lower leaf surface and forms a linear serpentine mine (Spencer, 1973). Pupariation takes place in the soil.
The larva hatches about three days after oviposition, the development of the larva takes 6.6-7.3 days, puparial stage ranges from 8.2-10.15 days (without diapause) (Beri, 1974).
In Europe there are two generations but in tropical areas there are certainly more, coinciding with the active growth of the host-plants (Spencer, 1973).
HOST PLANTS
Various Brassicaceae (Cruciferae) species, of these some cultivated genera: Brassica, Cheiranthus, Nasturtium, Raphanus, Sinapis. The species also was found on Capparaceae, Pisum (Fabaceae) and the ornamental plants Tropaeolum (Tropaeolaceae) and Dahlia rosea (Asteraceae). Despite the wide host range reported by various authors, the plant are not equally attractive for the species of certain cultivars. For example Abdel and Ismail, 1999 reported that the mustards Sinapis alba and Brassica nigra were resistant and Brassica campestris were "tolerant" against L. brassicae.
DISTRIBUTION
Accidental human introduction made L. brassicae cosmopolitan or nearly so.
ECONOMIC IMPORTANCE
Apparently the importance of brassicae can vary through time and space. Spencer, 1973 concluded - basing his conclusion on various references and personal observations - that "L. brassicae must be considered as a potentially serious pest both of brassicacean plants and also peas". He reported heavy infestations on cabbages from Senegal, and Hawaii. In India, Liriomyza brassicae is regarded as one of the most important pests on the oil seed Brassica campestris (Singh et al., 1991). However, in California the populations appeared to be normally small and not dangerous (Parrella, 1983).