Biology Reference
In-Depth Information
450
451
450
Mines of
Liriomyza congesta
in leaf of
Lathyrus
.
451
Mine of South American leaf miner (
Liriomyza
huidobrensis
) on
Chrysanthemum
.
452
453
452
Mine of
Liriomyza strigata
in leaf of
Valeriana
.
453
Mine of holly leaf miner (
Phytomyza ilicis
).
LIFE HISTORY
Adults occur in May and June, depositing eggs near the
base of the midrib on the underside of young holly
leaves. Eggs soon hatch and the larvae enter the midrib
to begin their development. They feed slowly until the
end of the summer, and then move into the leaf blade.
The larvae usually remain undetected until December,
when the first signs of a yellowish to purplish-brown
blotch appear on the upper surface of the leaf. The often
somewhat linear mine continues to develop throughout
the winter, and is completed by the spring, the larva
becoming fully fed in March or April. Pupation occurs
within the mine, with the anterior tip of the puparium
protruding through the upper surface of the leaf. The
adult eventually emerges through a pin-head-sized hole.
Galled leaves remain on bushes throughout the year
and, within each, the remains of the puparium may be
found close to the adult emergence hole.
DAMAGE
Infested leaves look unsightly and heavy attacks on
nursery stock may cause concern; however, plant
growth is rarely affected.
Phytomyza aconiti
Hendel
Unlike most other phytomyzids, larvae of this species
feed gregariously. They form large, irregular, brown
blotch mines in the leaves of
Delphinium
and
monkshood (
Aconitum angelicum
); significant damage
often occurs on such plants in gardens, as in southern
England. Up to six larvae occur within each blotch,
individuals eventually pupating in dark brown puparia.
Adults (wings 2.4-2.7 mm long) are black with the
sides of the thorax yellowish.
Search WWH ::
Custom Search