144
N. WALOFP
13. THE BIOLOGY A N D POPULATION STUDIES OF Lezwptera
epartifoliella HUBNER (LEPIDOPTEBA , LYONETIIDAE) (Agwu, 1967)
The larvaa of the Lyonetiid moth Lemptera spartifoliella form mines
in the green twigs of broom and this species is being used to control the
shrub in California.
1. The effect of Leucoptera on the hast plant
The type of damage inflicted by Leumptera has been studied by the
United States Department of Agriculture in California and Frick (1964)
reports that larval activity causes the twigs of broom to be weakened
or to die and that heavily attacked shrubs become covered with dead
branches and produce half the amount of seeds of unattacked planh.
Leumptera occurs in every broom area in Silwood Park and its populations are numerically second only to those of psyllids and aphids. The
moth shows a preference for the young bushes or those with abundant
growth of the current year's green twigs on which it oviposits and heavy
infestations, such as occurred in Area 4 in 1964, cause death of many
host plants.
Agwu (1967), who studied the biology of Lezlcoptera from 1963-66
attempted to assess the damage caused by the moth. He took samples
of dead and living twigs from each of twelve bushes selected at random,
measured the lengths of the twigs and estimated the density of the
larval mines. This density was much greater on the dead twigs than on
the living ones moreover, 95.2% of all the dead twigs were mined,
whereas mines occurred on only 81.1% of the living onea (see Table
XXXI).
TABLE XXXI
Density of Leucoptera mines in live and dead twigs and percentage of
live and dead twig8 with naim (After Agwu, 1967)
State of
Total no.
Meanfcm t 2-38 P < 0.06
twig
of mines
Live
162
0.18
Desd
284
0.36
"/b living twigs with minee
yo deed tsvige with minee
61.1
98.2
Mining larvae destroy the chlorenchymatous cells, which in broom
photoeynthesiae. After the leaves are shed in autumn, chlorenchyma
may have an important function until the appearance of new leaves
in spring.
N. WALOFP
13. THE BIOLOGY A N D POPULATION STUDIES OF Lezwptera
epartifoliella HUBNER (LEPIDOPTEBA , LYONETIIDAE) (Agwu, 1967)
The larvaa of the Lyonetiid moth Lemptera spartifoliella form mines
in the green twigs of broom and this species is being used to control the
shrub in California.
1. The effect of Leucoptera on the hast plant
The type of damage inflicted by Leumptera has been studied by the
United States Department of Agriculture in California and Frick (1964)
reports that larval activity causes the twigs of broom to be weakened
or to die and that heavily attacked shrubs become covered with dead
branches and produce half the amount of seeds of unattacked planh.
Leumptera occurs in every broom area in Silwood Park and its populations are numerically second only to those of psyllids and aphids. The
moth shows a preference for the young bushes or those with abundant
growth of the current year's green twigs on which it oviposits and heavy
infestations, such as occurred in Area 4 in 1964, cause death of many
host plants.
Agwu (1967), who studied the biology of Lezlcoptera from 1963-66
attempted to assess the damage caused by the moth. He took samples
of dead and living twigs from each of twelve bushes selected at random,
measured the lengths of the twigs and estimated the density of the
larval mines. This density was much greater on the dead twigs than on
the living ones moreover, 95.2% of all the dead twigs were mined,
whereas mines occurred on only 81.1% of the living onea (see Table
XXXI).
TABLE XXXI
Density of Leucoptera mines in live and dead twigs and percentage of
live and dead twig8 with naim (After Agwu, 1967)
State of
Total no.
Meanfcm t 2-38 P < 0.06
twig
of mines
Live
162
0.18
Desd
284
0.36
"/b living twigs with minee
yo deed tsvige with minee
61.1
98.2
Mining larvae destroy the chlorenchymatous cells, which in broom
photoeynthesiae. After the leaves are shed in autumn, chlorenchyma
may have an important function until the appearance of new leaves
in spring.