Life
Cycle of the Brown
Hairstreak
Ovum:
The tiny white bun-shaped eggs are c.0.65 mm in diameter and
laid singly or in pairs in a leaf axil or among
the buds of the food plant in late
July or August. They do not hatch until the following spring. The embryo
is
partially developed before overwintering
and resumes developing in spring, eventually hatching over
a
period of 10 days in late April and early May.
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Brown Hairstreak
ovum on
Blackthorn
©
DHardiman 2001
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Larva:
The adult larva measures up to 18 mm in length.
Its
woodlouse shaped body is broad and plump becoming flattened at the extremities
and is strongly indented
between the
segments. The green body has whitish divisions between the segments and two close pale yellow
dorsal
lines that diverge towards the head. A series of oblique pale yellow lines extend along both sides.
The
dark brown head withdraws into the body at rest.
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© DHardiman 2002
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After the first instar the larva rests by day on a silken pad spun on
the underside of a Prunus leaf and feeds by
night. Feeding takes place between late April and the end of
June. This larval stage lasts 4-6 weeks.
Pupa:
Pupa attaches itself to the undersides of leaves or among leaf
litter beneath its food plant by a group of spines
that are present in the anal region covered over by larval skin, this
taking the place of the cremasteral hooks.
The presence of a silken girdle, in addition to this, is
disputed. When the larva pupates among leaf litter it
forms
a shelter by drawing a few leaves together with silk threads. This pupal
stage lasts 30-40 days.
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© DHardiman 2002 |
Adult:
The adult emerges in late July or early August and is on the wing until
mid-September.
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