Biology Reference
In-Depth Information
962
Caliroa cerasi
(Linnaeus) (
962-963
)
syn.
C. limacina
(Retzius)
Pear slug sawfly
larva
pear & cherry slugworm
A locally common pest of rosaceous trees and shrubs,
including, almond (
Prunus dulcis
), flowering cherry
(
Prunus
), hawthorn (
Crataegus
), japonica (
Chaenomeles
speciosa
), ornamental pear (
Pyrus calleryana
'Chanticleer') and rowan (
Sorbus aucuparia
). Eurasiatic.
Present throughout Europe; accidentally introduced into
many other parts of the world, including Africa,
Australasia, North and South America.
=
DESCRIPTION
Adult:
4-6 mm long; black and shiny.
Larva:
up to
10 mm long; greenish yellow to yellowish orange but
covered in olive-black, shiny slime; body pear-shaped,
tapering towards the hind end; head and legs
inconspicuous.
962
Pear & cherry slugworm (
Caliroa cerasi
).
963
LIFE HISTORY
Adults appear in late May and June. Eggs are then laid
in small slits cut into the underside of leaves, often
several on the same leaf. The larvae rest and feed whilst
fully exposed on the upper surface of expanded leaves,
browsing away the epidermis but without biting through
the entire blade. Larvae are fully grown in July.
They then pupate in small, black cocoons formed in the
soil about 10 cm below the surface. Adults emerge a
week or two later. There are usually two, sometimes
three, generations each year, the larvae occurring
throughout the summer and early autumn. Reproduction
is parthenogenetic, males being very rare.
963
Pear & cherry slugworm (
Caliroa cerasi
) damage to
leaves of
Sorbus aucuparia
.
DAMAGE
Leaf browsing is often extensive, and very disfiguring
to ornamentals. Severe infestations cause premature leaf
fall and affect the growth of plants in the following
season.
964
Caliroa cinxia
(Klug) (
964
)
This species occurs on oak (
Quercus
) in various parts
of mainland Europe; also present in central and
southern England. The larvae browse on the underside
of the leaves, damage being identical to that caused by
Caliroa annulipes
.
C. cinxia
is single brooded,
infestations being most evident in the autumn from
September to October. Adults are mainly black, and
distinguished from those of
C. annulipes
by their less
cloudy wings and (in females) by the less extensive
area of white on the hind legs; the larvae of both
species are also similar but those of
C. cinxia
have a
uniformly reddish-brown head.
964
Young larvae of
Caliroa cinxia
.
Search WWH ::
Custom Search