Insects - Pests of Ornamental Trees, Shrubs and Flowers - page 332

886 887

886 Rosy rustic moth ( Hydraecia micacea ). 887 Larva of rosy rustic moth ( Hydraecia micacea ).

Hydraecia micacea (Esper) ( 886-887 )
Rosy rustic moth
A minor pest of robust herbaceous plants, including
ornamentals such as Chrysanthemum , Dahlia , Iris ,
snapdragon ( Antirrhinum ) and sunflower ( Helianthus
annuus ). Holarctic. Widely distributed in Europe but
most common in coastal areas.

most significant damage occurs on Chrysanthemum and
Dianthus . Eurasiatic. Widely distributed in Europe.

DESCRIPTION
Adult: 35-45 mm wingspan; fore wings reddish brown
to purplish brown, with a small, yellowish stigma and a
whitish subterminal line; hind wings pale brownish
grey. Egg: greenish, hemispherical, slightly ribbed and
reticulated. Larva: up to 40 mm long; green, yellowish
brown or brown, finely speckled with white and, less
densely, with black; dorsal and subdorsal lines pale, the
spiracular line broad, and yellow or orange-yellow,
darkly edged above; spiracles white, ringed with black;
head light brown. Pupa: 16-19 mm long; dark brown to
black, and coarsely punctured; cremaster with a pair of
blunt-tipped spines.

DESCRIPTION
Adult: 40-45 mm wingspan; fore wings reddish brown,
somewhat darker centrally; hind wings pale, with a dark
crossline. Larva: up to 45 mm long; slender-bodied,
dull pinkish and translucent, with a slightly darker
dorsal line and several brownish-black pinacula, each
bearing a pinkish-brown hair; head and prothoracic
plate yellowish brown.

LIFE HISTORY
Adults are most numerous in the autumn, depositing eggs
close to the ground on the stems of grasses and certain
other plants. The eggs hatch in the following spring,
usually in late April or May. The young larvae then bore
into the stems of suitable host plants, tunnelling
downwards into the crowns, roots or rhizomes. Larval
development is completed in July or August, fully fed
individuals pupating in the soil a few centimetres below
the surface. Adults emerge a few weeks later.

LIFE HISTORY
Adults emerge outdoors from late May or early June
onwards but the first individuals often appear from late
January onwards in heated greenhouses. Eggs are
deposited in large batches of 30-200 on the underside of
leaves, and hatch in 1-2 weeks. Larvae then feed in
groups on the lower surface of leaves. After their second
instar, they disperse and tend to occur singly, each larva
feeding voraciously and becoming fully grown a few
weeks later. Larvae are most abundant from July to
September. Pupation takes place in a flimsy cocoon,
either in the soil or amongst debris or attached to a
suitable surface. In favourable conditions there is a
second generation of adults in the autumn; under glass
there is commonly a second generation in the summer
and a partial third in the autumn.

DAMAGE
Attacked plants are weakened and may wilt and die.
Infestations are usually most severe on or near field
headlands and on weedy sites.

Lacanobia oleracea (Linnaeus) ( 888-890 )
syn. Mamestra oleracea (Linnaeus)
Tomato moth
An often common pest of herbaceous plants, including
ornamentals growing outdoors and in greenhouses;

DAMAGE
Although young larvae merely graze away the lower
surface of leaves, older larvae bite completely through
the leaf and often reduce the foliage to a skeleton of