Miscellaneous Pests - Pests of Ornamental Trees, Shrubs and Flowers - page 426

Chapter 4
Miscellaneous Pests

WOODLICE

Family ARMADILLIDIIDAE adult coloration after about two weeks, and a seventh

pair of legs appears after two moults. Further moults
occur, even after the adult stage is attained, but
individuals do not reach sexual maturity until the
following year. Mortality of young woodlice is high and
few individuals survive for more than a couple of
months; adults, however, may survive for up to four
years.

Woodlice with flagellar segment of the antennae
divided into two sections; body strongly arched, and
individuals capable of rolling into a ball.

Armadillidium nasatum Budde-Lunde ( 1139 )
Blunt snout pillbug
Widespread and often common in heated greenhouses,
occasionally causing damage to ornamental plants. DAMAGE

Woodlice produce irregular holes in leaves, mainly in
those close to the ground; growing points of young
plants may also be destroyed. Stems of potted plants and
transplants are often grazed but those of older plants are
rarely attacked.

DESCRIPTION
Adult: 21 mm long; grey, with a pale median line and
pale lateral patches; snout drawn into a narrow, square-
sided projection.

Armadillidium vulgare (Latreille) ( 1140 )
Common pillbug
This species often occurs in unheated greenhouses and
garden frames, causing damage to plant roots; seedlings
are frequently destroyed and the growth of older plants
may also be affected if soil infestations are heavy.
Adults are 18 mm long, dark slate-grey to reddish, with
several pale patches along the body; the snout is slightly
raised.

LIFE HISTORY
Adults occur throughout the year, usually hibernating in
piles of soil. Breeding occurs from April to October,
there being two or more generations each year. Females
deposit about 50 eggs, and these are retained in a special
pouch on the underside of the thorax. The eggs hatch in
about 1-2 months. Young, white, 12-legged woodlice
(each about 1 mm long) then escape from the maternal
pouch to begin feeding. Individuals acquire the typical

1139 1140

1139 Blunt snout pillbug ( Armadillidium nasatum ). 1140 Common pillbug ( Armadillidium vulgare ).