Agriculture Reference
In-Depth Information
BIOLOGY
This species breeds continuously, there being
five or more overlapping generations annually.
Eggs are inserted singly into the leaf veins and, at
normal glasshouse temperatures, each hatches
in about a week. The active nymphs then feed
for about a month before becoming adults, each
passing through five instars. Under colder condi-
tions, however, development from egg to adult is
greatly protracted and, in winter, may take sev-
eral months. Adults are relatively long-lived and
many survive for up to 3 months, each female
depositing about 50 eggs.
tumn and the nymphs feed briefly before over-
wintering. Activity is resumed in the spring, and
nymphal development is completed in the early
summer. In Britain, this species is single-
brooded. Female leafhoppers carrying cereal or
grass mycoplasmic diseases are capable of trans-
ferring the causal organisms to their offspring via
the eggs.
DESCRIPTION
Adult female (macropterous form)
4.0-4.5 mm
long, pale brownish-yellow with black markings;
elytra
yellowish, semi-transparent;
hind tibia
with a large, moveable apical spur (typical of
family)
(Fig. 186). Adult male (macropterous
form)
mainly black, marked with white and
yellow;
elytra
hyaline-whitish.
Brachypterous
forms
in both sexes vary from pale yellowish to
black and are 3 mm long.
DESCRIPTION
Adult
3.1-3.7mm long, mainly pale yellow,
marked with grey or brown;
elytra
each with a
pair of brownish-grey bands
(Fig. 185)
which, in
repose, form two chevron-like markings over the
back.
Family PSYLLIDAE (psyllids)
Psylla mali
(Schmidberger)
Apple sucker
Family DELPHACIDAE
(planthoppers)
Javesella pellucida
(F.)
Cereal leafhopper
This insect is a potentially damaging pest of
apple but rarely occurs on regularly sprayed
This often abundant leafhopper is associated
with wild and cultivated grasses and also infests
cereal crops. Although direct feeding by adults
and nymphs is usually of little or no significance,
the insects are capable of transmitting virus-like
(mycoplasmic) diseases, including wheat striate
mosaic; this disease can cause stunting of cereals,
including barley, oats, rye and wheat.
BIOLOGY
Adults occur in the summer. Eggs are then de-
posited in the leaf sheaths and hollow stems of
cereals and grasses. The eggs hatch in the au-
Fig. 185
Forewing of glasshouse leafhopper.
Hauptidia maroccana
(x25).
Fig. 186
Cereal leafhopper,
Javesella pellucida
(x15).
