Agriculture Reference
In-Depth Information
Fig. 180
Forewing of
Aeolothrips intermedius
(x50).
spin cocoons in the soil or amongst leaf litter (in
which they then spend the winter), adults emerg-
ing in the spring. There is just one generation
annually.
Fig. 181
Outline of the head and pronotum: (a)
Aptinothrips;
(b)
Chirothrips.
DESCRIPTION
Adult
2mm long, black-bodied;
forewings
white, banded with black (imparting a striking
banded appearance to the insect)
(Fig. 180)
and with the vein around the tip pale (cf.
Aeolothrips tenuicornis,
below).
greatest from July to September, and there are
up to three overlapping generations annually.
The egg stage is moderately protracted and lasts
for almost 3 weeks. Nymphs feed for about 2
weeks and adults appear just over a week later,
after very brief propupal and pupal stages.
Nymph
white
to creamish-white.
Aeolothrips tenuicornis
Bagnall
Banded-wing flower thrips
DESCRIPTION
Adult
0.8-1.Omm long, yellowish-brown, nar-
row-bodied, apterous;
head
longer than wide
(Fig. 181a);
pronotum
more or less quadrate;
antennae
6-segmented.
Nymph
pale yellowish-
orange.
NOTE Other species are also of significance on
cultivated grasses, at least in continental Europe.
These include
Anaphothrips obscurus
Miiller and
Aptinothrips stylifer
Trybom.
This common species is also associated
with Asteraceae, Brassicaceae, Fabaceae and
Linaceae, and has a similar life-cycle to that of
the previous species. Adults are distinguished
from those of
Aeolothrips intermedius
(above)
by the dark colour of the marginal vein at the tip
of the forewing.
Family THRIPIDAE
Aptinothrips rufus
(Haliday)
Grass thrips
Chirothrips
spp.
Members of the genus
Chirothrips
breed on wild
and cultivated grasses and, in continental
Europe, sometimes reach pest status. The thrips
are readily distinguished from members of other
grass-infesting genera (e.g.
Aptinothrips,
above),
as the head is distinctly smaller than the pro-
notum
(Fig. 181b).
Also (but not in the meadow
foxtail thrips,
Chirothrips hamatus
Trybom).
the second antennal segment is asymmetrical,
usually having an outwardly directed apical
projection. The grass flower thrips
{Chirothrips
manicatus
Haliday) is a very polyphagous species
and that most frequently encountered.
This widely distributed and often abundant
thrips is associated mainly with grasses. It will
also breed on cereals, such as barley, oats and
wheat, but is not an important pest of these
crops.
BIOLOGY
Adults of this mainly parthenogenetic species
overwinter in tufts of dead grass, amongst turf
and in other sheltered situations. They become
active in the spring and eventually deposit eggs.
Populations of adults and nymphs are at their
