Agriculture Reference
In-Depth Information
Fig. 204
Adult click beetle,
Agriotes lineatus
(x7).
Fig. 205
Terminal body segment of various
wireworms: (a)
Agriotes lineatus;
(b)
Athous
haemorrhoidalis;
(c)
Ctenicera
sp.
legs;
ninth abdominal segment
pointed and with a
pair of distinctive dorsolateral pits
(Fig. 205a).
mainly from mid-May to July and, in the adult
stage, are usually the most frequently encoun-
tered species. The larvae (wireworms) are
slightly flatter than those of
Agriotes
and the
ninth abdominal segment, which lacks the
dorsolateral pits, is bifurcated posteriorly and
has an ornamented outline
(Fig. 205b).
Agriotes obscurus
(L.); A.
sputator
(L.)
Common click beetles
These two species are similar in habits to
Agriotes lineatus
(p. 132). Although both are also
widely distributed,
A. obscurus
is most abundant
in northerly districts, especially on lighter soils
with a high organic content;
A. sputator
has
a more southerly distribution. Adults of
A.
obscurus
are 7-10 mm long and uniformly dark
brown, with a relatively large, densely punctured
pronotum; those of
A. sputator
are 6-7 mm
long and mainly reddish-brown, with the pro-
notum somewhat darker and relatively shiny.
Larvae of all three species are very similar in
appearance.
Ctenicera cupreus
(F.)
Upland click beetle
This locally common species occurs mainly in
upland pastures. The larvae (known as 'upland
wireworms') take up to 5 years to complete their
development, and usually then pupate in late
July or early August. Adults emerge in the fol-
lowing year and occur in greatest numbers in
June and July. Although capable of inflicting
considerable damage, upland wireworms are
rarely sufficiently numerous to cause significant
damage. Individuals are relatively stout-bodied,
with the ninth abdominal segment bifurcated
posteriorly by a bulb-shaped notch
(Fig. 205c).
Adults are 11-16 mm long and mainly dark
Athous haemorrhoidalis
(F.)
Garden click beetle
Adults of this generally common click beetle are
reddish-brown and up to 12 mm long. They occur
