Periodical cicada
OVIPOSITION INJURY
When insects lay
they eggs inside the stems of trees they girdle twigs, and effectively cutting
them of the trees water and nutrient supply.
This causes twigs to wither, turn brown and drop.
Because there is little that can be done to
effectively manage these pests, it is important to learn their life cycles so
that you can effectively explain these problems to your clients.
Annual and periodical cicadas Tibicen spp, and Magicada
spp.
Order and Family:
Homoptera: Cicadidae
Host Plants: Many deciduous trees
Damage and Diagnosis: When
adults lay enough eggs in twigs they can kill them.
This is primarily a problem on new nursery
stock, and when large numbers of periodical cicadas emerge.
Damaged twigs and branches have a series of
slits where females have laid their eggs.
Damage from the periodical cicada is most severe near mature stand of
trees where cicadas can complete their long life cycle. Adult periodical
cicadas have orange wings with black bodies and red legs.
In contrast damage from the annual or dog
day cicada is minimal.
Biology: Nymphs of all cicadas feed on roots of
trees.
Nymphs of annual cicadas feed
on roots from 2-5 years and those of periodical cicadas feed on roots for 13
or 17 years before they become adults.
Adult annual cicadas are present from mid-July to late summer.
After adult periodical cicadas emerge in
late May or early June, they fly for 6 weeks.
Male cicadas produce a shrill call that is quite distinctive.
When they emerge by the thousand, the shrill
call of the males to their mates is both distinctive and overwhelming.
During the adult flight period adults mate
and females lay egg in twigs.
Several
weeks after eggs are laid a nymph hatches, feeds and drops to the ground to
dig for tree roots where they suck on plant sap.
Damage associated with root feeding has not
been measured and is assumed to be minimal.
Control: Field trials with applications of broad
spectrum insecticides show that none can effectively reduce injury from the
periodical cicada.
Contact your local
Extension service to find out when and if periodical is expected in your
area.
Discussing the issue with your
clients
before trees are covered
with cicadas will help you better manage the situation.