[ Insect Pests:
ipm | landscape;
trunk, root |
turf grass; root,
outdoor | citrus |
Ch. 3, pp. 52 - 53
Orange Dog Caterpillar
Orange Dog Caterpillar
Orange dog caterpillars feed on citrus. They are mottled dark
grey to light brown, and are said to look like "bird
droppings." If disturbed, two orange, horn-like projections
emerge from the head and the caterpillar produces a pungent lemony
odor. When mature the caterpillar is about 1 1/2 inch long. The
adult is beautiful black and yellow butterfly called the giant
Orange dogs are potentially harmful to young trees
only, older trees can easily withstand the loss of a few leaves.
Orange dogs can be controlled on small trees by finding and
crushing eggs and caterpillars. Most are controlled naturally by
parasites and other natural enemies.
Cotton Aphid Nymph
The cotton or melon aphid may occasionally become a pest in
citrus, particularly in young trees. It may transmit a virus of
citrus known as tristeza virus. To control aphids, encourage
natural enemies such as lady beetles or lacewings. Parasitic wasps
attack aphids and cause them to form rigid brown or tan structure
called "mummies." Leave any mummies you see alone,
because a parasitic wasp will emerge from them and attack more
Mature females have bright orange-red, yellow or brown bodies
about 1/2 inch long, often covered with ridges of yellow or
whitish wax. The eggs and newly hatched immatures are bright red.
Cottony-cushion scales may feed on citrus, acacia, grape,
ironwood, pittosporum, and other ornamentals.
This pest was introduced and became a serious pest of
citrus in the 1880's. In one of the classical success stories for
biological control, cottony-cushion scales were completely
controlled by the introduction of a ladybeetle called the vedalia
beetle. Where the beetle is not found, infested branches should be
cut out and destroyed immediately.
Thrips are slender, tubular insects about 1/20 to 1/16 inch long.
Their wings are narrow with a fringe of hairs.
Citrus thrips begin to feed on new leaves, green twigs,
and small fruit of citrus in late February and March. This causes
leaves to curl and may cause scarring of fruit. However, the
damage is mostly cosmetic and does not effect the internal quality
of the fruit. To check for thrips, turn a leaf or flower onto a
piece of white paper and tap gently. The insects will show up as
tiny slivers on the white background.
Another type of thrips, flower thrips, may be feeding
on blossoms at the same time as citrus thrips. The flower thrips
are about twice as long as citrus thrips and slightly darker in
color. They may also cause cosmetic damage to fruit, but may be
predaceous as well.
Six-spotted thrips feed on spider mites and are
therefore beneficial. They may be distinguished from other thrips
because they have three dark spots on each forewing (a total of
Citrus Red Mite
Mites are difficult to see without the aid of a hand lens. They
have rounded bodies with eight legs. Mite damage is usually more
apparent than the mites themselves. They produce yellow stippling
(tiny spots) on the leaves. Some types leave a fine webbing on the
underside of leaves or between fruit. Mites are often associated
with water stress and dust. Keep trees well irrigated,
particularly in the late summer and early fall when monsoon winds
can kick up dust storms.