Agriculture Reference
In-Depth Information
three black stripes, and spotted, which is yel-
low with twelve black spots on its back. Both
are about ¼-inch long. Signs of infestation in-
clude chewed leaves and stems, and marks on
fruit. The beetles also spread bacteria on plants
when they munch on them, causing leaves to
wilt.
signs of bacterial wilt. You can protect
seedlings with a floating row cover.
Leaf
miners
Leaf miners are larvae of small flies that live
in and eat the inner membrane of plant leaves.
You'll see the damage before you see the insect
itself—look for dried brown patches or maze-
like patterns on leaves.
Remove affected leaves, since it's hard to
reach the insects inside the leaves. Float-
ing row covers help prevent flies from lay-
ing their eggs in the first place.
Slugs and
snails
Slugs and snails eat all kinds of vegetation, in-
cluding leaves, stems, and the fruit of plants. If
you see large chunks missing from your plants,
chances are a snail or slug is nearby. During the
day they retreat to damp, shady spots. Look un-
der big rocks, piles of grass clippings, or other
debris-laden areas to find them. It's best to do
this at dusk, at night with a flashlight, or on a
rainy day.
Remove by hand, and eliminate their hab-
itats as well (for example, your cabbage
that's resting on the ground should be
staked up). Repel them by putting a copper
barrier around your bed (the flexible tape
emits a natural electrical charge), or use
non-toxic baits such as iron phosphate or
beer (poured into a pie tin and sunk into
the ground).
Squash
vine borer
Squash vine borers prefer winter squash, zuc-
chini and other summer squash, and, to a lesser
degree, melon plants. The borers are larvae of
moths that lay their eggs at the plant's base.
Caterpillars develop and feed inside the stalk,
migrating to the main stem. If you catch the
larvae early, you can effectively control them.
Check for dots of frass protruding from holes
on the stem of the plant, near the base. If you
see wilting vines or leaves, it may be too late to
save the plant.
Use a knife to carefully cut the stem along
its axis where you see signs of infestation.
Split open the stem and look for the cater-
pillar—it will be cream colored and up to
an inch long. Remove it with a toothpick
or stiff wire, then squish it or snip it in
half. Cover the hole in the stem imme-
diately with moist soil. You can prevent
egg laying by wrapping the lower stem of
the plant in nylon stockings or aluminum
foil, or by using a floating row cover (until
the plant starts blooming, at which point it
will need to stay uncovered so it can pol-
linate).
Tomato
hornworm
Tomato hornworms are the larvae of hawk or
sphinx moths and commonly affect tomatoes,
as well as eggplants, peppers, and potatoes.
The caterpillar is green in color with eight
white V-shaped marks along its sides and a
black hornlike protrusion from its rear end. At
full size, it's three to four inches long. Even
though hornworms are quite large, they blend
well into plant foliage, so you'll probably no-
tice damage to plants before you see the cater-
Since they're so big, hornworms are easy
to remove by hand. You can squish them,
snip them with scissors, or toss them into
a pail of soapy water.
Or you could eat them! Some people even
claim that the little ones taste like toma-
toes!
