Transcript insect pests of potato

INSECT PESTS OF POTATO
•Potatoes
are attacked by most of the insects
which infest closely related solanaceous plants
like tomato, eggplant, and pepper.
•However, since potatoes are grown for their
edible tubers, they must receive greater
protection from soil-inhabiting pests.
•Wireworms, tuberworms, white grubs, and
vegetable weevils are pests for which growers
should watch.
KEY TO POTATO PESTS
A.
Pests that feed externally on the upper plant
1. Chewing pests that make holes in leaves : Blister
beetles, Colorado potato beetle, Flea beetles
2. Sap-sucking pests that cause discoloration,
deformation, or abscission
B.
Pests that feed on underground plant parts,
bore into stems, or mine in leaves and petioles
Chewing pests
Blister beetles
Several species of slender, elongate beetles up to 19
mm long; have prominent heads; bodies variously
colored but usually black, black with yellow
margins, or black and yellow striped; stringy black
excrement on heavily infested plants; foliage
ragged; plants sometimes stunted
Colorado potato beetle
Yellowish-brown, oval, convex beetle up to 14 mm
long with 5 black longitudinal stripes on each
wing cover and several black spots on
pronotum (area behind the head) feeds on
leaves and terminal growth
Flea beetles
Various species of tiny, darkly colored beetles 2.5
to 4.5 mm long; solid-color body or dark with
pale yellow stripe on each wing cover tiny
round holes in foliage
Sap-sucking pests
Aphids
Soft-bodied, pear-shaped insects with a pair of
dark cornicles and a cauda protruding from the
abdomen; may be winged or wingless - wingless
forms most common; feed in colonies; cause
discoloration or mottling of the foliage; often
transmit virus diseases; excrete honeydew on
which sooty mold grows
 Green peach aphid, Potato aphid

Green peach aphid
Pale yellow to green, wingless adult up to 2.4 mm
long; winged adult with dark dorsal blotch on
yellowish-green abdomen; cornicles over twice
as long as cauda and slightly swollen toward tip;
yellow-green nymphs with 3 dark lines on
abdomen
Potato aphid
Adult and nymph both solid pink, green and pink
mottled, or light green with dark stripe; adult up
to 3.5 mm long; long slender cornicles about
twice as long as cauda
Potato leafhopper
Spindle-shaped pest, up to 3 mm long; green body
with yellowish to dark green spots usually
jumps instead of flies; extracts sap from
underside of leaf causing leaf to crinkle and curl
upward; also causes yellowing of leaf tips and
margins (hopperburn)
European corn borer
Cream to light pink caterpillar with reddishbrown to black head; body up to 26 mm long
with several rows of dark spots; has 3 pairs of
legs near head and 5 pairs of prolegs bores into
stem; tangled frass and silk near entrance hole;
stem may break, plant may yellow or wilt readily
Potato tuberworm
Creamy white (young) or green to pink (mature)
caterpillar up to 19 mm long with dark brown head; 3
pairs of legs near head and 5 pairs of prolegs mines in
older lower leaves causing grayish papery blotches;
tunnels in exposed tubers or those close to soil surface,
filling tunnels with excrement; entrance holes usually
near the eyes and surrounded by a pink coloration
Vegetable weevil and larva
Adult - dull grayish-brown weevil, about 6.4 mm long, with
short, stout snout and light V-shaped mark on wing
covers larva - pale green, legless, up to 10 mm long, with
dark mottled head both feed at night making large open
holes in surface of potatoes. Feeds primarily at night on
underground plant parts, but sometimes consumes buds
and foliage
White grubs
Several species of creamy white grubs with a
distinct brown head capsule, three pairs of legs
near the head, and slightly enlarged abdomen;
body C-shaped and up to 50 mm long sever
roots and stems of potatoes; leave large, shallow
circular holes in tubers
Wireworms
Several species of slender, wire-like larvae with
three pairs of short legs near the head and a
pair of prolegs at the tip of the abdomen; large
shallow cavities in sweet potatoes - evidence of
early injury; deep ragged holes - later injury
 Melanotus communis
 Southern potato wireworm
 Tobacco wireworm

Melanotus communis

Yellowish-brown with darker head; body up to
25 mm long; last abdominal segment with
scalloped edges
Southern potato wireworm

Cream colored or yellowish-gray with reddishorange head; body up to 17 mm long; oval notch
in last abdominal segment
Tobacco wireworm

White with brown head; body up to 19 mm
long;V-shaped notch in last abdosssssminal
segment