MP-313
NOVEMBER 1958
PECAN DISEASES AND INSECTS
AND THEIR CONTROL
TEXAS AGRICULTURAL EXPERIMENT STATION ...
TEXAS AGRICULTURAL EXTENSION SERVICE
College Station, Texas
Key to Pecan Diseases
| DISEASES OF THE LEAVES | |||
| Olive spots on underside | [page 5] | Scab | |
| Downy, buff, or greenish-yellow lesions | [page 7] | Downy Spot | |
| Small, reddish-brown to gray spots on underside | [page 6] | Brown Leaf Spot | |
| Dark brown to black lesions on veins and stems | [page 6] | Vein Spot | |
| Tiny white tufts of fungal growth on underside | [page 9] | Articularia Leaf Mold | |
| Small olive green velvety spots. By midsummer, black pimple-like dots appear in the spots | [page 7] | Leaf Blotch | |
| Leaflets yellowish, mottled, narrowed and crinkled with reddish-brown spots, may be perforated | [page 8] | Rosette | |
| Broomy type of twig growth, bunching of leaves | [page 8] | Bunch Disease | |
| DISEASES OF THE NUTS | |||
| Small black sunken or raised spots which may fuse to cover entire surface of shuck | [page 5] | Scab | |
| Pink spore masses on shuck surface | [page 9] | Pink Mold | |
| DISEASES OF THE ROOTS | |||
| Galls of various sizes on larger roots | [page 7] | Crown Gall | |
| Splitting and deterioration of bark of infected roots, strands of buff-colored fungal growth may be present | [page 10] | Cotton Root Rot | |
| NONPARASITIC PLANTS ON THE LIMBS AND BARK | |||
| Whitish-gray mosslike masses on the bark | [page 9] | Lichens | |
| Accumulations of grayish strands hanging from limbs and twigs or ball-like growth on limbs and branches | [page 9] | Spanish Moss, Ball Moss | |
Key to Pecan Insects
| INSECTS ATTACKING THE NUTS | ||||
| Olive-green caterpillars up to ½ inch long feeding in the nuts, or later in the season, in the shucks | [page 10] | Pecan Nut Casebearer | ||
| White caterpillars up to ⅜ inch long tunneling in the shucks | [page 11] | Hickory Shuckworm | ||
| White legless grubs feeding in the nuts in late summer | [page 12] | Pecan Weevil | ||
| Green or brown bugs sucking the sap from the nuts | [page 12] | Stink Bugs and Plant Bugs | ||
| INSECTS ATTACKING THE FOLIAGE | ||||
| Soft-bodied yellow insects producing honeydew or small black insects causing yellow blotches on the foliage | [page 13] | Aphids | ||
| Tiny green arthropods in webs near the midrib, leaves appear scorched | [page 13] | Mites | ||
| Caterpillars feeding in gray cases about ½ inch long in the spring; small winding blotches produced in the leaves in the summer | [page 14] | Pecan Leaf Casebearer | ||
| Olive-green caterpillars tunneling in the shoots in the early spring | [page 10] | Pecan Nut Casebearer | ||
| Tiny caterpillars in light brown cigar-shaped cases about ¼ inch long | [page 15] | Pecan Cigar Casebearer | ||
| Galls on the leaves, twigs and nuts | [page 14] | Pecan Phylloxera | ||
| Leaves eaten in the early spring by a light green caterpillar which leaves the midribs and veins intact | [page 14] | Sawfly | ||
| Beetles feeding on the foliage at night | [page 15] | May Beetles | ||
| Caterpillars in large white webs encasing entire branches | [page 15] | Fall Webworm | ||
| Caterpillars with long soft hairs feeding in colonies on the foliage without producing webs | [page 16] | Walnut Caterpillar | ||
| Dark gray, active caterpillars up to 3 inches long feeding on the foliage in early spring | [page 16] | Pecan Catocala | ||
| Masses of frothy white foam enclosing tiny, light green insects in the spring | [page 16] | Pecan Spittlebug | ||
| Tiny greenish caterpillars feeding in the terminals and axils of the buds on young pecan trees | [page 16] | Pecan Bud Moth | ||
| INSECTS ATTACKING THE LIMBS, TRUNK AND TWIGS | ||||
| Beetle girdling twigs and limbs in late summer and fall | [page 17] | Pecan Twig Girdler | ||
| Holes about ⅛ inch in diameter in dying limbs | [page 17] | Red-shouldered Shot-hole Borer | ||
| White borers with an enlargement behind the head tunneling underneath the bark of trunk and limbs | [page 17] | Flatheaded Borers | ||
| Limbs encrusted with scales, which closely resemble the color of the bark | [page 18] | Obscure Scale | ||
CONTENTS
[Key to Pecan Diseases] 2 [Key to Pecan Insects] 2 [Spray Schedule for the Control of Pecan Diseases and Insects] 4 [Introduction] 5 [Pecan Diseases and Their Control] 5 [Scab] 5 [Brown Leaf Spot] 6 [Vein Spot] 6 [Leaf Blotch] 7 [Crown Gall] 7 [Downy Spot] 7 [Bunch Disease] 8 [Rosette] 8 [Lichens] 9 [Articularia Leaf Mold] 9 [Pink Mold] 9 [Spanish and Ball Moss] 9 [Cotton Root Rot] 10 [Pecan Insects and Their Control] 10 [Pecan Nut Casebearer] 10 [Hickory Shuckworm] 11 [Pecan Weevil] 12 [Stink and Plant Bugs] 12 [Aphids] 13 [Mites] 13 [Pecan Leaf Casebearer] 14 [Pecan Phylloxera] 14 [Sawflies] 14 [May Beetles] 15 [Pecan Cigar Casebearer] 15 [Fall Webworm] 15 [Walnut Caterpillar] 16 [Pecan Catocala] 16 [Pecan Spittlebug] 16 [Pecan Bud Moth] 16 [Twig Girdler] 17 [Red-shouldered Shot-hole Borer] 17 [Flatheaded Borers] 17 [Obscure Scale] 18 [Application of Fungicides and Insecticides] 18 [Spray Equipment] 18 [Literature Cited] 19