Plant Protection Dept. 3rd Stage Students Practical Forest Mr. Hazim S. Ahmed and Mrs. Dlpak B. Yaba Lecture 03 2- Leaf folding (rolling) insects: Leaf folders are characterized by the ability of spinning large amounts of threads to bind the leaves or other plant parts. (1) Spruce budworm, Choristoneura fumiferana Order: Family: Totricidae Description: Adults have a wingspan of about 20mm, are gray with dark brown markings or red-brown with gray markings. Eggs are light green, 1mm long and 0.2mm wide and laid in elongate masses of 2 to 60 eggs that overlap. Larvae: 1st Instar larvae are about 2mm long with a yellow-green body and brown head. 2nd Instar larvae are yellow with a dark brown or black head. During the next four instars, larval body color changes from pale yellow to dark brown with light-colored spots along the back. 5th Instar larvae average 25mm long with a dark brown-black head. Pupae are pale green at first and later change to red brown, marked with dark bands and spots.

Damage: Larvae feed on expanding buds, flowers and on new foliage. Spruce budworm is considered as the most destructive forest defoliator in Canada and the USA. Outbreaks often cover millions of hectares and persist for 8 to 10 years. Outbreaks are associated with maturing of balsam fir and increased staminate flower production, which are a favorite food of young larvae. Successive years of bud damage and defoliation cause growth loss, top kill and tree mortality.

12 Plant Protection Dept. 3rd Stage Students Practical Forest Insects Mr. Hazim S. Ahmed and Mrs. Dlpak B. Yaba (2) Leaf Roller, semiferanus Order: Lepidoptera Family: Description: The Adult The are small with a wingspan of 18 to 22 millimeters; the wings have a characteristic bell shape. Wing color can vary considerably. Hind wings are a mixture of "creamy brown and gray" with gray found at the wingtips. The Forewings have a darker band of brown or gray crossing obliquely. Egg The flat egg masses are white-gray in color and oval shaped, and are about 4.8 millimeters across. The eggs overwinter and hatch in spring of the next year. When fully grown, the larvae are between 25 to 29 millimeters long with a body that can be yellow-green or darker shades of green. The larvae pupate in cocoons which are found inside the rolled leaves or in "bark crevices". Damage: The larvae feed on the leaves of oak trees and are a major defoliator of oak trees, which can lead to tree mortality. In in the late 1960s and early 1970s, Oak leaf rollers defoliated over 423,000 ha and over $100,000,000 of timber was lost. The larvae eat tree buds and young leaves, then roll leaves together with silk (hence the name).

13 Plant Protection Dept. 3rd Stage Students Practical Forest Insects Mr. Hazim S. Ahmed and Mrs. Dlpak B. Yaba 3- Tent making insects: The larvae of this group make a web or tissue like the tents fixed it on the tree branches or herbs (grasses) and live underneath and feed and molt until it reach the last instar. (1) Spring webworm, Ocnogyna loewii Order: Lepidoptera Family: Arctidae Description: The adult insects have a brown color in general. The forewing has brown color crossed by several bands with pale color and extended in different direction in the male. The forewings in the female it's dorsal or upper surface contain some black spots and the hind wing with the same color but pale. The fully grown larvae reach 40 to 45mm in length. Its color is gray with darker spots. On the entire body segment distribute fleshy processes (growths) each of which bears a cluster of long hairs with different color (between white, black and orange).

Damage: The larvae feed on young leaves and buds, and also destroy the meristem tops because of the making of large quantities of silk thread. The damage increase in the last instars especially for the fourth and last instar; where the larvae eat large areas from the leaves and buds.

14 Plant Protection Dept. 3rd Stage Students Practical Forest Insects Mr. Hazim S. Ahmed and Mrs. Dlpak B. Yaba (2) European tent caterpillar, Malacosoma neustria Order: Lepidoptera Family: Lasiocampidae Description: Adult: Adult moths vary greatly in color. There are two common morphs, one light and one dark, with less frequent intermediates. The basic color is brown, but can range from ochre-yellow to red brown. Males have a wingspan of 30 to 40mm, with the more robust females having a wingspan of 36 to 40mm. Forewings have a brownish, narrow- edged, oblique, central transverse band. The fringes of the forewings are irregularly variegated and checkered. Male and female antennae are Bipectinate, with females having shorter antennal branches and shorter antennae.

Egg: Eggs are white or gray-brown. Larva: 1st instar larvae are black and approximately 2mm long. Mature larvae are 40 to 55mm long, slender and are covered with numerous fine secondary setae. Larvae are marked with a distinct white dorsal line and blue or gray-blue, and red-yellow lateral bands separated by black edging.

Damage: Newly emerged larvae immediately crawl to the crown. Larvae feed gregariously and gather at major branch forks to construct tents. Although larvae feed within these tents, they also feed throughout the entire crown. Larvae can completely defoliate trees during outbreaks. Defoliation can cause growth loss and can predispose host trees to mortality by other organisms. Trees may be killed after a few years of severe defoliation.

15 Plant Protection Dept. 3rd Stage Students Practical Forest Insects Mr. Hazim S. Ahmed and Mrs. Dlpak B. Yaba 4- Leaf miner insects: Leaf miners are insects which their larvae spend part of their life between the two surfaces of plant leaf. The effect differs according to the plant families (hosts). It may cause wilting or complete dryness.

Blotch miner, Phyllonorycter blancardella Order: Lepidoptera Family: Totricidae Description: Adult: small, wingspan 8 to 9 mm. Silvery grey head; fore wings narrow and golden brown, with large white or yellowish stripes, heavily fringed. Hind wings very narrow with wide fringes. Egg: lenticular. Larva: 7 to 8 mm long, yellow to brownish at the edge of the body, pale brown spots on the 7th and 8th segments.

Damage: Damage caused by this consists entirely of leaf mining. Each completed mine reduces the leaf’s green tissue by about 5 percent. Sap-feeding mines are visible as light areas on the bottom of the leaf. The completed tissue-feeding mine buckles the leaf like a small tent and has white spots on the upper surface, hence the name spotted tentiform leaf miner.

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