Leaffooted pine seed bug, Leptoglossus corculus (Say) (12, 14, 15, 16, 17, 37, 46) (continued)

DAMAGE IDENTIFICATION. - Seed bugs feed upon developing seed by inserting their mouthparts between conelet scales or by puncturing cone scales, leaving only a microscopic vestige of their visit. Aborted conelets (or cones) lacking any obvious signs of injury, low yields of seed, high numbers of empty seed, poor seed viability, or mold in germination tests - all these conditions may be the result of feeding by the leaffooted pine seed bug.

Damage to nearly mature seed can often be identified under magnification. Partial digestion of the seedcoat by the insect saliva produces a fleck on the seed and sometimes the minute hole penetrating the seedcoat can be detected. Seeds damaged late in the growing season can often be identified on radiographs of mature seeds. This technique is valuable for comparing seed bug damage among clones or among treatments in insecticide tests, but it usually provides very conservative estimates of the total impact of the leaffooted pine seed bug on seed production.

Leaffooted pine seed bug damage (left) to developing seed in immature cone. Undamaged seed on right (3X)

Slash pine seed with two seed bug feeding holes in seed coat. (10X)

Shortleaf pine conelet (right) aborted by leaffooted pine seed bug feeding on immature seed. (3X)

Effects of seed bug feeding vary with the stage of seed development: seed damaged early in the summer are flattened (left); in midsummer damaged seed often have a partially digested seedcoat (center); and seed damaged in the late summer are full size but have internal damage (right). (3X)

IMPORTANCE. - The leaffooted pine seed bug is of major importance throughout the Eastern United States. All species of pines grown in seed orchards in the South are hosts. Since this seed bug is active throughout the growing season, producing multiple generations each year, relatively few seed bugs per tree cause extensive losses by aborting conelets and destroying immature seeds. The leaffooted pine seed bug is not readily observed in orchards until cone harvest, but by then losses may have already occurred at earlier stages of seed development. In seed orchards it is not unusual to double the yields of filled seed per cone by protecting conelets and cones with screenwire cages or insecticides. In some orchards, increases in yields of filled seed per cone as high as tenfold have occurred.