Phylloxera notabilis

Pergande, 1904

Pecan Leaf Phylloxera

Phylloxera notabilis is a gall-forming insect in the Phylloxeridae, closely related to aphids. It is a significant pest of pecan trees (Carya illinoinensis), forming characteristic galls on leaf tissue. The has -associated on both pecan and water hickory (Carya aquatica), with documented differences in bacterial diversity between these populations. Unlike the more destructive pecan phylloxera (Phylloxera devastatrix), which attacks shoots and nuts, P. notabilis primarily damages leaves and may cause defoliation in heavy .

Phylloxera notabilis by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Phylloxera notabilis: /fɪˈlɒksərə noʊˈtæbɪlɪs/

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Identification

Distinguished from the pecan phylloxera (Phylloxera devastatrix) by its restriction to leaf galls rather than shoot and nut galls. Galls range from 1/10 to 1 inch in diameter and form exclusively on leaf tissue. Winged emerge when galls crack open. The is closely related to aphids but forms enclosed galls during development. Molecular studies indicate bacterial differences between on pecan versus water hickory .

Images

Habitat

Associated with pecan orchards and natural stands of pecan and water hickory trees. move slowly between trees as have limited capability.

Distribution

Native to North America; occurs in pecan-growing regions of the United States, particularly Texas and surrounding states where pecan (Carya illinoinensis) and water hickory (Carya aquatica) are present.

Seasonality

Overwinters as in bark crevices. Nymphs emerge during spring bud break and initiate gall formation. Multiple may occur if new growth remains available, with second and sometimes third generations producing additional galls. Winged emerge from cracked galls in late spring to summer.

Diet

Feeds on phloem sap of pecan and water hickory leaves; nymphs develop inside protective galls formed through plant tissue manipulation.

Host Associations

Carya illinoinensis - primary pecan
Carya aquatica - primary water hickory

Life Cycle

overwinter in bark crevices. Fundatrix nymphs hatch during bud break, feed on new leaf growth, and secrete substances that stimulate gall formation. Nymphs complete development enclosed within galls. Galls crack open to release winged . Some females deposit eggs producing additional ; others overwinter.

Behavior

Gall-forming; nymphs feed within plant-induced galls that provide protection and nutrition. have limited ability, causing to spread slowly between trees.

Ecological Role

Herbivore; gall formation reduces photosynthetic leaf area. Heavy may cause defoliation and reduce tree vitality. Serves as for associated bacterial that differ between host plant .

Human Relevance

Economic pest of commercial pecan production. Management involves monitoring orchards in May, marking infested trees, and applying after bud break when growth is 1-2 inches long but before nymphs become protected inside galls. Native and improved pecan varieties vary in susceptibility.

Similar Taxa

Phylloxera devastatrixAlso attacks pecans but forms galls on shoots and nuts rather than leaves; considered more economically damaging
Phylloxera caryaecaulisHickory phylloxeran that forms galls on hickory leaves, petioles, and twigs; similar gall and

More Details

Bacterial associates

on pecan and water hickory distinct bacterial as revealed by 16S rRNA gene sequencing, suggesting host-associated divergence in symbiotic .

Taxonomic note

Some authorities classify this in the Daktulosphaira rather than Phylloxera.