Insects and Plants

Plant Galls of Alaska

Dominique Collet Galls are plant tissues modified by another organism

Gall-inducing Organisms

• Nematodes • Fungi • Bacteria • Plant • Algae • Acarina (mites) • Insects Galled organisms

Algae Fungi

Lichens Flowering plants Gall Types

Plant tissue growth inhibited : Leaf rolls Rosette galls Willow beaked galls Cottonwood petiole galls

• New plant tissue stimulated • Rose spiny galls • Some stem galls

Common Alaskan Plants Affected by Galls

Achillea sp. Cecidomyiidae Arctostaphyllos uva-ursi Tamalia coweni (Aphididae) Betula Massalongia spp., Oligotrophus spp., (Cecidomyiidae) Calamagrostis canadensis Mayetiola sp. (Cecidomyiidae) Epilobium angustifolium Mompha sp. (Momphidae) Picea glauca: Adelges spp., Pineus spp. (Adelgidae) Populus trichocarpa Pemphigus sp. (Eriosomatidae) Eriophiidae Rosa spp. Diplolepis spp. (Cynipidae) Salix spp. Rabdophaga spp., Iteomyia spp.(Cecidomyiidae) Euura spp., Pontania spp., Phyllocolpa spp. (Tenthredinidae) Eriophiidae Galling arthropods

• Eriophyiid mites (pouch galls) • Sawflies: stem galls (Euura), leaf margin roll (Phyllocolpa), leaf galls (Pontania) • Cecidomyiidae: stem galls, bud galls, petiole galls (Rabdophaga) • Aphids: petiole galls (Adelges, Pemphigus) Plant Organ Galled

• Leaf buds • Stem • Flower buds- fruits- seeds • Roots Tortricidae leaf roll on birch

Phyllocolpa sp. Tamalia coweni leaf leaf margin roll on margin roll on Salix alaxensis Arctostaphyllos uva-ursi Eriophiid mites induced leaf curling on Populus balsamiferous Epilobium angustifolium stem gall induced by Mompha sp.

Mompha sp. caterpillars inside the gall Calamagrostis canadensis and Arctagrostis latifolia inflorescences galled by Mayetiola spp. (Cecidomyiidae) Diplolepis polita and its spiny galls on Rosa acicularis Revision in progress of the taxonomy of Euura, Phyllocolpa and Pontania of Alaska by Dr. Jens Peter Kopelke of the Senckenberg Institute in Frankfurt, Germany.

Euura sp. Pontania spp.- induced galls on willow Rabdophaga rosaria and R. strobiloides galls S. barclayi

Multiple Larva in a single chambers chamber Single empty chamber S. bebbiana S. pulchra S. sitchensis Cross-section showing the location of gall-inducer larva chambers

Rabdophaga specimens inducing rosettes on these willows are included in a comparative DNA study with similar Japanese and European specimens by Dr. Junici Yukawa and Shinsuke Sato at the University of Kyushu, Fukuoka, Japan S. commutata

S. bebbiana S. fuscescens S. barclayi S. babylonica S. richardsonii S. sitchensis

S. glauca S. myrtillifolia S. pulchra

Rabdophaga rigidae galls on Salix S. myrtillifolia S. glauca S. fuscescens

S. alaxensis S. barclayi

S. bebbiana

S. pulchra Galls useful for the winter identification of Alaskan willows

S. sitchensis

S. pulchra S. barclayi

S. glauca S. bebbiana S. arbusculoides