Submitted to: Journal of Plant Interactions
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/22/2008
Publication Date: 10/1/2008
Citation: Pecinar, I., Stevanovic, B., Rector, B.G., Petanovic, R. 2008. Morphological injury to cut-leaf teasel, Dipsacus laciniatus L. (Dipsacaceae) induced by the eriophyid mite Leipothrix dipsacivagus Petanovic et Rector (Acari: Eriophyoidea). Journal of Plant Interactions. 4:1-6 Interpretive Summary: At least two species of teasels (Dipsacus spp.) are invasive weeds in the U.S. Teasels are native to Eurasia and have also become invasive in other parts of North and South America. A biological control program was initiated by USDA-ARS to seek and study insects and other natural enemies of teasels as potential agents of their control. This study describes the damaging effects to cut-leaf teasel caused by one such potential agent, the eriophyid mite Leipothrix dipsacivagus, which was discovered and described by an ARS scientist in collaboration with a foreign cooperator. This study documented severe damage to cutleaf teasel plants caused by L. dipsacivagus under field conditions as well as under controlled infestation conditions in the laboratory. Based on these findings, the mite is worthy of further consideration as a potential teasel biological control agent.
Technical Abstract: The eriophyid mite Leipothrix dipsacivagus Petanovic et Rector provokes severe malformations to its host plant, cut-leaf teasel (Dipsacus laciniatus L.), in the field. These injuries were examined at the morpho-anatomical level in infested plants collected in the field and experimentally infested plants under controlled laboratory conditions. A number of symptoms were observed including reduced growth, internode shortening, leaf rolling and wrinkling, and shrunken inflorescences. After severe attack, the leaves of bolted plants became chlorotic with necrotic spots and started to wilt. Young rosettes died. Morphometric analysis revealed significant differences between infested and healthy field-collected bolting plants. Infested plants were significantly shorter than healthy plants, with smaller leaves and flower heads. Striking injuries were also observed on young leaves of experimentally infested plants. It is expected that further investigations will elucidate the full extent of the damage to aboveground parts of D. laciniatus due to infestation by L. dipsacivagus.