Timing Control Efforts to Limit Seed Set of Common Mullein (Verbascum thapsus)

Control options for the nonnative common mullein are of increasing interest to land managers in the west. Common mullein is a prolific seed producer, with a single plant able to produce well over 100,000 seeds. We found that mechanical control of common mullein before mature seed capsules developed along the raceme significantly reduced viable seed production. Seeds from immature capsules had very low viability (early reproductive stage = 0.08%, 95% CI = 0.06%, 0.67%; mid reproductive stage = 1.52%, 95% CI = 0.49%, 3.11%). This information allows managers to time their management efforts so that they can reduce the amount of plant material that must be disposed of in order to control the spread of common mullein seeds.

Taxonomic and nomenclatural notes on the Rhinusa tetra (Fabricius) species complex (Coleoptera: Curculionidae)

All taxa closely related to or synonymized with Rhinusa tetra (Fabricius, 1792) are studied, including the available type mate-rial. Four species are considered taxonomically valid: Rhinusa tetra, R. comosa (Rosenschoeld, 1838), R. moroderi (Reitter,1906), R. verbasci (Rosenschoeld, 1838). The following four new synonymies are proposed: R. tetra (= Gymnetron eoumRosenschoeld, 1838 syn. n.; = Cleopus uncinatus Dufour, 1843 syn. n.; = Cleopus verbasci Dufour, 1843 syn. n.); R. moroderi(= Gymnetron otini Hustache, 1946 syn. n). Neotypes are designated for Cionus amictus Germar, 1821, Cleopus uncinatus andCleopus verbasci. Lectotypes are designated for Curculio teter, Gymnetron comosum, Gymnetron crassirostre Lucas, 1849,Gymnetron eoum, Gymnetron fuscescens Rosenschoeld, 1838, Gymnetron haemorrhoum Rosenhauer, 1847, Gymnetron moro-deri, Gymnetron plagiellum Gyllenhal, 1838, Gymnetron trigonale Gyllenhal, 1838 and Gymnetron verbasci, all currentlyincluded in Rhinusa. A key separating the four valid species is supported by diagnoses, biological notes, distributional data andillustrations. These new findings are important because R. tetra in the broad sense was proposed as a potential candidate for the biological control of invasive Common Mullein (Verbascum thapsus L.) in North America.