Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2007
Publication Date: 7/12/2008
Citation: Gultekin, L., Cristofaro, M., Borovec, R., Smith, L. 2008. Broad-nosed weevils feeding on Centaurea solstitialis L. in Turkey, with a description of the new species Araxia cristofario sp. n. (Coleoptera: Curculionidae: Entiminae). Annals of the Entomological Society of America. 101(1):7-12.
Interpretive Summary: Yellow starthistle is an alien weed that has invaded about 20 million acres in the western U.S. It is especially abundant in Pacific western states. The spiny plant interferes with grazing livestock and outdoors recreation, it is fatally poisonous to horses, and it outcompetes desirable vegetation. Six species of insects have been introduced as biological control agents, but they are not providing sufficient control. Foreign exploration in Eastern Turkey has uncovered four species of beetles that were unknown to attack this plant. One of these species is new to science. These discoveries increase the possibility of finding safe, effective biological control agents for yellow starthistle. Successful development of a biological control program would permanently reduce populations of this weed, which will reduce herbicide use, increase value of rangeland and recreational wildlands.
Technical Abstract: During exploration for new biological control agents of yellow starthistle (Centaurea solstitialis, Asteraceae) in eastern Turkey, we observed four species of broad-nosed weevils (Curculionidae) that are newly associated with this plant. They are Epiphanops persicus, Eusomomorphus oligops, Altonomus modestus and a new species: Araxia cristofaroi. Adults of E. persicus feed on young spines of yellow starthistle flower heads, A. modestus, and A. cristofaroi feed on leaves of yellow starthistle rosettes. Large numbers of E. oligops adults were observed feeding on leaves of both yellow starthistle and Russian knapweed. We redescribed the genus Araxia and transferred it from tribe Brachyderini to the tribe Sciaphilini. Female genitalia of this genus were studied and described for the first time. We described the new species, Araxia cristofaroi, made a taxonomic key with morphological illustrations to distinguish the two known Araxia species. Host plants of these species are reported for the first time.