|Ceutorhynchus rapae |
This species is cosmopolitan and occurs wherever its host plants exist (Anderson 1997).
One generation per year. Adults emerge from hibernation in April or May (Blatchley & Leng 1916). Newly emerged adults appear in June (Blatchley & Leng 1916) and have been collected into July.
According to Blatchley & Leng (1916), adults are oblong-oval, and black overall with white scales. The dorsal surface is covered in small narrow scales, while the ventral surface is covered with larger wider scales. The funicle (antennal segments between the scape and the clubbed) is seven segmented with the first and second segments being longer than the third and forth together. The beak is slender, cylindrical and about the length of head and thorax combined. The hind femora are toothed. Length 2.7 – 3.2 mm.
The adults overwinter and emerge in the spring to lay eggs in the stems of their host plants (Blatchley & Leng 1916). The eggs hatch in five to eight days (Blatchley & Leng 1916). The larvae feed within the stems and roots of their host plants (Anderson 1997). The larvae pupate in tiny earthen cocoons just below the soil surface (Blatchley & Leng 1916). The time of development between egg and adult is six to seven weeks (Blatchley & Leng 1916).
This species is cosmopolitan in distribution (Anderson 1997) and in no need of conservation.
This weevil has been found on several members of the mustard family (Brassicaceae) as well as Cannabis sativa L. (Colonnelli 2004). They seem to prefer wild mustards to cultivated forms (Blatchley & Leng 1916).
This species is native to the old world but was introduced to New England in the 1850s (Blatchley & Leng 1916). It has since become widespread in the new world and achieved a Holarctic distribution (Anderson 1997; Colonnelli 2004).
|species page author||Blake, A. J.||2007 |