Hvornår var cikader sidst ude?
Periodical cicadas
De 17-årige cikader er fordelt over de østlige, øvre midtvestlige og Great Plains-stater i USA, mens de 13-årige cikader forekommer i de sydlige stater og Mississippi Valley-staterne, men nogle af dem kan overlappe en smule. F.eks. overlapper yngleflokkene IV (17-årig cyklus) og XIX (13-årig cyklus) hinanden i det vestlige Missouri og det østlige Oklahoma. Deres fremkomster skulle igen falde sammen i 2219, 2440, 2661 osv., som de gjorde i 1998 (selv om fordelingen ændrer sig lidt fra generation til generation, og ældre fordelingskort kan være upålidelige). Der er i øjeblikket en indsats i gang for at generere nye udbredelseskort over alle periodiske cikadeudbrud. Denne indsats gør brug af crowdsourced registreringer og registreringer indsamlet af entomologer.
Periodical cicadas
The 17-year periodical cicadas are distributed across the eastern, upper midwestern, and Great Plains states within the U.S., while the 13-year cicadas occur in the southern and Mississippi Valley states, but some may overlap slightly. For example, Broods IV (17-year cycle) and XIX (13-year cycle) overlap in western Missouri and eastern Oklahoma. Their emergences should again coincide in 2219, 2440, 2661, etc., as they did in 1998 (although distributions change slightly from generation to generation and older distribution maps can be unreliable.). An effort is currently underway to generate new distribution maps of all periodical cicada broods. This effort makes use of crowdsourced records and records collected by entomologists.
Periodical cicadas