Butterflies with Complex Patterning

Peacock

  • Eggs laid on large vigorous plants in middle of nettle bed

  • Larvae build communal webs over growing tips of nettles

  • Some migration from Europe likely but relatively small number

  • Distribution not constrained by larval foodplant; lack of semi-natural habitat impacts on courtship, mating and pre-hibernation feeding

  • Male territories are typically sunny spots in corners of woodland or hedges

    • Vigorously defended.

Small Tortoiseshell

  • Significant decline in numbers:

    • A parasitic fly (Sturmia bella) appeared in late 1990s. This caused a noticeable drop in numbers, but some resurgence has subsequently occurred

    • Reduced abundance where drought conditions occur that force the butterfly to enter hibernation in mid-summer and cancel a second generation typically seen in September

  • Hibernating adults emerge in March / April

    • Hibernate in houses less often than in past – centrally heated homes are too warm

  • Temperature determines number of generations each year

  • Daylength cue determines whether:

    • Larvae develop into adults that breed immediately, or

    • Hibernate and breed in following season

  • Migratory – immigration from Europe frequent

  • Gregarious larvae can raise their body temperature above surroundings

    • Allows more rapid development in cool locations, reducing risk or predation / parasites.

Red Admiral

  • Strongly migrant

    • Earliest adults arrive from north Africa / Mediterranean

  • Nowadays over-winters in southern Britain

    • In all four life-stages

  • Mating historically rarely observed in UK – adults arriving having mated first

  • Larvae feed in neat nettle leaf-tents

  • Depicted in historical texts – but not as a positive omen.

Painted Lady

  • Although migrant, peak autumnal numbers arise from local breeding

  • Life cycle comprises several (six?) generations

    • Maybe 20 000 km migration

    • Use angle of sunlight and Earth’s magnetic field to navigate

  • UK population certainly involves generation in sub-Saharan Africa

    • Chad through to Benin

    • Breeding grounds across central Africa’s savannah and highlands

    • Possibly migrants reach southern Africa

    • Can travel up to 500 km / day

    • At heights of 500 to 1 000 m

  • It is believed some butterflies travel from Africa to South America