The highly invasive Siam Weed, Chromolaena odorata (L.) King and Robinson (Asteraceae), as a seasonal prime nectar source for butterflies (Lepidoptera: Papilionoidea) and other insects (Insecta: Lepidoptera, Hymenoptera, Coleoptera) in West Africa

Abstract

During mass-blooming in the dry season, the highly invasive Siam Weed, Chromolaena odorata, appears to be a prime nectar source for butterflies and a range of diurnal moths and other insects in West Africa. About 10 % of the West African butterfly fauna were recorded visiting C. odorata flowers between Sierra Leone and Western Cameroon as a result of opportunistic observations between 2010 and 2021. Predators on flower-visiting insects, such as crab-spiders and Flower Mantises, also seem to have become adapted to the newly available food-source. These records indicate that beyond the well-known adverse effects of C. odorata invasion to regeneration of natural vegetation on disturbed ground and the exposure of natural rainforest habitats to wildfires because of the plant’s susceptibility to fire, the diet shift of a considerable proportion of pollinators could imply further threats to biodiversity, such as reducing the reproductive rate of forest plants pollinated by butterflies. Specific studies further targeting the subject are urgently needed.

A preliminary butterfly checklist (Lepidoptera: Papilionoidea) for Cyamudongo tropical forest fragment, Rwanda

“…With increasing human population demands, models predict an increase of tropical forest fragmentation with time (Taubert et al, 2018) which negatively impacts resident biodiversity including the butterfly population. For example, large body size butterflies were found to be more vulnerable to extinction due to forest fragmentation (Shahabuddin & Ponte 2005), and predictive models have shown limitations in expansion range for some butterfly species within fragmented forests (Wilson et al, 2009). Some of the remaining Afrotropical forest fragments are under protection due to their cultural value or conservation significance (Bossart et al, 2006).…”

“…Butterflies as a biodiversity component of forest ecosystems play an important role in plant pollination (Winfree et al, 2011;Barrios et al, 2016;Majewska et al, 2018;Sáfián, 2021) and have been largely used as bioindicators of environmental change and forest restoration and management (Kremen, 1992;Maleque et al, 2009;Nyafwono et al, 2014;Oloya et al, 2021). While some butterfly surveys have been conducted in protected areas within countries neighbouring Rwanda (e.g.…”