Plains Cupid (Luthrodes pandava): A New Record of An Invasive Species

Attribution: Nidal Issa

Husein Ali Zorkot

On October 3, 2019, a small population of plains cupid (Luthrodes pandava) butterflies was identified through field observation in northern Lebanon, in the university town of Deddeh near Tripoli. Nidal Issa and his wife Dalia said they first saw these butterflies back in September when they came to Lebanon for vacation. They said they kept seeing these butterflies every day circling around some lemon thyme (Thymus citriodorus) planted in their garden, which consists of numerous tropical species, including sago palms or cycads (Cycas revoluta), lantanas (Lantana camara), pomegranates (Punica granatum), mangos (Mangifera indica), and a number of conifers.

At first, we thought these butterflies were small cupids (Chilades parrhasius). Knowing these butterflies live off acacia trees (Acacia spp.), I looked around for them in the garden and the nearby residences, but there weren’t any in sight. However, careful observation soon determined these small butterflies were the related plains cupid (L. pandava), a species known to be invasive in recent years. This species, which lives off sago palms (Cycas spp.), has spread from its original range in India and southeast Asia to other parts of the world, such as Egypt, the Persian Gulf, Madagascar, and far off places like Guam. This is the first time it’s been recorded here in Lebanon. The plains cupid, like other blue butterflies, is one of a number of myrmecophilic species that depend on ants to raise them while still larvae, a sort of symbiotic relationship where the butterfly larva provides the ants honeydew in return for protection. This butterfly is considered a serious invasive pest on indigenous cycads, many of which are threatened and endangered. Also, in places where the butterfly is native, it has become deleterious to native cycads due to the introduction of non-native horticultural species. Sago (C. revoluta) has been shown to be highly susceptible to this type of damage. The butterfly lays its eggs in the soft tissue of the leaf buds and new leaves, which are then eaten by the larvae. The plains cupid might also potentially effect a number of other host plants such as acacia and legumes.

The plains cupid is related to the native resident species, the small desert blue (Chilades galba) and the jewel blue (C. trochylus). We so far do not know the effects this non-native species will have on the native ones. However, since these species all live in the same types of habitats and fill the same niches, the effects will probably be damaging.

Year 2019 has already been a phenomenal year with respect to Lebanese butterflies, millions of painted ladies migrated through the country in early spring enroute to Europe from Africa, probably due to increased rain in tropical parts of their cosmopolitan range. Global warming and climate change will probably also have drastic effects on the diversity of local butterfly species, with the incidence of more desert and tropical species while native butterflies will be more likely to emigrate or become increasingly isolated on mountaintops. So you might ask what the moral of the story is. Well, we cannot emphasise more on the importance of butterfly gardening, a sustainable, organic type of wildlife gardening where native species are grown as host and nectar-source plants. These native plants will encourage local butterflies and limit the spread of invasive species.