Plotina muelleri was collected near Shillong Peak in the Khasi Hills, while Plotina octomaculata was found within Nokrek National Park in Garo Hills.
Guwahati, Oct 21: Discovery of two rare ladybird beetles – recorded never before in India – have once again placed Meghalaya on the world biodiversity map, according to a major international taxonomic review published in the latest issue of Zootaxa.
The study documents Plotina muelleri and Plotina octomaculata from Khasi and Garo Hills, marking the first-ever record of the genus Plotina in the country.
It was authored by Dr J Poorani of the ICAR–National Research Centre for Banana, along with Jaroslav Větrovec from the Czech Republic and Karol Szawaryn of the Polish Academy of Sciences.
The review provides the most comprehensive account yet of the tribe Plotinini, a small but evolutionarily distinct group of ladybird beetles found only in Asia. Until now, only six species across three genera were known from India.
The new review expands the count to nine species in four genera, adding two Plotina species from Meghalaya and a newly described Buprestodera reclusa from the Western Ghats.
The Meghalaya records are especially significant, revealing how the state’s montane forests continue to harbour little-known insect species. Plotina muelleri was collected near Shillong Peak in the Khasi Hills, while Plotina octomaculata was found within Nokrek National Park in the Garo Hills—both regions recognized as part of the Indo-Burma biodiversity hotspot.
Plotina muelleri is a delicately patterned beetle, measuring between 3.08 and 3.78 millimetres in length. It has an elongate oval shape and a glossy reddish-brown body with two prominent white-yellowish spots—one near the front and another below the middle—each flanked by four smaller black spots forming an ‘L’-shaped pattern.
The pronotum is yellowish brown with black basal markings and creamy white-yellow corners, while the underside is yellowish with distinct postcoxal lines. Originally described from China in 1955 and later recorded in Vietnam, its discovery in Meghalaya fills a major geographical gap in the known distribution of the genus.
Smaller and even more striking, Plotina octomaculata measures about 2.42 millimetres long. Its dark reddish-brown elytra bear eight pale yellowish spots with large, connected black halos arranged in two rows—two near the anterior edge and two near the posterior, giving a symmetrical 4-4 pattern across both wing covers.
The smooth, glabrous body and vivid coloration resemble the more familiar members of the Coccinellini tribe, but Plotina species are far rarer and less studied. The specimen was collected from Nokrek National Park, a UNESCO Biosphere Reserve known for its subtropical forests and exceptional insect fauna.
The study emphasizes that despite India’s long entomological history, much of the Northeast—especially Meghalaya—remains poorly explored for beetle diversity. The newly documented Plotina species underline the region’s role as a natural bridge between the Indian and Southeast Asian biogeographic zones, carrying signatures of evolutionary exchange.
With these discoveries, Meghalaya joins the Western Ghats as a critical hub for rare ladybird beetles, reaffirming its importance in India’s biodiversity landscape. Each new finding, the study notes, adds a small but vital piece to the puzzle of Asia’s rich evolutionary history—where even the tiniest beetles carry stories that span continents.
