Invasive Whitefly (Hemiptera: Aleyrodidae) Complex and Diversity in Coconut Landscapes in Tamil Nadu

Abstract

Coconut, Cocos nucifera L., in Tamil Nadu, India, was invaded by four whitefly (Hemiptera: Aleyrodidae) species between 2016 and 2019, increasing the total to six, along with Aleurodicus dispersus Russell and Aleurocanthus arecae David and Manjunatha. We examined the complexity and diversity of whiteflies in coconut across different agroclimatic zones of Tamil Nadu and found high and low damage levels by whiteflies at Veppankulam (70.4%) and Rameswaram (11.0%), respectively. The rugose spiraling whitefly, Aleurodicus rugioperculatus Martin, was the most dominant species but was effectively managed by the parasitoids Encarsia guadeloupae Viggiani and E. dispersa Polaszek, with the highest rate parasitism of 83.8% at Aliyar Nagar and the lowest (2.9%) in the Kanchipuram district. Aleurodicus rugioperculatus and Bondar’s nesting whitefly, Paraleyrodes bondari Peracchi, have spread throughout Tamil Nadu. The population of A. rugioperculaus was high at Veppankulam and that of P. bondari was higher at Dharmapuri (28.6 and 31.1 adults/leaflet, respectively). All five invasive whitefly species in coconut were found only in 7 of 34 locations—Coimbatore, Sirumugai, Salem, Dharmapuri, Krishnagiri, Vellore, and Erode. Paraleyrodes minei Iaccarino and Aleurotrachelus atratus Hempel were distributed in the northwestern zone adjoining the western ghats of Tamil Nadu. Coconut plantations at Sirumugai (western ghats) supported the most diverse collection of whiteflies, with 0.61 and 1.09 Simpson and Shannon diversity indices. Among the 29 districts, adjoining Dindigul and Theni districts showed the highest Bray–Curtis Similarity Matrix. Butterfly palm, Dypsis lutescens H. Wendel, custard apple, Annona squamosa L., and guava, Psidium guajava L., are whitefly hosts in coconut landscapes.