Md. Amanullah, BAU

Coconuts are a key economic crop in Bangladesh, historically found in abundance across rural areas, with cottage industries relying heavily on their availability. However, recent years have seen a sharp decline in coconut yields, with pests and diseases emerging as significant threats. Among these is the Rugose Spiraling Whitefly (Aleurodicus rugioperculatus), an invasive species first identified in the country in 2019 by entomologists at the Bangladesh Agricultural Research Institute (BARI).

Now, researchers from Bangladesh Agricultural University (BAU) have identified a new species of whitefly attacking coconut trees. The species, named Paraleyrodes bondari, commonly referred to as the “Bondar Nesting Whitefly,” was detected during field surveys in the Jessore, Khulna, and Bagerhat districts. Following laboratory analysis, the researchers confirmed the presence of this new pest species.

The study is led by Dr. Gopal Das, a professor in BAU's Department of Entomology, with support from postgraduate researcher Md. Sohel Rana. The research, funded by the Krishi Gobeshona Foundation (KGF), is part of an ongoing project examining the bio-ecology of whiteflies, molecular studies, and the effectiveness of new-generation pesticides against these pests.

Whiteflies wreak havoc by sucking sap from the underside of coconut leaves, causing the leaves to turn white and reducing photosynthesis. They also excrete a sticky, sugary substance called “honeydew,” which facilitates the growth of black sooty mold. This mold covers leaf surfaces, further disrupting photosynthesis and eventually leading to smaller coconuts with less water inside.

Dr. Gopal Das stated, “Our team has identified 61 host plants for whiteflies across Bangladesh, with the findings published in an American journal in 2023. We are currently focusing on identifying species, studying their bio-ecology, and testing eco-friendly pest control methods.”

The Paraleyrodes bondari is significantly smaller than the Rugose Spiraling Whitefly, measuring only 1.1 to 1.2 millimeters in length. Unlike its counterpart, which lays eggs in a spiral pattern, this species constructs waxy, cotton-like nests resembling bird nests, within which it lays eggs. The eggs feature a unique petiole-like structure, not seen in other whitefly species. Additionally, its pupae lack tail-like projections, and further molecular studies are underway to better understand its characteristics.

This new species has so far only been detected in the Jessore, Khulna, and Bagerhat districts, and not in other agro-ecological zones surveyed.

Dr. Das warned that the Paraleyrodes bondari could become a significant threat to Bangladesh’s coconut industry. The species was first detected in Kerala, India, in 2018 and later in West Bengal in 2021. By early 2024, it was also reported in Sri Lanka.