Krishnan Selvaraj

Morphological similarity with related whitefly species and limited access to rapid diagnostics hinder timely detection and management of Aleurotrachelus trachoides (Back). To address this gap, a geographically validated, rapid, and potentially field-deployable colorimetric recombinase polymerase amplification (RPA) was developed for decentralized detection of A. trachoides. Specimens collected from seven agroclimatic zones in India were confirmed through morphological identification and mitochondrial cytochrome oxidase I (mtCOI) sequencing, with phylogenetic analysis confirming A. trachoides as a distinct monophyletic clade. A species-specific 150 bp mtCOI region was identified through in silico and validated by cloning and Sanger sequencing to design species-specific primers for PCR and RPA assays. The RPA assay detected as little as 10 pg/µL, outperforming conventional PCR (1 ng/µL), and generated results within 20 min at 38 °C without a thermal cycler. No cross-reactivity was observed with the nine nontarget whitefly species. Colorimetric detection using SYBR Safe and hydroxynaphthol blue (HNB) dyes enabled direct visual detection. Large-scale geographical validation (160 target and 90 nontarget samples) showed 98.81% sensitivity and 99.26% specificity, and detection from crude DNA extracts via HNB dye confirmed its field applicability. This study presents a species-specific colorimetric RPA assay with potential as a rapid and reliable molecular tool to support early surveillance, quarantine inspection, and sustainable management of A. trachoides in affected agroecosystems.

In recent years, whiteflies (Hemiptera: Aleyrodidae) have emerged as the key pests on many economically important agricultural, horticultural and ornamental plants across the tropics and subtropics...

Classical biological control of exotic invasive weeds first took place in India in 1795. Thus far, a total of 174 natural enemies have been imported into India, and out of these, 77 have established themselves in the field. Twelve exotic insect pests and four weeds were successfully controlled with a combination of classical, augmentative, and conservation biological control. Additionally, eight insect pests and one weed were substantially controlled. Augmentative biological control has been adopted as per the needs and availability of resources. Conservation biological control is ubiquitous and has been facilitated by the adoption of integrated pest management. In the past, biological control activities were sporadic; however, since 1977, the Indian Council of Agricultural Research—National Bureau for Agricultural Insect Resources has been regularly implementing classical biological control of invasive agricultural insect pests of economic importance. Unfortunately, the importance given to invasive weeds and insect pests of natural resources has fallen behind in recent years.

First classical biological control of an exotic invasive weed took place in India in 1795. Thus far, 174 natural enemies have been imported into India and of these, 77 have established in the field. Twelve exotic insect pests and four weeds were successfully controlled with a combination of classical, augmentative, and conservation biological control. Additionally, eight insect pests and one weed were substantially controlled. Augmentative biological control has been adopted as per the needs and availability of resources. Conservation biological control is ubiquitous and it has been facilitated by the adoption of integrated pest management. In the past, biological control activities were sporadic, however, since 1977, Indian Council of Agricultural Research - National Bureau for Agricultural Insect Resources has been implementing classical biological control regularly in India.