Observations on iNaturalist reveal the establishment of non-native Eucalyptus weevil Gonipterus platensis (Coleoptera: Curculionidae) in Tamil Nadu, India

Abstract

We report the establishment of the invasive eucalyptus weevil Gonipterus platensis in the high elevation Nilgiri Plateau in the state of Tamil Nadu, India. Its presence was first brought to light by observations uploaded on iNaturalist, a citizen science platform, from Eucalyptus globulus plantations. Specimens collected from the plantations were examined morphologically and dissected to reveal the diagnostic characters of G. platensis. DNA sequences of the cytochrome c oxidase gene (COI) amplified from Indian specimens were 0.3% different from G. platensis sequences from Tasmanian populations and over 4% different from any other Gonipterus species for which DNA data are available. Sequence data from 6 invasive populations of G. platensis indicates multiple, independent invasions from a Tasmanian source population to different parts of the world. The collection of specimens, including larvae, over multiple years indicates that the population in the Nilgiris is persistent, with the earliest evidence for its presence in the region being March 2019. We recommend further monitoring and assessment of population growth and spread of Gonipterus platensis to minimize the economic impact of this potentially important pest of Eucalyptus in India. Citizen science played a critical role in this discovery, and we recommend that subject experts engage with nature enthusiasts on platforms like iNaturalist so that the wide reach of public participation is harnessed to effectively monitor biodiversity.

Introduction

Several species in the genus Eucalyptus have been introduced around the world as forestry trees. Originating in Australia, these trees make up an important component of the Australian flora and, consequently, a wide range of insect species have evolved close host relationships with these plants (Froggatt 1923, Ohmart and Edwards 1991). A number of these species have been introduced into plantation forests throughout the globe, where they have become significant pests (Paine et al. 2011). One of the most important groups of these pests are weevils in the genus Gonipterus (Coleoptera: Curculionidae) (Wingfield et al. 2008).

Gonipterus is a large genus of weevils that live exclusively on Eucalyptus trees throughout Australia. A total of 21 species have been described in the genus (Pullen et al. 2014), however, most of these were described over one century ago and there is no modern taxonomic revision of the genus. Various names have been applied to the Gonipterus found outside Australia (Barratt et al. 2018), however, for much of the 20th Century, the invasive populations in South Africa, South America, New Zealand, and elsewhere were known as Gonipterus scutellatus Gyllenhal. Recent research employing DNA sequence data has shown that this was a misidentification and that the true G. scutellatus is presently known only from Tasmania (Mapondera et al. 2012). The majority of the introduced populations were found to be G. platensis (Marelli, 1926), which has a native range restricted to Tasmania (Gonçalves et al. 2019) but has been widely introduced into New Zealand, Ecuador, the United States of America (California), Hawaii, Chile, Argentina, Brazil, Colombia, Spain, Portugal, and the Canary Islands (Mapondera et al. 2012, Barratt et al. 2018, Mascaró et al. 2023). However, populations of Gonipterus in South and East Africa, St Helena, and Italy were shown to be an undescribed species, presently known as Gonipterus sp. n. 2 (Mapondera et al. 2012). This species has a wide distribution in southeastern Australia but has low genetic diversity in its introduced range in Kenya, Rwanda, South Africa and Zimbabwe (Wondafrash et al. 2020). A third species, G. pulverulentus Lea, 1898, has been introduced into southern Brazil, Uruguay and northern Argentina (Mapondera et al. 2012, Barratt et al. 2018).

Although Eucalyptus was introduced into India in 1790, regular plantations were established at the Nilgiri Hills of Madras Presidency (now in Tamil Nadu state) only by 1843 and later during 1856 (Bennett 2014). It is only since the 1960s, however, that Eucalyptus species have been grown in large-scale plantations covering over 1 million ha across the country, including Andhra Pradesh, Bihar, Haryana, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Punjab, Uttar Pradesh, West Bengal, and Tamil Nadu states (Palanna 1996, Mathew 2014) and have become a resource of considerable economic value, estimated at over 480 billion rupees ($5 billion USD) (Dhiman et al. 2023). Today, Eucalyptus grandis is the most widely grown species, but significant plantations of E. globulus, E. citriodora, E. tereticornis, E. camaldulensis, and eucalyptus hybrids also exist (Palanna 1996). Several insects have been previously recorded on Eucalyptus in India, with the gall-forming eulophid wasp Leptocybe invasa and subterranean termites being the pests of greatest importance to Indian Eucalyptus forestry to date (Mathew 2014). The threat posed by Gonipterus weevils to the industry was recognized, but until now these weevils had not been detected in India.

Materials and Methods

Initial Discovery

The presence of a eucalyptus weevil in India (Fig. 1) was first uncovered when AV uploaded an observation of an unidentified weevil found near Ooty (Udhagamandalam), the Nilgiris, Tamil Nadu (Viswanathan 2022a) on iNaturalist (Mesaglio 2024), a citizen science platform. AV had identified it as Gonipterus sp. based on a suggestion provided by the built-in iNaturalist computer vision model. SDJB soon noticed this observation, and commented on the observation explaining its significance and the need for closer examination of physical specimens. AV soon found larvae as well (Fig. 2) and documented them on iNaturalist (Viswanathan 2022b). This conversation between AV and SDJB, made possible by iNaturalist because it allows members of the larger community to identify and comment on observations, was the start of the larger collaboration that shaped this manuscript. Some specimens were brought back by AV immediately after the initial discovery, but this was soon followed by a larger search for specimens in the landscape that produced the remaining samples used here.

Insect Collection and Curation

All specimens were collected by hand from Eucalyptus globulus plantations in the Nilgiris, Tamil Nadu and preserved in 95% ethanol until DNA extraction (Table 1). Genitalia were dissected by removal of the abdomen followed by clearing with 10% potassium hydroxide. The endophallus was everted without inflation by inserting a 31G syringe needle into the basal opening of the penis and slowly pushing forward toward the anterior opening while the penis was firmly held using forceps (Van Dam 2014). This procedure was carried out while the penis together with its endophallus was submerged in a mixture of 2 ml distilled water and 5 ml K-Y gel (Reckitt Benckiser, Slough, United Kingdom). Photographs were taken using a Canon 7D camera with a 65 mm macro lens while the details of the endophallus were photographed by placing the Canon 200D-II camera onto the trinocular port of a compound microscope and stacking multiple images. Voucher specimens have been deposited in the collections of University of Agricultural Sciences, Bengaluru (UASB), Karnataka, India (Table 1).

Molecular Analysis

DNA was extracted from the thorax of a single specimen. The 3' region of the cytochrome c oxidase 1 (COI) gene was amplified using the primers C1-J-2183 (Jerry) (5'- CAA CAT TTA TTT TGA TTT TTT GG-3') and TL2-N-3014 (Pat) (5'- TCC AAT GCA CTA ATC TGC CAT ATT A-3'). In a thermal cycler (ABI-Applied Biosystems, Veriti, USA), the polymerase chain reaction (PCR) was performed using the following protocol: 2 min of initial denaturation at 95 °C, 40 cycles of denaturation at 94 °C for 30 s, 60 s of annealing at 46 °C, 60 s of extension at 72 °C, and 5 min of final extension at 72 °C. About 0.2 µM of each primer, 10× LA PCR Buffer ll (Mg²⁺free), 1.5 mM MgCl₂, 0.25 mM of each dNTP, 50 ng of DNA template, and 0.25U of LA Taq DNA Polymerase (Takara Bio Inc., USA) were employed for 25 μl reaction volume. The amplified products were resolved on a 1.2% agarose gel. The amplicon was ligated to the pTZ57R/T cloning vector (Thermo Scientific, USA) after being eluted using a Nucleo-Spin Gel and PCR clean-up kit (Macherey-Nagel, Germany). The ligated products were cloned into chemically competent Escherichia coli strain DH5α cells. Afterward, the transformants were selected in an LB plate containing ampicillin (100 mg/ml) using blue/white selection. Using a plasmid isolation kit (Thermo Scientific, USA), plasmids were isolated and then verified by differential mobility testing on a 1.2% agarose gel. The cloned plasmids underwent sanger sequencing in Molsys Private Limited, Bengaluru, Karnataka, India. This region was amplified to make use of the extensive library of Gonipterus sequences available on GenBank from specimens of multiple species collected in Australia and throughout the invasive range of the genus (Mapondera et al. 2012). The 5' region of COI corresponding to the DNA “barcode” region (Hebert et al. 2003) was also amplified from a single specimen using the primers LCO1490 (5'-GGT CAA CAA ATC ATA AAG ATA TTG G-3') and HCO (5'-TAA ACT TCA GGG TGA CCA AAA AAT CA-3') (Folmer et al. 1994).

Trace files from the sequencing runs were viewed using CutePeaks (Schutz et al. 2021) and a consensus sequence was made by reverse complementing the reverse sequence and evaluating relative peak strengths between the 2 trace files for bases where the 2 reads conflicted. Previously published reference sequences (Mapondera et al. 2012, Gunter et al. 2016, Garcia et al. 2019, Schröder et al. 2021, Stüben et al. 2021, Nanini et al. 2022, Crespo-Pérez et al. 2023) were downloaded from GenBank (Sayers et al. 2020) and aligned using SeaView (Guoy et al. 2010). From this alignment, a distance matrix was calculated using uncorrected p-distances and a tree inferred using a neighbor-joining method. Support for nodes in the trees were evaluated using a bootstrapping approach with 100 resamples of the original DNA sequence data matrix. A haplotype network was inferred for the 52 sequences available for G. platensis by calculating the number of substitutions between unique haplotypes, and then inferring a randomized minimum spanning tree that linked the haplotypes into a network (Paradis 2018). These analyses were conducted in R Studio (Version 4.2), using functions provided by the ape (Paradis et al. 2004), pegas (Paradis 2010), and spider (Brown et al. 2012) packages.

Results

Morphological Examination

From the initial photographs and later the physical examination of specimens (Table 1), the darkened humeral area of the elytra and lateral margins of the pronotum (Fig. 1) indicated that G. platensis was a strong possibility. Moreover, the specimens lacked white scales on the lateral areas of the elytra, a feature typically seen in G. pulverulentus, and lacked white scales around the scutellum and medial area of the pronotum, a feature typically seen in G. sp. n. 2. These are the 2 other Gonipterus species that have been found outside of Australia.

Our examination of dissected specimens showed that the hemisternites VIII (Fig. 3G, s8) of the Indian Gonipterus were separated into two, with each part rounded near the apex, distinctly sinuate on the inner side, acutely pointed mesad distally, and the basal half of inner margins on each side were moderately fringed with light brown setae. The spiculum gastrale (Fig. 3G, sg) thickness varied between individuals based on age. However, it was always distinctly elongated and conspicuously curved pre-apically, widest near the middle and weakly narrowed at both ends. The penis in dorsal view was 3 times longer than wide, slightly narrowed in the middle and broadest in the apical 1/4, with its apex having a medial squarish truncated projection (Fig. 2F); the apical margin of this projection slightly deflected backwards. The penis in lateral view was largest at the base and gradually narrowed toward the apex with its apex directed slightly below the plane of the long axis of the penis (Fig. 2E). The endophallus (Fig. 3) was armed with 2 types of sclerites: the base when everted was adorned with crescent-shaped sclerites, while the apex had a complex unit of sclerites. The crescent-shaped sclerites (Figs. 2F cs, 3D) were paired, broad, thickest near the outer margin and thin, explanate on the inner side. The apical sclerites formed a unit made up of a basal piece and apical rods (Fig. 3B, 3C). The basal piece was oval in ventral view, with its lateral margins folded inwards forming a hollow concavity (Fig. 3C bp). The distal portion was narrowly split into a pair of asymmetrical concave teeth, with the right one wider than left tooth, and each encased in an obtusely pointed tubular membranous envelope (Fig. 4C pt). The proximal end of the basal piece was laterally provided on each side with a narrow, weakly sinuate, elongate needle-like accessory sclerite, encased inside an acutely pointed membranous envelope (Fig. 3B, 3C acs). The entire basal piece was encased in a densely setose, oval, membranous pouch that was continuous and thicker dorsally with a hemispherical thin membranous opening ventrally (Fig. 3B, 3C mp). Apical rods (Fig. 3B, 3C) were 3 in number, 2 lateral and one medial. Each apical rod was asymmetrical and longitudinally concave while the medial apical rod (observed in all dissected specimens) was widest, obtusely pointed, and not encased in any membranous envelope but attached to the inner side of the dorsal membrane of the endophallus when intact and everted. The lateral rods were acutely pointed and individually encased in an obtusely pointed membranous tubular envelope, and the left apical rod had 3 slightly widened, obtuse teeth near the base in dorsal view (Fig. 4B rt). The membrane of the endophallus was ornamented on the ventral surface with oval to elongate-oval, flat spicules, and on the dorsal surface near the basal piece of apical sclerites with densely distributed setae-like spicules.

Multiple Gonipterus larvae have been found on E. globulus in the different locations of Ooty, Tamil Nadu, India. These feed externally on Eucalyptus leaves and are colored yellow-green with circular shining brown setal bases and distinctive dark-green lateral stripes originating on abdominal segment 1 and terminating on abdominal segment 9 (Fig. 2). A much less prominent dorsal line is also present. The head is dark-brown and is deeply retracted into the pronotum.

DNA Sequence Data

The 3' COI sequence obtained was 762 bp in length. The trace files for this fragment had high-quality base calls (quality score (QS) of 43.7) and no ambiguity codes were required. When analyzed with the sequences of 16 Gonipterus species, the Indian specimen was found to be 0.3% different from sequences of G. platensis from Tasmania, Australia (Fig. 5). All sequences of G. platensis were clustered in a single clade, supported with a high bootstrap value of 96%. Gonipterus pulverulentus was resolved as being the sister taxon to G. platensis, with moderate support (70% bootstrap value). The Indian sequence was 4.5% different from the closest G. pulverulentus sequence. The other 14 Gonipterus species were all over 6% different from the Indian specimen.

The 5' COI sequence obtained was 647 bp in length. The quality of the base calls in the trace files were relatively low (QS of 20.4) and high background noise occasionally necessitated the coding of nucleotides in the consensus sequence using IUPAC ambiguity codes. The resulting sequence was 0.9% different from sequences of G. platensis from Ecuador and the Canary Islands, with no differences between these reference sequences. No other sequences from other Gonipterus species were available for this gene region.

A haplotype network of 104 G. platensis sequences from the 3' COI region (Table 2) shows that the original population in Tasmania has the greatest diversity, with 8 of the 14 haplotypes sampled found there (Fig. 6). The most common haplotype in Tasmania was haplotype VI, represented by 19 sequences. This haplotype was also the dominant haplotype in Brazil (22 sequences) and the only haplotype found in Ecuador (9 sequences). The only other haplotype shared between populations was haplotype I, found in Tasmania, Western Australia, and Brazil where it was the third-most common haplotype (9 sequences). Haplotype V was the second-most numerous haplotype in Tasmania, with 14 sequences, but was not found in any other population. Three haplotypes were found only in Brazil (XII, XIII, and XIV), the first being the second-most numerous haplotype there, with the other two represented by a single sequence each. The single sequences from India, Spain, and Portugal were all unique haplotypes (XI, IV, and III, respectively) that did not cluster with each other. The sequences from Spain and Portugal were also found to be dissimilar to each other, and from any of the other haplotypes represented in the dataset. A total of 18 substitutions separated haplotypes III and IV, and the nearest haplotypes to these were haplotypes X and I, respectively, by 9 and 8 substitutions, respectively (Fig. 6).

Geographic Extent

A search of literature showed no evidence that Gonipterus had been previously detected in India. To our knowledge, specimens have thus far only been found in the high elevation Nilgiris plateau in the Nilgiris District (Table 1, Fig. 7). Additional observations posted to iNaturalist show that Gonipterus was present in the Nilgiris in March 2019 (Karthik 2019). This is the earliest record of Gonipterus in India that we know of.

Discussion

Species Identification

We identified all physical specimens of Gonipterus as G. platensis (Marelli 1926), through a combination of morphological and molecular analyses, corroborating initial suspicions about the identity of this species on iNaturalist.

Genitalic Morphology

The structure of the male genitalia from Indian specimens closely corresponded with illustrations of Gonipterus platensis provided by Rosado-Neto and Marques (1996) (described as G. scutellatus), Mapondera et al. (2012), Gamarra et al. (2022), and Mascaró et al. (2023) with slight variations. An examination of genitalia was key here, particularly the structure of the endophallic sclerites, which is stable and useful for resolving species boundaries in taxonomically complex insect groups such as Gonipterus. We must caution, however, that the illustrations provided in some previous studies (Rosado-Neto and Marques 1996, Mascaró et al. 2023) are apparently incomplete and may confound identification. The apical sclerites illustrated by these authors depict only 2 apical rods while the medial apical rod is missing. Because the medial apical rod is attached to the dorsal wall of endophallus internally, this sclerite was likely lost while clearing the membrane surrounding the apical sclerites. In general, the examination of endophallic sclerites without eversion can be misleading as the associated structures are often complex, and can be folded up or be overlapped upon themselves in the membrane when retracted inside the penis. Moreover, the entirety of the structures cannot be properly viewed through the dorsal lobes of the penis without eversion or inflation.

Of the other invasive Gonipterus weevils, G. pulverulentus and G. sp. n. 2 both have longer apical sclerites that extend toward the ostium and occupy a substantial portion of the penis when the endophallus is retracted (Rosado-Neto and Marques 1996, Mapondera et al. 2012). The only other Gonipterus species photographed by Mapondera et al. (2012) with short apical sclerites is G. scutellatus. This species differs from G. platensis by having a shorter, more rounded basal piece of the apical sclerite and lacks the long, thin accessory sclerites and apical rods.

Larval Morphology

Only a few Gonipterus species have had their larvae described. The Indian larvae match the description of Gonipterus platensis larvae from New Zealand (May 1993). The larvae of G. pulverulentus (described as G. gibberus) lack the distinctive dark-green lateral stripes that are present in G. platensis larvae (Rosado-Neto and Marques 1996)

DNA-based Identification

Our identification as G. platensis based on morphology was further supported by genetic evidence through sequencing of the COI gene. We found high correspondence to reference sequences of G. platensis produced by Mapondera et al. (2012) and Garcia et al. (2019), and low correspondence with 15 other species of Gonipterus sampled by those authors.

Invasion History of G. platensis in India and Globally

We present evidence that G. platensis has become established in Eucalyptus globulus in the upper Nilgiris, Tamil Nadu, India, with the earliest evidence for its establishment being in March 2019. We do not have evidence of association with any other Eucalyptus species. So far, there is also no evidence that the weevil has spread into plantations of E. globulus outside the Nilgiris despite the widespread presence of E. globulus, its preferred host, in the peninsula (Bennett 2010). Surprisingly, no Gonipterus species had been reported in India despite several efforts to document its pests due to the economic significance of Eucalyptus. One reason G. platensis may have been missed in India’s entomological history is because it may be absent in the extensive plantations of other Eucalyptus species in the peninsula and perhaps even absent in plantations of E. globulus outside the Nilgiris. In a summary of the history of Eucalyptus plantations in India and elsewhere in the world, Bennett (2010) traces the origins of E. globulus in the Nilgiris to the mid-1800s when it was planted aggressively in the landscape. Bennett (2010) also mentions that E. globulus was successful in the Nilgiris, but attempts to introduce it elsewhere in the country were largely unsuccessful, particularly in the Himalaya and northern parts of India. Subsequent waves of Eucalyptus introductions in the mid-1900s in India were largely constituted of other Eucalyptus species such as E. tereticornis, E. camaldulensis, and eucalyptus hybrids. Given that the E. globulus introduction in the Nilgiris is now rather old, we might infer that G. platensis associated with E. globulus may have also been in this landscape for a long time. Another possibility is that G. platensis is a recent exotic entrant into India. Given that the discovery of this weevil population was rather fortuitous, other populations of the weevil may remain undiscovered.

The unique COI haplotype we found in India that has not yet been found elsewhere suggests that the Indian population of G. platensis is an independent introduction from a Tasmanian source population and is not related to other invasive populations of G. platensis elsewhere. Moreover, we infer that there have been multiple, independent introductions of Gonipterus platensis out of Tasmania to the various regions where it is now found. At least 4 independent introductions can be inferred from these data, with G. platensis populations in India, Spain, Portugal, and Brazil each having COI haplotypes that are not shared with other introduced populations. However, our dataset is limited, with only 6 introduced populations of G. platensis represented and several of these (Portugal, Spain and India) being represented only by single sequences. Sampling of additional specimens from these populations may reveal greater genetic diversity, potentially with haplotypes shared with other introduced populations. Further research, including specimens from other parts of the adventive range of G. platensis, including New Zealand, the Canary Islands, Hawaii, California, Chile, and Argentina, will be necessary to confirm and extend these findings.

Notes on the Potential Impact and Management of G. platensis on Eucalyptus in India

In the Nilgiris, or elsewhere in India, there have not yet been reports of large-scale mortality of E. globulus due to symptoms resembling weevil herbivory, despite E. globulus being known to be highly susceptible to herbivory by G. platensis (Gonçalves et al. 2019). Observations in Spain suggest that E. grandis can also be heavily attacked, though to a lesser extent than E. globulus (Cordero Rivera and Santolamazza Carbone 2000); while experiments in Brazil indicate that E. grandis is a poor host for G. platensis (Oliveira et al. 2022). Similarly, E. citriodora (also called Corymbia citriodora) is moderately browsed by G. platensis in Spain (Cordero Rivera and Santolamazza Carbone 2000). Eucalyptus tereticornis was heavily browsed by G. sp. n. 2 in a South African study (Newete et al. 2011 as “G. scutellatus”, Mapondera et al. 2012), but there is no evidence that E. tereticornis is palatable to G. platensis. Another species widely grown in the northern regions of India, Eucalyptus camaldulensis, is a suboptimal host for G. platensis (Oliveira et al. 2022). If G. platensis is indeed geographically restricted to the Nilgiris and E. globulus remains its primary host, with other Eucalyptus species less favored, its potential as a pest of significance in India may be low. However, we recommend that initiatives are implemented to monitor the population growth and spread of G. platensis populations in India. Monitoring of G. platensis in Spain has utilized remote sensing of Eucalyptus defoliation from satellite data combined with digital terrain modeling to coordinate ground surveys to measure the incidence of G. platensis adults, larvae, and parasitoid wasps (Taboada et al. 2004, Ayuga-Téllez et al. 2022). Strategies like these may be an effective way of monitoring large Eucalyptus plantations.

Research into the response of G. platensis to various volatile organic compounds from E. globulus identified 3 attractive compounds: camphene, (+)-α-pinene, and 2-phenylethanol; and 2 repellent chemicals: phenylethyl and globulol (Branco et al. 2019). Related research into potential pheromones found that virgin females and virgin males were both attracted to the male-produced chemical cis‐verbenol (Branco et al. 2020). Although these results suggest promising avenues for further research into lure-and-kill or push–pull management systems (Cook et al. 2007, El-Sayed et al. 2009), initial attempts at implementing these techniques in the field have not been successful and no viable semiochemical-based management tools for controlling G. platensis in Eucalyptus plantations have yet been used at scale.

Although some insecticides such as flufenoxuron, azadirachtin, λ-cyhalothrin, and certain strains of the entomopathogenic fungus Beauveria bassiana are effective against G. platensis (Santolamazza-Carbone and Fernández de Ana Magán 2004, Echeverri-Molina and Santolamazza-Carbone 2010), the primary means by which G. platensis is controlled in forestry situations is by biological control. The egg parasitoid wasp Anaphes nitens (Girault) (Hymenoptera: Mymaridae) has been introduced into various countries (Reis et al. 2012, Valente et al. 2018). Although previously conducted biological control studies have suffered from misunderstandings about the identity and origin of the Gonipterus species involved (Barratt et al. 2018), we trust that our demonstration of the Indian species being G. platensis will allow any biological control program in India to begin from a secure taxonomic foundation of the identity of the pest species involved. This will allow past research to be critically evaluated as to its relevance and will allow future experiments to be designed with greater certainty.

The Role of Citizen Science

Our study demonstrates once again that citizen science is an excellent tool to monitor (Lourenço et al. 2024, Potgieter et al. 2024) and discover (Larson et al. 2020) invasive populations. Going forward, we may expect several such discoveries with the phenomenal growth in public biodiversity monitoring that we are witnessing in India (Namdeo and Koley 2023, Sekhsaria and Thayyil 2023) and around the world today. Such contributions are especially significant in the context of invasive species, which can spread rapidly and cause extensive ecological and economic damage if not detected early and correctly identified. This case is a good example of how public participation can enhance surveillance of invasive species and help preserve native ecosystems.

This study also highlights how collaborative efforts between scientists and the public can contribute to important taxonomic and ecological research and biodiversity monitoring. An important factor in this collaborative process is the engagement of subject experts (like SDJB) on citizen science platforms like iNaturalist. Such expert engagement encourages the community and facilitates learning, therefore enabling better monitoring of cryptic taxa. On iNaturalist in India, many taxa like frogs, reptiles, spiders, and several economically important insect groups do not have subject experts actively involved in identification, greatly slowing down the learning process for the community. This limits the platform’s potential to serve as a tool to discover and monitor populations, as well as resolve species distribution ranges. We strongly urge subject experts in India to engage with such platforms and help this community-driven movement reach its potential.

Acknowledgments

SRH thanks Karunya Institute of Technology and Sciences, Coimbatore for providing the facilities for carrying out the part of the research work. AV thanks the iNaturalist community for providing a platform to better understand lesser-known taxa. HMY thanks Head, Department of Entomology, UASB for the support and facilities.

Author contributions

Yeshwanth H M (Conceptualization [equal], Data curation [equal], Formal analysis [equal], Investigation [equal], Methodology [equal], Resources [equal], Supervision [equal], Writing—original draft [equal]), Ashwin Viswanathan (Data curation [equal], Formal analysis [equal], Methodology [equal], Software [equal], Supervision [equal], Validation [equal], Writing—review & editing [equal]), Sankararaman. H Sankararaman (Investigation [equal], Methodology [equal], Software [equal], Writing—original draft [equal]), Samuel Brown (Conceptualization [equal], Resources [equal], Software [equal], Supervision [equal], Validation [equal], Visualization [equal], Writing—review & editing [equal]), Ashok Karuppannasamy (Investigation [equal], Methodology [equal], Software [equal], Validation [equal]), and Sangamesh Hiremath (Data curation [equal], Formal analysis [equal], Investigation [equal], Methodology [equal], Software [equal], Validation [equal])

Funding

None declared.

Conflicts of interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Compliance with ethical standards

The authors declare that they have complied with ethical standards.

Data Availability

The data that support the findings of this study are available from the corresponding author upon request.

References