Diagnosis and potential invasion risk of Thrips parvispinus under current and future climate change scenarios

Abstract

Background and Objective Invasive thrips, Thrips parvispinus Karny recently reported in India, causing a widespread severe infestation in more than 0.4 million ha of chilli (Capsicum annum L.) growing areas. This species is native to Thailand and most prevalent in other South East Asian countries. Large scale cultivation of the major host plants (chilli and papaya), and favourable climatic conditions in India and other countries similar to native range of Thrips parvispinus expected to favour its further spread and establishment to new areas. Materials and Methods The present study was undertaken to confirm invasive thrips species identity through both morphological and molecular approaches and predict its potential invasion using the maximum entropy (MaxEnt) algorithm. Results The model predicted species range in respect of discrimination of suitable and unsuitable areas for its occurrence both in current and future climatic scenarios. The model provided a good fit for species distribution with a high value of area under the curve (0.957). The jackknife test indicated annual mean temperature and precipitation were found to be the most important bioclimatic variable in determining the distribution of T. parvispinus. High suitability areas were predicted in the countries wherever its occurrence was reported with high discrimination ability of suitable and unsuitable areas. Key distinguishing morphological characters of T. parvispinus were illustrated through high-resolution scanning electron microscopic images. Conclusion The identity of the thrips causing wide spread damage in chilli confirmed through morphological and molecular approaches. Key identifying characters were described through high resolution scanning electron microscopic images for accurate identification of the species. MaxEnt model identified high suitability regions for the potential establishment of T. parvispinus in India and other parts of the world. This study facilitates forecasting of further spread and also suggests imposing strict domestic quarantine measures to curtail its establishment in the new areas.

First report of invasive thrips, Thrips parvispinus (Karny) infestation on chilli from Eastern part of India

“…Some of the farmers of Mirzapur removed the chilli and sown the wheat crop due to severe leaf curl and there is no profitable yield. Similar, reports of crop loss reported earlier in Telangana, Andra Pradesh and Karntaka (Basavaraj et al, 2022;Hulagappa et al, 2022). Since the thrips is expanding its geographical area and host range in India, monitoring on other host plants and non-reported area must be under taken on priority basis.…”

“…Morphological identification of thrips: The thrips were identified using the characters presented in research papers (Rachana et al, 2021 andTyagi et al, 2022) and certain key characters presented in scanning electron images (Hulagappa et al, 2022). Out of the ten specimens examined, all ten found to be females.…”

“…ports of infestation on Dahlia rosea (Rachana et al, 2018), Brugmansia sp., (Roselin et al, 2021), cotton (Amutha and Rachana, 2022) and on cow pea (Vigna unguiculata) (Nagdev et al, 2022) was followed. Later the severe infestation on chilli (Capsicum annum) was reported from Karnataka (Basavaraj et al, 2022), Telangana and Andhra Pradesh (Hulagappa et al, 2022;Veerannaet al, 2022), Gujarat (Patel et al, 2022) (Fig. 3).…”

Prediction of Oncomelania hupensis distribution in association with climate change using machine learning models

“…Ecological niche models predict which areas meet the ecological requirements of a species by analyzing the geographical distribution of the target species and linking it to environmental factors within the location [ 9 ]. They have been successfully used in predicting species distribution, risk assessment of invasive alien species, conservation of endangered species, and mapping the risk of disease transmission [ 10 – 12 ].…”