RESUMEN
The present study unveils the intricate details on the morphology of thrips through optical, field emission scanning electron microscopy (FE-SEM) and mitochondrial cytochrome oxidase I gene-based molecular identification tools. The variation in the morphological characters namely, antennae (seven-segmented with forked sensorium on third, fourth segments), ctenidia (paired ctenidia were present in 5th-8th abdominal segments laterally), pronotum (two pairs of posteroangular setae) were observed in both Thrips tabaci and Thrips parvispinus, respectively. Similarly, ocelli color (brown and red colored), ocellar setae (two and three pairs of ocellar setae on the head of T. tabaci and T. parvispinus, respectively. Irregular reticulate striations on metascutum and medial striations are present in the metanotum of T. parvispinus; forewings with 6 distal setae in the first vein and 15 distal setae in the second vein in T. tabaci and forewings of T. parvispinus with complete rows of setae in the first and second vein in T. parvispinus; abdomen with median dorsal setae present in the tergite of T. tabaci and presence of 6-12 discal setae in sternites III-VI segments, absence of discal setae on sternites II and VII in T. parvispinus were observed, respectively. Further, FE-SEM studies revealed that similar type of sensilla namely, sensilla basiconica (SBI, SBII, SBIII), sensilla chaetica (SChI, SChII), sensilla trichodea (ST), sensilla campaniformia (SCa), and sensilla cavity (SCav) were recorded in both the species and variations were observed in length of above sensilla of T. tabaci and T. parvispinus. Additionally, Bohm bristles (Bb) and microtrichia (Mt) on the antennal surface contributed to a comprehensive understanding of their ultrastructural features. The molecular characterization revealed a single ~450 bp nucleotide fragment with over 98% similarity for the confirmation of T. tabaci and T. parvispinus in concurrence with NCBI data. RESEARCH HIGHLIGHTS: Microscopy-based morphological and ultrastructural characterization of Thrips tabaci Lindeman and Thrips parvispinus Karny.
RESUMEN
Global food security is a critical challenge to fulfill the demands of an exponentially growing population. To date, growers rely on chemicals; the broad-spectrum application of synthetic molecules leads to environmental contamination, resistance development, residual toxicity, pest resurgence, and a detrimental effect on human health and cattle. Crop production needs to be improved considering environmental and human health concerns to ensure food security. Furthermore, economically important crops are prone to attack by insect pests, causing considerable yield losses. Microbes are an eco-friendly, versatile alternative, and a potential candidate for combatting destructive pests below the economic injury level and improving the plant's health and productivity. Several microbial pathogens, including parasites, predators, parasitoids, pollinators, and many beneficial microorganisms, possess toxic properties against target organisms but do not cause harm to the non-target organisms. Entomopathogens (ENMs) have great potential for pest suppression due to their remarkable properties. Bacteria are host-specific, but fungi have a broader host range and can be significantly affected by both soil-dwelling and terrestrial insect pests. Virulent pathogens cause mortality in target insect pests known as ENMs and can penetrate through natural openings, ingestions, and integuments to cause a possible effect on target insect pests. The objective of using ENMs is to sustain productivity, improve environmental health, reduce pesticides, and conserve natural resources. Moreover, research is ongoing to discover other possible aspects, especially exploring potential ENMs. Therefore, there is a need for identification, isolation, and bioformulation to overcome the existing issues. This study is mainly focused on the status of bio-formulations, pathogenicity, their mode of action, and the potential application of different types of microbial formulations for sustainable pest management.
