Introduction: Owing to the poor socioeconomic conditions and lack of sanitary hygiene, a large number of population in developing countries remain under constant threat of different parasitic infections causing severe morbidity and mortality. Enough measures to prevent and reduce the disease burden are still to be undertaken.Aim: Aim of the study was to determine the spectrum of parasitic infections in patients with complaints of diarrhoea and other gastrointestinal symptoms attending a tertiary care hospital in Western Rajasthan, India. Results: Out of 968 cases, 158 (16.3%) were found to be infected with either a parasite or a commensal or both. A maximum number of isolates (21.1%) were from the age group of 31-40 years. Overall, protozoans (95.38%) were detected in excess of helminths (4.62%). The most common protozoa isolated was Entamoeba histolytica (37.57%) followed by Giardia lamblia (23.12%), and the most common helminth isolated was Hymenolepis nana (2.9%) followed by Ascaris lumbricoides (1.15%). Out of 17 stool samples, where modified ZN staining was performed, Cryptosporidium spp., Isospora belli, and Cyclospora spp. were detected in one sample each.Conclusion: Intestinal protozoal infections are more prevalent as compared to helminthic infections in this study group.

23Mature plants can detect and respond to herbivore-induced plant volatiles (HIPVs) by priming or 24 directly activating defenses against future herbivores. Whether other plant life stages can respond 25 to HIPVs in similar manners is poorly understood. For example, seeds are known to respond to a 26 variety of environment cues that are essential for proper germination timing and survival. Seeds 27 may also be exposed to HIPVs prior to germination, and such exposure may affect the growth, 28 development, and defense profiles when the seeds grow into mature plants. Here, we investigated 29 the effect of seed exposure to common HIPVs on growth, reproduction and defense 30 characteristics in the model plants Arabidopsis thaliana and Medicago truncatula. Of all the 31 HIPVs tested, indole specifically reduced both beet armyworm growth on A. thaliana and pea 32 aphid fecundity on M. truncatula. Induction of defense genes was not affected by seed exposure 33to indole in either plant species, suggesting that seed priming operates independently of induced 34 resistance. Moreover, neither species showed any negative effect of seed exposure to HIPVs on 35 vegetative and reproductive growth. Rather, M. truncatula plants derived from seeds exposed to 36 z-3-hexanol and z-3-hexenyl acetate grew faster and produced larger leaves compared to 37 controls. Our results indicate that seeds are sensitive to specific HIPVs, which represents a novel 38 ecological mechanism of plant-to-plant communication. 39 40 42 43 44 71 plants against spider mite, caterpillars, aphids, and pathogens (Worrall et al., 2012). Seed 72 treatment with JA also changes the volatile composition of mature plants, making their blends 73 more attractive to predatory mites (Smart et al., 2013). Similarly, seed treatment with salicylic 74 acid (SA) enhances the expression of SA-related genes and the endogenous SA level against root 75 4 holoparasite (Orobanche cumana) (Yang et al., 2016). Additionally, seed coating with plant 76 growth promoting rhizobacteria (PGPR) and plant growth promoting fungus (PGPF) enhances 77 seed germination, seedling establishment, and boosts induced defenses in future plants in 78 ET-, and JA-dependent manners (Ryu et al., 2004; Rudrappa et al., 2010; Sharifi & Ryu, 2016). 79 Seeds also come in contact with biotic agents that are volatile. Inhibitory and allelopathic 80 effects of some plant and microbial derived volatile organic compounds (VOCs) have been . Whereas these VOCs do not 83 necessarily provide contextual information about future environmental conditions, herbivore-84 induced plant volatiles (HIPVs) represent potentially reliable and adaptive indicators of 85 herbivory. The function of HIPVs in priming or directly inducing plant defenses is now well 86 established ( Engelberth et al., 2004; Frost et al., 2007; Rodriguez-Saona & Frost, 2010), and 87 exposure of undamaged plants to HIPVs is known to induce or prime the genes in phytohormone 88 pathways (Bate & Rothstein, 1998; Engelberth et al., 2007; Frost et al.,...

Herbivore-induced plant volatiles (HIPVs) provide direct benefits to plants as antimicrobials and herbivore repellents, but their potential as direct toxins to herbivores is unclear. Here we assayed the larvicidal activity of six common HIPVs from three different biochemical pathways and tested the hypothesis that the larvicidal activity of HIPVs is related to the host specialization of the insect pest. We first assessed β-caryophyllene, linalool, z-3hexenyl acetate, z-3-hexenol, e-2-hexenol, and indole against the beet armyworm (Spodoptera exigua), and found that indole was 7-fold more toxic compared to the other volatiles when incorporated into diet. Then, we tested the larvicidal activity of indole against six common, destructive pest caterpillars with varying host ranges. Consistent with our hypothesis, indole toxicity varied with caterpillar host range: indole toxicity was seven-fold higher in more specialized insect species relative to generalist insect species. That said, the LC 50 of indole was comparable to other reported anti-herbivore agents even against the generalist caterpillars. Yet, indole in headspace had neither larvicidal nor ovicidal activity on any caterpillar species tested.These results support a key ecological precept regarding tradeoffs between host specialization and chemical detoxification, and also indicate that indole functions as a direct defense against herbivores that could be potentially useful in integrated pest management strategies. KeywordsCaterpillars, Green leaf volatiles (GLVs), Herbivore-induced plant volatiles (HIPVs), Host Range, Indole, Pest, Toxicity, Specialist vs Generalist herbivore Key message• We measured the direct toxicity of six common HIPVs against the beet armyworm.• Indole was the most toxic HIPV against the beet armyworm.• We determined the toxicity of indole against six different pest caterpillar species.• Toxicity of indole was associated with the host preference of the insect species.• Indole exposure in headspace had no effect on egg hatching or caterpillar survival.• Indole has the potential to be developed as an insecticide against crop pests.

207 21 Abstract 33Herbivore-induced plant volatiles (HIPVs) provide direct benefits to plants as 34 antimicrobials and herbivore repellents, but their potential as direct toxins to herbivores is 35 unclear. Here we assayed the larvicidal activity of six common HIPVs from three different 36 biochemical pathways and tested the hypothesis that the larvicidal activity of HIPVs is related to 37 the host specialization of the insect pest. We first assessed β-caryophyllene, linalool, z-3-38 hexenyl acetate, z-3-hexenol, e-2-hexenol, and indole against the beet armyworm (Spodoptera 39 exigua), and found that indole was 7-fold more toxic compared to the other volatiles when 40 incorporated into diet. Then, we tested the larvicidal activity of indole against six common, 41 destructive pest caterpillars with varying host ranges. Consistent with our hypothesis, indole 42 toxicity varied with caterpillar host range: indole toxicity was seven-fold higher in more 43 specialized insect species relative to generalist insect species. That said, the LC 50 of indole was 44 comparable to other reported anti-herbivore agents even against the generalist caterpillars. Yet, 45 indole in headspace had neither larvicidal nor ovicidal activity on any caterpillar species tested. 46 These results support a key ecological precept regarding tradeoffs between host specialization 47 49 50 Keywords 51 Caterpillars, Green leaf volatiles (GLVs), Herbivore-induced plant volatiles (HIPVs), Host Range, 52 Indole, Pest, Toxicity, Specialist vs Generalist herbivore 53 54Key message 55 • We measured the direct toxicity of six common HIPVs against the beet armyworm. 56• Indole was the most toxic HIPV against the beet armyworm. 57• We determined the toxicity of indole against six different pest caterpillar species. 58• Toxicity of indole was associated with the host preference of the insect species. 59• Indole exposure in headspace had no effect on egg hatching or caterpillar survival. 60