Ashok Kumar Chaubey

Aedes mosquitoes are transmitters of arboviruses, such as dengue, yellow fever, chikungunya, and zika virus. Dengue is becoming a global problem with a 5% death rate. This study was conducted to characterise gut bacterial diversity in Aedes albopictus from the National Capital Region (NCR) using a culture-independent methodology. Bar plots and heat maps were prepared for the study of relative abundance after amplification of the 16S rRNA gene (V3 and V4 hypervariable regions) using Illumina sequencing. Proteobacteria and Actinobacteria were the dominant phyla, whereas the Wolbachia, Aeromonas, Limnobacter, and Hydrogenophilus genera showed the highest abundance in our samples. An overlap of 0.28% of reads showing the common gut bacterial genera was noticed across all five sampling sites. Alpha diversity analysis by utilising different metrics, viz., Observed, Chao1, ACE, Shannon, Simpson and Pielou, showed the highest and lowest values from Ghaziabad, Uttar Pradesh and Sonipat, Haryana samples, respectively. Beta-diversity analysis indicated the hierarchical relatedness between mosquitoes collected from Delhi and Meerut, whereas mosquitoes collected from Sonipat were found to be the least related.

Summary: Two populations of slug-associated nematodes were isolated in different habitats, including agricultural fields and mango gardens in the Baghpat district of Western Uttar Pradesh, India. Initial morphological characterisation shows that they resemble the nematodes of the family Panagrolaimidae. Morphological and morphometrical characterisation confirm this and show that both populations belong to the species described initially as Cephalobus ( Neocephalobus ) aberrans (later as Neocephalobus aberrans , currently as Panagrolaimus aberrans , and here reinstated as Neocephalobus aberrans ). Using morphological and molecular data, we found that this species does not belong to the genus Panagrolaimus . Hence, the last taxonomic proposal of transferring it from the genus Neocephalobus to the genus Panagrolaimus should be reversed, and therefore, the genus Neocephalobus is reinstated as a valid genus, and Neocephalobus aberrans a valid species. In addition, we observed that the species described initially as Evaginorhabditis agaricus (currently as Panagrolaimus agaricus ) is morphologically identical to C . ( N .) aberrans , and therefore, should be considered its junior synonym, and the genus Evaginorhabditis a junior synonym of Neocephalobus . In addition, we observed that the species of the Neocephalobus are morphologically very similar to those of the genus Tricephalobus . Accordingly, we propose the genus Tricephalobus as a junior synonym of Neocephalobus . Thereby species included in the genus Tricephalobus are transferred to the genus Neocephalobus as N. aestivus n. comb., N. lignicola n. comb. and N. steineri n. comb.

Termites play an important role in the world ecosystem. Termites mostly feed on dead plant material and cellulose, generally in the form of wood, leaf litter, soil, or animal dung. These are common wood eaters, damaging the wood and wood bases of building materials. Since the supply of wood is limited, it is necessary to protect the wood and wood products from biological deterioration. For controlling termites, different management techniques are available. However, the efficiency of controlling mechanism depends on the distribution, biology, and ecology. Moreover, an integrated termite management is an environmentally safe and economically affordable mechanism of termite management. Various viable options in termite management are termite baits, the use of synthetic pesticides/insecticides/termiticides, chemicals, or botanicals. Furthermore, natural enemies include mammals, birds, insects, Araneae, microbes-bacteria, fungi, and nematodes. Here, we discuss how to utilise many integrated pest management components, so as to save crops and environment.

Agricultural crops are subject to serious, significant, and widespread damage from attacks by a wide variety of harmful destructive pest species. Insect pests are the primary biotic stressors for crops and significantly reduce agricultural production. The herbivorous insects are responsible for the destruction of approximately one-fifth of global crop production each year. For controlling these insect pests, insecticides play a vital role in Integrated Pest Management (IPM), through which insects can be destroyed or the specific developmental stages of insects can be inhibited but with time, these insects develop resistance against synthetic chemical insecticides which is a very common problem in effective control of insect pests. Over the past few decades, interest in the use of nematodes as biological control of insect pests has increased dramatically throughout the globe. Thus, the classification of insect parasitic nematodes and the use of entomopathogenic nematodes as potential biocontrol agent against harmful insect pests are discussed in this chapter.

Summary: A nematode population (SF7) belonging to the genus Laimydorus siddiqi , 1969, was isolated from the soils of sugarcane fields in the Haridwar district of Uttarakhand, India. Based on morphological, morphometrical, and molecular studies, the nematode was identified as Laimydorus siddiqii . This work represents the first molecular report of this species. Laimydorus siddiqui has a 2.6 to 3.08 mm long body, with a truncate lip region, linear odontostyle, double guiding ring, female genital system amphidelphic, longitudinal vulva, and females with a very long, filiform tail. Males have 56 – 63 μm long spicules and 28 – 29 ventromedial supplements. Molecular analyses utilizing segments of the 28S rDNA placed Laimydorus siddiqi in a clade with Laimydorus zehsaziani from Iran and other representatives of the genera Labronema , Dorylaimus , Prodorylaimus , Calcaridorylaimus , Mesodorylaimus , and Aporcelamellus . However, there is no available 18S rRNA sequence of any known species of Laimydorus , and our sequence is the first SSU rRNA of this genus. These molecular findings support the taxonomic positioning of Laimydorus siddiqui within the broader phylogenetic framework of the family Dorylaimidae, highlighting its relationships with closely related genera.

Discolaimus haridwarensis sp. n. is described from agricultural fields of sugarcane in the Haridwar district, India. It is characterized by its 2.11–2.32 mm long body, lip region offset by deep constriction and 27–30 μm wide, odontostyle 20–23 μm long with aperture occupying 50–54% of its length, 436–487 μm long neck, pharyngeal expansion 57–59% of total neck length, uterus a simple tube-like structure 22–31 μm long or 0.3–0.5 times the corresponding body diameter, pars refringens vaginae absent, transverse vulva (V = 48–55), female tail conoid (34–40 µm, c = 53–68, c′ = 1.0–1.3) with rounded terminus, and males absent. The phylogenetic analysis inferred from the D2-D3 expansion segments of 28S rRNA gene and 18S rRNA gene sequences showed that Discolaimus haridwarensis sp. n. clustered with other dorylaimid species from the genus Discolaimus and the subfamily Discolaiminae.

The novel technologies in all areas of agriculture have improved agricultural production, but some modern practices cause environmental pollution and human hazards. The recent challenge faced by advanced farming has been to achieve higher yields. Thus, there is an immediate need to find eco-friendly solutions. Among the various types of species being used as biocontrol agents, fungi of the genus Trichodermaare a very large group of microorganisms widely used as biocontrol agents against different kinds of plant pathogens. Trichoderma spp. are asexual, free-living organisms that are abundantly present in all types of agricultural soils. Recent studies have shown that Trichoderma can not only prevent diseases but also promote plant growth, improve nutrient utilization efficiency, enhance plant resistance, and improve the agrochemical pollution environment. Trichoderma spp. behaves as a low-cost, effective, and eco-friendly biocontrol agent for different crop species. This chapter provides information on Trichoderma as a biocontrol agent, its biocontrol activity, and plant disease management programs.

A species of genus Panagrellus was discovered from a wet season form of an oriental common evening brown butterfly Melanitis leda. In this study, a detailed description of Panagrellus ceylonensis is provided including the morphometry, light microscopy and molecular (18S and 28S rDNA genes) studies. Morphological studies on the species agree with original description and characterized by having 1250–1481µm long body in females and 949–1305µm in males, lateral fields with four longitudinal incisures, lip region continuous and 8–11 µm wide, six offset lips with protruding labial sensilla, neck 124–173 µm long, excretory pore at the level of basal bulb, vulva post-equatorial (V = 68–71), vagina anteriorly orientated with heavily muscled vaginal walls, post-vulval uterine sac 111–135 µm long or 1.7–2.6 times as long as the corresponding body diameter, tail conical elongate with an acute terminus in both sexes, spicule 71–91 µm long, ventrally curved having hooked manubrium and bifurcated lamina tip, lamina ventrally curved with dorsal deflexion at about 60% of spicule length, gubernaculum 26–31 µm long and well developed. Morphologically, the Indian population of P. ceylonensis does not show a significant difference from the type material of P. ceylonensis in the original description. For molecular studies of this species, the sequence of 18S rDNA is obtained for the first time. Phylogenetic trees based on 18S and 28S rDNA sequences are provided in this study. Additionally, bionomics and global distribution of the species of Panagrellus genus are also discussed. In conclusion, our study provides a comprehensive morphological characterisation and molecular marker sequences of 18S, and 28S genes that can be used to support future taxonomical research on this species and emphasizes the importance of combining molecular data with morphological data to describe the species accurately.

Plant parasitic nematodes are major pests of the agricultural industry in developing countries. This group is associated with different parts viz., flower, leaves, buds, roots, trunk etc., of approximately all crucial crops of agronomy due to their omnipresent nature. They are categorized as endo, ecto and semi-endoparasite based on the feeding habits. PPNs possess remarkable characteristics especially, parasitic adaptations which help in combating adverse conditions. Furthermore, they interact with other microorganisms (pathogens) forming complex diseases in crops. For effective management of the PPNs through biological control, it is essential to understand their parasitic mechanism, adaptation of J2 stages, feeding mechanism, host-nematode relationship and identification of associated microbiota. This review focuses on the basic biology of PPN, feeding habits, parasitic potential, molecular insights for understanding host-nematode relationship and their management by exploiting the inherent abilities of biocontrol agents.

Chemical fertilizers and pesticides are presently accumulating in the environment harming the ecosystem, causing pollution, and spreading some of the diseases. Nematodes can be considered as entomopath¬ogenic (EPN) if they fulfil criteria for entomo-pathogenicity when they bearing a pathogenic bacterium within a dauer juveniles juvenile, releasing the bacterium within the host, active host-seeking and penetration by dauer, rap¬id insect death, nematode and bacterial reproduction, reassociation of the pathogenic bacteria with new generations of dauer juveniles; and emergence of IJs from the cadaver so that the cycle can be repeated. Synthetic chemical pesticides have various disadvantages which include crop and soil contamination; killing of beneficial fauna and flora; resistance development in insects and adverse effects due to contamination in food chain and other environment related issues. To minimize pesticides contamination, EPN were identified as biological control agents and most suitable natural enemies of problematic insects because they reduce risk to humans and other related vertebrates