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    Natural history of the curry leaf tortoise beetle Silana farinosa (Boheman, 1856) (Coleoptera, Chrysomelidae, Cassidinae, Cassidini) in Kerala
    (Department of Entomology, College of Agriculture , Vellayani, 2024-04-06) Sneha, M Sabu.; Prathapan, K D
    The study entitled “Natural history of the curry leaf tortoise beetle Silana farinosa (Boheman, 1856) (Coleoptera, Chrysomelidae, Cassidinae, Cassidini) in Kerala” was carried out at the College of Agriculture, Vellayani during 2022-2023. The main objectives were to study the external morphology, genitalia, immature stages, life history, seasonality and natural enemies of the curry leaf tortoise beetle Silana farinosa. The curry leaf tortoise beetle, S. farinosa is a major defoliating pest of Bergera koenigii (L.) (= Murraya koenigii (L.) Spreng.) (Sapindales, Rutaceae). Originally described from Sri Lanka, Premila et al. (2003) reported its occurrence in India from Kerala. External morphology of all life stages of the pest were studied, illustrated and detailed descriptions were prepared using light microscopy as well as scanning electron microscopy. A laboratory culture was established and the life history, behaviour, nature and intensity of damage, seasonality and natural enemies were studied. Adults are 6.39–7.85 mm long and can be separated from other Cassidini by the second antennomere subequal to third; pronotum with explanate margin separated from disc by a deep, longitudinal groove on either side; pronotum basally with a shallow transverse depression in front of scutellum; pronotum and elytra with short setae, especially towards lateral sides; and the dorsum of adult in life is covered with white, powdery, waxy coating. Other salient characters of the species include aedeagus in ventral view with broadly truncate apex; spermatheca is long, hookshaped; fully everted endophallus has several lobes and a long sclerite apically. Genitalia in S. farinosa has been studied and illustrated for the first time. Sexual dimorphism in S. farinosa was observed for the first time. The last female ventrite has curved, minute ridges and a window, visible in macerated specimens. Final instar larvae measured 4.26–7.24 mm long and 1.42–2.8 mm wide. Stemmata 6; four in a curved line, equidistant; 5, 6 ventral. Mandible palmate with 6 sharp denticles. Pronotum pigmented, overlapping head, margin with three pairs of scoli, two anterolateral, fused basally, one posterolateral. Mesonotum with three pairs of lateral scoli – one anterolateral, one medio-lateral and one posteriolateral, mediolateral being shortest. Spiracle uniforus, rounded, raised, white on black socket. Pronotum with short, seta bearing, dark, raised randomly distributed pinnacles. Metanotum with two pairs of scoli, anterior pair shorter than posterior. Abdomen 10 segmented, 1 – 8 with a pair of scoli laterally. Segments 9, 10 without scoli. Tergum 8 modified with a pair of long caudal processes, reaching beyond apex of anal tube. First instar 2.24 – 2.69 mm long, 0.76 – 0.78 mm wide. Spiracles 8, elevated, annular biforous. Body with 16 pairs of lateral scoli, and a pair of supraanal processes. All scoli unbranched, tapering towards apex, armed apically with a seta longer than half length of scolus. Pupa 6.66 – 7.03 mm long, 5.35− 6.25 mm wide. Colour creamy white with brown patches. Pronotum widest anteriorly, anterolateral corners slightly produced laterally. Posterolateral corners with a postero-mesally directed, finger-like process. Abdominal tergum VI or VII and beyond covered with exuvia, fecal shield not retained. Eggs are enclosed in ootheca, 3.31 – 3.61 mm long, 4.0 – 4.47 mm wide. Single egg measures 1.08– 1.46 mm long and 0.54 – 0.77 mm wide. Total longevity ranged from 105 – 128 days, with egg period of 6-7 days, larval period of 15–22 days and pupal period of 4–7 days. Five larval instars with duration as follows: I 2 to 3, II 3 to 4; III 3 to 4; IV 3 to 4 and V 4 to 7 days. The lifecycle was completed in about 32 – 41 days (mean 35.6 days). The adults lived for 80-92 days under laboratory conditions. Cycloalexy, a characteristic subsocial defensive behaviour, performed by the larvae of cassidinae, was observed. Mating lasted for about 2–3 hours and mostly occured at night. Female laid about 24 oothecae within a month. Feeding behaviour of all larval instars and adult were recorded. The white powdery coating on the dorsum of adult was fully formed within 6 – 8 days of emergence. Formation of fecal shield and moulting were recorded. Adults exhibited thanatosis, a defensive tactic by feigning death, for about one minute, when they were kept upside down. The population of S. farinosa was directly dependent on the rain. The highest population was observed from 3 July to 2 September 2023. The population declined from 14 March and disappeared by 14 April 2023 and reappeared in May following premonsoon showers. Of the 50 plants observed, 22 (44%) were infested. On the infested plants, 6.7 – 93.8 % of branches were affected (mean 36 %). Proportion of damaged leaves varied from 6.6 – 82.7% (mean 40.5%). The natural enemies of S. farinosa such as predators, Oecophylla smaragdina on larvae, unidentified ants on eggs, a pupal parasitoid Brachymeria apicicornis and native isolates of fungal pathogens Fusarium longifundum and Cordyceps javanica, were reported for the first time. The red ant Oecophylla smaragdina collected and fed on the white powder on the dorsum of the adult. The chemical composition of both white powder and fecal shield was analysed. The white powder contained tetratetracontane and the fecal shield has decanoic acid, both the compounds having anti-microbial property as per literature. Males of Bactrocera cucurbitae and Bactrocera caudatus were found attracted to fecal shield. The male fruit flies are usually attracted to kairomones and feed on them to attain sexual maturity. Hence, we suspect that some attractant chemicals are present in the fecal shield. Hong and Nishida (2005) reported that various species of Bactrocera were attracted to the flowers of Bulbophyllum apertum due to the release of raspberry ketone by the plant. The fecal shield also contains a ketone compound and the possibility of it being an attractant needs to be further explored.
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    Diversity of coccinellid beetles (Coleoptera: Coccinellidae) of northern Kerala
    (Department of agricultural entomology, college of agriculture ,  Padannakkad, 2023) Gokul Goutham;  Vidya, C V
    Coccinellid beetles, commonly known as ladybirds or lady beetles, belong to the family Coccinellidae of order Coleoptera, are species rich and play a significant and multifaceted role in agriculture. Coccinellids are ecologically and morphologically diverse and exhibit a wide range of food habits spanning kingdoms and trophic levels. Most of the coccinellids are predaceous on various agricultural pests, whereas a few are phytophagous, and some are mycophagous. The research work on “Diversity of coccinellid beetles (Coleoptera: Coccinellidae) of northern Kerala” was undertaken in the Department of Agricultural Entomology, College of Agriculture, Padannakkad during 2021-2023 for the documentation of the species composition and estimation of diversity indices of coccinellid beetles in different agro-ecological zones of northern Kerala and to generate DNA barcodes and carry out molecular analysis of coccinellids associated with different cropping systems. Purposive surveys were conducted across four different agro-ecological zones, viz., coastal plain, midland laterites, foothill, and high hill, covering Kasaragod, Kannur, Kozhikode, and Wayanad districts. Different cropping systems, viz., rice, vegetables, fruits, and plantation crops were covered during the survey. A total of 27 species of coccinellids belonging to six tribes were recorded. Among these, three were phytophagous viz., Afidenta misera, Henosepilachna septima, and H. vigintioctopunctata and two were mycophagous viz., Illeis bielawskii and Illeis cincta and rest of 22 species were predacious in nature. Total number of coccinellid species recorded from rice, vegetables, plantation crops and fruits were seven, 18, 11 and eight, respectively. Among different agroecological zones, high hills recorded maximum number of coccinellids (20) followed by coastal plain (19), midland laterites (14) and foothills (10). Diversity indices to assess species richness, diversity, dominance and evenness were estimated. The most abundant coccinellid species was H. vigintioctopunctata, with a relative abundance of 29.86 per cent. The predominant predatory coccinellid was Cheilomenes sexmaculata (11.88%), followed by Coccinella transversalis (11.72%). Among various cropping systems the vegetable cropping system displayed highest species richness, while rice showed lowest richness. High hills showed the highest richness and least rich was foot hills. Species diversity was estimated in terms of Shannon-Wiener index (H) and the most diverse cropping system was plantation crops (1.96) and least diverse was rice (1.15) ecosystem. Among the agroecological zones, high hill (2.47) was the most diverse, and the foothill was the least diverse zone (1.91). Species dominance was studied by using Simpson’s index. The highest value of Simpson’s index was observed in rice (0.46) and lowest value in plantation crops (0.17). Among agroecological zones, coastal plain was least diverse with highest dominance value (0.21) and lowest dominance value was in midland laterites (0.11). Pielou's evenness index (J) estimated how evenly species are distributed in a community. The vegetable cropping system had the lowest species evenness (0.39) while the plantation crops had the highest (0.65). The species were more evenly distributed in midland laterites (0.75), while less evenly in coastal plains (0.42). Total genomic DNA was isolated and mitochondrial Cytochrome Oxidase 1 (CO1) locus was amplified using LCO1490 /HCO2198 primers. DNA sequencing was done by outsourcing. The forward and reverse COI sequences were trimmed using BioEdit Sequence Alignment Editor software and assembled using CAP3 sequence assembler. Molecular analysis of 20 sequences representing 17 species was done using MEGA11 software. Homology analysis of 14 DNA sequences, encompassing 13 distinct species using Nucleotide BLAST of NCBI revealed a substantial similarity of over 98 per cent when compared to sequences present in the NCBI database. Six sequences of four species showed less than 90 per cent similarity to other sequences in the NCBI database. Phylogenetic trees were constructed using MEGA11 software with the Maximum likelyhood method and a bootstrap value of 1000. The analysis incorporated 20 generated sequences in this study and 20 sequences (including Amphix laevigatus as outgroup) retrieved from the NCBI database. The tree formed two major clades, one includes I. cincta and all other species formed the second major clade. Within the second major clade, members of each tribe formed as separate clade except for S. sp. nr. posticalis. Twenty accessions of 17 species were submitted to NCBI and BOLD databases
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    Review of the insect pests of pulsecrops and studies on the biology of the pea leaf roller Nacoleia vulgalis Guence (Pyralidae)
    (Division of Entomology, Agricultural College and Research Institute, Vellayani, 1963) Mammen, K V; Joseph, K V
    Literature on the insect pests of the important pilse crops, with special reference to the work done in India has been reviewed. The biology and bionomics of the pea leaf roller Nacoleia vulgalis Gn. (Pyralidae) have been worked out in detail. The moths mate a day after emergence. The female moth lays creamy yellow, oval, scale like eggs during night in rows, generally on tender leaves . On an average , about 542 eggs are laid by one female. Incubation period is 4 days. Larval period lasts 13 to 15 days, the larva undergoing five instars. Durations of the different instars are 3 to 4 , 2 to 3, 2 to 3, 2 to 3 and 4 to 6 days respectively. The first instar caterpillars nibble and feed on the green matter on the undersurface at the base of the leaves and the later stage caterpillars web the leaves together and feed from inside skeletonising the leaves.
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    Augmentation of pollination in culinary melon (Cucumis melo var. acidulus L. Naudin) with Indian bee (Apis cerana indica Fab.)
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2019) Aneetta, M R; Amritha, V S
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    Potential of the narural bio polymers, chitin and chitosan in pest management
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2017) Archana, N H; Reji Rani, O P