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Open Access
Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs
(Department of Agricultural Entomology, College of Agriculture ,Vellayani, 2022) Anitha, N; KAU; Mithra, Mohan
The study on “Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs” was conducted at College of Agriculture, Vellayani during 2017 to 2020 with the objectives to identify mealybugs and their natural enemy fauna in solanaceous and cucurbitaceous vegetables, to carry out the molecular characterization of mealy bugs in solanaceous and cucurbitaceous vegetables and to find out the tritrophic interactions of mealybugs infesting brinjal. An investigation on mealybug diversity in solanaceous and cucurbitaceous crops of Kerala revealed a total of six mealybug species viz., Coccidohystrix insolita, Ferrisia virgata, Paracoccus marginatus, Phenacoccus solenopsis, Planococcus citri and Pseudococcus jackbeardsleyi. Besides, four mealybugs viz., Crisicoccus hirsutus, Maconellicoccus hirsutus, Planococcus lilacinus and Rastrococcus iceryoides infesting other vegetable crops were also recorded from Kerala. The study also revealed that the population of mealybug, C. insolita collected from different regions of Kerala exhibited significant morphological variation. The molecular characterization studies proved that the population belongs to C. insolita and the variations may be environmental induced. An exploration of the host range of mealybugs infesting solanaceous and cucurbitaceous vegetables in Kerala revealed a total of 113 plants under 73 genera belonging to 31 families, out of which 14 plants were recorded as new host reports. A rich natural enemy fauna on mealybugs belongs to five orders viz., Coleoptera, Lepidoptera, Diptera, Neuroptera and Hymenoptera were documented from Kerala. Twenty species of mealybug predators from five different families were recorded, among which the predominant family was Coccinellidae with 16 species under six genera. Among the various predators collected, Cacoxenus sp. was recorded for the first time as a predator of P. jackbeardsleyi. Eleven hymenopteran parasitoids belonging to five families were documented from mealybugs, of which the majority belongs to the family Encyrtidae. Four new host-parasitoid associations were also recorded for the first 288 time. The study also identified six hyperparasitoids under the family Encyrtidae, of which two species were recorded as new report which includes Cheiloneurus sp. and Prochilonerus sp. associated with the mealybug P. solenopsis. The ants associated with mealybugs in different agroecosystems were also investigated and a total of 14 species of ants belonging to nine genera under three subfamilies were recorded, of which the most dominant subfamily was Formicinae followed by Myrmicinae and Dolichoderinae. The present study also revealed 15 new ant-mealybug associations for the first time. The molecular characterization of eight mealybug species was carried out that complemented the morphological identification of species. A total of eight nucleotide sequences were submitted to NCBI GenBank and accession numbers were generated. The sequences were also submitted to BOLD and illustrative barcodes were generated. The barcodes of C. insolita, C. hirsutus and P. jackbeardsleyi were generated for the first time. The diversity of endosymbionts of the mealybug C. insolita was carried out for the first time. The study revealed a total of 15 phyla of endosymbionts on C. insolita, of which Proteobacteria was the predominant one. An experiment was conducted at Instructional Farm, Vellayani to identify the tritrophic interaction in brinjal, C. insolita and its natural enemies. The study revealed that out of the ten brinjal cultivars evaluated, the lowest mean population of mealybugs was observed in Pusa Uttam whereas the hybrid cultivar, Udit recorded the highest number of mealybugs. The lowest mean per cent leaf infestation was recorded in Pusa Purple Long which was statistically on par with Pusa Uttam whereas the hybrid cultivar, Udit was severely damaged by the mealybugs. Among the tested cultivars, Pusa Purple Long was recorded under the group resistant whereas Udit and Haritha were included under the highly susceptible group based on the mean per cent leaf infestation caused by C. insolita. The cultivar Haritha attracted the highest number of predators whereas the maximum mean population of spiders were observed in Pusa Purple Long. 289 The correlation analysis on the mean population of mealy bugs with biophysical parameters revealed that trichome density, length width ratio of leaf and number of branches exhibited a significant positive correlation with mean population of mealybugs. Correlation studies on the mean population of natural enemies with biophysical parameters revealed that plant height exhibited a significant negative correlation whereas leaf thickness and number of branches revealed a non-significant negative correlation with the mean population of natural enemies. Among the biochemical parameters of brinjal cultivars, total phenol content exhibited a significant negative correlation with the mean population of mealybugs whereas total chlorophyll content showed a significant positive correlation. The correlation between biochemical parameters of brinjal cultivars with the mean population of natural enemies revealed that total phenol and carotenoid content exhibited a non-significant negative correlation whereas total protein content, reducing sugar and total chlorophyll content showed a nonsignificant positive correlation. The info-chemical mediated interactions in brinjal cultivars, mealybug and its natural enemies were studied using a multi-armed olfactometer and Y-shaped olfactometer assay. The results revealed that the cultivar Udit attracted the highest number of natural enemy Chrysoperla zastrowii sillemi while the cultivar Pusa Uttam attracted the lowest number. The variation in preference shown by the natural enemies may be related to the difference in volatile compounds emanating from the host cultivar. The GC-MS analysis of the synomonal compounds of the cultivar, Udit revealed a total of eleven compounds whereas the cultivar Pusa Uttam was recorded with a total of five compounds. The Y shaped olfactometer studies revealed that C. zastrowi sillemi adults showed more preference towards the synomonal compounds of mealybug infested plants than that of healthy plant synomonal extracts. On comparing the volatile profile of synomones of mealybug infested and healthy plants revealed that the synomonal extracts of the mealybug infested cultivar Udit comprised of 11 compounds whereas healthy plant synomonal extracts contained nine compounds. 290 The relative response of C. zastrowi sillemi towards the kairomonal compounds of C. insolita was evaluated in a Y tube olfactometer and the results revealed that the highest mean number of adult lacewings were attracted to the kairomonal compounds of mealybug compared to control. The kairomonal extracts of the mealybug comprised of seven compounds and the composition of these hydrocarbons may determine the selectivity of natural enemies towards the preferred host. The present study recorded a total of six mealybug species infesting solanaceous and cucurbitaceous vegetables and its host range, natural enemies and associated ants in different agro ecological regions of Kerala. The molecular characterization studies supported the morphological taxonomy and the sequences were submitted to NCBI Genbank and BOLD. The study also elucidated the interactions mediated by plant traits and info-chemicals in brinjal-mealybugnatural enemy tritrophic systems. The study recorded Pusa Purple Long as resistant cultivar and Udit and Haritha as highly susceptible cultivar to C. insolita. The plant traits viz., trichome density, length width ratio of leaf, number of branches, total phenol content and total chlorophyll content exhibited significant correlation with mean population of mealybugs whereas plant height exhibited significant correlation with mean population of natural enemies. The study on info-chemical mediated tritrophic interactions revealed that the concentration and composition of volatile compounds determine the differential selectivity of natural enemies. The volatile compounds identified in this study can also be used as a cue in moderating the behavior of natural enemies in the ecosystems. So a thorough knowledge on the tritrophic relations in the ecosystem will aid in manipulating these interactions to devise a better pest management strategy.
Open Access
Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2022) Mithra, Mohan; KAU; Anitha, N
The study on “Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs” was conducted at College of Agriculture, Vellayani during 2017 to 2020 with the objectives to identify mealybugs and their natural enemy fauna in solanaceous and cucurbitaceous vegetables, to carry out the molecular characterization of mealy bugs in solanaceous and cucurbitaceous vegetables and to find out the tritrophic interactions of mealybugs infesting brinjal. An investigation on mealybug diversity in solanaceous and cucurbitaceous crops of Kerala revealed a total of six mealybug species viz., Coccidohystrix insolita, Ferrisia virgata, Paracoccus marginatus, Phenacoccus solenopsis, Planococcus citri and Pseudococcus jackbeardsleyi. Besides, four mealybugs viz., Crisicoccus hirsutus, Maconellicoccus hirsutus, Planococcus lilacinus and Rastrococcus iceryoides infesting other vegetable crops were also recorded from Kerala. The study also revealed that the population of mealybug, C. insolita collected from different regions of Kerala exhibited significant morphological variation. The molecular characterization studies proved that the population belongs to C. insolita and the variations may be environmental induced. An exploration of the host range of mealybugs infesting solanaceous and cucurbitaceous vegetables in Kerala revealed a total of 113 plants under 73 genera belonging to 31 families, out of which 14 plants were recorded as new host reports. A rich natural enemy fauna on mealybugs belongs to five orders viz., Coleoptera, Lepidoptera, Diptera, Neuroptera and Hymenoptera were documented from Kerala. Twenty species of mealybug predators from five different families were recorded, among which the predominant family was Coccinellidae with 16 species under six genera. Among the various predators collected, Cacoxenus sp. was recorded for the first time as a predator of P. jackbeardsleyi. Eleven hymenopteran parasitoids belonging to five families were documented from mealybugs, of which the majority belongs to the family Encyrtidae. Four new host-parasitoid associations were also recorded for the first 288 time. The study also identified six hyperparasitoids under the family Encyrtidae, of which two species were recorded as new report which includes Cheiloneurus sp. and Prochilonerus sp. associated with the mealybug P. solenopsis. The ants associated with mealybugs in different agroecosystems were also investigated and a total of 14 species of ants belonging to nine genera under three subfamilies were recorded, of which the most dominant subfamily was Formicinae followed by Myrmicinae and Dolichoderinae. The present study also revealed 15 new ant-mealybug associations for the first time. The molecular characterization of eight mealybug species was carried out that complemented the morphological identification of species. A total of eight nucleotide sequences were submitted to NCBI GenBank and accession numbers were generated. The sequences were also submitted to BOLD and illustrative barcodes were generated. The barcodes of C. insolita, C. hirsutus and P. jackbeardsleyi were generated for the first time. The diversity of endosymbionts of the mealybug C. insolita was carried out for the first time. The study revealed a total of 15 phyla of endosymbionts on C. insolita, of which Proteobacteria was the predominant one. An experiment was conducted at Instructional Farm, Vellayani to identify the tritrophic interaction in brinjal, C. insolita and its natural enemies. The study revealed that out of the ten brinjal cultivars evaluated, the lowest mean population of mealybugs was observed in Pusa Uttam whereas the hybrid cultivar, Udit recorded the highest number of mealybugs. The lowest mean per cent leaf infestation was recorded in Pusa Purple Long which was statistically on par with Pusa Uttam whereas the hybrid cultivar, Udit was severely damaged by the mealybugs. Among the tested cultivars, Pusa Purple Long was recorded under the group resistant whereas Udit and Haritha were included under the highly susceptible group based on the mean per cent leaf infestation caused by C. insolita. The cultivar Haritha attracted the highest number of predators whereas the maximum mean population of spiders were observed in Pusa Purple Long. 289 The correlation analysis on the mean population of mealy bugs with biophysical parameters revealed that trichome density, length width ratio of leaf and number of branches exhibited a significant positive correlation with mean population of mealybugs. Correlation studies on the mean population of natural enemies with biophysical parameters revealed that plant height exhibited a significant negative correlation whereas leaf thickness and number of branches revealed a non-significant negative correlation with the mean population of natural enemies. Among the biochemical parameters of brinjal cultivars, total phenol content exhibited a significant negative correlation with the mean population of mealybugs whereas total chlorophyll content showed a significant positive correlation. The correlation between biochemical parameters of brinjal cultivars with the mean population of natural enemies revealed that total phenol and carotenoid content exhibited a non-significant negative correlation whereas total protein content, reducing sugar and total chlorophyll content showed a nonsignificant positive correlation. The info-chemical mediated interactions in brinjal cultivars, mealybug and its natural enemies were studied using a multi-armed olfactometer and Y-shaped olfactometer assay. The results revealed that the cultivar Udit attracted the highest number of natural enemy Chrysoperla zastrowii sillemi while the cultivar Pusa Uttam attracted the lowest number. The variation in preference shown by the natural enemies may be related to the difference in volatile compounds emanating from the host cultivar. The GC-MS analysis of the synomonal compounds of the cultivar, Udit revealed a total of eleven compounds whereas the cultivar Pusa Uttam was recorded with a total of five compounds. The Y shaped olfactometer studies revealed that C. zastrowi sillemi adults showed more preference towards the synomonal compounds of mealybug infested plants than that of healthy plant synomonal extracts. On comparing the volatile profile of synomones of mealybug infested and healthy plants revealed that the synomonal extracts of the mealybug infested cultivar Udit comprised of 11 compounds whereas healthy plant synomonal extracts contained nine compounds. 290 The relative response of C. zastrowi sillemi towards the kairomonal compounds of C. insolita was evaluated in a Y tube olfactometer and the results revealed that the highest mean number of adult lacewings were attracted to the kairomonal compounds of mealybug compared to control. The kairomonal extracts of the mealybug comprised of seven compounds and the composition of these hydrocarbons may determine the selectivity of natural enemies towards the preferred host. The present study recorded a total of six mealybug species infesting solanaceous and cucurbitaceous vegetables and its host range, natural enemies and associated ants in different agro ecological regions of Kerala. The molecular characterization studies supported the morphological taxonomy and the sequences were submitted to NCBI Genbank and BOLD. The study also elucidated the interactions mediated by plant traits and info-chemicals in brinjal-mealybugnatural enemy tritrophic systems. The study recorded Pusa Purple Long as resistant cultivar and Udit and Haritha as highly susceptible cultivar to C. insolita. The plant traits viz., trichome density, length width ratio of leaf, number of branches, total phenol content and total chlorophyll content exhibited significant correlation with mean population of mealybugs whereas plant height exhibited significant correlation with mean population of natural enemies. The study on info-chemical mediated tritrophic interactions revealed that the concentration and composition of volatile compounds determine the differential selectivity of natural enemies. The volatile compounds identified in this study can also be used as a cue in moderating the behavior of natural enemies in the ecosystems. So a thorough knowledge on the tritrophic relations in the ecosystem will aid in manipulating these interactions to devise a better pest management strategy.
Open Access
Eumolpinae (Coleoptera: Chrysomelidae) of southern India
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2021) Amritha Kumari, S; KAU; Prathapan, K D
The present study entitled “The Eumolpinae (Coleoptera: Chrysomelidae) of southern India” was carried out at Collage of Agriculture, Vellayani from October 2015 to March 2020. The study was designed with the objectives of collection and identification of the eumolpine leaf beetles of south India, preparation of illustrated keys to genera and species with emphasis on the characters of male and female genitalia and documentation of host plants in all possible cases. One thousand five hundred and two specimens from various ecosystems in south India were studied. Hand picking, aspiration, sweep netting and light traps were used to collect eumolpines. Specimens were also procured on loan basis from different institutions in India and abroad. Collected specimens were mounted and labelled. Available ecological and biological information was gathered in all cases. Genitalia was dissected as per standard procedures. Inflation and eversion of endophallus follow Yamasako & Obhayashi (2011). Specimens were identified tentatively based on the available literature and then confirmed by comparing with type specimens or consulting with experts. Measurements were made with a calibrated ocular micrometer and pertinent ratios were worked out. Illustrated keys, descriptions and diagnosis are provided. Male genitalia, including endophallus and female genitalia are described and illustrated. The Afrotropical genus Microeurydemus is newly reported from the Oriental Region. Malegia and Scelolanka are new reports to India. Pagria ingibbosa, P. ceylonica and P. pseudograta are new species records for India. Range of distribution of Basilepta subcostata and Trichochrysea are extended to south India. Tricliona Lefèvre, 1885 new snynonym is a new junior synonym of Bathseba Motschulsky, 1866. Neofidia Strother new name, is proposed as the replacement name for Fidia Baly, 1863, a junior homonym of Fidia Motschulsky, 1861. Bathseba syzygium n. sp. and Pseudostonopa palynophaga n. sp. are described as new to science. Eleven putative new species in the genera Mesocolaspis, Malegia, Microeurydemus, Basilepta, Cleoporus, Dermorhytis, Edistus, Pagria, Scelolanka and Trichochrysea were described. New host plant records include Anacardium occidentale L. (for Fidia kanaraensis), Ixora (for Eurypelta modesta), Aegle marmelos (for Colasposoma downesi), Mallotus atrovirens (for Cleoporus inornatus), Antidesma acidum (for Edistus sp.), Milletia pinnata (for Scelolanka). Bathseba syzygium n. sp. has been reported on Syzygium cumini and Pseudostonopa palynophaga n. sp. has been reported as a pollen feeder of Poaceae. Pagria signata species group warrants further investigations, due to inconsistencies in morphological, genetalic and molecular characters. The eumolpine leaf beetle fauna of south India comprises 146 species placed in 35 genera. Checklist of Eumolpinae of south India is provided. The study treated 53 species under 20 genera. Two new species, 11 putative new species in 10 genera, 12 new host plant records, several new distributional records and new characters of taxonomic value are reported. Nomenclature of many economically important eumolpines are updated.
Open Access
Galerucine leaf beetles (Coleoptera: Chrysomelidae: Galerucinae: Galerucini) of southern India
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2021) Viswajyothi, K; KAU; Prathapan, K D
The study entitled ‘The galerucine leaf beetles (Coleoptera: Chrysomelidae: Galerucinae: Galerucini) of southern India’ was carried out at College of Agriculture, Vellayani during September 2016−April 2021. The study was designed with the objectives of collection and identification of galerucine leaf beetles of southern India; documentation of host plants and other ecological data in all possible cases; preparation of illustrations and descriptions, with emphasis on characters of male and female genitalia; and preparation of an illustrated key to species. The study area encompasses the states of Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and Telangana. Eight hundred and thirty-three specimens belonging to 41 species in 27 genera were studied. Detailed descriptions were prepared, with colour photographs of dorsal, ventral, lateral and anterior habitus as well as diagnostic characters, including male and female genitalia. Additionally, internal sac or endophallus was everted in relevant and possible cases and illustrated. Measurements and proportions are provided. An illustrated key to select genera and species of Galerucini of south India is given. A checklist of known galerucine leaf beetles of south India is provided. Two putative new genera and two putative new species are described and illustrated. A new species Charaea sahyadrica Bezdek and Viswajyothi was published from this study. The habiti of 20 species in colour, male genitalia of 22 species and female genitalia of 24 species are given for the first time. Twenty-seven new host plants, including eleven (40.7%) economically important ones, were recorded. New host plant records are Aulacophora calva on Coccinia grandis (L.) Voigt, Cucumis sativus L. and Cucurbita moschata Duchesne ex Poir. (Cucurbitaceae); A. cincta on Manilkara hexandra (Roxb.) Dubard (Sapotaceae); A. frontalis on Trichosanthes tricuspidata Lour. (Cucurbitaceae); A. impressa on Cucumis sativus L., Cucurbita moschata Duchesne ex Poir. and Trichosanthes cucumerina L. (Cucurbitaceae); A. opacipennis on Momordica charantia L. and Trichosanthes tricuspidata Lour. (Cucurbitaceae); Cassena bengalensis on Mucuna bracteata (L.) DC. (Fabaceae); Erganoides flavicollis on Naravelia ceylanica (L.) DC. (Ranunculaceae) and an unidentified legume (Fabaceae); Galerotella sp. on Cayratia Juss. sp. (Vitaceae); Hoplosaenidea indica on Aphanamixis polystachya (Wall.) R. N. Parker (Meliaceae); Monolepta longitarsis on Piper nigrum L. (Piperaceae) and Spondias pinnata (L. f.) Kurz (Anacardiaceae); Oides affinis on Spermacoce hispida L. and Spermacoce ocymoides Burm.F. (Rubiaceae); Oides flava (Olivier) on Cayratia sp. (Vitaceae); Gallerucida sp. on Cayratia sp.; Sphenoraia hopei on Desmodium triflorum (L.) DC. (Fabaceae) and Myristica fragrans Houtt. (Myristicaceae); Trichomimastra hirsuta on Syzygium cumini (L.) Skeels) (Myrtaceae); Genus 1 on Spatholobus parviflorus (DC.) Kuntze (Fabaceae) and Genus 2 on Aporosa lindleyana (Wight) Baill. (Phyllanthaceae). New distribution records include two new country records and 10 new state records. The new records to India are A. opacipennis in Karnataka and Kerala and A. tibialis in Kerala. The new records to Kerala are A. frontalis; Cassena bengalensis; Erganoides flavicollis; Galerotella simplicicollis; Kanarella unicolor; Liroetes apicicornis; Mimastra alternata; Oides flava (Olivier); Genus 1 and Genus 2. The new records to Karnataka are Aulacophora parambikulamensis; Hoplasoma costatipennis; Mimastracella hirsuta; Sastroides besucheti and Trichomimastra hirsuta. Aulacophora calva is being reported for the first time in Karnataka and Kerala.
Open Access
Lamiinae (Coleoptera: Cerambycidae) of southern India
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2021) Sangamesh, R Hiremath; KAU; Prathapan, K D
The present study entitled “The Lamiinae (Coleoptera: Cerambycidae) of southern India” was carried out at College of Agriculture, Vellayani during 2015 to 2020 with the objectives of collection and identification of the flat faced long-horned beetles (Lamiinae) of southern India, preparation of descriptions and illustrated key to species, with emphasis on characters of male and female genitalia and documentation of host plants in all possible cases. The specimens were collected using different methods viz., hand picking, sweep netting, light traps, jackfruit twig trap and rearing from the infected plant parts. The specimens were processed following the standard procedures. Similarly, dissections, photographs and illustrations were prepared. Details of the specimens examined and the measurements of different body parts including that of male and female genitalia are included under each species. All the species included in the present study were identified using available literature. Taxon descriptions were prepared by considering all the morphological variations and also including the variations of male and female genitalia wherever available. A checklist of the species and illustrated key to the genera documented in the present study are also provided. Present study has generated taxonomic and ecological information on the Lamiinae fauna of south India. Sixty six species belonging to 41 genera of south Indian Lamiinae were studied. Detailed descriptions and illustrations, including that of male and female genitalia, are provided. Species-wise distribution and host plant data are furnished wherever available. Ecological information is also provided for a few of the species. Descriptions of two new species, Miccolamia ferruginea and Notomulciber viraktamathi were published. These include species descriptions, key to Indian species of the respective genera and a discussion on the need for redefinition of the respective subgenera. Description of the male of Monochamus shembaganurensis, with additional information on its distribution, was published. Four new species were recognised, one each belonging to the genera Eunidia and Falsoropica and two of Glenea. New distributional and ecological data are furnished for Acalolepta tenuipes, Agelasta quadrimaculata, Apomecyna saltator, Apriona trilineata, Batocera rufomaculata, Coptops aedificator, Epepeotes uncinatus, Eucomatocera vittata, Eunidia bicolor, Eunidia variegata, Eunidia simplex, Exocentrus (Camptomyne) vittatus, Hirtaeschopalaea albolineata, Macrochenus tigrinus, Nupserha bicolor, Olenecamptus bilobus, Phelipara indica, Sthenias grisator, Sybra praeusta, Thylactus angularis, Zotalemimon posticatum and Zotalemimon procerum. Among the south Indian Lamiinae, Apomecyna saltator, Batocera rufomaculata, Celosterna scabrator, Cleonaria bicolor, Coptops aedificator, Glenea multiguttata, Nupserha bicolor, Olenecamptus bilobus, Sthenias grisator and Sybra praeusta are well known pestiferous species. There are many Lamiinae still awaiting discovery and formal naming. Hence, studies encompassing the different ecozones of the country are sure to add several new species of flat faced longhorned beetles to the Indian fauna. Many species are known only by original descriptions based on a single specimen. Hence, there is an urgent need for intensive studies to generate information on their natural history. Future studies should concentrate on revising and updating the taxonomy of Lamiinae of economic importance so as to develop effective IPM programmes. To promote and facilitate studies on biodiversity and conservation of the native fauna of longhorned beetles, there is an urgent need to digitalize the type specimens of Indian Cerambycidae deposited in several European natural history museums besides developing a database with interactive keys for easy identification. The future taxonomic works on Indian Cerambycidae should also aim for Phylogeny of Indian fauna based on integrative taxonomy.
Open Access
Characterization, evaluation and formulation of beauveria bassiana (Bals.) strains against rice bug, leptocorisa spp. (Hemiptera:alydidae)
(Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2021) Nasiya Beegum, A N; KAU; Madhu Subramanian
The rice bug, Leptocorisaspp. is one of the most important sap sucking insect pests of rice in the tropics. Both nymphs and adults suck sap from developing rice grains during the milky grain stage, leading to discoloured, empty or half-filled grains. Yield loss due to the bug infestation ranges from 10 to 35 per cent. Management of the bug essentially involves spraying with insecticides, for want of safer options. Biological control of rice bug remains hampered by absence of ideal bioagents. The entomopathogenic fungus (EPF), Beauveria bassiana (Bals.) has been reported as infecting rice bug, from several parts of the world, including India. In this context, the present study was undertaken with the objectives of collection, isolation and molecular characterization of local strains of B. bassiana, evaluation against Leptocorisa spp., identification of a cost effective mass production technology for the selected strain of B. bassiana, and formulation of the most effective strain of B. bassiana. Surveys were conducted over two seasons during 2016-17 at major rice growing tracts of Alappuzha, Ernakulam, Thrissur and Palakkad districts of Kerala to collect EPF infecting rice bug. However, EPF infected rice bug cadavers were obtained only from one location i.e., Pattambi in Palghat district.As only one isolate was obtained, a potential fungal pathogen earlier obtained from rice bug at Vellanikkara, Thrissur and maintained at AICRP on BCCP was also included in further studies. The above two isolates were identified through study of colony characters as well as through ITS sequencingand Basic Local Alignment Search Tool (BLAST). The isolate from Vellanikkara was identified as Beauveria bassiana, while the isolate from Pattambi was identified as Choanephora cucurbitarum. The pathogenicity of the two isolates was assessed through laboratory as well as pot culture studies. In the laboratory, B. bassianaisolate recorded more than 90 per cent reduction in population of rice bug nymphs and adults five andseven days after treatment respectively at all concentrations evaluated while C. cucurbitarum recorded only 18 to 53 per cent reduction in bug population. Pot culture studies confirmed the superiority of B. bassianaisolate over C. cucurbitarum with B. bassiana treated pots registering over 99 per cent mortality by 20 th day after treatment as against 27 to 31 per cent mortality in case of the latter.B. bassianaisolate was further evaluated at its most effective concentration, under field conditions in both Thrissur and Palakkad districts.B. bassiana proved to be on par with the insecticide malathion from 10 th day onwards at both locations. The compatibility of B. bassiana isolate with selected insecticides and fungicides was assessed using poisoned food technique. The results showed that the insecticide acephate was the most compatible with 31.29 per cent growth inhibition while the fungicide propiconazole was the least compatible with 85.71 per cent inhibition. Methods for talc based, oil based and aqueous formulations of B. bassianawere standardized.Palm oil was identified as the most suited carrier for oil based formulation through inhibition zone technique as well as through assessment of viability of B. bassiana spores. Glycerol(3%), carboxy methyl cellulose (0.5%) and chitin (5%) formed the best adjuvants for oil based, aqueousand talc based formulations respectively, based on viable cfu count 30 days after storage. All the three formulations were as effective as malathion in reducing rice bug populations in field trials. However, talc formulation was significantly superior to the remaining formulations in terms of yield as well as grain damage. Talc, oil and aqueous formulations had shelf life durations of six, five and four months respectively.

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