1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)

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    Documentation and management of oriental fruit fly, Bactrocera Spp.(Diptera:Tephritidae) in banana
    (Department of Agricultural Entomology, College of Agriculture , Vellayani, 2022-03-16) Remya , S R.; Ambily Paul
    The study on “Documentation and management of Oriental fruit fly, Bactrocera spp. (Diptera: Tephritidae) in banana” was carried out at the Department of Agricultural Entomology, College of Agriculture, Vellayani during 2019 to 2021. The objectives were to document the species complex and cultivar preference of Bactrocera spp. infesting banana and to find out the effective management practices against them. Purposive survey conducted among 20 farmers each of two districts viz., Thiruvananthapuram and Kollam revealed that Palayankodan was the most susceptible cultivar to the fruit flies followed by Red banana. High TSS (17.80°Brix) of Palayankodan favoured the infestation. Fruit fly species infesting the banana cultivars viz., Palayankodan, Red banana and Nendran was identified as Bactrocera dorsalis Hendel. Bactrocera caryeae Kapoor was reported along with B. dorsalis from guava. Studies on the biology of B.dorsalis in banana under laboratory condition revealed that egg, larva, pupa and total life cycle ranged from 1-3, 7-12, 7-10 and 51- 58 days respectively. Morphometric studies revealed that the average length and breadth of eggs, full-grown maggots and pupae were 2.52±0.10 and 0.95±0.04 mm, 6.38±2.67 and 1.26±0.24 mm, 5.58±0.29 and 2.47±0.08 mm respectively. The investigation on the assessment of critical stage of banana susceptible to fruit flies was studied on Palayankodan fruits at different ripening maturity viz., under- mature, mature and over-mature. The critical stage of infestation by fruit flies was identified as “over mature”. Significantly higher number of oviposition punctures (13.30) and maggots (12.10) per banana finger was observed in “over-mature” fruit. Though oviposition punctures was noticed in mature (6.90) and under mature (3.20) fruits, no maggots were emerged from them. The tannin content in peel and pulp of Palayankodan fruits at different ripening maturity was estimated using folin-denis method to determine the defensive role played by tannin in the prevention of B.dorsalis infestation. The highest tannin level was found on both peel (235.29 mg g-1 DW) and pulp (265.62 mg g-1 DW) of under mature fruits. In over mature fruits, both peel (120.08 mg g-1 DW) and pulp (98.88 mg g-1 DW) recorded less tannin content which supported oviposition and growth of maggots. Laboratory experiment was laid out in CRD to study the efficacy of treatments against B. dorsalis on Palayankodan immediately after the harvest. Among various treatments, quinalphos 25 EC 0.05% was found to be the best treatment in reducing fruit fly infestation in banana followed by spinosad 45 EC 0.02%, azadirachtin 0.03% and salicylic acid 2mM. The oviposition deterrence recorded was significantly higher in quinalphos 25 EC (97.03%) followed by spinosad 45 EC (93.97%), azadirachtin (80.14%) and salicylic acid 2mM (63.44%). Presence of residues of quinalphos (0.021 mg kg -1) and spinosad (0.069 mg kg -1) in banana at the time of harvest was above MRL (0.01 mg kg-1), hence the next effective treatment, azadirachtin (0.03%) which was on par with Spinosad could be recommeded after harvest for the management of fruit flies in banana. The study could be concluded that the species of fruit fly infesting banana cultivars was identified as B. dorsalis and Palayankodan is the preferred cultivar and the critical stage of infestation by B. dorsalis was “overmature”. Post harvest spraying of azadirachtin (0.03%) was found to be effective and safe for the management of fruit flies, B. dorsalis in banana.
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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.