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ThesisItem Open Access Exploration of the feasibility of developing races of trichograma Australicum girault ( trichogramatidar, hymenoptera) suitable for different environments(Division of entomology ,Agricultural college and research institute ,Vellayani., 1970) Abraham, C C; KAU; Pradhan, SThesisItem Open Access Evaluation of the toxicity of O,O-diethyl-thiono phosphoric acid O (quinoxalyl (2) ester (sandoz insecticide-6538)to insect pests(Division of entomology ,Agricultural college and research institute ,Vellayani., 1970) Gopinathan Nair, P; KAU; Nair, M R G KThesisItem Open Access Control of nematode parasites of brinjal with insecticide and nematicide granules(Division of entomology ,Agricultural college and research institute ,Vellayani., 1970) Vergis, P C; KAU; Mohas Das, NThesisItem Open Access Investigations on nuclear polyhedrosis of black hairy caterpillar, Pericallia Ricini fabricius (Arctiidae: Lepidoptera)(Division of Entomology, College of Agriculture, Vellayani, 1975) Vasudevan Nair, K P; KAU; Abraham JacobDetailed investigations were carried out on the nuclear polyhedrosis of the black hairy caterpillar,Pericallia ricini (Arotiidae) covering symptomatology, larval susceptibility, effect of the virus on the larval moulting, changes in the number of circulating haemocytes in the infected larvae, nature of causative agent, effect of temperature and sunlight on the infectivity of the virus and the cross infectivity of the virus to other species of lepidoptera. The virus infected larvae exhibited a ll the typical symptoms of nuclear polyhedrosis infection as reported from other lepidopterous larvae. The larvae infected in the early instars appeared paler and thinner. The infected larvae showed loss of appetite and became sluggish. The dead or dying larvae showed the characteristic symptom of hanging head downwards from the top o f the containers with the aid of prolegs. In the advanced stages of infection the cuticle became fragile and it ruptured liberating the liquefied body contents. The susceptibility of the larvae to virus infection decreased with increase in the age of the larvae. The averageincubation period varied from 5*24 days for the second instar to 8 days for the sixth instar larvae. The virus infection inhibited moulting in the later stages of the disease. No significant difference was observed in the THC of healthy larvae and virus infected larvae up to 24 hours after inoculation; there was significant reduction in the THC of diseased larvae after 24 hours of inoculation.ThesisItem Open Access Studies on the effects of juvenile hormone analogues on the development of Spodoptera mauritia (Boisduval) (Lepidoptera : Noctuidae)(Department of Entomology, College of Agriculture, Vellayani, 1975) Krishnadas, V S; KAU; Jhonson, JMorphogenetic effects of two juvenile hormone analogues viz. altosid and farnesyl methyl ether (FME) on spodoptera mauritia were studied under laboratory conditions. Ovicidal action was first tested by using different concentrations of juvenile hormone analogues diluted in pure acetone. All the treatments and control (acetone treatment) prevented embryonic development to varying degrees. Since the solvent also caused mortality in eggs, one per cent acetone solution in water was used in later experiments. Treatments ranging from 0.0125 to 0.1 per cent altosid resulted in egg mortality ranging between 40 to 60 per cent . The corresponding mortality figures caused by FME were 36 and 52 per cent, the values were comparatively less than those with altosid. Freshly moulted last larval instar was the most susceptyible stage to the action of JHA’s. All the hormonal concentrations used in the study affected normal metamorphosis and moulting. Some of the treated larvae moulted into supernumerary larval instars and larval pupal mosaid. Prolonged larval duration, failure of normal moulting altered body pigmentation, reduction in water content of the excreta and slight swelling of the thoracic legs and prolegs were also recorded as hormonal effects on the last instar larvae. Higher dosages of FME had direct toxicity to the larvae. Pupae were more susceptible to the action of altosid than of FME. Metamorphosis was completely inhibited at all doses used. All the treated pupae showed darker colouration than control pupae. Altosid and FME had effects on fecundity, embryogenesis and latent effect on post embryonic development when the female moths were treated. Reduction of fecundity upto 36 per cent was recorded by 10 µg per µl of both the hormonal analogues used in the experiment. A sizable number of eggs failed to hatch since the embryonic larval differentiation was seriously affected. The progeny of the treated females suffered heavy latent mortality especially in the first larval instar stage. The average adult longevity of the treated moths increased significantly. There was only a marginal increase in the time for laying the first batch of eggs in treated moths. In general altosid was found to be superior to FME in producing morphogenetic effects on spodoptera mauritia.ThesisItem Open Access Studies on the chemical control and insect-plant relationships of the rice leafroller, Cnaphalocrocis Medinalis Guenee (Pyraustidae:Lepidoptera)(Division of Entomology, College of Agriculture, Vellayani, 1975) Mohandas, N; KAU; Gopalakrishnan Nair, M RThe series of laboratory and field experiments were conducted to study the relative toxicity of 24 insecticides to noths and larvae of the rice leaf roller, cnaphalocreoois medinalis the relative effiency of these insecticides in controlling the pest in the field and the insect plant relationships between c.medinalis and different rice varieties. Suitable methods for the collection of moths of c.mdinalis from the field for the collection of their eggs and first instar larvae in sufficiently large numbers and for rearing the insect in the laboratory were eveloved.
