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ThesisItem Open Access Studies on the regulation of progeny production and sex-ratio of Wesmael(Department of Agricultural Entomology, College of Horticulture,Vellanikkara, 1979) Susamma, Jacob; KAU; Abraham, C CThe fecundity, progeny production, female – male composition of the progeny and duration of development of Bracon brevicornis wesmael as influenced by the density and size (weight) of host larvae of Corcvra cephalonica Stainton and the sex-ratio of the parent parasite population were studied at three temperature- humidity (TH) combinations, viz, 280c and 75% RH (TH1), 300c and 60% RH (TH2) and 320c and 50% RH (TH3). The maximum fecundity of the parasite was registered consistently at all the three TH levels at a host density level of two larvae per female parasite. The exclusive use of light weight larvae (weight range 8 to 10 mg) as hosts produced significantly less number of eggs at the TH1 and TH2 levels, while at the TH3 level the fecundity was maximum when the heavier host larvae (weight range 30 to 35 mg) were used. The parental sex-ratio levels of 2:1 and 3:1 (female:male ) led to the production of higher number of eggs than under the ratios of 1:1, 1:2 and 1:3. The maximum progeny production in B. brevicornis at the TH1 and TH2 levels was attained under a host density level of two larvae per female parasite. The progeny production was relatively higher at the TH1 and TH2 levels when heavier larvae were exposed for parasitisation. The superiority of the parental sex-ratio of 2:1 (female: male) in the production of higher number of progeny was established at the TH2 and TH3 conditions. Significant influence of the host larval density on the female progeny production was detected at the TH1 and TH2 levels. The female progeny production was maximum at a host larval density level of two per female parasite at the TH2 combination, while this was found to be the highest at a density level of one larva per female parasite at the TH1 level. Relatively heavier host larvae produced significantly higher number of female offsprings at the TH2 and TH3 combinations. The parental sex-ratio level of 2:1 (female:male) consistently produced maximum number of female progeny. The influence of host larval density on the proportion of females was pronounced only at the TH3 level and a density level of two laevae per female parasite was found to be better with reference to the production of a higher proportion of females. The sex-ratio of the parent parasite population influenced the proportion of females in the F progeny and a ratio of 1:3 (female:male) produced higher proportion of females at the TH2 and TH3 combinations. The host larval density, weight of host larvae and the sex –ratio of the parent parasite population exerted significant influence on the duration of development of B. bravicornis. The feasibility of manipulating the ambient temperature-humidity conditions for maintaining laboratory cultures of B. brevicornis at the maximum possible levels has been discussedThesisItem Open Access Studies of rats and rat traps of Kerala(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1979) George, C M; KAU; Joy, P JIn order to study the distribution of different species of rate in the State a detailed survey was conducted in different parts during the period from September 1978 to February 1979. Burrows of the various species were excavated to get detailed information on the special features of the burrow patterns. The findings of the present investigation are summarized below. It was found that 15 species of rats occur in Kerala. 1. Tatera indica cuvieri Of the four subspecies of Tatera indica, only T. indica cuvieri was present in Kerala. This species was distributed all over Kerala except in higher elevations like Wynad. The burrow system followed no specific patterns with a minimum of three openings. The emergency escape were concealed underneath. The burrowed out soil was expelled through a particular opening. More than one adult lived in a burrow system. 2. Rattus norvegicus This was a serious pest of paddy in Idukki district and Kuttanad and was mostly a field rat in Kerala. 3. Bandicota bengalensis bengalensis This species was more predominant in garden lands. Burrow were found extensive. Burrow entrances were concealed by heaps of soil. Food was found stored in the burrow system only in a few cases. Male and female rats lived in separate burrows. 4. Bandicota indica indica A field rat causing great damage to tuber crops. The burrow openings were larger in size than those of other species. The exit for removal of soil was always located on a higher point. Definite runways starting from the entrances were seen. 5. Mus platythrix The burrow openings of this mouse were encircled by pebbles. It lived in discarded burrows of other species of rats and not a fossorial type. 6. Mus saxicola Similar to M. platythrix in every aspect. 7. Mus booduga booduga It lived in small burrows in paddy fields and garden lands. The burrow system was always seen provided with one or more emergency escapes. 8. Mus cervicolor Found similar to M. booduga booduga in appearances, habits and habitats. 9. Mus musculus Found in houses and shops. 10. Rattus rattus Two subspecies were found in Kerala viz., R. rattus ruffescens and R.r. wroughtoni and the latter was found attacking coconuts. 11. Vandeleuria oleracea Found inhabiting trees and under grass growth around crop fields. 12. Golunda elliotti Found in forest and in thick grass growth around crop fields. 13. Millardia meltada meltada Seen in paddy fields in Wyanad, Calicut district. 14. Rattus raniiniae A new species of rat found in Trivandrum District. 15. Platacanthomys lasiurus A spiny rat damaging cashewnut in Idukki district. Study on indigenous rat traps. A total number of 17 indigenous rat traps were collected from various parts of Kerala. Among the various traps, Moncompu traps, for capturing rice field rats, bamboo-noose trap for trapping mole rat from live burrows, and the bamboo bow-trap for capturing rats infesting coconut crowns were found most useful.ThesisItem Open Access Studies on the granulosis virus of Pericallia ricini Fabricius (Arctiidae: Lepidoptera)(Department of Agricultural Entomology, College of Agriculture, Vellayani, 1978) Babu, M Philip; KAU; Abraham, JacobThe black headed hairy caterpillar, Pericallia ricini Fab., is a polyphagour pest feeding on a wide variety of crops such as castor, cotton, banana, cucurbits, sunflower, field beans, and gingelly. The occurrence of a granulosis in this insect was recorded in 1972, but no detailed studies have so far been made on this disease. A through knowledge of the disease including the host pathogen relationships and the physico-chemical properties of the pathogen is essential to judge its suitability in practical pest management programmes. With a view to collect these information the present studies were taken up. Studies were made in the laboratory and in field cages. Larvas of P. ricini reared in the laboratory on castor leaves were used. Third instar larvas were used in all studies except those on symptamatology and larval susceptibility. A purified suspension of granules derived from 300 dead larvae in 3 litres of distilled water formed the inoculam. All the experiment were conducted at room temperature and humidity.ThesisItem Open Access Studies on the root-knot nematode of pepper (Piper nigrum L.)(Department of Agricultural Entomology, College of Agriculture, Vellayani, 1977) Arthur Jacob, J; KAU; John Kuriyan, KNematodes have recently been observed to constitute a major threat and limiting factor to the pepper production in Kerala State, Among the nematodes, neloidecyne spp, causing root-knots on pepper is one of the most important. Investigation on this nematode in pepper was not done in this state, Therefore, to gather some information on the extent of damage done by this nematode and pepper and to evolve control measures the present work was carried outThesisItem Open Access Biology ecology and host plant relations of the brown planthopper, Nilavaravata lugens Stal(Division of Agricultural Entomology, College of Agriculture , Vellayani, 1977) Thomas, M J; KAU; Gopalakrishnan, Nair M RThesisItem Open Access Effect of oil cakes on soil nematodes of bhindi in relation to fungal and bacterial flora and pH of soil(Division of Entomology, Agricultural College and Research Institute, Vellayani, 1972) Joseph, J; KAU; Gopalakrishnan, Nair M RThesisItem 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; Mohan, Das N
