Volume 97, Issue 1
January 1988, pages 1-115
pp 1-12 January 1988
Light and transmission electron microscopic studies of the developing oocytes from the germarium to the vitellogenic oocyte of the panoistic ovaries ofArrhenothrips ramakrishnae are included with a view to understand the sequential structural and behavioural changes involved in the development of the oocyte. Sufficient evidence is presented of these changes relating to the preliminary stages of development of the oocyte till the initiation of yolk formation and completion of the follicle cell epithelium, based on transmission electron microscopy.
pp 13-27 January 1988
Transmission electron microscopic studies relating to the changes taking place in the follicular epithelial cells and oocyte cytoplasm of the penultimate and terminal oocytes ofArrhenothrips ramakrishnae Hood during vitellogenesis and the role of the follicular cells in this process are discussed.
pp 29-34 January 1988
Adult females are fed at regular intervals after emerging from the puparium, then forced to diapause at temperatures ranging from 5–10°C. Longevity, oviposition and the diapausing period are recorded. Ageing is indirectly proportional to the diapausing ability and directly proportional to the maturation of the gonads and oviposition.
pp 35-40 January 1988
Statistically significant correlation coefficients were obtained for the relation between defecation rate and development rate as well as energy contents of pupa and imago of the noctuid mothAchaea janata. Using simple regression equations, the dependent variables development rate, pupa and imago were predicted against values of defecation rate obtained in a factorial design of experiment. The predicted and observed values did not significantly differ from each other indicating the possibility of predicting these parameters from easily estimatable faecal weight. The validity of the concept was tested using the data available in literature.
pp 41-48 January 1988
The pin and jab type of predatory behaviour ofRhinocoris marginatus Fabricius is distinctly different from the feeding behaviour of other subfamilies known so far. The thin long legs, tibial pads, long slender rostrum capable of more than 90° forward extension, slow gait of this predator are idenlly suited for efficient capture of soft-bodied prey types, particularly caterpillars. As in other predatory reduviids, visual stimuli provided by the moving prey, elicit feeding responses inRhinocoris marginatus and this is augumented by other sensory system, including olfactory. The predatory feeding behaviour ofRhinocoris marginatus consists of disinct stimuli—response mediated sequences of events and based on these the feeding behaviour models for this insect is depicted.
pp 49-54 January 1988
Eggs of Rhaphidosomatinae share with the eggs of other subfamilies, several characters common to Reduviidae. The chorion with simple follicle cells, short, highly porous collar rim, 6 micropyles and the operculum with a central highly porous conical disc are characters to distinguish the eggs of this from other reduviid subfamilies. The ultrastructural details of the chorion, the operculum, and the aero-micropylar system of the eggs ofRhaphidosoma atkinsoni, the only species represented in India, are reported.
pp 55-65 January 1988
The effect of topical application of juvenile hormone analogues farnesyl methyl ether and kinoprene (ZR 777) at different doses to eggs immediately after laying, germ band formation and blastokinesis, produced different types of abnormal embryos with varying degrees of derangement of development, most of them ultimately resulting in failure to hatch. Some of the embryos were almost normal but failed to hatch even though they continued to develop inside the chorion and died two days later. On the whole, there was correlation between dose of the analogue applied and mortality rate. Kinoprene was much more effective than farnesyl methyl ether. With given dose, per cent embryonic mortality was more or less the same whether the analogues were applied just after oviposition or germ band formation, but was lesser when applied immediately after blastokinesis. The period just after germ band formation appeared to be most sensitive. Treatments affected the endocrine system. The neurosecretory index was higher in the treated embryos. Prothoracic glands and their nuclei showed considerable enlargement in treated embryos continuing development inside chorion even after their controls hatched. The corpus allatum was smaller in treated embryos and corpora cardiaca were filled with neurosecretory material. Cuticle development was abnormal after treatment.
pp 67-71 January 1988
Protease, amylase, lipase and trehalase are present in the larval and adult midguts ofOryctes rhinoceros; cellulase is absent. Invertase is present only in the adult. The presence of trehalase in the pupal midgut suggests that food digestion is not the normal function of gut trehalase. Quantitative studies reveal that protease and amylase in the third instar larvae reach very low levels as the larvae become older and consume little or no food. These two enzymes are not measurable in the non-feeding prepupa and pupa and reappear in the adult with commencement of feeding. Secretion of digestive enzymes is correlated with feeding.
pp 73-78 January 1988
The effect of midgut epithelial extract on digestive enzyme secretion in the third instar larva ofOryctes rhinoceros was studied. Midguts dissected out from third instar larvae were cut at both ends, emptied of their contents, washed in insect saline, ligated at the open ends and incubated in a medium containing extract of 2 midgut epithelia/10 ml incubation solution. In control experiments midgut preparations were incubated in insect saline without midgut epithelial extract. After 30 min of incubation, the contents of the midgut preparations incubated with midgut epithelial extract showed increased secretion of protease and amylase when compared with controls. Digestive enzyme release into gut lumen appears to be due to the action of a hormone present in the midgut epithelium.
pp 79-87 January 1988
A unique club-shaped hair on the first instars of an Australian geometrid caterpillar is described. The sensory hairs occur on the body segments and is absent on the head and the last abdominal segment. These hairs have different orientations and are replaced by filiform hairs after the first moult. Regression lines describing the movement of hairs of different orientations in relation to a force is presented. With these results the deflection in the sensory hair due to gravity when the caterpillar is on a vertical plane was calculated. These calculations suggest that the hairs may not function as gravity receptors. The possible role of these hairs in the behaviour of caterpillars is discussed.
pp 89-96 January 1988
Survival, growth and reproduction ofCyprinus carpio were studied in ponds treated with mahua oil cake and single superphosphate. The results indicated that single superphosphate (500 kg/ha) compensated for the deleterious effects of mahua oil cake (2,000 kg/ha) on survival, growth and reproduction of fish. Better fecundity-weight relationship of fish and bottom organisms were evident at the same input levels. In order to maintain ammonia concentration in ponds below the toxic threshold, application of single superphosphate seems to be essential. For better fish culture management, use of mahua oil cake in high amount or its frequent addition should be avoided.
pp 97-101 January 1988
One hundred ppm of phenol in 2% NPK fertilizer treatments of 4Meloidogyne incognita susceptible hosts, reduced the pathogenic impact and improved their tolerance.
pp 103-109 January 1988
With NPK solution as the basic nutrient applied to the root-knot nematode infected cowpea plants, amendments were made with 100 ppm of phenol prepared from alcoholic extract of palmyrah wood sawdust. Further amendments consisted in adding gibberellic acid or indole acetic acid or gibberellic acid+indole acetic acid. Amended nutrient applications reduced galling, fecundity of the pathogen, pathogenic impact, improved root weights and synthesis of metabolites which signified the improved vigour of the infected host.
pp 111-115 January 1988
The chemical analysis of the abdominal scent glands ofChrysocoris purpureus Westw, showed the presence oftrans hex-2-enal, n-dodecane,trans hex-2-enyl butyrate and n-octyl acetate. The scent components are metabolically synthesized within the cells of exocrine glands of bugs and are used as defensive in nature. They do not show any correlation with the secondary metabolites of the host plant.