Volume 97, Issue 5
September 1988, pages 379-470
pp 379-415 September 1988
As a result of excessive consumption of nitrogen more than necessary for their normal life processes, insects eliminate the excess quantities in one form or the other lest the ensuing toxicity should prove fatal to them. Voiding of several other nitrogenous compounds by insects besides uric acid via one common opening—the rectum, has posed difficulties in determining their nature as true excretory products or fecal nitrogenous waste matter. In the present review article an attempt has been made to present an almost up to date knowledge on the topic based on an intense search of literature which also includes the findings from the author’s laboratory.
pp 417-421 September 1988
Cytochalasin B treated (20 μ/ml) and deciliated tetrahymenae consistently show an initial 1 h lag in cilia regeneration. The scanning electron microscopic observations reveal the altered cell morphology in cytochalasin B treated cells around this time. The possible interactions of cytochalasin B with deciliation induced protein and/or cytoskeletal matrix fibres for the observed delay in cilia regeneration kinetics and morphological alteration inTetrahymena have been discussed.
pp 423-427 September 1988
Quantitative and qualitative aspects of the haemolymph proteins during the entire life span of both sexes ofGesonula punctifrons Stal. in relation to their variations during gonadotrophic period are discussed. The appearance of a female-specific protein in 8-day old female which was absent in freshly-emerged and senescent females and in males, is of interest.
pp 429-434 September 1988
Activities of some of the dehydrogenases involved in the formation of polyols were examined in diapause, non-diapause and acid treated artificial non-diapause eggs. The studies revealed that NADP-SDH may be important in the production of sorbitol during the onset of diapause and that NAD-GPDH may be playing a more important role than NADP-GDH in the production of glycerol.
pp 435-442 September 1988
FemaleTrogoderma granarium pupae, 0–96 h old, were treated with precocene-I at 6 h intervals. Reduction in the vitellogenic oocyte number was observed in adults after precocene treatment at specific ages. Precocene-I was effective when applied to 6, 18, 30, 42, 54 and 90 h old pupae while in 0, 12, 24, 36, 48, 60, 66, 72, 78, 84 and 96 h old pupae this compound was not significantly effective. Corpus allatum activity is a major contributory factor towards precocene susceptibility. The results suggest that pupae at different ages exhibit periodic changes in corpus allatum activity that might be related to cycles of development in the reproductive system.
pp 443-448 September 1988
Toxic stress due to DDT, malathion and mercury on the tissue carbohydrate metabolism ofSarotherodon mossambicus revealed the following manifest effects: (i) concentration of free sugars in the liver and muscle increased due to mobilisation of it from its bound form, glycogen and (ii) the normal carbohydrate metabolic pathway was altered indicating a switch over to anaerobic state involving the conversion of sugars into more lactate via pyruvate.
pp 449-453 September 1988
Eighty Wistar rats from age-groups of 3, 12 and 36 months were selected at random from the inbred colony. Ten animals from each group were treated with the ageing-reversal drug, centrophenoxine (100 mg/kg/day, intraperitoneally for 10 weeks). The Purkinje cell population of the brain of these animals were scanned histopathologically to record the impact of chronological age on the rate of conversion of ‘light’ into ‘dark’ type. The population of ‘dark’ cells increased by 52% from 3–36 months. The ‘dark’ neurons, even in the 3 month-old animals had substantial amount of histochemically detectable and autofluorescent age-pigment. While centrophenoxine could remove most of the pigment present in the ‘light’ type Purkinje neurons it failed to influence the pigment in any way in the ‘dark’ cells. The drug could not also influence the conversion of the ‘light’ cells into ‘dark’ type.
pp 455-461 September 1988
Reproductive strategies in relation to host diversity of a scelionid egg parasitoid,Trissolcus sp. onEupaleopada concinna Fab. andHomoeocerus prominulus (Tagus) are discussed, followed by the life table analysis of the parasitoid, indicating the preponderance of females due to solitary parasitism on the former host and a balanced sex ratio due to superparasitism on the latter.
pp 463-470 September 1988
Fortnightly sampling of the edible oyster,Crassostrea madrasensis was made from the natural bed of Pulicat lake during the years 1980–1982. The stomach contents of the oyster composed of 52·8% of diatoms, 45·7% of detritus and 1·5% animal matter. Among phytoplankton, the following is the order of importance:Navicula, Coscinodiscus, Nitzschia, Pleurosigma, Rhizosolenia, Amphora andPeridinium; and among zooplankton, bivalve veliger ranked first, followed by the ciliate tintinnids. Plankton was also collected from the natural bed to correlate with the gut contents of oyster. The oyster showed preference especially for diatoms likePleurosigma, Coscinodiscus andPeridinium, even though these diatoms were found in low quantities in the natural bed area. Two peaks of feeding intensities were observed one during December–January and the other during May–June. Oyster fed poorly during monsoon season (October–November) due to prevalence of low saline conditions in the lake.