Volume 66, Issue 6
December 1967, pages 231-281
pp 231-236 December 1967
Two commercial preparations ofBacillus thuringiensis thuringiensis Berl. were used in laboratory tests on two noctuids:Prodenia litura (F.) andPlusia orichalcea (F.); two pyralids,Leucinodesorbonalis Guen. andChilo partellus (Swinh.); and one papilionid,Papilio demoleus L.
On the basis of the results obtained it was evident that all the larval stages ofPapilio were highly susceptible to both bacterial preparations, whileProdenia showed moderate susceptibility. The larvae ofPlusia, Leucinodes andChilo showed less susceptibility to one of the bacterial preparations tested. The results suggest thatPapilio demoleus, a serious pest of young citrus in nurseries in India, may be efficiently controlled through spray applications ofB. thuringiensis.
The larvae ofP. demoleus exhibited a fairly rapid paralysis followed by an increase of blood alkalinity after ingestion of spores, whereasP. litura larvae did not show any sign of paralysis or appreciable change in the pH of the haemolymph.
pp 237-242 December 1967
The structure of stomata on the leaf, stem, petiole, peduncle, bract and sepal is described. The development has been studied in all organs except the peduncle. Three types of stomata—paracytic, anisocytic and anomocytic—occur on the leaf, bract and sepal but only the first two types are present in the remaining organs. Stomata with one or two subsidiary cells unilaterally flanking the guard cells are also found in the last two organs. In all the organs the paracytic type is by far the commonest, anomocytic one rare. An increase in number of subsidiary cells is either by their division or by the adjacent perigenes becoming subsidiary cell-like. Though there is a diversity of the structure of mature stomata on the same surface of each organ, the different types develop similarly in all organs.
pp 243-249 December 1967
Histologically different types of muscle fibres have been observed. The dehydrogenase activity in the muscles of pedipalp, leg and heart has been investigated. The heart and pedipalpal muscle have higher and lower dehydrogenase activity respectively than the leg muscle. The pattern of carbohydrate breakdown seems to be different in the leg muscle due to the interference of lipid metabolism, perhaps because of the differences in the muscle fibre composition of the muscle. As the scropion happens to be the nocturnal animal, there are conspicuous differences in the dehydrogenase activity during day and night times. During night time there seems to be stress on the anaerobic phase of metabolism. In general, increase in dehydrogenase activity during night has been correlated with increased activity of the organism. Hence this shows the existence of diurnal variations in the dehydrogenase activity.
pp 250-265 December 1967
Trace element studies were carried out on six species ofHelminthosporium—H. sativum P. K. B.,H. avenae Eidam,H. teres Sacc.,H. oryzae Br. de Haan,H. turcicum Pass., andH. sacchari (Br. de Haan) Butler. The trace element contaminants from glassware, water, basal medium and inoculum were removed by various usual means. In addition, disodium salt of Ethylene diamine tetra acetic acid (EDTA) was used to remove trace elements from glassware and water. Out of the 16 trace elements tested, Fe, Zn and Mn were found essential for the growth of all these species ofHelminthosporium; Cu for the growth ofH. avenae, H. oryzae, H. turcicum andH. sacchari but not for the growth ofH. sativum andH. teres; Mo and Ca for the growth ofH. oryzae andH. sacchari but not for the growth ofH. sativum, H. avenae, H. teres andH. turcicum. No other trace element was found essential for the growth of any of these fungi. Optimum concentrations in ppm of the essential trace elements for these fungi were as follows:H. sativum: Fe 10·0, Zn 0·0001, Mn 100·0,H. avenae: Fe 1·0; Zn 10·0; Mn 0·1, Cu 0·1;H. teres: Fe 0·01, Zn 10·0, Mn 0·01;H. oryzae: Fe 0·001, Zn 10·0, Mn 0·1, Cu 0·0001, Mo 0·0001, Ca 750·0;H. turcicum: Fe 0·1, Zn 0·1, Mn 1·0, Cu 0·1;H. sacchari: Fe 1·0, Zn 10·0, Mn 100·0, Cu 0·01, Mo 0·0001, Ca 250·0. Concentrations higher than the optimum were inhibitory to the respective fungi.
pp 266-272 December 1967
This paper records 22 different fungi which are new host records for India.
pp 273-278 December 1967
Oxygen consumption in relation to weight and in relation to salinity was investigated inMoringua linearis.
For all sizes investigated oxygen consumption was minimum in 18·8‰ salinity and increased in higher as well as in lower salinities investigated.
The changes in metabolic rate in relation to salinity are ascribable to osmotic stress.
pp 279-281 December 1967
Sarcopyramis subramanii Nayar, a new species from Lushai Hills, Assam, is described with illustrations.