Volume 83, Issue 2
February 1976, pages 47-84
pp 47-54 February 1976
Fecundity of 84 specimens ofCoilia ramcarati (Ham.-Buch.), collected from the Hooghly estuarine system, was studied. The relationships between standard length and fecundity, total weight and fecundity, ovary weight and fecundity, standard length and ovary weight and total weight and ovary weight have been determined for the species. Statistically significant relationships were found to exist between the above variables. Close resemblances in most of the above relationships betweenC. ramcarati andC. dussumieri have been observed.
pp 55-65 February 1976
Heliothis peltigera (Schiff.) (Noctuidae) was found infesting the weedAcanthospermum hispidum at Anand (Gujarat State), and our observations indicated a close synchrony between the seasonal history ofA. hispidum andH. peltigera. Both appear with the onset of monsoon (July) and disappear as winter approaches (October/November).H. peltigera larvae were observed to feed primarily on the growing tips and terminal leaves, the young larvae forming characteristic leaf-webs. The extent of damage, population of the insect and its natural parasitism were recorded. Peak period of larval activity was in September when up to 53.3% shoots were damaged and 35 larvae/100 shoots were encountered.
The parasites recorded included the egg-parasiteTrichogramma chilotraeae Nag. and Nagar. (Trichogrammatidae), the egg-larval parasiteChelonus heliopae Gupta (Braconidae) and the larval parasitesCampoletis maculipes (Tschek),Eriborus sp.,Pristomerus sp. (all Ichneumonidae),Eucarcelia illota Curran,Palexorista laxa Curran andExorista xanthaspis Wied. (all Tachinidae). ExceptC. heliopae andPristomerus sp., all other parasites are new records onH. peltigera. T. chilotraeae was the most predominant parasite, giving consistently high degree of parasitism which reached up to 100% in October 1973.C. maculipes was next in importance which gave up to 26·7% parasitism in September 1973. A predatory ant,Camponotus sericeus (F.) (Formicidae) and larvae ofChrysopa carnea Steph. (Chrysopidae) were observed preying on youngH. peltigera larvae for the first time.
The survey revealed thatH. peltigera feeds primarily onA. hispidum and is not a serious pest of any economic plants in this region.
The distribution, host-plants and natural enemies ofH. peltigera in different countries is reviewed from literature records.
pp 66-72 February 1976
The paper is an account of some salient embryological features in four genera and five species belonging to the family Cyperaceae (Eleocharis atropurpurea, E. congesta, Fimbristylis tetragona, Fuirena trilobites andScirpus lateriflorus). InE. atropurpurea double pollen grains are occasionally observed. Their significance in systematic considerations of the family is discussed. The development of the female gametophyte conforms to thePolygonum type.
pp 73-78 February 1976
The adrenals of female house rat exhibit gravimetric as well as histological changes in response to reproductive activity. Sexually active females have larger and heavier adrenals than those of nonactive ones. The adrenals of oestrous females are significantly heavier than those of either the juveniles or the non-pregnant females. There is a progressive increase in adrenal weight from oestrus through pregnancy to lactation. Lactating females have the heaviest adrenals. Increase in adrenal weight is chiefly due to the enlargement of the zona reticularis of the adrenal cortex, accompanied by increased vascularity. In non-pregnant females, the reticularis is much smaller than the fasciculata and there is diminished vascularity.
pp 79-84 February 1976
Structure, development and organographic distribution of hairs have been studied on both vegetative and floral parts ofTinantia fugax (Commelinaceae). A total of eight types of non-glandular and glandular hairs have been recognised. Of these, unicellular, bicelled vesicular, uniseriate acicular and fusiform glandular hairs have not been reported in Commelinaceae by the previous workers.