Ceylon Journal of Science (Biological Sciences)
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Item Preliminary observations on graminaceous aphids (Homoptera: Aphididae) of the Peradeniya University Park(1995) Wijerathna, M.A.P.; Edirisinghe, J.P.Fourty two grass species, mostly weeds, found within about 70 heactares of the Peradeniya University Park, were examined for aphids.Eight species of aphids were recorded from 21 grass species in the study area. Two of the aphid species collected, Hysteroneura setariae (Thomas) and Rhopalosiphum Padi (L.) had not bee previously recorded from Sri Lanka.Item An annotated list of aphids of Peradeniya Campus, Sri Lanka(1994) Edirisinghe, J.P.A list is given of 17 species of aphids with their host plants (52 plant species in 29 familes) from Peradeniya campus, located in the Central Province of Sri Lanka. Nine of the aphid species had not been previously recorded from Sri Lanka. Of them, Sitobion wikstroemiae (Mamet) has been recorded only from Mauritius and East Africa and Uroleucon minutus van der Goot is considered a rare species. Two of the aphid hyperparasitoids collected. Syrphophagus hofferi (Hayat) and Coagerus boucaki Noyes and Hayat are without previous host recordsItem Instar determination and larval distribution in brinjal shoot and fruit borer, Leucinoides orbonalis (Guen)(1992) Sandanayake, W.R.M.Larval instars of Leucinodes orbonalis Guen. reared on Solanum melingena (L) were determined by measuring the width of the intact as well as the shed larval head capsules. Larvae were separable into five, distinct, non-overlapping instars by cluster analysis (of both intact and shed head capsule measurements) and by frequency distribution (of only the shed head capsule measurements). Larvae were found to shed their head capsules five times during a total larval period of 11-16 days. The mean widths of the shed head capsules corresponding to the five instars were 0.2, 0.36, 0.64, 0.95 and 1.46 mm respectively. The stadial periods of the five instars were 3.5, 1.6, 1.8, 3.2 and 2.0 days respectively. First instar larvae were confined to flower-buds and flowers whilst the second instars larvae were present in all the susceptible parts of the plant. Third to fourth instar larvae were confined to the shoots and fruits while final instar larvae fed exclusively on the fruits. The size of the entrance hole made by a larva entering the plant was found to be a good indicator of its instar status.Item Water mite parasitism in four species of Culex mosquitoes at Kandy, Sri Lanka(1992) Karunaratne, S.H.P.P.; Amerasinghe, F.P.Item A guide to the identification of the anopheline mosquitoes (Diptera: culicidae) of Sri Lanka(1992) Amerasinghe, F.P.The taxonomy of Oriental and SE Asian anopheline mosquitoes has been extensively studied over the past two decades, resulting in greatly improved characterization of species and the definition of taxonomy features that are important in identification. However, published taxonomic keys for Sri Lankan anophelines have not been revised for over 50 years. This paper presents an illustrated key for the identification of larvae of 21 of the 22 currently recognized local anopheline species (the larval stage of the 22nd species is presently unknown), as a guide to workers engaged in malaria surveillance and control in Sri LankaItem Item Notes on a collection of Dermaptera from Darjeeling Dist. (India) with the description of a new species.(1975) Srivastava, G.K.; Saha, S.K.Item The digestive enzymes in the alimentary system of Acrotelsa collaris (Thysanura:Lepismatidae)(University of Peradeniya. Peradeniya, 1964) Modder, W.W.D.