Browsing by Author "Ganehiarachchi G.A.S.M."
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Item Aspects of the Biology of Diaphania indica (Saunders) (Lepidoptera:Pyralidae)(Journal of National Science Council of Sri Lanka, 1997) Ganehiarachchi G.A.S.M.Item Association between ovipositional preferences and offspring fitness in Hessian fly (Diptera: Cecidomyiidae)(Sri Lanka Association for the Advancement of Science, 2013) Ganehiarachchi G.A.S.M.; Harris, M.O.Item Bertha Armyworm. Biology and Integrated Pest Management in Wheat(North Dakota State University, 2008) Knodel, J.J.; Ganehiarachchi G.A.S.M.The bertha armyworm, Mamestra confi gurata Walker, belongs to the order Lepidoptera and family Noctuidae. It often is referred to as the “Miller Moth” or “climbing cutworm.” Its geographical range extends as far south as Mexico City, Mexico, and as far north as Keg River, Alberta, Canada. It is native to North America and is an important insect pest of canola in the northern Great Plains. In North Dakota, bertha armyworm occurs primarily throughout the northern canola-producing counties. Severe infestations of bertha armyworm can be sporadic or widespread and usually occur every fi ve to seven years. However, in years when outbreaks have occurred, larval feeding has caused economic crop losses and increased production costs from spraying insecticidesItem Biology of Pyrilla perpusilla Walker (Homoptera:Lophopidae), A pest of Sugarcane in the Wet Zone of Sri Lanka.(Journal of Entomology, 2006) Ganehiarachchi G.A.S.M.; Fernando, I.V.S.Item Diamondback moth. Biology and Integrated Pest Management in Canola(North Dakota State University, 2008) Knodel, J.J.; Ganehiarachchi G.A.S.M.The diamondback moth, Plutella xylostella (Linnaeus), belongs to the order Lepidoptera and family Plutellidae. It is an important, occasional pest of canola in North Dakota. The immature stage, or larva, injures the leaves, buds, fl owers and seed pods of canola. In the North Dakota, the severity of infestation varies considerably from year to year and depends on the numbers and seasonal timing of migrating moths. The most recent outbreaks occurred in 2001 and 2007, primarily in the northcentral and northeastern regions of North Dakota.Item Discovery of the Critically Endangered Tarantula Species of the Genus Poecilotheria, (Araneae: Theraphosidae), Poecilotheria hanumavilasumica, from Sri Lanka(Journal of Asia – Pacific Biodiversity, 2015) Nanayakkara R.P.; Ganehiarachchi G.A.S.M.; Vishvanath N.; Kusuminda T.G.TThe arboreal spiders in the genus Poecilotheria is represented by 16 species and restricted to India and Sri Lanka. Each country has eight endemic species. During a survey on mygalomorph spiders in the Northern Province of Sri Lanka, the critically endangered species of Theraphosidae Poecilotheria hanumavilasumica was discovered for the first time outside of its native habitat in India, expanding its range to northern Sri Lanka. The discovery of P. hanumavilasumica is unique, as it used to be a critically endangered and endemic species of the genus Poecilotheria found in India, and it is evident that during the land bridge connection between India and Sri Lanka, when the Pleistocene epoch biotic exchange took place between the two countries, taxa were dispersed through the land connections.Item The effect of height from ground level and the age of coconut shell on the oviposition and fecundity of Aedes albopictus mosquitoes(Institute of Biology, Sri Lanka, 2013) Weerakoon, S.N.; Ganehiarachchi G.A.S.M.Item Fitness consequences of selecting young leaves for oviposition in the Hessian fly(Entomological Society of America, Cincinnati, Ohio., 2003) Ganehiarachchi G.A.S.M.; Harris, M.O.As well selecting particular genotypes for oviposition, female Hessian flies select particular sites within an individual host plant. The youngest leaves of the wheat plant typically receive the greatest numbers of eggs. We quantified the preference of the ovipositing female for the younger leaves and then studied the consequences of this preference for the feeding stages of the Hessian fly. The survival and growth of larva that eclosed from the egg on young versus old leaves was compared across different larval densities. Species 1: Diptera Cecidomyiidae Mayetiola destructor (Hessian fly)Item Integrated Pest management of Alfalfa Weevil in North Dakota.(North Dakota State University, 2013) Beauzay, P.B.; Knodel, J.J.; Ganehiarachchi G.A.S.M.Item Integrated Pest Management of the orange wheat blossom midge in North Dakota(North Dakota State University, 2008) Knodel, J.J.; Ganehiarachchi G.A.S.M.Item The invertebrate fauna colonizing two submerged aquatic plants in the stream at Horton Plains, Sri Lanka(Sri Lanka Association for Fisheries and Aquatic Resources, 1995) Ganehiarachchi G.A.S.M.; Costa, H.H.Item Investigation on Oviposition responses of container breeding mosquitoes to different coloured containers and to the location using tap water, hay infusion and ariconut infusion(Institute of Biology, Sri Lanka, 2013) Fernando, H.M.S.N; Ganehiarachchi G.A.S.M.Item Larvivorous efficacy of selected fish species in controlling Anopheles mosquito larvae in Mahaoya, Ampara in Sri Lanka(Institute of Biology, Sri Lanka, 2013) Ganehiarachchi G.A.S.M.; Amarasinghe, L.D.Item Leaf species identity and their combination effect on oviposition choice and growth performance of Asian tiger mosquito, Aedes albopictus (Diptera: Culicidae) Lanka(Institute of Biology, Sri Lanka, 2014) Nayakarathne, N.M.N.G.; Ganehiarachchi G.A.S.M.Item Natural enemies of sugarcane Planthopper Pyrilla perpusilla Walker (Homoptera: Lophopidae)(Journal of the National Science Foundation of Sri Lanka, 2000) Ganehiarachchi G.A.S.M.; Fernando, I.V.S.Item A new species of tiger spider, genus Poecilotheria, from northern Sri Lanka(British Terantula Society, 2012) Nanayakkara R.P.; Kirk, P.J.; Dayananda S.J.; Ganehiarachchi G.A.S.M.; Vishvanath N.; Kusuminda T.Item Occurrence and Parasitism of Sitodiplosis mosellana (Diptera: Cecidomyiidae) in North Dakota(Entomological Society of America, San Diego,California, 2007) Knodel, J.J.; Ganehiarachchi G.A.S.M.; Kirk, A.; Harris, M.O.Item Ovipositing females of a short-lived gall midge take time to assess grass seed heads(Physiological Entomology, 2008) Ganehiarachchi G.A.S.M.; Marion O.H.The short-lived adult wheat midge Sitodiplosis mosellana deposits eggs on the seed head of various grasses close to the developing seeds on which larvae feed. The time taken to make egg-laying decisions is investigated using three types of wheat Triticum aestivum seed heads. Young Roblin, Old Roblin and Young Key differ in their effects on ovipositing females (72%, 22% and 6% of eggs in choice tests, respectively) and effects on feeding larvae (75%, 25% and 5% larval survival, respectively). Within seconds of arriving, the female is able to distinguish Young Roblin from the two lower-ranked types. However, the lower-ranked types are not rejected at this time. Instead, all head types are examined before the female eventually flies away. On Young Roblin, probing with the ovipositor is the first behaviour that occurs. Thereafter probing and insertion of the ovipositor occupy most of the female’s time and behavioural transitions tend to be ‘progressive’, signalling a shift from low to high intensity examining. Differences between females visiting Old Roblin and Young Key are significant but take longer to emerge. On both, sitting is the first behaviour but, over the next 5–10 min, the female on Young Key exhibits more sitting, walking and ‘regressive’ transitions than the female on Old Roblin. It is suggested that, when the ovipositing female is short-lived and incapable of controlled flight in all but essentially windless conditions, her behaviour is designed to thoroughly, rather than rapidly, examine a suboptimal host before abandoning it for the uncertain future of finding a better host.Item Oviposition behavior of orange wheat blossom midge on low – versus high ranked grass heads(Entomologia Experimentalis et Applicata, 2007) Ganehiarachchi G.A.S.M.; Marion O.H.The discovery of Sm1 , a highly effective resistance ( R ) gene that targets the first instar of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), has created concerns about wheat midge adaptation. Strategies for delaying adaptation to Sm1 include the simultaneous deployment of a resistance trait targeting a different life stage, i.e., the ovipositing adult female. Previous studies have shown that adult females distinguish between wheat genotypes and seed head developmental stages and are attracted by volatiles from young wheat heads. We focused on what happens after the female lands on the seed head, comparing in three tests a seed head of the high-ranked pre-anthesis ‘Roblin’ wheat, Triticum aestivum L. (Poaceae), and a head of one of three lower-ranked types: post-anthesis ‘Roblin’, pre-anthesis ‘Key’ wheat ( T. aestivum ), and pre-anthesis ‘Robust’ barley ( Hordeum vulgare L.). Within each test, high- and low-ranked heads were presented in choice and no-choice assays, with the behavior of wheat midge females scored every 5 min from 20:30 to 23:00 hours, under mid-summer natural light conditions and sunset occurring between 20:50 and 21:20 hours. Head type influenced both proportions of females observed on the head and proportions of females probing with the ovipositor. Head*assay interactions occurred only in the test comparing wheat to barley, with barley reducing females observed on the wheat head and wheat increasing females probing on barley. Results indicate that the wheat midge female detects plant cues while examining the seed head and that this detection contributes to differences in egg counts.Item Oviposition behavior of orange wheat blossom midge on low – versus high ranked grass heads(Entomological Society of America, Fort Lauderdale, Florida, 2005) Ganehiarachchi G.A.S.M.; Harris, M.O.The wheat midge, Sitodiplosis mosellana (Géhan) (Diptera: Cecidomyiidae), is a serious pest of wheat in North America, Europe, and China. Adult females oviposit on the modified leaves of the seed head. Larvae hatch and migrate short distances, establishing a feeding site on a developing seed. Oviposition behavior was described on low-ranked versus high-ranked grass heads. The high-ranked type was ‘Roblin’ hard red spring wheat (Triticum aestivum), with the seed head at an early stage of development, i.e. pre-anthesis. The three low-ranked plant types were 1) post-anthesis ‘Roblin’, 2) pre-anthesis ‘Key 24’ hard red spring wheat, and 3) pre-anthesis ‘Robust’ barley (Hordeum vulgare). The three low-ranked types were chosen because they consistently receive fewer eggs in the field. Observations of 2-day old mated females were conducted from mid-June to mid-August, during the 1 to 1.5 hours before and after sunset. In initial observations, behaviors of groups of females (4 per cage) were quantified using scan sampling methods, with the following scored: 1) the location of each female, i.e. on the seed head or the walls of the cage, and 2) behavior on the seed head, i.e. examining, with the ovipositor extended and touching the modified leaves, or sitting or walking, with the ovipositor telescoped. In a second set of observations, focal animal sampling was used to quantify the behavior of individual females from landing to flight away from the seed head. Observations showed that oviposition decisions are clearly influenced by information gained by examining the modified leaves of the seed head. Species 1: Diptera Cecidomyiidae Sitodiplosis mosellana (orange wheat blossom midge)