Zoology
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Item Records of fruit files(Diptera: Tephritidae: Dacinae: Dacini) in a selected mango (Mangifera indica L.)(Kautha Kollomban) cultivation in Ambalanthota, Sri Lanka.(Proceedings of the lnternational Symposium on Agriculture and Environment 2022,University of Ruhunu, Sri Lanka., 2022) Wijekoon, W.M.C.D.; Ganehiarachchi, G.A.S.M.; Wegiriya, H.C.E.; Vidanage, S.P.Fn1lr flies are one of the widely dlstrlbuted Insect pests and rhey mostly damage economically Important fruits and vegetables In the tropical region. However. there are no recently published reports of fruit fly assemblages associated with conunerclal fruit plantations In Srt Lanka. Hence. the present study aimed to investigate the abundance and d.lversll)' of fruit files arcracted to the methyl-eugenol tleld rraps In a selected mango cultivation ("Kan11ha kollomban· vartecy) In Ambalanthota Srt Lanka. Six fruit fly traps (5 cm diameter. 10 cm height two cirrnlar openinglmm radius and a methyl-eugenol coated sponge) were bun: (1.5· 4 m above the ground level and 20111 inter-trap dlsrance) In six mango trees which were located In die middle of each randomly selected slx sampling plots (400111') in die cultivation (0.54 ha). Trapped flies were collected twice a month from October to December 2021 (during the fruiting season) replacing new traps In each sampling round. Collected samples were ldentlfled using s tandard taxonomic keys by observing wider the light microscope (Nlkon-ECLIPSE-ElOO) ( 10•4). Two Indices: Simpson Population Dominance lnde.~ and the Abundance Index were calatlated The variation or species abw1dance was compared using one-way ANOVA test. Seven fruit fly species: Baccrocera dorsalls (Hendel). R kandlansts (Drew and Hancock). B. correaa (Be-zzl). B. /arlfrons (Hendel), B. cubercr,lara (Bezzl), B, ntgrofemoralts (White and Tsuruta) and B. cacumfnaca (Hering) were recorded In this smdy. Out or the total 803 specimens examined, B. dorsalis had a slgnltlcanrly higher abundance ( 412, 51.31 %) (P<0.05) dian other species, and B. cacumlnaca had the lowest abmtdance (26. 3.24%). The highest Simpson Dominance Index (0.26) 1vas recorded for B. dorsolls while other recorded slx fruit fly species were less dominant In the selected mango cultivation. Smdy tlndlngs will be Important for fruit cultivators to design and Implement fruit fly control measures.Item Socio-economic and ecological impacts on dispersal of cutaneous leishmaniasis in North Central Province, Sri Lanka(International Journal of Tropical Insect Science, 2022) Nayakarathna, N.M.N.G.; Jayatunga, D.P.W.; Ganehiarachchi, G.A.S.M.Leishmaniasis is a fatal disease caused by a parasitic protist of the genus Leishmania through the infected primary vectors, Phlebotomine (Diptera: Psychodidae) female sand flies. In Sri Lanka, cutaneous leishmaniasis (CL) is established in Anuradhapura district. The present study was carried out to determine the socio-economic and environmental factors on the distribution of CL. A survey was conducted among CL patients on selected demographic and socio-economic factors and environmental characteristics at three study localities throughout a year. Phlebotomine sand flies were collected using sticky traps and Centers for Disease Control (CDC) light traps around residences of CL patients. Significant differences were shown between mean abundance of primary vectors and different environmental characteristics. The sand flies were reported to gather in shrubs, jungle areas, gardening areas, wet soil areas, leaf litter and around termite hills. The data obtained showed poor knowledge and lack of awareness about leishmaniasis among the local communities. Therefore, it is paramount to conduct awareness programs on leishmaniasis transmission, potential risk factors, sand fly vector of the disease, preventing the sand fly bites and how domestic surrounding areas must be managed for reducing vector populations to prevent disease spreading among local community.Item The effect of chemical exudates of three larvivorous fish species on oviposition preference of Aedes aegypti and Aedes albopictus (Diptera: Culicidae)(Med Vet Entomol, 2021) Rathnayaka, R.M.G.S.; Jayatunga, D.P.W.; Ganehiarachchi, G.A.S.M.Mosquito species Aedes aegypti and Aedes albopictus are vectors of dengue worldwide. Mosquito vector control through maintaining larvivorous fish in water bodies is generally suggested, however, its underlying role towards oviposition preference of these dengue vectors is unknown in the Sri Lankan context. The current study investigated the effect of chemical exudates from larvivorous fish species Poecilia reticulata, Rasbora daniconius and Applocheilus dayi on the oviposition preference of Aedes mosquitoes. The number of eggs laid by each mosquito species was determined using ovitraps that contained water conditioned by the fish species both separately and in combination. The ovitraps were placed inside insect cages containing engorged gravid Aedes females. Both the mosquito species had the least preference of oviposition in water conditioned by A. dayi followed by R. daniconius. The highest preference of oviposition was shown for water conditioned by P. reticulata. The current study indicated that oviposition site selection in Ae. aegypti and Ae. albopictus was reduced by A. dayi and R. daniconius, however, it was not influenced by the fish combinations used. Further studies are warranted to understand the chemical cues associated with larvivorous fish towards the oviposition preference in Aedes mosquitoes.Item Influence of Vertebrate Excreta on Attraction, Oviposition and Development of the Asian Tiger Mosquito, Aedes albopictus (Diptera: Culicidae)(MDPI, 2021) Rajapaksha, R.D.T.; Jayatunga, D.P.W; Ganehiarachchi, G.A.S.M.Aedes albopictus is an important vector of dengue worldwide. Eliminating dengue in Sri Lanka depends entirely on controlling the vector and human-vector contact. Thus, studying the bionomics and behavior of Ae. albopictus is paramount. The objective of this study was to evaluate the effect of the excreta of cow, goat and pig on the attraction, oviposition and development of Ae. albopictus. Bioassay chambers determined the mosquito stimulatory response. Ovitraps determined Ae. albopictus oviposition preference to excreta singly, in combination and on fermentation. The excreta effect on larval development was also determined. The results revealed that Ae. albopictus gravid females were significantly attracted to goat excreta but were repelled by pig excreta. The oviposition preference was highest for cow excreta and lowest for pig excreta. For excreta combinations, the Cow+Goat combination increased the oviposition while the Pig+Goat combination reduced the oviposition. The oviposition preference of Ae. albopictus increased with the rate of fermentation. The pig excreta increased the Ae. albopictus larval mortality, larval and pupal duration and reduced adult fecundity, whereas the cow excreta positively affected all these aspects. Our findings additionally suggest that a high abundance of Ae. albopictus in rural areas of Sri Lanka may be due to its oviposition attraction and growth performance for vertebrate excreta.Item Effect of predatory fish chemical exudates on oviposition preference of two Aedes mosquito species; Aedes aegypti and Aedes albopictus(Sri Lanka Association for Fisheries and Aquatic Resources, 2016) Rathnayaka, R.M.G.H.; Ganehiarachchi, G.A.S.M.Item Comparison of larvicidal and repellent efficacy of Ocimum basilicum (L.); “Maduruthala”, leaves and pods, against dengue vector, Aedes aegypti (L.)(Institute of Biology, Sri Lanka, 2015) Abhayawickrama, W.L.B.P.; Ganehiarachchi, G.A.S.M.; Paranagama, P.A.Item Investigation of oviposition responses of container breeding mosquitoes to different colored 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 Bionomics and Intergrated Control of the Sunflower Seed Maggot (Neotephritis finalis) and the Sunflower Bud Moth (Suleima helianthana) in the Nothern Plains Sunflower Production Region. 2009 Results.(National Sunflower Association Research Forum, 2010) Knodel, J.J.; Ganehiarachchi, G.A.S.M.; Charlet, L.D.; Beauzay, P.In the past several years, sunflower producers, field scouts and seed companies have expressed concern about the injury to sunflower resulting in deformed and misshapen areas in the head. The head damage was unlike that caused by sunflower midge and was attributed to feeding injury caused by the sunflower seed maggot, Neotephritis finalis (Loew) (Fig. 1) and/or sunflower bud moth, Suleima helianthana (Riley) (Fig. 2). Although reported from a number of sources, the exact extent and economic loss from these insect pests are not known. Although sunflower seed maggot and sunflower bud moth have been reported in the literature as insect pests of sunflower, a better understanding of their economic impact and potentially useful pest management strategies is needed. This research determined the biology of sunflower seed maggot in North Dakota, and examined two different pest management strategies for control of sunflower seed maggot and sunflower bud moth in North Dakota: 1) Planting dates, and 2) Insecticide timing and insecticide mode of action. Biology of Sunflower Seed Maggot: The bionomics of sunflower seed maggot was determined and findings are summarized in this report. Planting Dates: Late planting date (early to mid-June) was effective in reducing the damage ratings and percentage of damaged heads for sunflower seed maggot at three of the five locations examined in 2009 in North Dakota. Overall, population densities of sunflower seed maggots were low in 2009 and decreased from previous years (source NSA Sunflower Survey) making damage assessments between early (early to late May) and late (early to mid-June) planting dates difficult. For sunflower seed maggot, the late planting date had a lower percentage of damaged heads than the early planting date at three of the five research sites examined. For sunflower bud moth, the late planting date also had a lower percentage of damage heads than the early planting date at two of the five research sites examined. However, sunflower bud moth also had very low population levels and was reported only in sporadic ‘hot spots’ in 2009. Yield differences were attributed to other agronomic factors or bird damage, and not due to head damage caused by sunflower seed maggot or sunflower bud moth. Efficacy of Insecticide Timing and Mode of Action: Neither insecticide timing nor mode of action had any significant effect on the sunflower seed maggot damage ratings, nor the percentage of heads damaged from sunflower seed maggot or sunflower bud moth at any location. The lack of differences could be due to low population densities of adults or missed application timing. Therefore, future plans include the addition of insecticide applications at the R1 growth stage in addition to the R3 and R5 stages. For insecticide mode of action, the pyrethroid insecticide (Asana) and the organophosphate + pyrethroid insecticide (Cobalt) typically had higher yields than the organophosphate insecticide (Lorsban) alone. This is probably due to organophosphate insecticide having a shorter residual effect than pyrethroids. Given that the lowest yields were those treatments with insecticides applied at R3, yield differences are probably due to later (R5.1) infestations of other insect pests, like banded sunflower moth and/or red sunflower seed weevil. In conclusion, it was difficult to assess the insecticide efficacy and mode of action due to low population densities of adult insects. 2009 results indicate that there is no insecticide treatment correlation to damage assessment for sunflower seed maggot and sunflower bud moth and yield. Additional research is necessary to determine viable pest management strategies for control of sunflower seed maggot and sunflower bud moth.Item Impact of Planting Dates on a seed Maggot, Neotephritis finalis (Diptera: Tephritidae), and Sunflower Bud Moth (Lepidoptera: Tortricidae) Damage in cultivated sunflower(Journal of Economic Entomology, 2011) Knodel, J.J.; Ganehiarachchi, G.A.S.M.; Beauzay, P.B.; Chirumamilla, A.; Charlet, L.D.Neotephritis finalis (Loew) (Diptera: Tephritidae), and sunflower bud moth, Suleima helianthana (Riley) (Lepidoptera: Tortricidae) are major head-infesting insect pests of cultivated sunflower (Helianthus annuus L.). Planting date was evaluated as a cultural pest management strategy for control of N. finalis and S. helianthana in several production regions of North Dakota during 2009 and 2010. Results of the nine site-year study revealed that late planting date (early to mid-June) reduced damage ratings and percentage of damaged heads for N. finalis compared with early planting dates (mid- to late May). Visual observations of adult N. finalis found that the majority of flies were found in the early planted sunflower (78.2%) compared with the late planted sunflower (21.8%). Late planting date also reduced the percentage of S. helianthana damaged heads compared with early planting dates. Yield losses were reduced with late planting date when populations of N. finalis and S. helianthana were high enough to cause damage. Results of this study showed that delayed planting is an effective integrated pest management strategy that can reduce head damage caused by N. finalis and S. helianthana and mitigate yield losses.