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Mosquito Species (mosquito + species)
Selected AbstractsEcology of invasive mosquitoes: effects on resident species and on human healthECOLOGY LETTERS, Issue 5 2005Steven A. Juliano Abstract Investigations of biological invasions focus on patterns and processes that are related to introduction, establishment, spread and impacts of introduced species. This review focuses on the ecological interactions operating during invasions by the most prominent group of insect vectors of disease, mosquitoes. First, we review characteristics of non-native mosquito species that have established viable populations, and those invasive species that have spread widely and had major impacts, testing whether biotic characteristics are associated with the transition from established non-native to invasive. Second, we review the roles of interspecific competition, apparent competition, predation, intraguild predation and climatic limitation as causes of impacts on residents or as barriers to invasion. We concentrate on the best-studied invasive mosquito, Aedes albopictus, evaluating the application of basic ecological theory to invasions by Aedes albopictus. We develop a model based on observations of Aedes albopictus for effects of resource competition and predation as barriers to invasion, evaluating which community and ecosystem characteristics favour invasion. Third, we evaluate the ways in which invasive mosquitoes have contributed to outbreaks of human and animal disease, considering specifically whether invasive mosquitoes create novel health threats, or modify disease transmission for existing pathogen,host systems. [source] Quantitative aspects of the regulation of ovarian development in selected anautogenous Diptera: integration of endocrinology and nutritionENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2001L. Barton Browne Abstract Aspects of the influence of nutrition on the degree of ovarian development in selected anautogenous Diptera are reviewed. The Diptera considered are several mosquito species, with emphasis on Aedes aegypti, the house fly, Musca domestica, the Australian bush fly, M. vetustissima and the blowflies, Lucilia cuprina and Phormia regina. All the selected species display discrete ovarian cycles in which all oocytes destined to reach maturity in a particular ovarian cycle develop synchronously. In these species, the proportion of females maturing oocytes and, where such data exist, the number of oocytes they mature are positively correlated with the amount of any particular nitrogen-containing material ingested or given by enema or by infusion. In addition, the degree of ovarian development may be affected by the chemical composition of nitrogen-containing food. Possible physiological bases for the observed relationships are discussed. Available evidence suggests that whether or not a female matures any oocytes is hormonally regulated and that the number of oocytes matured is probably regulated by the availability of nutrients. Some approaches that might further elucidate the physiological regulatory mechanisms involved in ovarian development are outlined. [source] Selective and frequency dependent predation of aquatic mosquito predator Diplonychus indicus Venkatesan & Rao (Hemiptera: Belostomatidae) on immature stages of three mosquito speciesENTOMOLOGICAL RESEARCH, Issue 6 2009Narayanasamy SIVAGNANAME Abstract Frequency dependent mosquito larval size (II and IV instars) and species selection by the water bug Diplonychus indicus against three mosquito species Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi was studied in the laboratory. The different frequencies used for each species selection were 20:30:50, 30:50:20, 50:20:30, 25:35:40, 35:40:25 and 40:25:35 of fourth instars of the respective three prey species. All nymphal water bugs (I,V instars) selected IV instar mosquito larvae and the mean proportion of late (larger) larvae eaten by the predator instars was significantly higher than the mean proportion of early (smaller) larvae eaten (F= 2.28; P < 0.001). In all six ratios used to determine the frequency dependent mosquito species selection, all the stages of the water bug selected Ae. aegypti over the other two species (F= 452.43; P < 0.001). The mean number of mosquito larvae eaten increased as its density increased based on various ratios of larvae offered. The study indicated that the predatory efficiency of D. indicus was high when Ae. aegypti was offered as prey, suggesting the utility of this mosquito predator in the control of dengue vectors. [source] Characterization of the Hox gene cluster in the malaria vector mosquito, Anopheles gambiaeEVOLUTION AND DEVELOPMENT, Issue 6 2000Martin P. Devenport SUMMARY The Hox genes play a central role in regulating development and are involved in the specification of cell fates along the anteroposterior axis. In insects and vertebrates, these genes are clustered and organized in an arrangement that is largely conserved across evolutionary lineages. By exploiting the sequence conservation of the homeobox, orthologues of the Hox genes Sex combs reduced (Scr ,), fushi tarazu (ftz,), Antennapedia (Antp), Ultrabithorax (Ubx,), and abdominal-A (abd-A) have been isolated from the malaria vector mosquito, Anopheles gambiae. These genes were first identified in Drosophila, where they achieve a high level of functional complexity, in part, by the use of alternative promoters, polyadenylation sites, and splicing to generate different protein isoforms. Preliminary analyses of the Anopheles Hox genes suggest that they do not achieve their functional complexity in the same manner. Using a combination of in situ hybridization to polytene chromosomes and chromosome walking, the Anopheles Hox genes have been localized to a single cluster in the region 19D,E on chromosome 2R, a situation distinct from that of Drosophila where the Hox complex is split into two clusters. This study, therefore, provides a framework for future comparative analyses of the structure, organization, and expression of developmental regulatory genes between the lower and higher Diptera. Moreover, the genes that have been isolated enhance the genetic and physical maps of chromosome 2R in this medically important mosquito species. [source] Evidence of multiple chromosomal inversions in Aedes aegypti formosus from SenegalINSECT MOLECULAR BIOLOGY, Issue 5 2009S. A. Bernhardt Abstract Chromosomal inversions are prevalent in mosquito species but polytene chromosomes are difficult to prepare and visualize in members of the tribe Aedinii and thus there exists only indirect evidence of inversions. We constructed an F1 intercross family using a P1 female from a laboratory strain of Aedes aegypti aegypti (Aaa) and a P1 male Aedes aegypti formosus (Aaf) from a strain collected from south-eastern Senegal. Recombination rates in the F2 offspring were severely reduced and genotype ratios suggested a deleterious recessive allele on chromosome 3. The F2 linkage map was incongruent in most respects with the established map for Aaa. Furthermore, no increased recombination was detected in F5 offspring. Recombination rates and gene order were consistent with the presence in Aaf of at least four large inversions on chromosome 1, a single small inversion on chromosome 2 and three inversions on chromosome 3. [source] Isolation of cDNA clones encoding putative odourant binding proteins from the antennae of the malaria-transmitting mosquito, Anopheles gambiaeINSECT MOLECULAR BIOLOGY, Issue 2 2002Harald Biessmann Abstract One way of controlling disease transmission by blood-feeding mosquitoes is to reduce the frequency of insect,host interaction, thus reducing the probability of parasite transmission and re-infection. A better understanding of the olfactory processes responsible for allowing mosquitoes to identify human hosts is required in order to develop methods that will interfere with host seeking. We have therefore initiated a molecular approach to isolate and characterize the genes and their products that are involved in the olfactory recognition pathway of the mosquito Anopheles gambiae, which is the main malaria vector in sub-Saharan Africa. We report here the isolation and preliminary characterization of several cDNAs from male and female A. gambiae antennal libraries that encode putative odourant binding proteins. Their conceptual translation products show extensive sequence similarity to known insect odourant binding proteins (OBPs)/pheromone binding proteins (PBPs), especially to those of D. melanogaster. The A. gambiae OBPs described here are expressed in the antennae of both genders, and some of the A. gambiae OBP genes are well conserved in other disease-transmitting mosquito species, such as Aedes aegypti and Culex quinquefasciatus. [source] Innate immunity against malaria parasites in Anopheles gambiaeINSECT SCIENCE, Issue 1 2008Yang Chen Abstract Malaria continues to exert a huge toll in the world today, causing approximately 400 million cases and killing between 1-2 million people annually. Most of the malaria burden is borne by countries in Africa. For this reason, the major vector for malaria in this continent, Anopheles gambiae, is under intense study. With the completion of the draft sequence of this important vector, efforts are underway to develop novel control strategies. One promising area is to harness the power of the innate immunity of this mosquito species to block the transmission of the malaria parasites. Recent studies have demonstrated that Toll and Imd signaling pathways and other immunity-related genes (encoding proteins possibly function in recognition or as effector molecules) play significant roles in two different arms of innate immunity: level of infection intensity and melanization of Plasmodium oocysts. The challenges in the future are to understand how the functions of these different genes are coordinated in defense against malaria parasites, and if different arms of innate immunity are cross,regulated or coordinated. [source] Complex population history of two Anopheles dirus mosquito species in Southeast Asia suggests the influence of Pleistocene climate change rather than human-mediated effectsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2008S. M. O'LOUGHLIN Abstract Anopheles dirus and Anopheles baimaii are closely related species which feed on primates, particularly humans, and transmit malaria in the tropical forests of mainland Southeast Asia. Here, we report an in-depth phylogeographic picture based on 269 individuals from 21 populations from mainland Southeast Asia. Analysis of 1537 bp of mtDNA sequence revealed that the population history of A. baimaii is far more complex than previously thought. An old expansion (pre-300 kyr BP) was inferred in northern India/Bangladesh with a wave of south-eastwards expansion arriving at the Thai border (ca 135,173 kyr BP) followed by leptokurtic dispersal very recently (ca 16 kyr BP) into peninsular Thailand. The long and complex population history of these anthropophilic species suggests their expansions are not in response to the relatively recent (ca 40 kyr BP) human expansions in mainland Southeast Asia but, rather, fit well with our understanding of Pleistocene climatic change there. [source] Towards a fuller understanding of mosquito behaviour: use of electrocuting grids to compare the odour-orientated responses of Anopheles arabiensis and An. quadriannulatus in the fieldMEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2008S. J. TORR Abstract The epidemiological role of and control options for any mosquito species depend on its degree of ,anthropophily'. However, the behavioural basis of this term is poorly understood. Accordingly, studies in Zimbabwe quantified the effects of natural odours from cattle and humans, and synthetic components of these odours, on the attraction, entry and landing responses of Anopheles arabiensis Giles (Diptera: Culicidae) and Anopheles quadriannulatus Theobald. The numbers of mosquitoes attracted to human or cattle odour were compared using electrocuting nets (E-nets), and entry responses were gauged by the catch from an odour-baited entry trap (OBET) relative to that from an odour-baited E-net. Landing responses were estimated by comparing the catches from E-nets and cloth targets covered with an electrocuting grid. For An. arabiensis, E-nets baited with odour from a single ox or a single man caught similar numbers, and increasing the dose of human odour from one to three men increased the catch four-fold. For An. quadriannulatus, catches from E-nets increased up to six-fold in the progression: man, three men, ox, and man + ox, with catch being correlated with bait mass. Entry responses of An. arabiensis were stronger with human odour (entry response 62%) than with ox odour (6%) or a mixture of cattle and human odours (15%). For An. quadriannulatus, the entry response was low (< 2%) with both cattle and human odour. Anopheles arabiensis did not exhibit a strong entry response to carbon dioxide (CO2) (0.2,2 L/min). The trends observed using OBETs and E-nets also applied to mosquitoes approaching and entering a hut. Catches from an electrocuting target baited with either CO2 or a blend of acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol , components of natural ox odour , showed that virtually all mosquitoes arriving there alighted on it. The propensity of An. arabiensis to enter human habitation seemed to be mediated by odours other than CO2 alone. Characterizing ,anthropophily' by comparing the numbers of mosquitoes caught by traps baited with different host odours can lead to spurious conclusions; OBETs baited with human odour caught around two to four times more An. arabiensis than cattle-baited OBETs, whereas a human-baited E-net caught less (, 0.7) An. arabiensis than a cattle-baited E-net. Similar caution is warranted for other species of mosquito vectors. A fuller understanding of how to exploit mosquito behaviour for control and surveys requires wider approaches and more use of appropriate tools. [source] The ,ghosts' that pester studies on learning in mosquitoes: guidelines to chase them offMEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2006W. J. ALONSO Abstract The identification of memory and learning in medically important mosquito species has been of epidemiological interest mainly because of the implications of learning on the pattern of contact between vectors and hosts. Empirical results either showing or suggesting the existence of cognitive abilities in mosquitoes have been reported in a number of experimental studies, mainly based on the observation of individual fidelity towards subsets of specific resources, such as hosts, resting sites or breeding sites. A closer inspection of the design of these experiments shows that, with the exception of recent studies providing stronger evidence of learning in the genus Culex (Diptera: Culicidae), methodological shortcomings still hinder the possibility of eliminating alternative interpretations for these findings, in some cases because the experiments were not specifically designed to identify the phenomenon, but mostly because of a lack of appropriate controls or replication. By highlighting these limitations, while acknowledging the practical difficulties that are inherent to the field, we aim to help expel from future research the ,ghosts' that still preclude the achievement of more definite conclusions about the prevalence of memory and learning in this group of insects. [source] Bacteriophage WO-B and Wolbachia in natural mosquito hosts: infection incidence, transmission mode and relative densityMOLECULAR ECOLOGY, Issue 9 2006N. CHAUVATCHARIN Abstract Bacteriophages of Wolbachia bacteria have been proposed as a potential transformation tool for genetically modifying mosquito vectors. In this study, we report the presence of the WO-B class of Wolbachia -associated phages among natural populations of several mosquito hosts. Eighty-eight percent (22/25) of Wolbachia -infected mosquito species surveyed were found to contain WO-B phages. WO-B phage orf7 sequence analysis suggested that a single strain of WO-B phage was found in most singly (23/24) or doubly (1/1) Wolbachia -infected mosquitoes. However, the single Wolbachia strain infecting Aedes perplexus was found to harbour at least two different WO-B phages. Phylogenetic analysis suggested that horizontal transmission of WO-B phages has occurred on an evolutionary scale between the Wolbachia residing in mosquitoes. On an ecological scale, a low trend of co-transmission occurred among specific WO-B phages within Wolbachia of each mosquito species. Assessment of the density of WO-B phage by real-time quantitative polymerase chain reaction (RTQ-PCR) revealed an average relative density of 7.76 × 105± 1.61 × 105 orf7 copies per individual mosquito for a single Wolbachia strain infecting mosquitoes, but a threefold higher density in the doubly Wolbachia-infected Aedes albopictus. However, the average combined density of WO-B phage(s) did not correlate with that of their Wolbachia hosts, which varied in different mosquito species. We also confirmed the presence of WO-B-like virus particles in the laboratory colony of Ae. albopictus (KLPP) morphologically, by transmission electron microscopy (TEM). The viral-like particles were detected after purification and filtration of Ae. albopictus ovary extract, suggesting that at least one WO-B-like phage is active (temperate) within the Wolbachia of this mosquito vector. Nevertheless, the idea of utilizing these bacteriophages as transformation vectors still needs more investigation and is likely to be unfeasible. [source] Paradoxical effects of sublethal exposure to the naturally derived insecticide spinosad in the dengue vector mosquito, Aedes aegyptiPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 3 2009Gloria E Antonio Abstract BACKGROUND: Recent studies have indicated that spinosad, a mixture of two tetracyclic macrolide compounds produced during the fermentation of a soil actinomycete, may be suitable for controlling a number of medically important mosquito species, including the dengue vector, Aedes aegypti L. The authors determined the effects of a 1 h exposure to a 50% lethal concentration (LC50) of spinosad in the larval stage on the wing length, longevity and reproductive capacity of the adult survivors. RESULTS: The LC50 of spinosad for a wild-caught population of Ae. aegypti from Chiapas, southern Mexico, was estimated to be 0.06 mg AI L,1 in late third instars. Paradoxically, the female survivors of exposure to this concentration were significantly larger (as determined by wing length) laid more eggs, but were slightly less fertile than control females. This was probably due to elimination of the smaller and more susceptible fraction of mosquito larvae from the experimental population following spinosad treatment. Male survivors, in contrast, were significantly smaller than controls. No significant differences were detected in the adult longevity of treated and control insects of either sex. CONCLUSIONS: The increase in reproductive capacity of spinosad-treated females did not compensate for mortality in the larval stage and would be unlikely to result in population increase in this mosquito under the conditions that were employed. Sustained-release formulations would likely assist in minimizing the occurrence of sublethal concentrations of this naturally derived product in mosquito breeding sites. Copyright © 2008 Society of Chemical Industry [source] Insecticide resistance in vector mosquitoes in ChinaPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2006Feng Cui Abstract Because of their special behaviour, physiology and close relationship with humans, mosquitoes act as one of the most important vectors of human diseases, such as filariasis, Japanese encephalitis, dengue and malaria. The major vector mosquitoes are members of the Culex, Aedes and Anopheles genera. Insecticides play important roles in agricultural production and public health, especially in a country with a huge human population, like China. Large quantities of four classes of insecticides, organochlorines, organophosphates, carbamates and pyrethroids, are applied annually to fields or indoors in China, directly or indirectly bringing heavy selection pressure on vector populations. The seven major species of vector mosquito in China are the Culex pipiens L. complex, C. tritaeniorhynchus Giles, Anopheles sinensis Wied., A. minimus Theobald, A. anthropophagus Xu & Feng, Aedes albopictus (Skuse) and Ae. aegypti L., and all have evolved resistance to all the above types of insecticide except the carbamates. The degree of resistance varies among mosquito species, insecticide classes and regions. This review summarizes the resistance status of these important vector mosquitoes, according to data reported since the 1990s, in order to improve resistance management and epidemic disease control, and to communicate this information from China to the wider community. Copyright © 2006 Society of Chemical Industry [source] Daily patterns of locomotor and sugar-feeding activity of the mosquito Culex annulirostris from geographically isolated populationsPHYSIOLOGICAL ENTOMOLOGY, Issue 4 2005Craig R. Williams Abstract., The daily patterns of locomotor and sugar-feeding activity of virgin female Culex annulirostris from three regions in Australia and a laboratory colony are studied using video techniques in the laboratory. Although all populations display a crepuscular/nocturnal locomotor pattern, significant variation exists between populations, with the pattern of those from southern Australia differing markedly from those in central and northern Australia. It is hypothesized that adaptation of populations to local climates is responsible. Sugar-feeding (inferred from landing on a sugar source) is mostly crepuscular/nocturnal in all populations. The behavioural variation that exists within wide-ranging mosquito species is highlighted, and indicates that significant behavioural differences exist between laboratory colonies and wild-types. [source] Mapping members of the Anopheles gambiae complex using climate dataPHYSIOLOGICAL ENTOMOLOGY, Issue 3 2004S. W. Lindsay Abstract., Climate is the most important factor governing the distribution of insects over large areas. Warmth and moisture are essential for most insects' reproduction, development and survival. Here, it is shown that the principal vectors of malaria in Africa, members of the Anopheles gambiae complex, flourish within specific climate envelopes. By identifying these climatic conditions empirically, using climate or environmental databases, it is possible to map the distribution and relative abundance of mosquito species, and their chromosomal forms, at continental scales. Alternatively, mathematical models based on a fundamental understanding of how mosquitoes are affected by different climate factors, such as temperature and humidity, can also be employed to map distributions. Empirical or process-driven models based on climate, or other environmental variables, provide simple tools for mapping the distribution and relative abundance of vectors at a coarse scale over large areas. [source] Oviposition habitat selection by mosquitoes in response to predator (Notonecta maculata) densityPHYSIOLOGICAL ENTOMOLOGY, Issue 2 2004Avi Eitam Abstract., Some species of mosquitoes can detect the presence of predatory notonectid bugs and avoid oviposition in predator pools. The oviposition response of two mosquito species, Culiseta longiareolata Macquart and Culex laticinctus Edwards (Diptera: Culicidae), to a range of densities of the predator, Notonecta maculata Fabricius (Heteroptera: Notonectidae), was tested here. Densities of 0, 1, 2 or 4 Notonecta were established in 30-L artificial pools. Both mosquito species oviposited less in predator pools, but the response was unrelated to predator density, whereas vulnerability of Culiseta immatures to predation was density-dependent. Thus, although mosquitoes can detect Notonecta at any density within the range tested, they may be unable to discriminate among predator densities. The avoidance of predator pools by Culiseta, as well as its vulnerability to predation, occurred to a lesser degree than in earlier studies. This may have been due to the mitigating effects of components of the biotic community. [source] Molecular Phytogeny and Evolution of Mosquito Parasitic Microsporidia (Microsporidia: Amblyosporidae),THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 1 2004CHARLES R. VOSSBRINCK ABSTRACT. Amblyospora species and other aquatic Microsporidia were isolated from mosquitoes, black flies, and copepods and the small subunit ribosomal RNA gene was sequenced. Comparative phylogenetic analysis showed a correspondence between the mosquito host genera and their Amblyospora parasite species. There is a clade of Amblyospora species that infect the Culex host group and a clade of Amblyospora that infect the Aedes/Ochlerotatus group of mosquitoes. Parathelohania species, which infect Anopheles mosquitoes, may be the sister group to the Amblyospora in the same way that the Anopheles mosquitoes are thought to be the sister group to the Amblyosporo and Aedes mosquitoes. In addition, by sequence analysis of small subunit rDNA from spores, we identified the alternate copepod host for four species of Amblyospora. Amblyospora species are specific for their primary (mosquito) host and each of these mosquito species serves as host for only one Amblyospora species. On the other hand, a single species of copepod can serve as an intermediate host to several Amblyospora species and some Amblyospora species may be found in more than one copepod host. Intrapredatorus barn, a species within a monotypic genus with Amblyospora-like characteristics, falls well within the Amblyospora clade. The genera Edhazardia and Culicospora, which do not have functional meiospores and do not require an intermediate host, but which do have a lanceolate spore type which is ultrastructurally very similar to the Amblyospora spore type found in the copepod, cluster among the Amblyospora species. In the future, the genus Amblyospora may be redefined to include species without obligate intermediate hosts. Hazardia, Berwaldia, Larssonia, Trichotuzetia, and Gurleya are members of a sister group to the Amblyospora clades infecting mosquitoes, and may be representatives of a large group of aquatic parasites. [source] Identification and expression of odorant-binding proteins of the malaria-carrying mosquitoes Anopheles gambiae and Anopheles arabiensisARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2005Zheng-Xi Li Abstract Host preference and blood feeding are restricted to female mosquitoes. Olfaction plays a major role in host-seeking behaviour, which is likely to be associated with a subset of mosquito olfactory genes. Proteins involved in olfaction include the odorant receptors (ORs) and the odorant-binding proteins (OBPs). OBPs are thought to function as a carrier within insect antennae for transporting odours to the olfactory receptors. Here we report the annotation of 32 genes encoding putative OBPs in the malaria mosquito Anopheles gambiae and their tissue-specific expression in two mosquito species of the Anopheles complex; a highly anthropophilic species An. gambiae sensu stricto and an opportunistic, but more zoophilic species, An. arabiensis. RT-PCR shows that some of the genes are expressed mainly in head tissue and a subset of these show highest expression in female heads. One of the genes (agCP1588) which has not been identified as an OBP, has a high similarity (40%) to the Drosophila pheromone-binding protein 4 (PBPRP4) and is only expressed in heads of both An. gambiae and An. arabiensis, and at higher levels in female heads. Two genes (agCP3071 and agCP15554) are expressed only in female heads and agC15554 also shows higher expression levels in An. gambiae. The expression profiles of the genes in the two members of the Anopheles complex provides the first step towards further molecular analysis of the mosquito olfactory apparatus. Arch. Insect Biochem. Physiol. 58:175,189, 2005. © 2005 Wiley-Liss, Inc. [source] Efficacy of bird-baited traps placed at different heights for collecting ornithophilic mosquitoes in eastern Queensland, AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2009Cassie C Jansen Abstract To compare the efficacy of bird-baited traps with standard CO2 -baited Centers for Disease Control (CDC) light traps for collecting ornithophilic mosquito species, seven Latin square trials were conducted at six urban sites in Cairns and Brisbane, Australia. Traps were placed 1 m above ground level and 5,10 m according to tree canopy height. CO2 -baited CDC traps consistently collected more mosquitoes of all species than the bird-baited traps at all locations. In Brisbane, CO2 -baited CDC traps placed at ground level collected significantly more Culex annulirostris Skuse than those at canopy height during two trials, and more Aedes vigilax (Skuse) and Ae. procax (Skuse) during one trial each. Conversely, in Cairns, CO2 -baited CDC traps placed in the tree canopy collected significantly more Cx. squamosus (Taylor) during two trials, and significantly more Aedeomyia catasticta Knab and Cx. cubiculi Marks during one trial each. Consistently low yields of ornithophilic species including Cx. australicus Dobrotworsky & Drummond and Cx. quinquefasciatus Say in all traps tested suggests the need to employ alternative trapping measures to target these species in urban areas. [source] Studies of Aedes aegypti (Diptera: Culicidae) ovipositional responses to newly identified semiochemicals from conspecific eggsAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2006Kumaran Ganesan Abstract, The chemical factors influencing the selection of oviposition site by gravid females of various mosquito species have been the subject of numerous investigations. Recent studies have revealed this behaviour to be controlled by semiochemicals. Here we report studies on semiochemicals of egg origin and their effect on the ovipositional behaviour of Aedes aegypti. The compounds present in egg extracts of Ae. aegypti mosquitoes were isolated and identified by gas chromatography-mass spectrometry. They were then evaluated for their effect on ovipositional behaviour against gravid females of Ae. aegypti mosquitoes at different concentrations. Gravid female Ae. aegypti were found to be sensitive to all the identified compounds: 6-hexanolactone, methyl dodecanoate, dodecanoic acid, methyl tetradecanoate, tetradecanoic acid, methyl (Z)-9-hexadecenoate, methyl hexadecanoate (Z)-9-hexadecenoic acid, hexadecanoic acid, methyl (Z)-9-octadecenoate, methyl octadecanoate (Z)-9-octadecenoic acid and octadecanoic acid. Among them, dodecanoic and (Z)-9-hexadecenoic acids showed significant positive ovipositional response at different concentrations whereas all the esters showed deterrent/repellent ovipositional effect. [source] Development time and survival of Verrallina funerea (Theobald) (Diptera: Culicidae) immatures and other brackish water mosquito species in southeast Queensland, AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2005Jason A L Jeffery Abstract,Verrallina funerea (Theobald) is a brackish water mosquito that is recognised as an important pest and vector in southeast Queensland, Australia. Immature development time and survival of Ve. funerea was defined in the laboratory in response to a range of temperatures (17,34°C) and salinities (0,35 parts per thousand (p.p.t)). The expression of autogeny in this species was also assessed. Salinity only had a slight effect on mean development time from hatching to adult emergence (7.0,7.4 d at salinities of 0, 17.5 and 31.5 p.p.t) and survival was uniformly high (97.5,99.0%). Mean development times were shorter at 26, 29 and 32°C (7.0, 6.8 and 6.8 d, respectively) and longest at 17°C (12.2 d). The threshold temperature (t) was 5.8°C and the thermal constant (K) was 142.9 degree-days above t. Survival to adulthood decreased from >95% (at 17,29°C) to 78% (at 32°C) and 0% (at 34°C). No expression of autogeny was observed. Immature development times of Ve. funerea, Ochlerotatus vigilax (Skuse) and Oc. procax (Skuse) were then determined under field conditions at Maroochy Shire. Following tide and rain inundation, cohorts of newly hatched larvae were monitored daily by dipping, and time until pupation was noted. Tidal inundation triggered hatching of Ve. funerea and Oc. vigilax larvae whereas Oc. procax larvae were found only after rain inundation. Estimates of Ve. funerea and Oc. vigilax field development times were similar (8,9 d) while Oc. procax development time was slightly longer (9,10 d). Based on these survey results, control activities targeting Ve. funerea must be initiated 4 d (if using Bacillus thuringiensis var. israelensis de Barjac) or 5 d (if using s -methoprene) after inundation. However, Casuarina glauca Sieber canopy and branchlets covering breeding habitats may present a problem for the penetration of such treatments. [source] | |||||||||||||||||||||||||