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L P Lounibos

Publications and source records attributed to L P Lounibos.

At least 19 recordsLinked to original sources
PubMed2006

Superior reproductive success on human blood without sugar is not limited to highly anthropophilic mosquito species.

Anthropophilic mosquitoes such as Aedes aegypti L. (Diptera: Culicidae) have been shown to have superior reproductive success on human blood when sugar is not available. Life-table experiments were conducted with Aedes albopictus Skuse and Ae. aegypti to compare the effects of sugar availability on age-specific survivorship, lifetime and daily fecundity, and blood-feeding frequency when offered human blood daily. There were no significant interactions between the effects of sugar availability and mosquito species for these four variables, indicating similar effects of sugar availability for both species. Lifetime fecundity was not significantly affected by sugar availability, but sugar-deprived females had significantly reduced age-specific survivorship than did sugar-fed females. In absence of sugar, females took bloodmeals twice as often, resulting in a higher daily fecundity. The results indicate that superior reproductive success on human blood without sugar does not seem to be limited to highly anthropophilic mosquito species, such as Ae. aegypti. We conclude that evolution of a highly anthropophilic feeding strategy is not an inevitable result of the ability to thrive on human blood alone.

Aedes↗
PubMed2002

Does temperature affect the outcome of larval competition between Aedes aegypti and Aedes albopictus?

The superior larval competitive ability of Aedes albopictus has been proposed to explain the recent displacement of Aedes aegyptiby the former species inparts of the southeastern U.S. Ae. aegypti persists, however, in sympatry with Ae. albopictus in urban areas of southern Louisiana, Florida, and Texas, and the impact of larval competition between these species has not been investigated at higher temperatures that may be characteristic of these urban environments. We compared growth and survivorship of the two species at controlled temperatures of 24 degrees and 30 degrees C in water-containing tires under conditions of intra- and interspecific competition and with or without leaf litter. When other variables were controlled statistically, the estimated finite rate of increase (lambda') was significantly higher for both species at the higher temperature, and the proportional increases in lambda' did not differ between species. Therefore, our experiment predicts that by itself, temperatures between 24 degrees and 30 degrees C would not alter the outcome of larval competition. Overall, response measures of Ae. albopictus were more sensitive than those of Ae. aegypti to the litter and species/density variables, although the development ofAe. aegypti females was uniquely retarded by a high density of its own species.

Adaptation, Physiological↗
PubMed2000

Life tables of Toxorhynchites rutilus (Diptera: Culicidae) in nature in southern Florida.

Stage-specific survivorship curves were constructed for the immature stages of a native, predatory mosquito, Toxorhynchites rutilus (Coquillet), by regular censuses in the summer and fall of water-holding treeholes and tires. Survival from egg to adult ranged from 1.8 to 5.6%, and survivorship patterns were significantly heterogeneous between seasons and container types. The probability of death was highest in the first and fourth larval instars. Rainfall and drought were relatively unimportant risk factors during this study, but the probabilities of disappearance of eggs and first and fourth instars were significantly higher in the presence of large conspecifics, suggesting that cannibalism is a major source of mortality.

Aging↗
PubMed1999

A description and morphometric comparison of eggs of species of the Anopheles gambiae complex.

Eggs of the 6 named species of the Anopheles gambiae complex are described from scanning electron micrographs of specimens obtained from laboratory colonies or wild-caught females. Morphometric measurements of eggs from 5 sources of Anopheles arabiensis, 2 of Anopheles gambiae, one of Anopheles quadriannulatus, 2 of Anopheles bwambae, 2 of Anopheles merus, and one of Anopheles melas are compared, and relationships are analyzed by multivariate statistics. No morphologic characters were species-diagnostic, although tendencies of the saltwater species An. merus and An. melas to have wider decks and shorter floats were confirmed. Species and populations overlapped considerably in principal components and discriminant function analyses based on 10 attributes of eggs. Nevertheless, discriminant functions revealed similarities in eggs of species believed to be most closely related, namely, An. gambiae and An. arabiensis, An. merus and An. melas, and An. quadriannulatus and An. bwambae.

Animals↗
PubMed1999

Eryngium spp. (Umbelliferae) as phytotelmata and their Culex (Culex) inhabitants in temperate Argentina.

The host-plant fidelity, seasonality, and population dynamics of 3 species of Culex (Culex) were examined from monthly samples of mosquito immatures extracted from the leaf axils of Eryngium pandanifolium and Eryngium cabrerae growing sympatrically in the Punta Lara region of Buenos Aires Province, Argentina. Culex hepperi was collected only from E. pandanifolium, and abundance peaks of its larvae and pupae were asynchronous in forest and field habitats. However, the proportion of plants positive for Cx. hepperi, as well as larval densities and developmental success, did not differ between forest and field. Culex renatoi was collected only from E. cabrerae in the field habitat. The monthly numbers of Cx. hepperi and Cx. renatoi were not significantly correlated with the proportion of their host plants that held water. The stage-specific distributions of Cx. hepperi and C. renatoi numbers were highly skewed towards 1st instars and did not differ between species or, for Cx. hepperi, between forest and field habitats. Culex castroi was collected regularly from the axils of both species of Eryngium, but usually in lesser numbers than either Cx. hepperi or Cx. renatoi. Association analyses indicated significant positive associations between Cx. castroi and the other 2 culicine species in host plants. Culex renatoi occurred preferentially in small E. cabrerae, but Cx. castroi did not discriminate plants based on their size. These 3 species of Culex are known only from Eryngium spp. phytotelmata. We suggest that their host-plant specificity is maintained by oviposition preferences, which are more highly selective for Cx. hepperi or Cx. renatoi than for Cx. castroi.

Animals↗
PubMed1998

Morphological, molecular, and chromosomal discrimination of cryptic Anopheles (Nyssorhynchus) (Diptera: Culicidae) from South America.

Based on similarity of male genitalia, the malaria vector Anopheles trinkae Faran from the eastern Andean piedmont of Colombia, Ecuador, Peru, and Bolivia was determined by Peyton (1993) to be a junior synonym of An. dunhami Causey, then known from a single locality in Amazonian Brazil. Following an appraisal of molecular, chromosomal, and morphological characters, we conclude herein that the 2 taxa are specifically distinct and remove An. trinkae from synonymy with An. dunhami. Eggs of the 2 species are distinguished easily by the anterior crown, long floats, and closed deck that occur only in An. trinkae. The X chromosome of larval polytenes is divisible into R and L arms in An. dunhami, but not in An. trinkae. A phenogram based on banding pattern scores from 18 random amplified polymorphic DNA primers separated with 100% resolution An. dunhami, An. trinkae, Anopheles nuneztovari Gabaldón and Anopheles darlingi Root. In the ITS2 region of rDNA, 25% of base sites distinguished An. trinkae from An. dunhami and 21% from the related An. nuneztovari; males of these 3 species had accessory glands of significantly different sizes. Preliminary isoenzyme screening indicated that 3 of 11 loci were diagnostic for separating An. trinkae from An. dunhami. The results indicate that An. dunhami is related more closely to An. nuneztovari than to An. trinkae and illustrate the merits of a multidisciplinary approach to mosquito systematics.

Animals↗
PubMed1998

Prompt mating of released Anopheles darlingi in western Amazonian Brazil.

To identify times and sites of mating, 1- and 2-day-old virgin female Anopheles darlingi were marked with fluorescent dusts and released at dusk, midnight or dawn in a village on the outskirts of Porto Velho, Rondônia State, Brazil. Dissections of marked females captured at human baits revealed that mating occurred in less than 2 h after dusk releases near houses, and among these early recaptures, older females were significantly more likely to be inseminated. We suggest that mating shortly after peridomestic releases occurred without swarming outside houses.

Animals↗
PubMed1998

Egg maturation in neotropical malaria vectors: one blood meal is usually enough.

The requirement of more than one blood meal to complete a gonotrophic cycle is reported here to be infrequent among field-collected Anopheles (Nyssorhynchus), including Anopheles darlingi, South America's most important malaria vector. The overall frequencies of host-seeking females that did not develop eggs after one blood feeding were low for Anopheles darlingi (6.6%), Anopheles rondoni (5.0%), and Anopheles triannulatus (2.2%); the majority of wild-caught females that did not develop eggs after one blood meal were nulliparous. Laboratory-reared Anopheles albimanus and Anopheles albitarsis, other species of the same subgenus, were grown on enriched and impoverished larval diets to yield a range of adult sizes and to examine relationships between egg maturation, body size, and blood meal intake. 10.7% of nulliparous An. albimanus and 22.9% of An. albitarsis failed to mature eggs after sugar and one blood meal, and shorter wings and smaller blood meals predisposed females to require multiple blood feeds for egg maturation. Unmated An. albitarsis were significantly more likely than mated females not to develop eggs. Multiple blood meals within a single gonotrophic cycle appear to be less important in the life histories of neotropical Nyssorhynchus species compared to afrotropical malaria vectors.

Animals↗
PubMed1997

Comparative egg morphology of six species of the Albimanus section of Anopheles (Nyssorhynchus) (Diptera:Culicidae).

Scanning electron micrographs were used to describe and compare structures of eggs obtained from wild-caught females of 6 species of the Albimanus section of Anopheles (Nyssorhynchus) from South America, which includes important regional vectors of human malaria. Among species from the Oswaldoi Complex, eggs of Anopheles oswaldoi (Peryassu) were not differentiated from those of its sibling Anopheles konderi Galvão & Damasceno, and eggs of the former species from Brazil, Ecuador, and Suriname showed no regionally distinguishing characteristics. Eggs of Anopheles dunhami Causey were recognized by the reticulate beadwork of outer chorion on the dorsal plastron, 1 of several egg characters separating this species from the related Anopheles trinkae Faran and Anophels nuneztovari Gabaldón. In both species examined from the Strodei Complex, Anopheles strodei Root and Anopheles benarrochi Gabaldón, Cova Garcia & Lopez, the anterior frill forms a distinctive ventral crown separated from the floats. Anopheles triannulatus (Neiva & Pinto), collected from 4 geographic sites, differed in the occurrence of perforated mounds on the dorsal plastron, but these chorionic structures and the extent of overlap of floats varied among eggs from single females. Changes among related species in the structure of the anterior frill and dorsal plastron are described for phylogenetic and developmental inferences.

Animals↗
PubMed1996

A description and morphometric comparison of eggs from eight geographic populations of the South American malaria vector Anopheles (Nyssorhynchus) nuneztovari (Diptera:Culicidae).

The egg of Anopheles nuneztovari is described from scanning electron micrographs of specimens collected from western Venezuela. Morphometric measurements of egg samples from 3 localities in Venezuela, one in Suriname, and 4 in Brazil are compared and relationships analyzed by multivariate statistics. Morphological characters were similar in 2 geographical groups, one Venezuelan and the other Amazonian, that were distinguishable on the basis of differences in size and density of tubercles in the anterior deck region and area of pores in the dorsal plastron. Eggs from western Brazil did not cluster with other Amazonian collections. The distinction of Venezuelan from Amazonian eggs of An. nuneztovari is consistent with chromosomal, ecologic, and molecular evidence for regional genetic differentiation in this species.

Animals↗
PubMed1993

Seasonal abundance, age composition, and body size of salt-marsh Anopheles (Diptera: Culicidae) in south Florida.

Five CO2-baited light traps operated fortnightly between November 1989 and May 1991 near a salt marsh in Vero Beach, FL, caught 1,961 Anopheles crucians Wiedemann (s.l.) and 691 An. atropos Dyar & Knab. Both species were most abundant in winter and least abundant in summer; their numbers correlated inversely with lagged mean ambient temperatures. Annual parous rates were 55% for An. crucians and 58% for An. atropos and varied little seasonally. Wing lengths of female An. crucians measured for eight consecutive months were negatively correlated with ambient temperatures, and parous females of this species had significantly longer wings than nullipars. Parous rates and wing length classes were positively correlated among An. crucians, confirming that larger mosquitoes are longer-lived.

Animals↗
PubMed1992

Predation of Mansonia (Diptera: Culicidae) by native mosquitofish in southern Florida.

In experimental tanks and wading pools, the mosquitofish Gambusia holbrooki reduced densities of Mansonia larvae which, because of their attachment to the roots of aquatic plants, have been regarded previously as relatively impervious to predation. Exoskeletal remains of larval Mansonia were recovered from 43.5% of stomachs dissected from G. holbrooki, but not from Heterandria formosa (least killifish) collected from two undisturbed ponds covered with water lettuce (Pistia stratiotes L.). After 24 h in aquaria exposed to ambient light, predation by G. holbrooki reduced densities of Mansonia on water lettuce to one-third that of controls but in the dark, no significant differences were observed. In reduced light, densities of second- and fourth-instar Mansonia were reduced significantly after 1 wk of exposure to G. holbrooki. Video recordings of predation in aquaria revealed that G. holbrooki glean water lettuce roots to locate attached Mansonia and also capture free-swimming, dislodged larvae.

Animals↗
PubMed1991

Measuring mosquito dispersal for control programs.

Simple and economic methods were developed for control programs to demonstrate the movement of mosquitoes from a breeding source to residential areas. Using mark-release-recapture methods and examples, mean, median and maximum distances traveled were estimated or observed and compared for 11 species produced in a wastewater treatment facility near Lakeland, FL. The applicability of these methods and data interpretation for operational mosquito control programs are discussed.

Animals↗
PubMed1990

Fine structure of the egg of Trichoprosopon digitatum (Diptera: Culicidae) and its relationship to egg raft formation.

Eggs of Trichoprosopon digitatum (Rondani) occur in rafts; the anterior poles are submerged, and the posterior two-thirds float above the water surface. Each egg is approximately 1,060 microns long and 270 microns wide. The hydrophilic end is more curved dorsally than ventrally and is covered with flattened, anteriorly pointed, scalelike tubercles except for a small area around the micropyle. The hydrophobic portion is clad in a layer of closely arrayed, small, round tubercles among which are positioned much larger, flattened, anteriorly directed tubercles with deeply fissured surfaces. At three positions equidistant around the periphery of the egg, narrow, tongue-shaped extensions (the embrasures) from the anterior hydrophilic region project posteriorly into the hydrophobic region. Along these embrasures, progressing posteriorly, the tubercles change in form from flattened and bladelike to finely tapered, then, at the extension's posterior two-thirds, to long filaments with well-developed terminal hooks. Eggs in rafts are maintained in polygonal rosettes by the interlocking of these filaments and hooks and the surface tension of menisci between contiguous embrasures.

Animals↗
PubMed1990

Parity, fecundity and body size of Mansonia dyari in Florida.

Seasonal trends in reproductive performance and size were examined among female Mansonia dyari. The incidence of parity ranged between 6.9 and 58.1% and averaged 22.5% during an 8-month interval, with 4 peaks in parous rate believed to follow periods of emergence. Parous rates were positively correlated with wing lengths, indicating size-dependent survivorship. Wing lengths were highest in the winter and early spring, decreased to a minimum at the end of summer, and increased in the autumn, showing negative correlations with ambient temperatures recorded prior to adult capture. Female biomasses and fecundities were positively correlated with wing lengths, and their mean values varied significantly among sample dates. Egg development in Ma. dyari was completed by 5.4 days post blood meal at 26 degrees C and 7.6 days at 20 degrees C. No evidence for autogeny was observed.

Animals↗