Learning to Live with West Nile Virus

Total Page：16

File Type：pdf, Size：1020Kb

Using DNA Fingerprinting to Identify the Blood-Feeding Patterns of Mosquito Vectors of West Nile Virus Theodore G. Andreadis The Connecticut Agricultural Experiment Station New Haven, CT Introduction • WNV has been detected in 18 different mosquito species in Connecticut • 5 species have been implicated as primary or secondary vectors • Physiologically competent • Frequently infected in nature • Closely associated with virus foci (human cases) Primary Vectors Culex pipiens Culex restuans Culex salinarius Secondary Vectors Aedes vexans Culiseta melanura West Nile Virus Transmission Cycle ? Enzootic Cycle Epidemic ? ? Transmission Wild Bird Reservoirs Mosquito Blood Feeding Study • To examine the feeding patterns of the principal mosquito vectors of WNV in Connecticut Birds Mammals • Identify specific bird and mammal hosts that mosquitoes feed on in nature • Determine the role of these animals in the ecology of WNV in the region Cs. melanura Cx. pipiens Cx. restuans Cx. salinarius Ae. vexans CO2 -baited CDC light trap Gravid trap Mosquito Collection Sites N = 80 Materials and Methods • Abdomens were removed under a dissecting microscope and DNA was isolated • The DNA was amplified by PCR using Avian and Mammalian specific primer pairs to the cytochrome b gene • The PCR amplification products were sequenced and identified to species by comparison to the Genbank® sequence data base Culex Mosquitoes 100 Bird Mammal 80 Bird & Mammal Amphibian 60 1.5% Percent 40 0.5% Human Human 20 0 Culex pipiens Culex restuans Culex salinarius Secondary Mosquito Vectors 100 Bird Mammal 80 Bird & Mammal 60 Percent 40 20 0 Culiseta melanura Secondary Mosquito Vectors 100 Bird Mammal 80 Bird & Mammal 60 Percent 40 20 0 Culiseta melanura Aedes vexans Percentage of Bird-Derived Blood Meals (n = 330) 40 42 different species 30 of birds identified 20 Percent of Total 10 0 American Gray Catbird House Chickadee Mourning American Robin Sparrow Dove Crow Percentage of Bird-Derived Blood Meals (n = 330) 40 • Abundant • Frequently infected 30 Æ • Reservoir competent • Are likely to be a 20 very important source of virus Percent of Total 10 0 American Gray Catbird House Chickadee Mourning American Robin Sparrow Dove Crow Percentage of Bird-Derived Blood Meals (n = 330) 40 • Crows acquire WNV through means 30 other than mosquito bites 20 ? • Crows are not likely to be the primary amplifying hosts Percent of Total 10 0 American Gray Catbird House Chickadee Mourning American Robin Sparrow Dove Crow Percentage of Mammal-Derived Blood Meals (n = 198) 80 70 12 different species of 60 mammals identified 50 40 30 Percent of Total 20 10 0 Deer Horse Cat Raccoon Rabbit Human Percentage of Mammal-Derived Blood Meals (n = 198) 80 • Most abundant large 70 Æ mammal in region 60 • Role in transmission unknown 50 • May divert feeding 40 from horses and humans 30 Percent of Total 20 10 0 Deer Horse Cat Raccoon Rabbit Human Percentage of Mammal-Derived Blood Meals (n = 198) 80 70 • Low level of feeding on humans 60 • Helps to explain 50 limited number of 40 human cases 30 Percent of Total 20 10 0 Deer Horse Cat Raccoon Rabbit Human Northeastern US West Nile Virus Transmission Cycle Overwinter Epidemic Transmission Culex salinarius Culex pipiens Culex pipiens Culex restuans Aedes vexans Culiseta melanura Enzootic June Cycle to Incidental Infections October Virus August to October Wild Bird Reservoir and Amplifying Hosts CAES Mosquito / West Nile Virus Research Group Mosquito Identification & Trapping John Shepard Michael Thomas Blood Meal Analysis Dr. Goudarz Molaei Virus Isolation & Identification Dr. Philip Armstrong Shannon Finan Dr. John Anderson Dr. Charles Vossbrinck.

Copy Link

Recommended publications

Twenty Years of Surveillance for Eastern Equine Encephalitis Virus In
Oliver et al. Parasites & Vectors (2018) 11:362 https://doi.org/10.1186/s13071-018-2950-1 RESEARCH Open Access Twenty years of surveillance for Eastern equine encephalitis virus in mosquitoes in New York State from 1993 to 2012 JoAnne Oliver1,2*, Gary Lukacik3, John Kokas4, Scott R. Campbell5, Laura D. Kramer6,7, James A. Sherwood1 and John J. Howard1 Abstract Background: The year 1971 was the first time in New York State (NYS) that Eastern equine encephalitis virus (EEEV) was identified in mosquitoes, in Culiseta melanura and Culiseta morsitans. At that time, state and county health departments began surveillance for EEEV in mosquitoes. Methods: From 1993 to 2012, county health departments continued voluntary participation with the state health department in mosquito and arbovirus surveillance. Adult female mosquitoes were trapped, identified, and pooled. Mosquito pools were tested for EEEV by Vero cell culture each of the twenty years. Beginning in 2000, mosquito extracts and cell culture supernatant were tested by reverse transcriptase-polymerase chain reaction (RT-PCR). Results: During the years 1993 to 2012, EEEV was identified in: Culiseta melanura, Culiseta morsitans, Coquillettidia perturbans, Aedes canadensis (Ochlerotatus canadensis), Aedes vexans, Anopheles punctipennis, Anopheles quadrimaculatus, Psorophora ferox, Culex salinarius, and Culex pipiens-restuans group. EEEV was detected in 427 adult mosquito pools of 107,156 pools tested totaling 3.96 million mosquitoes. Detections of EEEV occurred in three geographical regions of NYS: Sullivan County, Suffolk County, and the contiguous counties of Madison, Oneida, Onondaga and Oswego. Detections of EEEV in mosquitoes occurred every year from 2003 to 2012, inclusive. EEEV was not detected in 1995, and 1998 to 2002, inclusive.
[Show full text]
Identification Key for Mosquito Species
‘Reverse’ identification key for mosquito species More and more people are getting involved in the surveillance of invasive mosquito species Species name used Synonyms Common name in the EU/EEA, not just professionals with formal training in entomology. There are many in the key taxonomic keys available for identifying mosquitoes of medical and veterinary importance, but they are almost all designed for professionally trained entomologists. Aedes aegypti Stegomyia aegypti Yellow fever mosquito The current identification key aims to provide non-specialists with a simple mosquito recog- Aedes albopictus Stegomyia albopicta Tiger mosquito nition tool for distinguishing between invasive mosquito species and native ones. On the Hulecoeteomyia japonica Asian bush or rock pool Aedes japonicus japonicus ‘female’ illustration page (p. 4) you can select the species that best resembles the specimen. On japonica mosquito the species-specific pages you will find additional information on those species that can easily be confused with that selected, so you can check these additional pages as well. Aedes koreicus Hulecoeteomyia koreica American Eastern tree hole Aedes triseriatus Ochlerotatus triseriatus This key provides the non-specialist with reference material to help recognise an invasive mosquito mosquito species and gives details on the morphology (in the species-specific pages) to help with verification and the compiling of a final list of candidates. The key displays six invasive Aedes atropalpus Georgecraigius atropalpus American rock pool mosquito mosquito species that are present in the EU/EEA or have been intercepted in the past. It also contains nine native species. The native species have been selected based on their morpho- Aedes cretinus Stegomyia cretina logical similarity with the invasive species, the likelihood of encountering them, whether they Aedes geniculatus Dahliana geniculata bite humans and how common they are.
[Show full text]
ARTHROPOD MONITORING: Mosquito Studies
64 ARTHROPOD MONITORING: Mosquito Studies - Greenwoods, Summer 1995 Wi~~iam L. Butts Expanded sampling of the area inunediately adj acent to the large bog ("Cranberry Bog") for anthrophilic mosquitoes was the main focus of studies at Greenwoods. Initial plans to conduct biting/alighting sampling from a boat at selected sites around the margin of the impoundment were abandoned due to logistical difficulties. Emergent and submerged obstructions made it impossible to move about by boat at a rate that would allow for sampling at a sufficient number of sites within the hours of feeding activity. It was also evident that repeated sampling by boat would cause an unacceptable level of disruption to aquatic vegetation. A series of eight sampling sites marked with bicolored streamers was established along the west side of the bog from the point of access to the main dam northward. A similar series was laid out along the east side with three sampling stations south of the one at the dock site and four stations north of it. Biting/alighting collections were made by the author sitting for 20 minutes at each site with one forearm exposed. Mosquitoes alighting upon that arm or at other points on the body within reach of the other arm were collected by inverting a small killing vial over the mosquitoes. Sampling series were begun at approximately first light and in late evening beginning at a time estimated to terminate the series when unaided visual observation became difficult. In most instances one side of the bog was sampled in the evening and the other side the following morning.
[Show full text]
Ecologically Sound Mosquito Management in Wetlands. the Xerces
Ecologically Sound Mosquito Management in Wetlands An Overview of Mosquito Control Practices, the Risks, Benefits, and Nontarget Impacts, and Recommendations on Effective Practices that Control Mosquitoes, Reduce Pesticide Use, and Protect Wetlands. Celeste Mazzacano and Scott Hoffman Black The Xerces Society FOR INVERTEBRATE CONSERVATION Ecologically Sound Mosquito Management in Wetlands An Overview of Mosquito Control Practices, the Risks, Benefits, and Nontarget Impacts, and Recommendations on Effective Practices that Control Mosquitoes, Reduce Pesticide Use, and Protect Wetlands. Celeste Mazzacano Scott Hoffman Black The Xerces Society for Invertebrate Conservation Oregon • California • Minnesota • Michigan New Jersey • North Carolina www.xerces.org The Xerces Society for Invertebrate Conservation is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat. Established in 1971, the Society is at the forefront of invertebrate protection, harnessing the knowledge of scientists and the enthusiasm of citi- zens to implement conservation programs worldwide. The Society uses advocacy, education, and ap- plied research to promote invertebrate conservation. The Xerces Society for Invertebrate Conservation 628 NE Broadway, Suite 200, Portland, OR 97232 Tel (855) 232-6639 Fax (503) 233-6794 www.xerces.org Regional offices in California, Minnesota, Michigan, New Jersey, and North Carolina. © 2013 by The Xerces Society for Invertebrate Conservation Acknowledgements Our thanks go to the photographers for allowing us to use their photos. Copyright of all photos re- mains with the photographers. In addition, we thank Jennifer Hopwood for reviewing the report. Editing and layout: Matthew Shepherd Funding for this report was provided by The New-Land Foundation, Meyer Memorial Trust, The Bul- litt Foundation, The Edward Gorey Charitable Trust, Cornell Douglas Foundation, Maki Foundation, and Xerces Society members.
[Show full text]
Eastern Equine Encephalomyelitis Virus and Culiseta Melanura Activity at the Patuxent Wildlife Research Center, 1985 90
328 JounNar, oF THE AlrnnrceN Moseurto CoNrnor, Assocrlrror.t VoL. 8, No. 3 EASTERN EQUINE ENCEPHALOMYELITIS VIRUS AND CULISETA MELANURA ACTIVITY AT THE PATUXENT WILDLIFE RESEARCH CENTER, 1985_90 BENEDICT B. PAGAC,I MICHAEL J. TURELL' ero GLENN H. OLSEN3 ABSTRACT. Mosquito population densities, virus isolations and seroconversionin sentinel quail were used to monitor eastern equine encephalomyelitisvirus (EEE) activity at the Patuxent Wildlife Research Center, Laurel, Maryland, from 1985 through 1990. A dramatic increase in the number of Culiseta mclanura collected in 1989, as comparedwith the 3 previous years, was associatedwith virus isolations from this species(5/75 pools; n : 542 mosquitoes)and with seroconversionin sentinel quail (4/22bids positive). This was the first detection of EEE virus activity in this area since a 1984 EEE outbreakkilled 7 whoopinscranes. During 1984, an outbreak of eastern equine ice. In 1985, four SSAM trapping sites were encephalomyelitis (EEE) virus occurred among establishedalong the Big Patuxent River flood birds at the Patuxent Wildlife ResearchCenter plain, within a 3.2 km radius of the crane pens. (PWRC), in Laurel, MD (Dein et al. 1986;Car- These consisted of 2 pairs of sites separatedby penter et al. 1987,1989). Of 39 whoopingcranes 3,000 meters. Within each pair, trapping loca- [Grus americono (Linn.)] at the PWRC, 21 tions were approximately 700 m apart. These 4 (54%) had,evidence of infection with EEE virus, sites were used from 1985-90, and trapping and 7 (33%) of the infected birds died (Dein et methods remained the same throughout this al. 1986). These deaths were of particular con- period.
[Show full text]
143 First Record of Culiseta Longiareolata (Macquart) For
European Mosquito Bulletin 29 (2011), 143-150 Journal of the European Mosquito Control Association ISSN 1460-6127; www.e-m-b.org First published online 21 December 2011 First record of Culiseta longiareolata (Macquart) for Germany Norbert Becker 1,2 and Daniel Hoffmann1 1German Mosquito Control Association (KABS/GFS), Ludwigstr. 99, 67165 Waldsee, Germany. 2University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany. E-mail: [email protected] Abstract For decades the German Mosquito Control Association (KABS) has conducted mosquito surveillance as part of a comprehensive mosquito control programme. During the summer of 2011 hundreds of dead birds, especially blackbirds (Turdus merula), were found infected with the tropical Usutu occurred to investigate whether nulliparous mosquitoes carry the virus. More than 6.000 breeding sites were investigated most of which were infested with Culex pipiens/ Cx. torrentium virus (USUV, Flaviviridae) which is mainly transmitted by ornithophilous mosquito species such as Culex pipiens. Developmental stages of mosquitoes are collected in areas where dead birds populations and some with the invasive species Ochlerotatus japonicus japonicus. However, in one water container, in an open allotment- garden located near Karlsruhe and the French border, third and fourth instar larva and five pupae of Culiseta longiareolata were found. Thus the number of mosquito species in Germany increases to 49 established species. Key words: Culiseta longiareolata, Usutu virus, mosquitoes of Germany Introduction Mosquitoes are at the centre of worldwide entomological research primarily because of their medical importance as vectors of dangerous diseases like malaria and arboviroses (Becker et al., 2010). However, floodwater mosquitoes e.g. Aedes vexans and Ochlerotatus caspius can also significantly reduce life quality as they are nuisance species due to their mass development in, for example, river systems, rice fields, lakes or salt marshes with water level fluctuations.
[Show full text]
A Guide to Mosquitoes Biology (510) 567-6800 •
A Guide to Mosquitoes Biology (510) 567-6800 • www.acvcsd.org Alameda County Department of Environmental Health Mosquitoes have four distinct life stages. The egg, larval and pupal stages are aquatic, and the adult stage is terrestrial. Mosquito eggs are deposited either directly onto the water surface or onto an area that will later become ﬂooded. After hatching, the larvae undergo four growth stages, called instars. During this time they consume microorganisms, algae, or organic matter. They can often be found at the Mosquitoes may be arranged into groups based on water surface, but when disturbed, exhibit a distinct various biological and ecological factors. Examples movement that give them the name “wrigglers”. At include host preference (the type of host upon which the end of the fourth instar, larvae undergo metamor- an adult feeds), larval breeding areas, and egg laying phosis and become pupae. The pupal stage is a strategies. Aedes mosquitoes usually bite mammal non-feeding stage, and it is where the transformation hosts and deposit their eggs singly in areas that will into an adult mosquito occurs. Pupae exhibit a ﬂood, either on vegetation or soil. Their larval breed- distinct movement in the water, giving them the name ing sources are quite varied, and may include man “tumblers”. The aquatic stages may last from 5-14 made containers, tree holes, marshes, or depressions days, or longer, depending on temperature and mos- in wooded areas. Most Culiseta mosquitoes prefer quito species. After emergence, the adult females mammal blood and deposit their eggs in clumps or seek a blood meal, which is digested and used to “rafts” of 50-200 eggs.
[Show full text]
Environmental Influences for the Tree Canopy Preference of Culex Pipiens and Culiseta Melanura
Environmental Influences for the Tree Canopy Preference of Culex pipiens and Culiseta melanura Senior Thesis December 2005 Frank Cornine Unity College 42 Murdock Drive Unity, Maine 04988 [email protected] 1 TABLE OF CONTENTS Abstract……………………………………………………………………………………3 Introduction………………………………………………………………………………..4 Methods……………………………………………………………………………………7 Results……………………………………………………………………………………..9 Discussion………………………………………………………………………………..14 References………………………………………………………………………………..17 Acknowledgments………………………………………………………………………..20 2 ABSTRACT In our study we found that when mosquito collections were made on the same night and location, with one trap placed in the tree canopy and the other trap at ground level, there were a significantly higher number of Culex pipiens and Culiseta melanura in the tree canopy traps. These two trap levels also exhibited no significant difference in temperature, although it was determined that there was a significantly higher relative humidity at the ground level than in the canopy. This difference in relative humidity was also found to not be significantly correlated with the collections. By learning more about the biology of Culex pipiens, as well as other mosquitoes, we will be able to devise more effective methods to hamper their negative effects on humans without impacting other parts of the ecosystem. 3 INTRODUCTION Since the discovery of West Nile virus (WNV) in the United States in 1999, much emphasis has been placed on learning more about its transmission and characteristics of the specific mosquito species involved (Kulasekera, 2001; Nasci, 2001; Kilpatrick, 2005). The first known human case of WNV was reported in New York City, in August of 1999. After this first case there were an additional 61 humans positive for WNV in New York, from August to October of 1999, consisting mostly of elderly people (Enserink, 2000; Rappole, 2000).
[Show full text]
Culiseta Melanura
Vector Hazard Report Culiseta (Climacura) melanura (Coquillett, 1902) Vector of Eastern Equine Encephalitis Virus IDENTIFICATION BIONOMICS Diagnostic Characters Bionomics Profile Additional References Additional Resources VECTOR HAZARD: As of October 2019, the Centers for Disease Control and Prevention have reported 35 human cases of Eastern Equine Encephalitis in the United States which has resulted in 13 deaths. This report details the biology, distribution and identification of the mosquito responsible for maintaining the virus in bird populations within the US, Culiseta melanura. DISTRIBUTION State-level Distribution Habitat Suitability Model Compiled by David Pecor, Alex Potter, Richard Wilkerson & Yvonne Linton November 2019 IDENTIFICATION Specimen Images Habitus: Cs. melanura Female Thorax Dorsal View: Cs. melanura Female Abdomen Lateral View: Cs. melanura Female Head Dorsal View: Cs. melanura Female Abdomen Dorsal View: Cs. melanura Female Head Lateral View: Cs. melanura Female IDENTIFICATION Diagnostic Characters: Adult Female C. B. A. Hindleg: Cs. melanura Female Character: Hindtarsi III dark Thorax Lateral View: Cs. melanura Female Characters: A. Anterior pronotal without scales or setae B. 1-5 prespiracular setae C. Spiracular setae dark Wing Lateral View: Cs. melanura Female Character: Wing costa entirely dark-scaled IDENTIFICATION Diagnostic Characters: Adult Female Thorax Lateral View: Cs. melanura Female Character: Abdominal sternal scales cream colored or yellowish sometimes with dark scales intermixed Diagnostic Characters: Larvae CS C PcrS 1-S Larval Head Dorsal View: Antennae at least as long as head; seta 1-A, multiple, aciculate, inserted in notch at outer 0.25 of shaft and extending much beyond tip. Larval Abdomen Lateral View: Comb (C) with about 25 large comb scales (CS) arranged in distinct bar-like row; seta 1-S with 8–16 tufts in midventral line, starting within pecten (Pt) and ending near apex of siphon (S); siphon with small dorsolateral setae; siphon index 6–7; a few precratal setae (PcrS) present.
[Show full text]
Diversity and Ecology of Host-Seeking Mosquitoes in Irrigated Agro-Ecosystems of Clay County, Nebraska Alister K
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Dissertations and Student Research in Entomology Entomology, Department of 5-2014 Diversity and ecology of host-seeking mosquitoes in irrigated agro-ecosystems of Clay County, Nebraska Alister K. Bryson University of Nebraska-Lincoln Follow this and additional works at: http://digitalcommons.unl.edu/entomologydiss Part of the Biodiversity Commons, Entomology Commons, and the Terrestrial and Aquatic Ecology Commons Bryson, Alister K., "Diversity and ecology of host-seeking mosquitoes in irrigated agro-ecosystems of Clay County, Nebraska" (2014). Dissertations and Student Research in Entomology. 31. http://digitalcommons.unl.edu/entomologydiss/31 This Article is brought to you for free and open access by the Entomology, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Dissertations and Student Research in Entomology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. DIVERSITY AND ECOLOGY OF HOST-SEEKING MOSQUITOES IN IRRIGATED AGRO-ECOSYSTEMS OF CLAY COUNTY, NEBRASKA By Alister Kinoshita Bryson A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science Major: Entomology Under the Supervision of Professor M. Roberto Cortiñas Lincoln, Nebraska May, 2014 DIVERSITY AND ECOLOGY OF HOST-SEEKING MOSQUITOES IN IRRIGATED AGRO-ECOSYSTEMS IN CLAY COUNTY, NEBRASKA Alister Kinoshita Bryson, M.S. University of Nebraska, 2014 Advisor: Roberto Cortiñas In the United States, Nebraska has the third highest incidence of human West Nile virus (WNV). Since WNV was first detected in the state in 2002, 3,422 confirmed cases and 57 deaths have been reported.
[Show full text]
Mosquito Management Procedures
Mosquito Management Procedures Mosquito management is a multi-disciplinary subject that combines the art of understanding mosquito behavior with the science of knowing how to locate and control mosquito populations. All mosquito management programs worldwide have their own unique control measures for their own specific management problems. However, the primary goal of all mosquito management programs is to enhance the health and comfort of the citizens. As with all career fields, the mosquito control industry has its own specific terminology. The following is a list of some of the more common terms. • Adulticide: an insecticide used to kill adult insects. • Larvicide: an insecticide used to kill larval (immature) insects. • Ultra Low Volume: commonly known as ULV, a method of applying adulticides at volumes less than 10 ounces per acre. • Thermal Fog: commonly known as fogger, a method of applying adulticides mixed with a carrying agent, usually diesel fuel, and heating it to form a fog. • Drift: the direction and distance the spray travels after leaving the spray head. • Crepuscular: the hours between one-half hour before and after sunset and one-half hour before and after sunrise. • Atomize: to reduce to minute particles or a fine spray. • Landing Rate: a surveillance method used to determine adult mosquito populations by counting the mosquitoes that land on the front half of your body for one minute. Mosquito Biology There are approximately 45 different species of mosquitoes in Lake County. However, only a few of these species have the potential of transmitting diseases and, therefore, are a primary concern for management purposes. Mosquito Species of Primary Concern Aedes aegypti Culiseta melanura Aedes albopictus Aedes vexans Coquillettidia perturbans Anopheles crucians Mansonia dyari Anopheles quadrimaculatus Mansonia titillans Culex nigripalpus Culex quinquefasciatus Culex salinarius Mosquito eggs are generally cylindrical in shape, tapered at the top and rounded at the bottom.
[Show full text]
Oviposition Habitat Selection by Mosquitoes (Culiseta Longiareolata) and Consequences for Population Size
Ecology, 83(3), 2002, pp. 669±679 q 2002 by the Ecological Society of America OVIPOSITION HABITAT SELECTION BY MOSQUITOES (CULISETA LONGIAREOLATA) AND CONSEQUENCES FOR POPULATION SIZE MATTHEW SPENCER,1,3 LEON BLAUSTEIN,1 AND JOEL E. COHEN2 1Community Ecology Laboratory, Institute of Evolution, University of Haifa, Haifa 31905 Israel 2Laboratory of Populations, Rockefeller University, 1230 York Avenue, Box 20, New York, New York 10021-6399 USA and Columbia University, USA Abstract. Many kinds of adaptive behavior, including responses to risk of predation, have been documented, but there have been few attempts to translate these behaviors into consequences for populations. We present one of the ®rst models to predict the consequences of adaptive behavior for population size in a speci®c natural system. Larvae of the mosquito Culiseta longiareolata (Diptera: Culicidae) develop in freshwater pools. They are vulnerable to predation by the backswimmer Notonecta maculata (Hemiptera: Heteroptera), and to intraspeci®c competition. Adult female C. longiareolata usually avoid ovipositing in pools that contain N. maculata. This is presumably an adaptive response that increases individual ®tness, but it is also likely to affect the size of the population. We take a novel approach to understanding the relationship between adaptive behavior and population dynamics in C. longiareolata. We use a nonlinear stage-structured population model to predict the evolutionarily stable oviposition strategy and its consequences for the size of the C. lon- giareolata population. Our model predicts that female C. longiareolata should always avoid ovipositing in pools with N. maculata. Such avoidance will increase the equilibrium size of the C. longiareolata population, relative to a population in which oviposition is indis- criminate with respect to N.
[Show full text]