Title
Establishment of a free-mating, long-standing and highly productive laboratory colony of Anopheles darlingi from the Peruvian Amazon
Date Issued
30 May 2015
Access level
open access
Resource Type
journal article
Author(s)
Unidad de Investigación Médica Naval-6
Unidad de Investigación Médica Naval-6
Unidad de Investigación Médica Naval-6
Unidad de Investigación Médica Naval-6
Unidad de Investigación Médica Naval-6
Publisher(s)
BioMed Central Ltd.
Abstract
Background: Anopheles darlingi is the main malaria vector in the Amazon region and is among the most efficient malaria vectors worldwide. However, due to the lack of a well-established laboratory colony, key control-relevant aspects of the bionomics, behaviour, genetics, and vector-parasite relationships of An. darlingi remain unknown. Here, biological parameters that had been successful in initiating other Anopheles colonies were optimized and improved for An. darlingi, with the aim of establish a free-mating, stable, and highly productive laboratory colony. Methods: Wild An. darlingi adult females were field collected from Zungarococha, Loreto Department, Peru (03 °49′32.40″S, 73° 21′00.08″W), and taken to the NAMRU-6 Insectary in Iquitos where F<inf>1</inf> offspring were produced and reared. Natural copulation was successfully induced in F<inf>1</inf> adults under a thermoperiod of 30 ± 1 °C during the day and 25 ± 1 °C at night, and with a 30-min LED light stimulation period at dusk. Oviposition success was enhanced using egg-laying containers with a dark-coloured surface. Larval feeding regimes were standardized for optimal larval development. Optimized copulation induction methods were used to facilitate mating in An. darlingi until the F<inf>10</inf> generation. No copulation induction assistance was needed in subsequent generations. Results: In 19 generations, the An. darlingi colony produced a total of 763,775 eggs; 441,124 larvae; 248,041 pupae; and 231,591 adults. A mean of 0.56 sexual encounters/female/cage (n = 36 cages) was recorded across the first ten generations (F<inf>1</inf>-F<inf>10</inf>). A mean insemination rate of 54.7 % (n = 5,907 females) ranging from 43.6 % (F<inf>2</inf>) to 66.6 % (F<inf>10</inf>) was recorded across nine generations (F<inf>2</inf>-F<inf>10</inf>). Free-mating was casually observed in the F<inf>8</inf> generation, and subsequently confirmed in the F<inf>9</inf> and F<inf>10</inf> generations; comparable insemination rates and egg laying between stimulated (51.6 %, 12.9 eggs/female), and non-stimulated (52.3 %, 11.2 eggs/female) females were recorded. The time from egg to adult development ranged from 10 to 20 days. Moreover, the colony was relocated to a new laboratory within Iquitos in the F<inf>14</inf> generation without any noted changes in its productivity. By March 2015, the An. darlingi colony has been successfully reared to the F<inf>26</inf> generation. Conclusions: This constitutes the first report of a free-mating, highly productive, and long-standing An. darlingi laboratory colony established through natural copulation induction, which will support critical malaria research. This rearing methodology may be a transferable, cost-effective alternative to labour-intensive forced mating practices widely used in maintaining other Anopheles colonies.
Volume
14
Issue
1
Language
English
OCDE Knowledge area
Parasitología
Scopus EID
2-s2.0-84931266875
PubMed ID
Source
Malaria Journal
ISSN of the container
14752875
Sponsor(s)
We would like to thank the Ministerio de Agricultura y Riego de Perú, Dirección General Forestal y de Fauna Silvestre, and the Dirección de Salud, Gobierno Regional de Loreto for permission to conduct these studies: Anopheles darlingi collections in Loreto were conducted under the auspices of Resolución Directoral No. 0406-2013-MINAGRI-DGFFS/DGEFFS; An. darlingi molecular identification was conducted under the auspices of Contrato de Acceso Marco a Recursos Geneticos No. 0017-2014-MINAGRI-DGFFS/DGEFFS. We would like to thank Fanny Castro, Geidin Chavez, Hugo Jaba, Luz Romero, Miguel Vásquez, and Alex Vásquez for technical support. Additionally, we would like to thank Dr. Craig Stoops for providing helpful comments on the manuscript. Financial support was provided by the Global Emerging Infections Surveillance and Response System (AFHSC/GEIS) of the U.S. Department of Defense sustainment funding award (FMS, GMV), the Consejo Nacional de Ciencia y Tecnología (CONACYT) México, grant CB2008-105806-M (CVT), and by the training grant 2D43 TW007393-06 awarded to NAMRU-6 by the Fogarty International Center of the U.S. National Institutes of Health. YML was supported by the National Research Council (NRC) Research Associate Program.
Sources of information: Directorio de Producción Científica Scopus