Publications: 1990–1999

Overview: This chapter examines small-scale agriculture in three contrasting areas of Southeast Asia: the Cordillera highlands of the Philippines, the uplands of West Java, Indonesia, and the Chiangmai Valley of northern Thailand. It describes the organization and management of ricefields, rainfed fields, and homegardens in each area, including cropping practices, soil fertility, labor, household production, and relationships between agricultural and social systems. The chapter then examines how population growth, expanding cash economies, new agricultural technologies, changing labor patterns, and intensified production are transforming these farming systems. Comparing traditional and modern practices, it considers the ecological and social problems associated with agricultural change and discusses how research and development might combine useful features of traditional systems with modern technologies while addressing farmers’ changing needs.

Overview: This paper examines the potential use of cyclopoid copepods as biological predators of mosquito larvae. It reviews characteristics that influence their effectiveness, including predatory behavior, survival in different aquatic habitats, resistance to desiccation, reproduction, storage, transport, and methods for introducing them into mosquito breeding sites. The paper considers which mosquito species and habitats are most suitable for control with cyclops and discusses their use alongside fish, larvicides, and other biological and chemical control methods. It also addresses practical questions involved in incorporating cyclops into mosquito-control programs, including mass production, application, persistence, safety, and community participation, and identifies areas where further research is needed.

Abstract: Six species of cyclopoid copepods in New Orleans were tested for biological control of Aedes albopictus larvae in discarded tires. Six to 8 weeks after introduction, Diacyclops navus, Acanthocyclops vernalis, Mesocyclops ruttneri and Mesocyclops edax reduced the number of Ae. albopictus larvae by 83, 90, 95 and 96%, respectively. Macrocyclops albidus and Mesocyclops longisetus were the most effective species. Six to 8 weeks after introduction, Macrocyclops albidus reduced Ae. albopictus larvae by 99%. Three months after introduction Macrocyclops albidus reduced Ae. albopictus larvae by 100%, and Mesocyclops longisetus reduced Ae. albopictus larvae by 99.8%. Macrocyclops albidus and Mesocyclops longisetus were equally effective at eliminating Ae. aegypti and Ae. triseriatus larvae.

Abstract: The copepod Macrocyclops albidus is an unusually promising new form of biological control for mosquito larvae. When introduced to two isolated tire piles, M. albidus eliminated all Aedes albopictus larvae from both piles within 2 months. Adult Ae. albopictus around the tire piles disappeared within another month. Complete suppression of Ae. albopictus larvae was still in effect in all treated tires a year later.

Abstract: A simple method for indoor and outdoor cultivation of Mesocyclops aspericornis, Macrocyclops albidus and Mesocyclops n. sp. copepods is presented. This method utilizes Chilomonas sp., Paramecium caudatum and fresh lettuce as food sources for copepod cultures. Steps for initiating and maintaining copepod cultures are provided.

Abstract: Larvivorous copepods (Macrocyclops, Mesocyclops and Acanthocyclops) were tested for their sensitivities to commonly used mosquito larvicides and adulticides. The cyclopoids were not harmed by Bacillus thuringiensis (H-14) (B.t.i.) or larviciding oil. Control of mosquito larvae in field trials was accelerated by applying B.t.i. at the same time cyclopoids were introduced to a breeding site. Among adulticides tested, the cyclopoids were least sensitive to permethrin. Field trials demonstrated that permethrin does not harm cyclopoids when applied at label specifications.

Abstract: Juvenile turtles, Trachemys scripta, provided highly effective control of mosquito larvae in cement tanks (pilas) where water was stored for household cleaning. When single turtles were introduced to tanks with histories of high mosquito production, nearly all turtles remained in good health and no mosquito larvae survived to the pupal stage. Families welcome turtles in their water storage containers in Honduras. Humane conditions for turtles can be assured by providing small quantities of table scraps to supplement their diet and by placing a small floating platform in the tank for basking. Although turtles can serve as alternate hosts for Salmonella, available evidence suggests that turtles in tanks should not be a source of human infection. Further confirmation that there is no Salmonella hazard should precede routine use of turtles for mosquito control.

Abstract: Mesocyclops longisetus (Thiébaud), Mesocyclops thermocyclopoides Harada, Mesocyclops venezolanus Dussart, and Macrocyclops albidus (Jurine) were tested for their effectiveness in controlling Aedes aegypti (L.) larvae in a variety of containers around homes in El Progreso, Honduras. All four cyclopoid species killed >20 larvae per cyclopoid per d under container conditions. M. longisetus was most effective, not only because it was the most voracious predator, but also because it survived best in the containers. M. longisetus maintained long-term populations in 200-liter drums, tires, vases, and cement tanks (without drains), providing the cyclopoids were not dried or poured out. M. longisetus reduced third- and fourth-instar Ae. aegypti larvae by >98% compared with control containers without cyclopoids. M. longisetus should be of practical value for community-based Ae. aegypti control if appropriate attention is directed to maintaining it in containers after introduction.

Abstract: The New Orleans Mosquito Control Board mass produces Mesocyclops longisetus and Macrocyclops albidus for introduction to mosquito breeding sites as a routine part of control operations. Mesocyclops longisetus is used in tires that collect rainwater; M. albidus is used in temporary pools. Field trials in a Spartina marsh, rice fields, and residential roadside ditches in Louisiana suggest that M. longisetus and M. albidus could be of use to control larvae of Anopheles spp. and Culex quinquefasciatus. Mesocyclops longisetus has proved to be effective for Aedes aegypti control in cisterns, 55-gallon drums, and other domestic containers in Honduras.

Abstract: The flora and fauna of 69 aquatic sites in Colombia were surveyed to identify ecological conditions that favor production of Anopheles albimanus. Anopheles albimanus larvae were most numerous at sun-exposed sites with abundant Culex larvae and grass at the edge of the water. Only 29% of the sites with An. albimanus larvae contained pupae, suggesting that poor larval survival prevented the production of adult mosquitoes at many sites. In the Atlantic region, An. albimanus production was highest from large ponds with an abundant and varied aquatic insect fauna, including many kinds of predators of An. albimanus larvae. Although productive sites were often covered with water hyacinth, aquatic vegetation was generally not a reliable indicator of An. albimanus production. In the Pacific region, An. albimanus production was highest from small water bodies with few aquatic macrophytes and an abundance of cladocera, reflecting an abundance of microalgal food for mosquito larvae. In both regions, An. albimanus production was negatively associated with a complete cover of Lemna, fish, hydrometrid nymphs, large species of cyclopoid copepods, and dragonfly or mayfly nymphs. Anopheles albimanus production was also negatively associated with dytiscid beetle larvae in the Pacific region.

Overview: This manual provides a comprehensive, step-by-step guide to the production and use of cyclopoid copepods (“cyclops”) for biological mosquito control, based on procedures developed by the New Orleans Mosquito Control Board. It begins with methods for collecting copepods in the field, establishing single-species cultures, identifying species, and evaluating their suitability as predators of mosquito larvae. The manual then describes the complete mass-production system, including cultivation of Chilomonas and Paramecium as live food, maintenance of food and copepod stock cultures, preparation and management of production trays, feeding, monitoring, cleaning, and harvesting. Later sections cover practical deployment of copepods to mosquito-breeding habitats, including tires and temporary bodies of water, using backpack and broadcast sprayers. The manual also addresses storage, transport, shipping, equipment, water quality, temperature, contamination, and other operational considerations involved in maintaining reliable large-scale production and field application. Together, the procedures document a complete system for moving from locally collected copepods to sustained laboratory production and their use as part of an operational mosquito-control program.

Abstract: In northern Vietnam, copepods of the genus Mesocyclops were used for biological control of Aedes aegypti, the principal vector of dengue viruses, by inoculation into wells, large cement tanks, ceramic jars, and other domestic containers that served as Ae. aegypti breeding sites. The use of Mesocyclops was complemented by community participation with respect to recycling to eliminate unused and discarded containers that collected rainwater and provided Ae. aegypti breeding sites that could not be treated effectively with Mesocyclops. Aedes aegypti disappeared from 400 houses of the treated village in August 1994 and has not reappeared, a result of particular significance, because there are virtually no other recorded instances of eradicating this mosquito anywhere in the world during the past 25 years, and certainly not with community-based approaches. When used in combination with community recycling, Mesocyclops is an easy and inexpensive method of Ae. aegypti control that should be effective for many communities in Vietnam and elsewhere.