Larvicidal Efficiency of Some Inorganic Compounds and Plant Extracts against the House Fly

Abstract

Insect control is a problem of increasing magnitude in intensive animal production systems where insects are not only a nuisance to animals and animal attendants, but are also involved in the transfer of a number of infectious diseases. This has led to frequent use of insecticides, many of which are injurious to health.Recently effons have been made all over the world to replace toxic inseeticides by natural or synthetic substances that are not injurious to higher warm-blooded organisms including man and have a satisfactory insecticidal efficiency. The rationale behind this approach is concern for the protection of the environment against growing pollution.Experience from honicultural practice (Novak 1978, Rolinkova 1979 has shown that extracts of some plants (e. g. horse-tail, nettle and garlic) have insecticidal effects. Of panicular importance is the recent observation of Schneider and Groth (1976) who found that sodium tetraborate was effective against Musca domestica larvae.The present study was designed to test larvicidal efficiency of some inorganic compounds and plant extracts against Musca domestica larvae under laboratory conditions. Materials and MethodsHouse flies (Musca domestica) were reared in 4 I-bottles by placing of at least 10 imagoes (males and females in approximately equal numbers) into each bottle, the bottom of which was previously filled with 125 g wetted wheat bran and overlaid with 40 g bovine faeces. An ample supply of honey diluted 1 : 10 with water was added as adult food. The necks of the bottles were closed with monofilament nets by means of rubber bands (Fig. 1). The contents of the bottles were wetted daily with water. The temperature of the room where the bottles were kept ranged between 23 and 28°C in summer months and was maintained at 27 to 29 °C in winter months by means of a heat lamp. The development of domestic flies at this temperature and sufficient relative humidity took 4 to 13 days (mean = 6.7 days) from oviposition to emergence of larvae, 4 to days (mean = = 8.8 days) from larval stage to puparium and 4 to 14 days (mean = 7.8 days) from puparium to imago. Thus the development of domestic flies was completed in 12 to 37 days (mean = 21.1 days). The rate of emergence of imagoes from puparia was 41.5 per cent.The compounds tested for larvicidal efficiency were copper sulphate (CuSOJ, iron sulphate (FeSO,), magnesium sulphate (MgSO,) and sodium tetraborate (Na2B.07). These compounds

Postingestive Effects of Phytochemicals On Insects: On Paracelsus and Plant Products

“…Thus, these methods have been applied to evaluate the effects of ingestion of antimetabolites such as ecdysone (Jones and Firn, 1978) and proteinase inhibitors (Gatehouse et al, 1979) as well as chronic and acute toxicants. Up to this point in time, the bulk of bioassays of plant constituents have been conducted in order to isolate and identify potential insecticides for commercial application (e.g., Willomitzer and Tomanek, 1981). Only recently has research been motivated by interest in coevolutionary interactions between insects and their plant hosts.…”