Temperature-Based Phenology Modeling and GIS-Based Risk Mapping: A Tool for Forecasting Potential Changes in the Abundance of Mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae)

Abstract

Unlike conventional pesticides, usually these natural aromatic products, present less risk to humans and the environment. Essential oils are recognized as alternatives to fumigants. The biological activity of essential oil extracted from nutmeg seed, Myristica fragrans against adults of Callosobruchus maculatus was investigated in a series of laboratory experiments carried out at 27 ± 1 °C and 60 ± 5 % relative humidity (RH), in dark condition. Dry seeds were subjected to hydrodistillation, using a modified Clevenger-type apparatus. The oil was applied against 1–3 day old adults of C. maculatus. The LC50 of M. fragrans on C. maculatus was 4.232 µL/L air. The relationship between exposure time and oil concentration on mortality showed that mortality increased as oil concentration and exposure time increased. The concentration of 30 µL/L and exposure time of 24 h was sufficient to obtain 100 % kill of insects. C. maculatus was significantly susceptible to this essential oil. Bioassays conducted in air-tight glass chambers showed fumigant toxicity as per the filter-paper method. The experiment was conducted in four replications using a completely randomized design. The results suggest that M. fragrans can be used to control C. maculatus.