Management, Biology and Ecology of the Fall Army Worm, Spodoptera frugiperda (J.E.Smith) (Lepidoptera: Noctuidae)in Sudan

Abstract

A survey was conducted to determine the levels of infestation, distribution and main hosts of fall army worm in 2018, one year after it,s discovery in Sudan. The Survey included 15 sites in nine States (eg, Northern, Khartoum, Al Gazira, Sinnar, Gedaref, Kassala, Blue Nile,South Kordofan and West Darfur States,). The final results of the survey showed that the affected area reached about 22.06% of the total area surveyed (more than 6ooo feddan). The main host plants found were Maize (Zea mays) Sorghum (sorghum Bicolor), Sunflowres (Helianthus giganteus), Sesame (sesamum indicum), paenut (Aarchis hypogaea), Tomatoes (Solanumlycopersicum) and Millet (pennisetum glaucum) With special preference to maize. In Khartoum State, the studies conducted showed that there was significant difference between Mean Percentage ofdamage of the FAW in five areas (Shambat, Alshehainab, Touti Alfaki-Hashim and Kafouri) during October, November and December (2018). Mean Percentage of damage of the FAW in November and December was significantly higher than October. Also, The Mean Percentage of damage of the FAWin Shambat and Alshehainab, Touti were significantly higher than Alfaki-Hashim and Kafouri. Detailed laboratory experiments were carried out to study the life cycle and annual generations of the fall army worm.In this respectRandomized Complete Block Design (RCBD) were carried out during the period from September 2018 up to August 2019. The Fall armyworm (FAW) was reared in the laboratory and fed on a nutrient medium composed of corn leaves. The results displayed the range of eggs laid by a female was 890–1169 eggs. The egg incubation period ranged between 3-13 days. The larval duration ranged between (13-50) days and the pupal duration was ranged between (7-20) days under a temperature of 21-30◦c and a Relative Humidity (RH) of 65 ± 5%. The longevity of the adults was 1-20 days, and the range of the full lifecycle was (24-100) days. Six generations of FAW were obtained within one year. This study also showed that in Sudan FAW breeds continuously through out the year The results of the collection and identification of natural enemies of fall army worm in Khartoum Stateshowed that, there are more than 20 different species of natural enemies. The collection of predators included: 5 species from Coleoptera, two species from Hemiptera, two species from Dermaptera, 5 species from Hymenoptera,3 different species of flies from Dipter. In addition, a number of larvae were found infected by different species of micro-organisms. With respect to biological controlof this pest experiments with an extract of a solution of Pathogenic Micro-organisms was tried and the result showed a good efficacy against FAW larvae under field condition. Furthermore and looking for efficient, less cost and environmentally friendly plant extract control methods for controlling fall armyworm worm in cereal crops. A Complete Randomized Block Design (CRBD) experiments with three replications were conducted in the laboratory to investigate the insecticidal effects of four plant extracts consisting of ethanolic extract of Neem (Azadirachta indica) seeds, Black pepper (Piper nigrum) seeds, Usher (Calotropis procera ) leaves and water extracts of Argel (Solenostemma argel) leaves on larvae of the Fall armyworm (FAW) (Spodoptera frugiperda). Newly emerged larvae of FAW were treated topically by 4 concentrations (10, 25, 50 and 75%) of each extract, and then the larval mortalities were calculated after 24, 48 and72 hrs. The results showed that, the highest concentrations (75%) of the three ethanolic extracts gave higher mortality percentages (100%) after 72 hrs of exposure, compared with other concentrations. Also, these were not significantly different from the recommended dose of the standard pesticide “Spinosad”. On the other hand, Argel water extract showed no effect on the (FAW) larvae.