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Enset root mealybugs, a major pest affecting the cultivation of the enset crop in the Ethiopian highlands, have for the first time been observed on banana mats indicating the potential host status of Musa spp. These observations were made under natural conditions in backyard gardens in the Gedeo zone, southern Ethiopia, on the root system of banana mats of the 'Pisang Awak' (local name 'Feranji Muz', ABB genome group) landrace. Here, we confirm the identification of the collected enset root mealybug specimens on banana mat root systems as Paraputo ensete (Williams & Matile-Ferrero) (Hemiptera: Pseudococcidae) through DNA analysis. [ABSTRACT FROM AUTHOR]

The fall armyworm, Spodoptera frugiperda (J.E. Smith) is native to the Americas and a major pest of corn and several other crops of economic importance. The species has characteristics that make it of particular concern as an invasive pest, including broad host range, long-distance migration behavior, and a propensity for field-evolved pesticide resistance. The discovery of fall armyworm in western Africa in 2016 was followed by what was apparently a remarkably rapid spread throughout sub-Saharan Africa by 2018, causing economic damage estimated in the tens of billions USD and threatening the food security of the continent. Understanding the history of the fall armyworm invasion of Africa and the genetic composition of the African populations is critical to assessing the risk posed to different crop types, the development of effective mitigation strategies, and to make Africa less vulnerable to future invasions of migratory moth pests. This paper tested and expanded on previous studies by combining data from 22 sub-Saharan nations during the period from 2016 to 2019. The results support initial descriptions of the fall armyworm invasion, including the near absence of the strain that prefers rice, millet, and pasture grasses, while providing additional evidence that the magnitude and extent of FAW natural migration on the continent is more limited than expected. The results also show that a second entry of fall armyworm likely occurred in western Africa from a source different than that of the original introduction. These findings indicate that western Africa continues to be at high risk of future introductions of FAW, which could complicate mitigation efforts. [ABSTRACT FROM AUTHOR]

The fall armyworm [FAW, Spodoptera frugiperda (J E Smith)], a moth native to America, has spread throughout the world since it was first discovered in Africa in 2016. The FAW is a polyphagous migratory pest that can travel over long distances using seasonal winds or typhoons because of its excellent flying ability, causing serious damage to many crops. For effective FAW control, accurate species identification is essential at the beginning of the invasion. In this study, the FAW-specific gene Sf00067 was discovered by performing bioinformatics to develop a fast and accurate tool for the species-specific diagnosis of this pest. An Sf00067 loop-mediated isothermal amplification (LAMP) assay was developed, and optimal conditions were established. The Sf00067 6 primer LAMP (Sf6p-LAMP) assay established in this study was able to diagnose various genotype-based strains of FAW captured in Korea and FAWs collected from Benin, Africa. Our FAW diagnostic protocol can be completed within 30 min, from the process of extracting genomic DNA from an egg or a 1st instar larva to species determination. [ABSTRACT FROM AUTHOR]

We investigated the diversity and the population dynamics of insects attacking seed stocks of Acacia macrostachya, an indigenous legume tree whose seeds constitute an important food source for rural and urban populations in Burkina Faso. For this purpose, six thousand four hundred and two seeds were collected from newly harvested dry pods in spontaneous vegetation around the research station of Saria, while 50kg of naturally infested seeds of A. macrostachya were purchased from nearby markets. To assess pest diversity and initial infestation, seeds collected from pods were divided into 3 batches of 2134 seeds, each batch representing a replication. Insect emergence in the laboratory was monitored for 45 days. The population dynamics of the pests was studied by incubating the seeds purchased on the market in 4 batches of 12.5kg each in polypropylene bags, which were kept under laboratory conditions and monitored for 8 months. Insects emerged from the samples included Coleoptera from three (3) families: Bruchidae (the most abundant), Tenebrionidae and Silvanidae, and Hymenoptera from four (4) families: Eulophidae, Pteromalidae, Eupelmidae, Eurytomidae. The initial seed infestation rate of the newly harvested pods was 50.67% with 47.14% caused by Bruchidius silaceus, 2.70% by Caryedon furcatus and 0.83% by Bruchidius sp. The most abundant species observed during the two first months of storage of the seeds obtained from the market was B. silaceus, but it disappeared from the stocks after March. Conversely, Caryedon furcatus populations remained steady and increased in February. Among the secondary pests observed, Oryzaephilus mercator was the most important. The initial seed perforation rate and weight loss were 16% and 2.8%, respectively, and increased to 35% and 7% after eight months of storage. The hymenopteran Eupelmus sp. was the most abundant parasitoid observed in storage. Our study allowed us to assess the diversity of A. macrostachya seed pests and their natural enemies. These results will contribute to a better understanding of their population dynamics and hence provide cues for further studies towards effective control methods. [ABSTRACT FROM AUTHOR]

The papaya mealybug (PM) is a known notorious polyphagous insect pest of many plant species and has always been found associated with a new host/s in newly invaded areas. This pest recently invaded West and Central Africa. Surveys were conducted randomly from July 2014 to May 2018 to determine the host range of this pest in the Center and Littoral regions in Cameroon. Plants infested by PM were recognized by the presence of black sooty mould, leaf deformation and/or chlorosis. A standard infestation scale was used to evaluate the infestation level on each plant. After collection, infested plants were pressed, dried and identified at the national Herbarium. A total of 52 plant species (only one undetermined) belonging to 23 families were found infested by PM associated with other mealybug or with two species of mealybugs with a percentage of (79.2%, N = 75) and (20.8%, N = 75) respectively. Two plant families (out of 23 identified) and 18 plant species (out of 52 infested) were reported as host plants for the first time. The Euphorbiaceae, Malvaceae and Solanaceae are the most infested families. In addition to plant species from its native zone (tropical America), PM has established new associations with plants from tropical Africa. Carica papaya and ten additional plants were categorized as favored hosts of P. marginatus. These results will be very useful to develop appropriate management options for PM in West and Central Africa. [ABSTRACT FROM AUTHOR]

In this study, we investigate the spatio-temporal fluctuations of the cashew leafminer Eteoryctis gemoniella Stainton, which was recently reported as one of the most devastating cashew pests in Benin. Eteoryctis gemoniella causes serious damage, especially to the young tender leaves, thus reducing the photosynthetic capacity of trees and hence their productivity. This study was carried out in three different cashew orchards in Northern Benin, West Africa, where we monitored the fluctuations of the infestation rates and population changes of E. gemoniella during a one-year cycle, from September 2010 to August 2011. In addition, we collected cashew leaves with mines to check for emergence of hymenopteran parasitoids. Our results show that infestation rates (as well as population densities of E. gemoniella) varied through time and among orchards. The most infested orchard was at Korou, whereas, the least infested was at Okoutaossé. In general, infestation rates and number of mines per leaf passed through two peaks, the first in July–August and the second in November, whereas no infestations were observed from January to June. Spatial distribution pattern of E. gemoniella within the orchards showed that this moth almost has a random distribution. Parasitoids attacking the leafminer were recovered from the samples. These were Apanteles sp., Chelonus (Microchelonus) nr. curvimaculatus Cameron (Hymenoptera: Braconidae) and Trathala sp. (Hymenoptera: Ichneumonidae). Further detailed studies on these natural enemies will be needed for evaluating their potential in controlling E. gemoniella in cashew orchards. [ABSTRACT FROM AUTHOR]

Powdered maize cobs were tested as an alternative for pesticide use in stored maize. Five doses (2, 4, 6, 8 and 10 g/250 g seed) of powdered maize cobs applied at particle sizes of 1.4 and 0.4 mm diameter were compared with actellic powder against Sitophilus zeamais Motschulsky for 120 days. Mortality and survival data showed that cob powders did not act as fumigant but exerted a potent inhibition of progeny on direct contact with S. zeamais adults. The particle size of powdered cobs had no effect on maize damage and losses. At doses equal to or higher than 6 g powdered maize cobs/250 g grain maize, i.e. 2.4% (w/w), damage to grain was < 5% and weight losses < 1%. The protection offered at the highest dose was comparable to the pesticide control. The use of powdered maize cobs is discussed as a natural alternative to synthetic pesticides for protection of maize against S. zeamais. [ABSTRACT FROM AUTHOR]