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Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) has become a major threat to maize production in Africa. In this study, six maize genotypes were assessed for their resistance to FAW under artificial infestation in both laboratory and net house conditions. These included two FAW-tolerant hybrids (CKHFAW180294 and CKH191221), two commercial hybrids (WE2115 and CKH10717), and two open-pollinated varieties (ZM523 and KDV4). Larval development time and reproductive potential were assessed on maize leaves in the laboratory and a life table for FAW was constructed. The maize genotypes were also artificially infested with three FAW neonates at two phenological stages (V5 and V7) and reproductive stage (R1) in the net house. Leaf and ear damage scores were recorded on a scale of 1–9. Larval development time varied significantly between maize genotypes with the highest on CKH191221 (16.4 days) and the lowest on KDV4 (13.7 days). The intrinsic rate of natural increase for life tables varied from 0.24 on CKH191221 to 0.41 on KDV4. Mean generation time of FAW ranged from 17.6 to 22.8 days on KDV4 and CKH191221, respectively. Foliar damage was the lowest on CKH191221, and the highest on KDV4 at V7 infestation stage in week 1. CKH191221 had the lowest ear damage score, whereas ZM523 had the highest scores at V5 infestation stage. The highest and lowest yield reductions were observed on ZM523 (64%) at V7 infestation stage and CKHFAW180294 (6%) at R1 infestation stage, respectively. The results indicated the potential for developing tropical mid-altitude maize germplasm with native genetic resistance to FAW.

Mango (Mangifera indica L.) is the third most important fruit crop in the tropics following citrus and banana. It is consumed as a fresh fruit and different forms of preparations for its multifaceted nutritional values. Mango production in Ethiopia is constrained by infestation of white mango scale (WMS), Aulacaspis tubercularis Newstead. White mango scale was recorded from Ethiopia for the first time in 2010, in a mango orchard in Loko in the western part of the country. This study was conducted from June 2013 to May 2014 to document the population dynamics of white mango scale in Western Ethiopia. Randomized Complete Block Design was used for the sampling in two mango orchards, Arjo and Bako. Scale population peaked in April at Arjo and in May at Bako showed marked decline with decreasing precipitation. Abundances of eggs, crawlers and sessile stages of the scale showed significant differences among most of the study months (Pi€¼0.05). The abundance of sessile scales was significantly higher at Bako than at Arjo (Pi€¼0.05). In both study areas, white mango scales were significantly more abundant on the upper leaf surfaces than the lower (Pi€¼0.05). At Bako, male scale numbers were significantly higher than those of the females (Pi€¼0.05). The study found that the decline and build-up of white mango scale populations are affected by rainfall, whereas the effects of other environmental factors on scale numbers need to be investigated. Key words: Developmental stages, fluctuation, infestation, orchard, rainfall, sessile.

White Mango Scale Aulacaspis tubercularis Newstead, 1906 was reported for the first time in 2010 from mango orchards belonging to Green Focus Ethiopia Ltd in western Ethiopia. It was hypothesized that the pest could en­ter Ethiopia with mango seedlings imported by the same company. The pre­sent study surveyed natural enemies of the pest and their population dynamics in western Ethiopia. Larvae of Chilocorus sp. (Coleo­ptera: Coccinelidae) were found feeding ravenously on live mango scales. There was a statistically sig­nificant (p A. tubercularis and Chi­locorus sp. populations in both orchards, implying that the predator was not suppressing the pest population. There was no significant difference in the mean numbers of the predatory larva populations between Arjo and Bako or­chards (p>0.05). Populations of White Mango Scale and its predator showed remarkably similar fluctuations, with their abundancies reaching peaks during same months. It has been concluded that the native predator got associated with the exotic insect pest recently, and its population may gra­dually build up. It is suggested that implementation of Chilocorus sp. as a biocontrol agent would be a sound strategy in the management of White Mango Scale in western Ethiopia, together with other control options.

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