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Pearl millet is the principal staple food crop in large portions of Western Sub-Sahelian Africa and the millet head miner (Heliocheilus albipunctella) is one of its most devastating insect pests. Since 2006, augmentative mass releases of the larval ectoparasitoid, Habrobracon hebetor, have been conducted in Mali, Burkina Faso and Niger as part of minimizing pearl millet grain losses imposed by millet head miners. These ongoing mass releases are based on low-cost mass-rearing of both host larvae and parasitoids. A release of parasitoids consists of placing jute bags containing pearl millet grain and flour and parasitized host larvae near pearl millet fields. The total production costs of a single jute bag with parasitized rice moth larvae are US$ 3-4. Based on a study of 6634 individual pearl millet heads collected at harvest in 12 farmers' fields in southern Niger in 2010, we demonstrated (i) a strong negative correlation between pearl millet head damage (mining) and grain yield and (ii) that parasitism by H. hebetor reduced grain losses by, on average, 34% (comparison of infested millet heads with/without parasitism) within the given growing season. Additional benefits may include reduction in millet head miners in subsequent generations. Data from 900 pearl millet heads collected in nine farmers' fields in 2011 were used to confirm data trends observed in the 2010 data and to characterize the dispersal of parasitoids in upwind and downwind directions from a release site. This study provided a quantitative description of the negative impact of millet head miner infestations on pearl millet grain yields and of benefits on grain yield of parasitism by H. hebetor. Our findings strongly support (i) intensification of mass-rearing of H. hebetor, (ii) expansion of educational activities to increase local empowerment and understanding of the potential of augmentative biological control and (iii) optimization of H. hebetor mass release programmes among smallholders in Sub-Sahelian Africa.

Computer vision and reflectance-based analyses are becoming increasingly important methods to quantify and characterize phenotypic responses by whole organisms to environmental factors. Here, we present the first study of how a non-destructive and completely non-invasive method, body reflectance profiling, can be used to detect and time stress responses in adult beetles. Based on high-resolution hyperspectral imaging, we acquired time series of average reflectance profiles (70 spectral bands from 434-876 nm) from adults in two beetle species, maize weevils (Sitophilus zeamais) and larger black flour beetles (Cynaus angustus). For each species, we acquired reflectance data from untreated controls and from individuals exposed continuously to killing agents (an insecticidal plant extract applied to maize kernels or entomopathogenic nematodes applied to soil applied at levels leading to ≈100% mortality). In maize weevils (exposed to hexanic plant extract), there was no significant effect of the on reflectance profiles acquired from adult beetles after 0 and 12 hours of exposure, but a significant treatment response in spectral bands from 434 to 550 nm was detected after 36 to 144 hours of exposure. In larger black flour beetles, there was no significant effect of exposure to entomopathogenic nematodes after 0 to 26 hours of exposure, but a significant response in spectral bands from 434-480 nm was detected after 45 and 69 hours of exposure. Spectral bands were used to develop reflectance-based classification models for each species, and independent validation of classification algorithms showed sensitivity (ability to positively detect terminal stress in beetles) and specificity (ability to positively detect healthy beetles) of about 90%. Significant changes in body reflectance occurred at exposure times, which coincided with published exposure times and known physiological responses to each killing agent. The results from this study underscore the potential of hyperspectral imaging as an approach to non-destructively and non-invasively quantify stress detection in insects and other animals.

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A series of indole derivatives related to tryptophan reacted with the osmium tetraoxide-pyridine reagent to form bis(pyridine)osmate esters by addition to the 2,3-position of the indole ring. l-Methyl-a-A'-acetyl-DLtryptophan formed a pair of easily separable diastereomeric esters. A study of the kinetics of these reactions showed the expected first-order dependence on osmium tetraoxide and on the indole component. The dependence on pyridine, however, varied with the structure of the indole. Those 3-indolyl derivatives with a threeor four-carbon side chain terminating in a carboxyl group showed an apparent pyridine dependence close to first order. Other