The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an insect native to the tropical and subtropical Americas that has recently spread to Africa, where it predominately attacks maize, sorghum and other plant species. Biological control is an environmentally friendly way of combatting the pest and contributes to an integrated pest management approach. In Africa, several trichogrammatid parasitoids and Telenomus remus Nixon (Hymenoptera: Platygastridae) have been found parasitizing eggs of the FAW. In Niger, the egg parasitoids encountered include Trichogrammatoidea sp. (Hymenoptera: Trichogrammatidae) and Telenomus remus Nixon. Parasitism of the FAW eggs by the two egg parasitoids was assessed in the laboratory, followed by field testing on sentinel eggs. In the laboratory, T. remus parasitized on average 78% of FAW eggs, compared to 25% for Trichogrammatoidea sp. Telenomus remus was able to parasitize egg masses that were fully covered with scales, while Trichogrammatoidea sp. parasitized only uncovered egg masses. On-farm releases of T. remus in sorghum fields caused up to 64% of FAW egg parasitism. Parasitized eggs yielded viable progeny, which can contribute to FAW egg parasitism build-up during the cropping season. Our findings lay the groundwork for the use of T. remus in augmentative releases against FAW in Africa.

Modern food systems facilitate rapid dispersal of pests and pathogens through multiple pathways. The complexity of spread dynamics and data inadequacy make it challenging to model the phenomenon and also to prepare for emerging invasions. We present a generic framework to study the spatio-temporal spread of invasive species as a multi-scale propagation process over a time-varying network accounting for climate, biology, seasonal production, trade and demographic information. Machine learning techniques are used in a novel manner to capture model variability and analyse parameter sensitivity. We applied the framework to understand the spread of a devastating pest of tomato, Tuta absoluta , in South and Southeast Asia, a region at the frontier of its current range. Analysis with respect to historical invasion records suggests that even with modest self-mediated spread capabilities, the pest can quickly expand its range through domestic city-to-city vegetable trade. Our models forecast that within 5–7 years, Tuta absoluta will invade all major vegetable growing areas of mainland Southeast Asia assuming unmitigated spread. Monitoring high-consumption areas can help in early detection, and targeted interventions at major production areas can effectively reduce the rate of spread.

Surveys of fall army worm, Spodoptera frugiperda (J. E. Smith), in the maize fields in Kenya, Tanzania, and Nepal revealed the occurrence of egg parasitoids, Trichogramma mwanzai in Tanzania, Trichogramma chilonis in Kenya and Nepal, and Telenomus remus in Kenya, Nepal and Tanzania.

The Chitwan Annapurna Landscape (CHAL) is the central part of the Himalayas and covers all bioclimatic zones with major endemism of flora, unique agro-biodiversity, environmental, cultural and socio-economic importance. Not much is known about temperature and precipitation trends along the different bioclimatic zones nor how changes in these parameters might impact the whole natural process, including biodiversity and ecosystems, in the CHAL. Analysis of daily temperature and precipitation time series data (1970–2019) was carried out in seven bioclimatic zones extending from lowland Terai to the higher Himalayas. The non-parametric Mann-Kendall test was applied to determine the trends, which were quantified by Sen’s slope. Annual and decade interval average temperature, precipitation trends, and lapse rate were analyzed in each bioclimatic zone. In the seven bioclimatic zones, precipitation showed a mixed pattern of decreasing and increasing trends (four bioclimatic zones showed a decreasing and three bioclimatic zones an increasing trend). Precipitation did not show any particular trend at decade intervals but the pattern of rainfall decreases after 2000AD. The average annual temperature at different bioclimatic zones clearly indicates that temperature at higher elevations is increasing significantly more than at lower elevations. In lower tropical bioclimatic zone (LTBZ), upper tropical bioclimatic zone (UTBZ), lower subtropical bioclimatic zone (LSBZ), upper subtropical bioclimatic zone (USBZ), and temperate bioclimatic zone (TBZ), the average temperature increased by 0.022, 0.030, 0.036, 0.042 and 0.051 °C/year, respectively. The decade level temperature scenario revealed that the hottest decade was from 1999–2009 and average decade level increases of temperature at different bioclimatic zones ranges from 0.2 to 0.27 °C /decade. The average temperature and precipitation was found clearly different from one bioclimatic zone to other. This is the first time that bioclimatic zone level precipitation and temperature trends have been analyzed for the CHAL. The rate of additional temperature rise at higher altitudes compared to lower elevations meets the requirements to mitigate climate change in different bioclimatic zones in a different ways. This information would be fundamental to safeguarding vulnerable communities, ecosystem and relevant climate-sensitive sectors from the impact of climate change through formulation of sector-wise climate change adaptation strategies and improving the livelihood of rural communities.

The rice moth, Corcyra cephalonica Stainton, an alternate host for the production of the parasitoid, Habrobracon hebetor Say, was reared on different diets, including pearl millet [Pennisetum glaucum (L.) R. Br.] (Poales: Poaceae) flour only, and in combinations of flours of sorghum [Sorghum bicolor (L.) Moench] (Poales: Poaceae), peanut (Arachis hypogea L.) (Fabales: Fabaceae), and cowpea [Vigna unguiculata (L.) Walp.] (Fabales: Fabaceae) to identify the optimal and economical proportion to be used under the conditions of Niger. The addition of cowpea or peanut to the pearl millet diet slightly increased C. cephalonica larval development time. Likewise, the addition of cowpea or peanut to cereal diets yielded a higher C. cephalonica larval survival. Female moths emerging from larvae fed on cereal and legume mixed diets produced higher eggs compared to the ones fed on sole and mixed cereals. Among legumes, cowpea addition is most interesting in terms of cost/production of C. cephalonica larvae. However, female moths emerging from larvae fed on different millet cowpea mix (5, 25, and 50%) laid significantly more eggs than those fed on sole pearl millet. Further, individual C. cephalonica larvae fed on 75% pearl millet + 25% cowpea produced significantly more H. hebetor. With an initial 25 C. cephalonica larvae kept for a 3-mo rearing period, the number of H. hebetor parasitoids produced will reach 2.68–10.07 million. In terms of cost/production ratio, the 75% pearl millet: 25% cowpea yielded better results.