Pathogenicity of local Metarhizium anisopliae var. acridum strains on Locusta migratoria migratorioides Reiche and Farmaire and Zonocerus variegatus Linnaeus in Senegal

Locusts and grasshoppers are the most important economical threat in the sahelian agricultural system. Principal control strategies of these pests are synthetic chemicals which are, however, harmful to the environment and human health. Metarhizium anisopliae based biopesticide Green Muscle IMI330189 has been recently developed for the control of locusts and grasshoppers. In this paper, we assessed the pathogenicity of three local strains of M. anisopliae var. acridum on Locusta migratoria migratorioides and Zonocerus variegatus, in comparison to the commercial product, IMI330189. There was various level of pathogenicity within the strains on the two pests. On L. migratoria, DPV5 caused the highest mortality after three weeks (91.2%). There was a significant difference between DPV5 and IMI330189. However, there were no significant differences between IMI330189 and the other strains. On Z. variegatus there were no significant differences between IMI330189 DPV5 and DPV10. DPV15 had the lowest pathogenic activity. Moreover, the comparison of susceptibility of both insect pests to Metarhizium strains showed that L. migratoria is more susceptible than Z. variegatus. DPV5 had the shortest LT50 on L. migratoria 7.1 days whereas on Z. variegatus, the LT50 value of DPV5 was comparable to IMI330189. Our study suggests that, DPV5 which was isolated from Kraussaria angulifera in Senegal is a promising candidate for future development for locusts and grasshoppers control in the country.Keywords: Green Muscle, African migratory locust, grasshoppers, local strains, biopesticide

Urban agriculture in Senegal: effect of wastewater on the agronomical performance and hygienic quality of tomato and lettuce

The use of wastewater in urban agriculture has gained a lot of interest in Senegal. The aim of this works was to assess the effect of wastewater on the agronomical performance of two vegetable crops and the hygienic threats as compared to tap water. We also compared the effect of irrigation mode and the addition of fertilizers. Results showed that there were no significant differences between the two irrigation modes. Thesturdiness at 2 months had a positive effect on the number of plant (tomato) at the harvest, the yield and fruit average weight. Considering the following parameters studied (overall yield, corrected yield, number of fruit per treatment and fruit average size, there were significant differences between plants (lettuce) treated with tap water and those treated with wastewater. In a chemical point of view, samples from aspersion and draining watering mode treatments were similar in term of their content in heavy metals. On the lettuce, results showed a low presence of worms on crop watered with wastewater. On the other hand, lettuce watered with theaspersion technique contents much more germs of pathogens than those watered in draining mode. As for tomato, there was a total absence of worms and other pathogenic germs in both irrigation modes. This studysuggests that use of wastewater in horticulture with a moderate fertilization and taking into account soil chemistry could be gainful to urban farmers. The study addresses the issue of preliminary studies on the wastewater and soil quality before deciding on the adequate crop to grow

Farmers' knowledge and perception of grain legume pests and their management in the Eastern province of Kenya

Grain legumes play an important role in community livelihood and in the national economy in Kenya. Unfortunately, in many African countries, production doesn't satisfy the demand in grains due to various constrains. Understanding farmers practices and behavior in the management of grain legume pests is a crucial step in the development of sustainable management strategies. A total of 216 farmers were surveyed in eight districts of eastern Kenya to evaluate farmers' knowledge and perceptions of grain legume pests; to examine current pest management practices, and to identify other production constraints. Grain legumes are grown by a wide age-group of farmers, with both genders equally represented. Chemical control remains the main pest management strategy, and, to ensure pesticide effectiveness, farmers also use increased application rates, chemical alternation, frequent application and mixtures of chemicals. While farmers used other control measures, they showed only limited interest in biological control. The majority of the farmers had experience in grain legume farming and were able to identify the major pests, which were the legume flower thrips Megalurothrips sjostedti Trybom, the cowpea aphid Aphis craccivora Koch and the legume pod borer Maruca vitrata Fabricius. Our survey revealed that education and proximity to extension services contributed significantly to farmers' knowledge of grain legume pests, suggesting the need to provide continuous training and capacity building on integrated pest management in grain legume farming. The study also suggests integration of other pest management strategies such as the use of early maturing varieties, biopesticides and biofertilizer to reduce the use of chemical for sustainable pest management

Diapause disruption in Cirina butyrospermi Vuillet (Lepidoptera, Attacidae), the shea caterpillar, in Burkina Faso

The shea caterpillar Cirina butyrospermi is an important insect, highly valued as a human food item in Burkina Faso. However, its appearance is seasonal due to its univoltine cycle. This study therefore investigated the possibilities of breaking the nymphal diapause by changing the environmental factors and through the hormonal treatment of prepupae and pupae using bovine insulin and 20-hydroxyecdysone. Changes in humidity and temperature did not result in emergence, suggesting a mandatory nature of the diapause in C. butyrospermi. Injection of 20-hydroxyecdysone between 20 and 40 ng on 20 C. butyrospermi pupae resulted in 15.24 and 47.5% emergence, respectively. The incubation time varied between 40 and 38 days, respectively. No emergence was observed with the injection of bovine insulin. Dipping of C. butyrospermi larvae and pupae in solutions of 20-hydroxyecdysone resulted in similar rates of emergence between the two stages, with slight variations between individual doses: (1) for larvae, emergence was recorded at 10, 8, 5 and 15 mg/l with 98.5, 62.14, 25.73 and 24.16%, respectively; the incubation times varied from 39 days at 5 mg/l to 26 days at 20 mg/l; and (2) for pupae, emergence occurred between 5 and 20 mg/l, with the highest emergence rate recorded at 10, 8 and 15 mg/l with 94.58, 65.83 and 29.58%, respectively; the incubation times varied from 53 days for the lowest dose (5 mg/l) to 37 days (20 mg/l); the best emergence rate of 94.58% coincided with an incubation time of 43 days at 10 mg/l. No emergence was observed beyond 20 mg/l in both stages. Hormonal treatment with 20-hydroxyecdysone did not affect the fecundity of C. butyrospermi, with the fecundity of artificially emerging adults overlapping with that of naturally emerging adults. The emergence rate for both was similar. These results contribute to a better understanding of the physiology of this insect, constituting a breakthrough in its sustainable use as human food

Host tree-based scenario modelling for predicting a key edible insect, mopane worm Gonimbrasia belina (Westwood, 1894) distribution in Southern Africa

Gonimbrasia belina, known as the mopane worm, is a large edible caterpillar in tropical and subtropical regions. However, little is known about the bioecology of this species as influenced by its host trees. This study evaluated the importance of different potential host trees in understanding mopane worms’ behaviour and spatial distribution. To assess their relative importance, the study compared models incorporating various mopane worm host trees and predictor variables. Using the species distribution modelling (SDM) package in R, an ensemble of random forest (RF), support vector machine (SVM), and boosted regression tree (BRT) algorithms were used to assess the spatial extent of mopane worm distribution in Southern Africa. Four host tree-based scenarios were developed to assess their contribution to the relative distribution of the mopane worm i.e. (1) by excluding all the potential host trees as explanatory variables and considering only the environmental variables, (2) focusing on the primary host tree, Colophospermum mopane as an explanatory variable together with the other environmental variables, (3) incorporating all the host trees, including C. mopane and (4) examining all other host trees excluding C. mopane. Results demonstrated that incorporating all host trees enhanced the models’ predictive abilities (mean AUC = 0.87) underscoring the significant impact of the alternative host trees on the mopane worm distribution patterns beyond just the C. mopane. This study highlights the significance of host trees in predicting the behaviour and distribution of mopane worm populations, providing valuable insights and decision-making for mopane worm use as an alternative protein source, conservation efforts, and land management practices.https://brill.com/view/journals/jiff/jiff-overview.xmlhj2024Zoology and EntomologySDG-15:Life on lan

Acute complications of preeclampsia: prognosis and management at Pikine National Hospital in Dakar (Senegal)

ABSTRACTBackground: The objective of this study was to evaluate the prevalence of acute complications of preeclampsia in order to describe the epidemiological profile of the disease, to assess its prognosis and management.Methods: This was a retrospective study of patients admitted to the Pikine National Hospital from 1 January 2010 to 31 December 2013 (48 months) with severe complicated pre-eclampsia. Included in this study were patients admitted or diagnosed with severe complicated pre-eclampsia and having given birth in the structure or not.Results: The incidence of severe preeclampsia in childbirth varied from 9.7% to 11.5% during the four years of our study. Patients were largely paucigest (55.7% of cases) and paucipares (58.5% of cases). The mean age was 28.14 years with extremes of 14 and 47 years. More than half of the patients (57.7%) were between 21 and 34 years of age. They were mostly married (90.7%). Three-quarters of the patients (76.8%) had proteinuria with ≥ 3 cross-bands. Thrombocytopenia was found in 9.7% of patients, hepatic cytolysis in 12.1%, and elevation of serum creatinine in 13.8%. The level of transaminases was found to be greater than 2 in the normal range in 12.1%. Complicated forms were the most represented in our study. These were acute complications, with 715 cases, or 57.3% of the patients. They were either isolated (52.8%) or associated (4.5%). These included eclampsia (24.9%), followed by retroplacental hematoma (24.6%), fetal death in utero (23.7%), HELLP syndrome (3.4%). , Acute edema of the lungs (1.5%), and acute renal failure (1.4%). The lethality was 2.4%. The causes of maternal death were dominated by eclampsia (14 cases), DIC (3 cases) and OAP (2 cases). We counted 77.7% of live births and a stillbirth of 254.5 ‰.Conclusions: Pre-eclampsia is a serious complication of pregnancy. Its frequency is still high in sub-Saharan Africa. In the presence of signs of severity, maternal (vital and functional) and neonatal prognosis are inevitably involved. If management is based on fetal extraction, resuscitation measures are a guarantee of maternal survival

Integrating temperature-dependent life table data into Insect Life Cycle Model for predicting the potential distribution of Scapsipedus icipe Hugel & Tanga

Open Access Journal; Published online: 25 Sept 2019Scapsipedus icipe Hugel and Tanga (Orthoptera: Gryllidae) is a newly described edible cricket species. Although, there is substantial interest in mass production of S. icipe for human food and animal feed, no information exists on the impact of temperature on their bionomics. Temperature-dependent development, survival, reproductive and life table parameters of S. icipe was generated and integrated into advanced Insect Life Cycle Modeling software to describe relative S. icipe population increase and spatial spread based on nine constant temperature conditions. We examined model predictions and implications for S. icipe potential distribution in Africa under current and future climate. These regions where entomophagy is widely practiced have distinctly different climates. Our results showed that S. icipe eggs were unable to hatch at 10 and 40˚C, while emerged nymphs failed to complete development at 15˚C. The developmental time of S. icipe was observed to decrease with increased in temperature. The lowest developmental threshold temperatures estimated using linear regressions was 14.3, 12.67 and 19.12˚C and the thermal constants for development were 185.2, 1111.1- and 40.7-degree days (DD) for egg, nymph and pre-adult stages, respectively. The highest total fecundity (3416 individuals/female/generation), intrinsic rate of natural increase (0.075 days), net reproductive rate (1330.8 female/female/generation) and shortest doubling time (9.2 days) was recorded at 30˚C. The regions predicted to be suitable by the model suggest that S. icipe is tolerant to a wider range of climatic conditions. Our findings provide for the first-time important information on the impact of temperature on the biology, establishment and spread of S. icipe across the Africa continent. The prospect of edible S. icipe production to become a new sector in food and feed industry is discussed

Exploiting thrips aggregation pheromones to develop a lure-and-kill strategy for the management of the bean flower thrips

The potential of semiochemicals to lure insect pests to a trap where they can be killed with biopesticides has been demonstrated as an eco-friendly pest management alternative. In this study, we tested two recently characterized male-produced aggregation pheromones of the bean flower thrips Megalurothrips sjostedti (Trybom), namely (R)-lavandulyl 3-methylbutanoate (major) and (R)-lavandulol (minor), for their field efficacy. Moreover, compatibility of these pheromones and two other thrips attractants, Lurem-TR and neryl (S)-2-methylbutanoate, with the entomopathogenic fungus (EPF) Metarhizium anisopliae ICIPE 69 has been determined. Our study revealed that the M. sjostedti aggregation pheromones have dose-dependent antifungal effects on the EPF viability, but showed no fungistatic effect at a field-realistic dose for attraction of thrips. (R)-lavandulyl 3-methylbutanoate had similar antifungal effects as neryl (S)-2-methylbutanoate 8 days after exposure; whereas, Lurem-TR had a stronger antifungal effect than other thrips attractants. In the semi-field experiments, all autoinoculation devices maintained at least 86% viability of M. anisopliae conidia after 12 days of exposure. Field trials demonstrated for the first time that (R)-lavandulyl 3-methylbutanoate increases trap catches. Our findings pave a way for designing a lure-and-kill thrips management strategy to control bean flower thrips using autoinoculation devices or spot spray application

Edible crickets (Orthoptera) around the world: distribution, nutritional value, and other benefits - a review

Open Access Journal; Published online: 12 Jan 2021Edible crickets are among the praised insects that are gaining recognition as human food and livestock feed with a potential of contributing to food security and reduction of malnutrition. Globally, the sustainable use of crickets as food or feed is undermined by lack of information on the number of the edible crickets, the country where they are consumed, and the developmental stages consumed. Furthermore, lack of data on their nutritional content and the potential risks to potential consumers limits their consumption or inclusion into other food sources. We reviewed published literature on edible cricket species, countries where they are consumed, and the stage at which they are consumed. We further reviewed information on their nutritional content, the safety of cricket consumption, and the sensory qualities of the edible crickets. We also looked at other benefits derived from the crickets, which include ethnomedicine, livestock feed, pest management strategies, contribution to economic development, and livelihood improvement, particularly in terms of use as food preservatives and use within music, sports, and cultural entomology. Lastly, we reviewed information on the farming of edible crickets. In this review, we report over 60 cricket species that are consumed in 49 countries globally. Nutritionally, crickets are reported to be rich in proteins, ranging from 55 to 73%, and lipids, which range from 4.30 to 33.44% of dry matter. The reported amount of polyunsaturated fatty acids (PUFA) is 58% of the total fatty acids. Edible crickets contain an appreciable amount of macro- and micro-mineral elements such as calcium, potassium, magnesium, phosphorus, sodium, iron, zinc, manganese, and copper. Also, the crickets are rich in the required amount of vitamins such as B group vitamins and vitamins A, C, D, E, and K. Overall, the cricket species examined in this review are safe to be consumed, and they display high proximate content that can replace plant and livestock products. The crickets play valuable roles in contributing to the economies of many countries and livelihoods, and they have medicinal and social benefits. This review is expected to promote greater recognition of crickets as a source of food, feed, and other benefits in the world and encourage up-scaling by farming them for sustainable utilization