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Studies were carried out in the laboratory to understand the optimum environmental conditions at which the ectoparasitoid, Habrobracon hebetor Say (Hymenoptera: Braconidae), can paralyze and lay eggs when reared on the larvae of the stored product pest, Plodia interpunctella Hübner (Lepidoptera: Pyralidae). At the four temperatures investigated (20, 25, 30, and 35 °C), optimum temperatures for oviposition were found to be 25 and 30 °C, while 35 °C was the least favorable temperature. No significant differences were found between the percentages of diapausing and non-diapausing larvae paralyzed by the wasp at the temperatures of 20, 25, 30, 35 °C within 5 days. However, in another experiment that investigated the effect of photoperiods at different temperatures that included 15, 19 and 28 °C, the number of paralyzed larvae was highly reduced at low temperatures (15 °C) but photoperiods had no significant impact on the number of host larvae paralyzed. In addition, observations at short time intervals also showed that lower temperatures slowed down host larvae paralysis. The results suggest that H. hebetor can paralyze host larvae of P. interpunctella more efficiently and deposit more eggs at temperatures within the range of 20–30 °C.
George N. Mbata; Sanower Warsi; Mark E. Payton. Influence of Temperature and Photoperiod on the Fecundity of Habrobracon hebetor Say (Hymenoptera: Braconidae) and on the Paralysis of Host Larvae, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae). Insects 2021, 12, 753 .
AMA StyleGeorge N. Mbata, Sanower Warsi, Mark E. Payton. Influence of Temperature and Photoperiod on the Fecundity of Habrobracon hebetor Say (Hymenoptera: Braconidae) and on the Paralysis of Host Larvae, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae). Insects. 2021; 12 (8):753.
Chicago/Turabian StyleGeorge N. Mbata; Sanower Warsi; Mark E. Payton. 2021. "Influence of Temperature and Photoperiod on the Fecundity of Habrobracon hebetor Say (Hymenoptera: Braconidae) and on the Paralysis of Host Larvae, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)." Insects 12, no. 8: 753.
A sizable proportion (about 8%) of the world population is facing food insecurity
George Mbata; Michael Toews. Recent Advances in Postharvest Pest Biology and Management. Insects 2021, 12, 543 .
AMA StyleGeorge Mbata, Michael Toews. Recent Advances in Postharvest Pest Biology and Management. Insects. 2021; 12 (6):543.
Chicago/Turabian StyleGeorge Mbata; Michael Toews. 2021. "Recent Advances in Postharvest Pest Biology and Management." Insects 12, no. 6: 543.
Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is among the most economically important insect pests of various vegetable crops in the Southern United States. This insect is considered a complex of at least 40 morphologically indistinguishable cryptic species. Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) was initially introduced in the United States around 1985 and has since rapidly spread across the Southern United States to Texas, Arizona, and California, where extreme field outbreaks have occurred on vegetable and other crops. This pest creates extensive plant damage through direct feeding on vegetables, secreting honeydew, causing plant physiological disorders, and vectoring plant viruses. The direct and indirect plant damage in vegetable crops has resulted in enormous economic losses in the Southern United States, especially in Florida, Georgia, and Texas. Effective management of B. tabaci on vegetables relies mainly on the utilization of chemical insecticides, particularly neonicotinoids. However, B. tabaci has developed considerable resistance to most insecticides. Therefore, alternative integrated pest management (IPM) strategies are required, such as cultural control by manipulation of production practices, resistant vegetable varieties, and biological control using a suite of natural enemies for the management of the pest.
Yinping Li; George Mbata; Somashekhar Punnuri; Alvin Simmons; David Shapiro-Ilan. Bemisia tabaci on Vegetables in the Southern United States: Incidence, Impact, and Management. Insects 2021, 12, 198 .
AMA StyleYinping Li, George Mbata, Somashekhar Punnuri, Alvin Simmons, David Shapiro-Ilan. Bemisia tabaci on Vegetables in the Southern United States: Incidence, Impact, and Management. Insects. 2021; 12 (3):198.
Chicago/Turabian StyleYinping Li; George Mbata; Somashekhar Punnuri; Alvin Simmons; David Shapiro-Ilan. 2021. "Bemisia tabaci on Vegetables in the Southern United States: Incidence, Impact, and Management." Insects 12, no. 3: 198.
Pest management in most sub-Saharan subsistence agriculture involves mainly the use of botanicals that are either applied as powders, solvent extracts, ash or essential oils. Two hydrogenated monoterpenes (α-pinene and 3-carene) from Cupressus sempervirens were tested against Sitophilus zeamais in the laboratory to evaluate the contact and fumigation effects on the mortality of adult and immature weevils, progeny production, and grain damage. Contact toxicity of the terpenes was investigated at these concentrations: 0.08, 4, 8 and 12 ppm (terpene/maize), while fumigant action was studied at the following doses: 1, 2, 3, and 4 ppm. The results indicate that insecticidal effects were concentration-dependent since mortality increased with dosage and exposure periods. After a 14-day exposure period at the concentration of 12 ppm of α-pinene and 3-carene/grain, more than 98% mortality of the mature weevils was observed at concentrations of 4.1333 and 1.642 ppm respectively and progeny production was reduced by 98% and 100%, respectively. When α-pinene and 3-carene were applied as fumigants, LC50s (lethal concentrations that generate 50% mortality) of 1.402 and 0.610 ppm were obtained after 24 h of exposure, respectively. At concentrations above 3 ppm, both monoterpenes acted as repellents to weevils and reduced grain damage by 80%. Both monoterpenes inhibited the development of immature stages of the weevil and reduced progeny by up to 94%. These compounds are very promising and effective and could be exploited as novel phytoinsecticides against the maize weevil.
Jacob D. Langsi; Elias N. Nukenine; Kary M. Oumarou; Hamadou Moktar; Charles N. Fokunang; George N. Mbata. Evaluation of the Insecticidal Activities of α-Pinene and 3-Carene on Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Insects 2020, 11, 540 .
AMA StyleJacob D. Langsi, Elias N. Nukenine, Kary M. Oumarou, Hamadou Moktar, Charles N. Fokunang, George N. Mbata. Evaluation of the Insecticidal Activities of α-Pinene and 3-Carene on Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Insects. 2020; 11 (8):540.
Chicago/Turabian StyleJacob D. Langsi; Elias N. Nukenine; Kary M. Oumarou; Hamadou Moktar; Charles N. Fokunang; George N. Mbata. 2020. "Evaluation of the Insecticidal Activities of α-Pinene and 3-Carene on Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)." Insects 11, no. 8: 540.
Consumers are increasingly demanding pesticide-free grain/legumes and processed foods. Additionally, there are more restrictions, or complete loss, of insecticides labelled for use in managing stored grain insects in post-harvest ecosystems. Suppression of post-harvest pests using parasitic wasps is a more sustainable alternative than chemical pesticides. Habrobracon hebetor (Say) (Hymenoptera: Braconidae) and Pteromalus cerealellae Ashmead (Hymenoptera: Pteromalidae) are two important parasitoids that limit economically important pests of stored products. Host searching ability and reproductive performances of H. hebetor and P. cerealellae depend on a wide range of factors, such as host species, commodities, and environmental conditions. Further, use of entomopathogens can complement the ability of parasitoids to regulate pest populations. This review provides information on aspects of H. hebetor and P. cerealellae biology and successful regulation of post-harvest pest populations.
George N. Mbata; Sanower Warsi. Habrobracon hebetor and Pteromalus cerealellae as Tools in Post-Harvest Integrated Pest Management. Insects 2019, 10, 85 .
AMA StyleGeorge N. Mbata, Sanower Warsi. Habrobracon hebetor and Pteromalus cerealellae as Tools in Post-Harvest Integrated Pest Management. Insects. 2019; 10 (4):85.
Chicago/Turabian StyleGeorge N. Mbata; Sanower Warsi. 2019. "Habrobracon hebetor and Pteromalus cerealellae as Tools in Post-Harvest Integrated Pest Management." Insects 10, no. 4: 85.
Maize (Zea mays L.) is an important cereal crop that is cultivated globally. In storage, maize is infested by the maize weevil (Sitophilus zeamais Motchulsky). In sub– Saharan Africa where maize is an important staple crop, infestation by S. zeamais is severe. Chemical pesticides have been the key pest management tools for this pest but these practices come with consequences such as insect resistance to pesticides, food and environmental contamination, and depletion of non-target species. These challenges associated with use of chemical pesticides may be overcome by controlling this pest with natural enemies such as entomopathogens. In the laboratory, this study evaluated the pathogenicity of six entomopathogenic nematodes (EPN) - Heterorhabditis bacteriophora Poinar (Lewiston, and Oswego strains); H. indica Poinar, Karunakar, and David (Homl strain), H. georgiana (K22), Steinernema feltiae (SN), and S. carpocapsae (All), and two fungi namely, Beauveria bassiana (GHA) and Metarhizium brunneum (F52) to adult weevils (S. zeamais). All nematodes used in the study were pathogenic to adult weevils. However, S. carpocapsae was the most virulent to the adult weevils. High doses (1 x 109 conidia/mL) of the fungi application caused significant weevil mortality compared to the control. Subsequently, in a novel approach, this study established the basis for effective storage of maize by treating storage bags (jute bags) with wettable powder of B. bassiana (2.13 x 107 conidia/mm2) and then exposing adult weevils to the treated jute bags. The results showed that adult weevils that walked for 30 min on the treated jute bags recorded 100% mortality at 14 days post-inoculation. Thus, there is the potential for using a wettable powder of B. bassiana to protect maize from S. zeamais during storage in jute bags.
George N. Mbata; Cleveland Ivey; David Shapiro-Ilan. The potential for using entomopathogenic nematodes and fungi in the management of the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae). Biological Control 2018, 125, 39 -43.
AMA StyleGeorge N. Mbata, Cleveland Ivey, David Shapiro-Ilan. The potential for using entomopathogenic nematodes and fungi in the management of the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae). Biological Control. 2018; 125 ():39-43.
Chicago/Turabian StyleGeorge N. Mbata; Cleveland Ivey; David Shapiro-Ilan. 2018. "The potential for using entomopathogenic nematodes and fungi in the management of the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae)." Biological Control 125, no. : 39-43.
George N. Mbata; Mark E. Payton. Effect of monoterpenoids on oviposition and mortality of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) under hermetic conditions. Journal of Stored Products Research 2013, 53, 43 -47.
AMA StyleGeorge N. Mbata, Mark E. Payton. Effect of monoterpenoids on oviposition and mortality of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) under hermetic conditions. Journal of Stored Products Research. 2013; 53 ():43-47.
Chicago/Turabian StyleGeorge N. Mbata; Mark E. Payton. 2013. "Effect of monoterpenoids on oviposition and mortality of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) under hermetic conditions." Journal of Stored Products Research 53, no. : 43-47.
George N. Mbata; Thomas W. Phillips; Mark E. Payton. Effects of cowpea varietal susceptibility and low pressure on the mortality of life stages of Callosobruchus maculatus (Coleoptera: Bruchidae). Journal of Stored Products Research 2009, 45, 232 -235.
AMA StyleGeorge N. Mbata, Thomas W. Phillips, Mark E. Payton. Effects of cowpea varietal susceptibility and low pressure on the mortality of life stages of Callosobruchus maculatus (Coleoptera: Bruchidae). Journal of Stored Products Research. 2009; 45 (4):232-235.
Chicago/Turabian StyleGeorge N. Mbata; Thomas W. Phillips; Mark E. Payton. 2009. "Effects of cowpea varietal susceptibility and low pressure on the mortality of life stages of Callosobruchus maculatus (Coleoptera: Bruchidae)." Journal of Stored Products Research 45, no. 4: 232-235.
Laboratory studies were carried out to determine the functional response of the parasitoid, Pteromalus cerealellae (Boucek) to cowpea weevil, Callosobruchus maculatus (F.) hosts, and the relationship between parasitism and cowpea variety susceptibility to the weevil. The attack response of P. cerealella to weevil larvae was best described by a type III functional response using an egg limitation model. The mean attack rate (a) of the parasitoid was estimated as 1.7 and the upper limit of the response was 24 weevil larvae per individual parasitoid within a 48-h period. The results also showed that cowpea varieties resistant to weevil infestation supported fewer weevil progeny and facilitated a greater suppression of the weevil by the parasitoid. The parasitoid progeny index, a measure that compares the number of the parasitoid progeny to the number of the beetle progeny was higher in cowpea weevil resistant varieties than in susceptible varieties. Additionally, the presence of P. cerealellae resulted in reduced weight losses of cowpea caused by the weevil infestation in both susceptible and resistant varieties.
George N. Mbata; Carlyle C. Brewster. Functional response of Pteromalus cerealellae (Hymenoptera: Pteromalidae) on the cowpea weevil, Callosbruchus maculatus (Coleoptera: Bruchidae), and interaction between parasitism and cowpea varietal susceptibility. BioControl 2009, 54, 751 -761.
AMA StyleGeorge N. Mbata, Carlyle C. Brewster. Functional response of Pteromalus cerealellae (Hymenoptera: Pteromalidae) on the cowpea weevil, Callosbruchus maculatus (Coleoptera: Bruchidae), and interaction between parasitism and cowpea varietal susceptibility. BioControl. 2009; 54 (6):751-761.
Chicago/Turabian StyleGeorge N. Mbata; Carlyle C. Brewster. 2009. "Functional response of Pteromalus cerealellae (Hymenoptera: Pteromalidae) on the cowpea weevil, Callosbruchus maculatus (Coleoptera: Bruchidae), and interaction between parasitism and cowpea varietal susceptibility." BioControl 54, no. 6: 751-761.
Previous studies have shown that low pressure creates a low oxygen controlled atmosphere that can kill stored-product insects. The current study was conducted to determine the mortality of life stages of the cowpea weevil, Callosbruchus maculatus (F.) (Coleoptera: Bruchidae), exposed to different low pressures and temperatures for various exposure periods. The adults were the most susceptible life stage to low pressure; 99% mortality was achieved within 0.8 h at 32.5 mmHg, 30°C. The pupae were the most tolerant life stage to low pressure, requiring exposure periods between 28.98 and 153.20 h at temperatures of 20–35°C to achieve 99% mortality. Mortality increased with exposure time and also with increasing temperature in all life stages. Early stage eggs (3 h old) and late stage eggs (48 h old) experienced higher mortality (values for LT99 of 42.331 and 46.652 h, respectively) compared with intermediate aged eggs (24 h old; LT99 of 74.735 h) under the same conditions of low pressure and temperature. Dried beans, including cowpea, Vigna unguiculata (Walp.), are currently protected with fumigants. Application of low pressure as a pest management tool represents a potential nonchemical alternative to fumigants such as methyl bromide and phosphine for controlling the cowpea weevil and related bruchids.
George N. Mbata; Mario Johnson; Thomas W. Phillips; Mark Payton. Mortality of Life Stages of Cowpea Weevil (Coleoptera: Bruchidae) Exposed to Low Pressure at Different Temperatures. Journal of Economic Entomology 2005, 98, 1070 -1075.
AMA StyleGeorge N. Mbata, Mario Johnson, Thomas W. Phillips, Mark Payton. Mortality of Life Stages of Cowpea Weevil (Coleoptera: Bruchidae) Exposed to Low Pressure at Different Temperatures. Journal of Economic Entomology. 2005; 98 (3):1070-1075.
Chicago/Turabian StyleGeorge N. Mbata; Mario Johnson; Thomas W. Phillips; Mark Payton. 2005. "Mortality of Life Stages of Cowpea Weevil (Coleoptera: Bruchidae) Exposed to Low Pressure at Different Temperatures." Journal of Economic Entomology 98, no. 3: 1070-1075.
The Indianmeal moth, Plodia interpunctella (Hübner), is a cosmopolitan pest of stored products, infesting most commodities in warehouses and grain bins. We studied the susceptibility of Indianmeal moth adults and larvae to seven entomopathogenic nematode species and strains. The nematodes studied were Heterorhabditis bacteriophora Poinar (HP88, Lewiston, and Oswego strains); H. indica Poinar, Karunakar, and David (Homl strain); H. marelatus Liu and Berry (Point Reyes strain); H. megidis Poinar, Jackson, and Klein (UK211 strain); and H. zealandica Poinar (NZH3 strain). Overall, the nematodes that had the highest virulence to larvae and adults of Indianmeal moth were H. indica, H. megidis, and H. marelatus. Adult Indianmeal moths seemed to be more susceptible to the nematodes than the larvae, and egg laying was significantly reduced by at least 44% in Indianmeal moths adults that survived exposure to the nematode strains. We conclude that H. indica, H. megidis, and H. marelatus should be studied further as potential biocontrol agents of Indianmeal moth in stored grains and processed commodities.
George N. Mbata; David Shapiro-Ilan. Laboratory Evaluation of Virulence of Heterorhabditid Nematodes toPlodia interpunctellaHübner (Lepidoptera: Pyralidae). Environmental Entomology 2005, 34, 676 -682.
AMA StyleGeorge N. Mbata, David Shapiro-Ilan. Laboratory Evaluation of Virulence of Heterorhabditid Nematodes toPlodia interpunctellaHübner (Lepidoptera: Pyralidae). Environmental Entomology. 2005; 34 (3):676-682.
Chicago/Turabian StyleGeorge N. Mbata; David Shapiro-Ilan. 2005. "Laboratory Evaluation of Virulence of Heterorhabditid Nematodes toPlodia interpunctellaHübner (Lepidoptera: Pyralidae)." Environmental Entomology 34, no. 3: 676-682.
George N Mbata; Thomas W Phillips; Mark Payton. Mortality of eggs of stored-product insects held under vacuum: effects of pressure, temperature, and exposure time. Journal of Economic Entomology 2004, 97, 1 .
AMA StyleGeorge N Mbata, Thomas W Phillips, Mark Payton. Mortality of eggs of stored-product insects held under vacuum: effects of pressure, temperature, and exposure time. Journal of Economic Entomology. 2004; 97 (2):1.
Chicago/Turabian StyleGeorge N Mbata; Thomas W Phillips; Mark Payton. 2004. "Mortality of eggs of stored-product insects held under vacuum: effects of pressure, temperature, and exposure time." Journal of Economic Entomology 97, no. 2: 1.
Low pressure applied to a commodity creates a low-oxygen atmosphere that can be effective to control stored-product insects. Previous work determined that eggs of several species of stored-product insects were among the most tolerant life stages to low pressure. The current study was conducted to determine the mortality of eggs in response to various pressures, temperatures, and exposure times. An initial experiment determined that the sensitivity of eggs to vacuum varied with their age. Eggs of Plodia interpunctella (Hübner) were most sensitive to low pressure when they were 3 or 48 h old, whereas those of Rhyzopertha dominica (F.) were most sensitive at 12 and 120 h of age. In subsequent experiments, eggs of Cadra cautella (Walker), P. interpunctella, R. dominica, and Tribolium castaneum (Herbst) were exposed to pressures of 50, 75, 100, 200, and 300 mmHg in glass chambers at 5, 15, 22.5, 30, and 37.5°C for times ranging from 12 to 168 h. Time-mortality data were subjected to probit analyses and lethal dose ratios were computed to determine differences in lethal time values among species across the 25 low pressure-temperature combinations for each species. In all four species the mortality of eggs increased with increasing exposure time and temperature. Low temperatures and high pressures were the least effective conditions for killing eggs, compared with high temperatures combined with low pressures in all species investigated. These results provide important guidelines for developing treatment schedules for disinfestation of commodities on a commercial scale.
George N. Mbata; Thomas W. Phillips; Mark Payton. Mortality of Eggs of Stored-Product Insects Held Under Vacuum: Effects of Pressure, Temperature, and Exposure Time. Journal of Economic Entomology 2004, 97, 695 -702.
AMA StyleGeorge N. Mbata, Thomas W. Phillips, Mark Payton. Mortality of Eggs of Stored-Product Insects Held Under Vacuum: Effects of Pressure, Temperature, and Exposure Time. Journal of Economic Entomology. 2004; 97 (2):695-702.
Chicago/Turabian StyleGeorge N. Mbata; Thomas W. Phillips; Mark Payton. 2004. "Mortality of Eggs of Stored-Product Insects Held Under Vacuum: Effects of Pressure, Temperature, and Exposure Time." Journal of Economic Entomology 97, no. 2: 695-702.