An experiment was conducted to test the efficacy of a mechanical barrier around the tree trunk with one spray of Cypermethrin @ 1 ml/l and turmeric powder extract @ 15 g/500ml of water applied in integrated approaches...An experiment was conducted to test the efficacy of a mechanical barrier around the tree trunk with one spray of Cypermethrin @ 1 ml/l and turmeric powder extract @ 15 g/500ml of water applied in integrated approaches against mango mealybug on mango tree. There were 7 treatments including a control. The treatments were Mechanical barrier, Cypermethrin spray @ 1 ml/l, Turmeric powder spray @ 15 g/500ml of water, Cypermethrin spray + Turmeric spray, Cypermethrin spray + Mechanical barrier, Turmeric + Mechanical barrier and untreated control. Three-year-old mango plants grafted from a 5-year-old mango tree (Variety Amropali) and planted in pots were used in the experiment. The treatment, Cypermethrin spray + Mechanical barrier gave the highest reduction of mango mealybug population 87.06% to 93.90% followed by Turmeric spray + Mechanical barrier and showed 81.13% to 86.04% and Mechanical barrier alone showed 81.13% to 84.59% population reduction. Turmeric powder extract showed only (8.42% to 23.77%) population reduction of mango mealybug which was lowest compared to other treatments.展开更多
The cotton mealybug Phenacoccus solenopsis Tinsley(Hemiptera: Pseudococcidae), which is native to North America, emerged as a major invasive insect pest of multiple crops in Asia at the beginning of the 21 st century....The cotton mealybug Phenacoccus solenopsis Tinsley(Hemiptera: Pseudococcidae), which is native to North America, emerged as a major invasive insect pest of multiple crops in Asia at the beginning of the 21 st century. Considering the economic significance of this insect and its rapid worldwide spread, we examined the possible factors driving its invasions. In this paper, we summarize the life history traits of P. solenopsis conceivably related to population development in invaded regions; these traits include its use of diverse host plants, reproductive capacity and mode, adaptation to temperature, response to food shortage, and insecticidal resistance. Then, focusing on the multiple trophic interactions that may promote or hinder invasion, we review the mutualistic relationship of this mealybug with ants and predation and parasitism by natural enemies. Finally, we suggest topics for future research and provide our perspective on the biological invasions of this mealybug. We speculate that specific biological factors associated with this mealybug, particularly its wide host range, high reproductive potential, evolved changes in life history traits, and mutualism with ants have played important roles in its invasions, allowing this pest to become established and rapidly increase its population upon its introduction into new regions.展开更多
The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an acc...The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an accurate,simple,and developmental-stage-independent detection method for P.manihoti is required.In the present study,a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I(SS-COI)marker was developed for rapid identification of P.manihoti.One pair of SS-COI primers(PMSSZW-1F and PMSSZW-1R)was designed based on sequence variations in the COI gene among P.manihoti and related mealybug species.Specificity of the primer pair was validated on 21 closely related species.Sensitivity tests were performed on four immature developmental stages and female adults.Efficacy tests demonstrated that at the relatively low concentration of(135.2±14.7)pgresuspended DNA,the specific fragment was detected in all replicates.Furthermore,the SS-COI primer pair was assayed on three populations of P.manihoti from major exporting countries of cassava.The PCR assay was proved to be a rapid,simple,and reliable molecular measure for the identification of P.manihoti.This tool will be useful for quarantine,monitoring,and management of this invasive pest.展开更多
Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using ...Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using aqueous leaf extract of Prosopis juliflora(mezquite)against P.solenopsis.The scanning electron microscope(SEM)showed bimetallic nanoparticles of Cu/Zn-NPs with spherical shape with varying size of 74.33 nm to 59.46 nm.More than 30%mortality of P.solenopsis was observed with Cu/Zn-nanoparticles(100 ppm)at 96 hours after treatment.Negligible mortality of P.solenopsis was recorded with Cu/Zn solution(100 ppm)and aqueous P.juliflora extracts.The results of the viability test for Cu/Zn-nanoparticles of P.juliflora showed a significant reduction of the cell viability by 50%in insect exposed to Cu/Zn-nanoparticles-P.juliflora.Therefore studies about nanotoxicity of Cu/Zn-NPs of P.juliflora are needed to reveal the mechanism of toxicity this phytonanoparticles in P.solenopsis.展开更多
As it was rear to find out detailed description, a study on biology and control measures ofP. marginatus was carried out at National Plant Quarantine Service, Katunayake Sri Lanka. Average length and width of differen...As it was rear to find out detailed description, a study on biology and control measures ofP. marginatus was carried out at National Plant Quarantine Service, Katunayake Sri Lanka. Average length and width of different stages, number of eggs in an egg sac, hatchability rate and duration of life cycle were studied. Control measures were tested using herbal oils and it was arranged in Completely Randomized Design with six replicates. Experiments were carried out in laboratory conditions under 28 ±2℃ and 70% RH. Range of length and width of different life stages revealed that, egg 0.3-0.1 mm ×0.15-0.10 mm, 1st instar 0.4-0.2 mm × 0.20-0.10 mm, 2nd instar 0.6-0.5 mm × 0.29-0.20 mm, 3rd instar male 0.8-0.5 mm × 0.30-0.20 mm, 3rd instar female 0.7-0.5 mm × 0.29-0.20 mm, adult male 0.9-0.7 mm× 0.20-0.10 mm and adult female 2.8-1.9 mm × 1.40-0.80 mm. A range of 100-200 eggs were in an ovisac and hatchability rate was 76-80%. Twenty to twenty-four days were taken to complete their life cycle. Cinnamon and Neem oil in cooperated with Surfactant and Kerosene oil could be effectively used as potential chemical agents for control of P. marginatus.展开更多
Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solen...Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solenopsis Tinsley emerged as a serious pest on cotton in India.Laboratory studies indicated that B.pallescens could feed on the cotton mealybug.Hence,further investigations were conducted to understand the stage of the predator which is most potential and the pest stage preferred by the predator.Mature nymphs and adults of B.pallescens could predate equally well on the neonates of cotton mealybug.Young (three to four-day-old) nymphs of the predator could not feed on any stage of the cotton mealybug.Mature nymphs (seven-day-old and above) and adults could effectively predate on both young and mature cotton mealybug crawlers,though preference was more for the younger crawlers.However,nymphs and adults of B.pallescens could not predate on the adult stage of the mealybug.Different predator:pest ratios were tested in cage studies and it emerged that B.pallescens adults released against the mealybug crawlers at a ratio of 1:5 and nymphal release at 1:10 caused maximum mortality of the mealybug crawlers.Considering the fast multiplication rate of cotton mealybug and the large number of predators which have to be released to manage them,further detailed studies are necessary on utilizing B.pallescens to target the neonates and younger stages of the cotton mealybug in field conditions.展开更多
[ Objective ] The paper aimed to establish a real-time fluorescent quantitative PCR (qPCR) detection method for Pineapple mealybug wilt associated vi- rus-3 ( PMWaV3 ). [ Method] Specific TaqMan probe and primers ...[ Objective ] The paper aimed to establish a real-time fluorescent quantitative PCR (qPCR) detection method for Pineapple mealybug wilt associated vi- rus-3 ( PMWaV3 ). [ Method] Specific TaqMan probe and primers were designed and synthesized according to the conserved sequence of coat protein(CP) gene of PMWaV-3, and the standard curve was established after optimizing the amplification condition of qPCR. [ Result] The results showed that the method was specific for the detection of PMWaV-3, and the sensitivity of the present method was about 10 times higher compared to general RT-PCR ; the variation coefficients of intra- assay and inter-assay were less than 1.73, respectively. [ Conclusion] The qPCR is an easy, fast and reliable method for quantitative detection of PMWaV-3.展开更多
Pineapple mealybug wilt disease (PMWD) is one of the latest outbreaks of diseases attacking pineapple in Uganda. However, its occurrence and effects have not been documented and quantified, yet the disease poses a s...Pineapple mealybug wilt disease (PMWD) is one of the latest outbreaks of diseases attacking pineapple in Uganda. However, its occurrence and effects have not been documented and quantified, yet the disease poses a serious threat to the pineapple industry. Therefore, the objective of this study was to assess the occurrence and effects of PMWD on pineapple in central Uganda. Semi-structured questionnaire was used to solicit information from 82 respondents consisting of farmers, opinion leaders, key informants, political and technical leadership during May 2011. PMWD was observed in all the fields surveyed but with varying incidences and severities. In addition, PMWD was more common during the dry seasons than the rainy seasons where higher incidences were associated with high mealybug populations. PMWD manifested as a syndrome characterized by yellowing of leaves, stunting, wilting and rotting of roots. The effects of PMWD were variable but yield reductions and low plant populations were widely reported. Although, the occurrence of PMWD was reported to the different level of authority in the districts, very little was done to curb its spread.展开更多
An experiment was conducted in mango orchard of Sher-E Bangla Agricultural University (SAU) campus, Dhaka to determine the effect of seasonal variation round the year and weather on population dynamics of mango mealyb...An experiment was conducted in mango orchard of Sher-E Bangla Agricultural University (SAU) campus, Dhaka to determine the effect of seasonal variation round the year and weather on population dynamics of mango mealybug (Drosicha mangiferae) on mango tree. The mango mealybug was first appeared in early December and disappeared in June in a year. Its population started to increase gradually from December and continued up to February when the ambient average temperature was 20.95°C, relative humidity 63% and rainfall was absent. The highest population of the insect (33.33/30 cm branch) was recorded in February and the lowest (3.75/30cm branch) in May. Adult insects appeared in February on the ground under the selected mango tree showing the population of 6.67 males and 123.33 females per 81 m<sup>2</sup>. Population of males (32.5/81m<sup>2</sup>) and that of females (352.75/81m<sup>2</sup>) reached to the peak when the ambient temperature was 28.19°C, relative humidity 61% and the rainfall was 0.00 mm. When relative humidity was high and rainfall started adult females enter into the soil and disappeared. Correlation between population of mealybug and temperature was positive. Its population was negatively correlated with relative humidity and rainfall.展开更多
Parasitization has an enormous impact on host physiology, development and reproduction. The effect of parasitism by endoparasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) on survival and reproduction of m...Parasitization has an enormous impact on host physiology, development and reproduction. The effect of parasitism by endoparasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) on survival and reproduction of mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) on different host stages was studied. Our data reveals that host mealybugs parasitized by the wasp at the 2<sup>nd</sup> instar stage were died during the 3<sup>rd</sup> instar stage of their life. However, those parasitized at the 3<sup>rd</sup> instar stage could reach the adult stage and were able to produce their progeny. After 6 days of parasitization, all parasitized hosts of the 2<sup>nd</sup>, 3<sup>rd</sup> and adult stages were died except the 1<sup>st</sup> instar. Results showed that parasitized host mealybugs had significantly lower reproductive potential than the unparasitized ones. Maximum parasitoid emergence was recorded in the 3<sup>rd</sup> instar host stage. This basic research regarding survival and reproduction of the parasitized host mealybugs would be very helpful in devising sustainable biological control strategies for cotton mealybug.展开更多
Rastrococus invadens was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug speci...Rastrococus invadens was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug species associated with the mango tree. It was also important to determine the periods of abundance of these species vis-a-vis R. invadens. For this purpose, the density of mealybugs was assessed in three study sites (Toussiana, Bérégadougou and Orodara) in Western Burkina Faso. The observations were made from June 2014 to June 2015 at a frequency of 15 ± 1 days. They focused on 20 leaves (5 leaves/cardinal point) levied on each mango tree. The species identified as Ferrisia virgata Cockerell and Icerya aegyptiaca Douglas were collected from mangos infested by R. invadens representing 98% - 99% of the density of the observed mealybug species. The periods of abundance of F. virgata and I. aegyptiaca were respectively the dry season and the rainy season. The effect of temperature, relative humidity and rainfall on the populations of F. virgata and I. aegyptiaca was also discussed. These results highlight the distribution range of F. virgata and I. aegyptiaca worldwide including Burkina Faso. R. invadens was the main mealybug species on mango in Burkina Faso in general and in the Western region of the country in particular.展开更多
<i>Rastrococus invadens</i> was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of o...<i>Rastrococus invadens</i> was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug species associated with the mango tree. It was also important to determine the periods of abundance of these species vis-a-vis <i>R. invadens</i>. For this purpose, the density of mealybugs was assessed in three study sites (Toussiana, Bérégadougou and Orodara) in Western Burkina Faso. The observations were made from June 2014 to June 2015 at a frequency of 15 ± 1 days. They focused on 20 leaves (5 leaves/cardinal point) levied on each mango tree. The species identified as <i>Ferrisia virgata</i> Cockerell and <i>Icerya aegyptiaca</i> Douglas were collected from mangos infested by <i>R. invadens</i> representing 98% - 99% of the density of the observed mealybug species. The periods of abundance of <i>F. virgata</i> and <i>I. aegyptiaca</i> were respectively the dry season and the rainy season. The effect of temperature, relative humidity and rainfall on the populations of <i>F. virgata</i> and <i>I. aegyptiaca</i> was also discussed. These results highlight the distribution range of <i>F. virgata</i> and <i>I. aegyptiaca</i> worldwide including Burkina Faso. <i>R. invadens</i> was the main mealybug species on mango in Burkina Faso in general and in the Western region of the country in particular.展开更多
Mealybugs are a major pest for many crops (such as the vegetable Cassava, in Thailand). An environmentally-friendly bio-control method is implemented using an introduced predator (green lacewings) of the mealybugs...Mealybugs are a major pest for many crops (such as the vegetable Cassava, in Thailand). An environmentally-friendly bio-control method is implemented using an introduced predator (green lacewings) of the mealybugs to mitigate plant damage. This is analyzed so as to devise and determine an optimal strategy for control of the mealybug population. A predator-prey model has been proposed and analyzed to study the effect of the biological control of the spread of the mealybugs in the plant field. The behaviour of the system in terms of stability, phase space and bifurcation diagrams are considered. The results obtained from different numbers of predators being released are compared. In particular we obtain thresholds of introduced-predator level above which the prey is driven to extinction. Future models will include age-structured multi-compartments for both the prey and predator populations.展开更多
文摘An experiment was conducted to test the efficacy of a mechanical barrier around the tree trunk with one spray of Cypermethrin @ 1 ml/l and turmeric powder extract @ 15 g/500ml of water applied in integrated approaches against mango mealybug on mango tree. There were 7 treatments including a control. The treatments were Mechanical barrier, Cypermethrin spray @ 1 ml/l, Turmeric powder spray @ 15 g/500ml of water, Cypermethrin spray + Turmeric spray, Cypermethrin spray + Mechanical barrier, Turmeric + Mechanical barrier and untreated control. Three-year-old mango plants grafted from a 5-year-old mango tree (Variety Amropali) and planted in pots were used in the experiment. The treatment, Cypermethrin spray + Mechanical barrier gave the highest reduction of mango mealybug population 87.06% to 93.90% followed by Turmeric spray + Mechanical barrier and showed 81.13% to 86.04% and Mechanical barrier alone showed 81.13% to 84.59% population reduction. Turmeric powder extract showed only (8.42% to 23.77%) population reduction of mango mealybug which was lowest compared to other treatments.
基金financially supported by the National Key Research and Development Program of China(2016YFC1200600)
文摘The cotton mealybug Phenacoccus solenopsis Tinsley(Hemiptera: Pseudococcidae), which is native to North America, emerged as a major invasive insect pest of multiple crops in Asia at the beginning of the 21 st century. Considering the economic significance of this insect and its rapid worldwide spread, we examined the possible factors driving its invasions. In this paper, we summarize the life history traits of P. solenopsis conceivably related to population development in invaded regions; these traits include its use of diverse host plants, reproductive capacity and mode, adaptation to temperature, response to food shortage, and insecticidal resistance. Then, focusing on the multiple trophic interactions that may promote or hinder invasion, we review the mutualistic relationship of this mealybug with ants and predation and parasitism by natural enemies. Finally, we suggest topics for future research and provide our perspective on the biological invasions of this mealybug. We speculate that specific biological factors associated with this mealybug, particularly its wide host range, high reproductive potential, evolved changes in life history traits, and mutualism with ants have played important roles in its invasions, allowing this pest to become established and rapidly increase its population upon its introduction into new regions.
基金supported by the National Key R&D Program of China(2017YFC1200600,2016YFC1201200 and 2015BAD08A16)the Science and Technology Innovation Program of CAAS(caascx-2013-2018-IAS)
文摘The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an accurate,simple,and developmental-stage-independent detection method for P.manihoti is required.In the present study,a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I(SS-COI)marker was developed for rapid identification of P.manihoti.One pair of SS-COI primers(PMSSZW-1F and PMSSZW-1R)was designed based on sequence variations in the COI gene among P.manihoti and related mealybug species.Specificity of the primer pair was validated on 21 closely related species.Sensitivity tests were performed on four immature developmental stages and female adults.Efficacy tests demonstrated that at the relatively low concentration of(135.2±14.7)pgresuspended DNA,the specific fragment was detected in all replicates.Furthermore,the SS-COI primer pair was assayed on three populations of P.manihoti from major exporting countries of cassava.The PCR assay was proved to be a rapid,simple,and reliable molecular measure for the identification of P.manihoti.This tool will be useful for quarantine,monitoring,and management of this invasive pest.
文摘Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using aqueous leaf extract of Prosopis juliflora(mezquite)against P.solenopsis.The scanning electron microscope(SEM)showed bimetallic nanoparticles of Cu/Zn-NPs with spherical shape with varying size of 74.33 nm to 59.46 nm.More than 30%mortality of P.solenopsis was observed with Cu/Zn-nanoparticles(100 ppm)at 96 hours after treatment.Negligible mortality of P.solenopsis was recorded with Cu/Zn solution(100 ppm)and aqueous P.juliflora extracts.The results of the viability test for Cu/Zn-nanoparticles of P.juliflora showed a significant reduction of the cell viability by 50%in insect exposed to Cu/Zn-nanoparticles-P.juliflora.Therefore studies about nanotoxicity of Cu/Zn-NPs of P.juliflora are needed to reveal the mechanism of toxicity this phytonanoparticles in P.solenopsis.
文摘As it was rear to find out detailed description, a study on biology and control measures ofP. marginatus was carried out at National Plant Quarantine Service, Katunayake Sri Lanka. Average length and width of different stages, number of eggs in an egg sac, hatchability rate and duration of life cycle were studied. Control measures were tested using herbal oils and it was arranged in Completely Randomized Design with six replicates. Experiments were carried out in laboratory conditions under 28 ±2℃ and 70% RH. Range of length and width of different life stages revealed that, egg 0.3-0.1 mm ×0.15-0.10 mm, 1st instar 0.4-0.2 mm × 0.20-0.10 mm, 2nd instar 0.6-0.5 mm × 0.29-0.20 mm, 3rd instar male 0.8-0.5 mm × 0.30-0.20 mm, 3rd instar female 0.7-0.5 mm × 0.29-0.20 mm, adult male 0.9-0.7 mm× 0.20-0.10 mm and adult female 2.8-1.9 mm × 1.40-0.80 mm. A range of 100-200 eggs were in an ovisac and hatchability rate was 76-80%. Twenty to twenty-four days were taken to complete their life cycle. Cinnamon and Neem oil in cooperated with Surfactant and Kerosene oil could be effectively used as potential chemical agents for control of P. marginatus.
基金financial support extended by the Cotton Mission Mode project TMC MM1 3. 3
文摘Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solenopsis Tinsley emerged as a serious pest on cotton in India.Laboratory studies indicated that B.pallescens could feed on the cotton mealybug.Hence,further investigations were conducted to understand the stage of the predator which is most potential and the pest stage preferred by the predator.Mature nymphs and adults of B.pallescens could predate equally well on the neonates of cotton mealybug.Young (three to four-day-old) nymphs of the predator could not feed on any stage of the cotton mealybug.Mature nymphs (seven-day-old and above) and adults could effectively predate on both young and mature cotton mealybug crawlers,though preference was more for the younger crawlers.However,nymphs and adults of B.pallescens could not predate on the adult stage of the mealybug.Different predator:pest ratios were tested in cage studies and it emerged that B.pallescens adults released against the mealybug crawlers at a ratio of 1:5 and nymphal release at 1:10 caused maximum mortality of the mealybug crawlers.Considering the fast multiplication rate of cotton mealybug and the large number of predators which have to be released to manage them,further detailed studies are necessary on utilizing B.pallescens to target the neonates and younger stages of the cotton mealybug in field conditions.
基金Supported by Applied Research and Industrialization Projects of Key Science and Technology Plan of Hainan Province(ZDXM20130031)Special Fund for Agro-scientific Research in the Public Interest(201203021)+1 种基金Scientific Operation Fund of Hainan Province(QCY[2013]131)Natural Science Foundation of Hainan Province(QK[2013]32)
文摘[ Objective ] The paper aimed to establish a real-time fluorescent quantitative PCR (qPCR) detection method for Pineapple mealybug wilt associated vi- rus-3 ( PMWaV3 ). [ Method] Specific TaqMan probe and primers were designed and synthesized according to the conserved sequence of coat protein(CP) gene of PMWaV-3, and the standard curve was established after optimizing the amplification condition of qPCR. [ Result] The results showed that the method was specific for the detection of PMWaV-3, and the sensitivity of the present method was about 10 times higher compared to general RT-PCR ; the variation coefficients of intra- assay and inter-assay were less than 1.73, respectively. [ Conclusion] The qPCR is an easy, fast and reliable method for quantitative detection of PMWaV-3.
文摘Pineapple mealybug wilt disease (PMWD) is one of the latest outbreaks of diseases attacking pineapple in Uganda. However, its occurrence and effects have not been documented and quantified, yet the disease poses a serious threat to the pineapple industry. Therefore, the objective of this study was to assess the occurrence and effects of PMWD on pineapple in central Uganda. Semi-structured questionnaire was used to solicit information from 82 respondents consisting of farmers, opinion leaders, key informants, political and technical leadership during May 2011. PMWD was observed in all the fields surveyed but with varying incidences and severities. In addition, PMWD was more common during the dry seasons than the rainy seasons where higher incidences were associated with high mealybug populations. PMWD manifested as a syndrome characterized by yellowing of leaves, stunting, wilting and rotting of roots. The effects of PMWD were variable but yield reductions and low plant populations were widely reported. Although, the occurrence of PMWD was reported to the different level of authority in the districts, very little was done to curb its spread.
文摘An experiment was conducted in mango orchard of Sher-E Bangla Agricultural University (SAU) campus, Dhaka to determine the effect of seasonal variation round the year and weather on population dynamics of mango mealybug (Drosicha mangiferae) on mango tree. The mango mealybug was first appeared in early December and disappeared in June in a year. Its population started to increase gradually from December and continued up to February when the ambient average temperature was 20.95°C, relative humidity 63% and rainfall was absent. The highest population of the insect (33.33/30 cm branch) was recorded in February and the lowest (3.75/30cm branch) in May. Adult insects appeared in February on the ground under the selected mango tree showing the population of 6.67 males and 123.33 females per 81 m<sup>2</sup>. Population of males (32.5/81m<sup>2</sup>) and that of females (352.75/81m<sup>2</sup>) reached to the peak when the ambient temperature was 28.19°C, relative humidity 61% and the rainfall was 0.00 mm. When relative humidity was high and rainfall started adult females enter into the soil and disappeared. Correlation between population of mealybug and temperature was positive. Its population was negatively correlated with relative humidity and rainfall.
文摘Parasitization has an enormous impact on host physiology, development and reproduction. The effect of parasitism by endoparasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) on survival and reproduction of mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) on different host stages was studied. Our data reveals that host mealybugs parasitized by the wasp at the 2<sup>nd</sup> instar stage were died during the 3<sup>rd</sup> instar stage of their life. However, those parasitized at the 3<sup>rd</sup> instar stage could reach the adult stage and were able to produce their progeny. After 6 days of parasitization, all parasitized hosts of the 2<sup>nd</sup>, 3<sup>rd</sup> and adult stages were died except the 1<sup>st</sup> instar. Results showed that parasitized host mealybugs had significantly lower reproductive potential than the unparasitized ones. Maximum parasitoid emergence was recorded in the 3<sup>rd</sup> instar host stage. This basic research regarding survival and reproduction of the parasitized host mealybugs would be very helpful in devising sustainable biological control strategies for cotton mealybug.
文摘Rastrococus invadens was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug species associated with the mango tree. It was also important to determine the periods of abundance of these species vis-a-vis R. invadens. For this purpose, the density of mealybugs was assessed in three study sites (Toussiana, Bérégadougou and Orodara) in Western Burkina Faso. The observations were made from June 2014 to June 2015 at a frequency of 15 ± 1 days. They focused on 20 leaves (5 leaves/cardinal point) levied on each mango tree. The species identified as Ferrisia virgata Cockerell and Icerya aegyptiaca Douglas were collected from mangos infested by R. invadens representing 98% - 99% of the density of the observed mealybug species. The periods of abundance of F. virgata and I. aegyptiaca were respectively the dry season and the rainy season. The effect of temperature, relative humidity and rainfall on the populations of F. virgata and I. aegyptiaca was also discussed. These results highlight the distribution range of F. virgata and I. aegyptiaca worldwide including Burkina Faso. R. invadens was the main mealybug species on mango in Burkina Faso in general and in the Western region of the country in particular.
文摘<i>Rastrococus invadens</i> was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug species associated with the mango tree. It was also important to determine the periods of abundance of these species vis-a-vis <i>R. invadens</i>. For this purpose, the density of mealybugs was assessed in three study sites (Toussiana, Bérégadougou and Orodara) in Western Burkina Faso. The observations were made from June 2014 to June 2015 at a frequency of 15 ± 1 days. They focused on 20 leaves (5 leaves/cardinal point) levied on each mango tree. The species identified as <i>Ferrisia virgata</i> Cockerell and <i>Icerya aegyptiaca</i> Douglas were collected from mangos infested by <i>R. invadens</i> representing 98% - 99% of the density of the observed mealybug species. The periods of abundance of <i>F. virgata</i> and <i>I. aegyptiaca</i> were respectively the dry season and the rainy season. The effect of temperature, relative humidity and rainfall on the populations of <i>F. virgata</i> and <i>I. aegyptiaca</i> was also discussed. These results highlight the distribution range of <i>F. virgata</i> and <i>I. aegyptiaca</i> worldwide including Burkina Faso. <i>R. invadens</i> was the main mealybug species on mango in Burkina Faso in general and in the Western region of the country in particular.
文摘Mealybugs are a major pest for many crops (such as the vegetable Cassava, in Thailand). An environmentally-friendly bio-control method is implemented using an introduced predator (green lacewings) of the mealybugs to mitigate plant damage. This is analyzed so as to devise and determine an optimal strategy for control of the mealybug population. A predator-prey model has been proposed and analyzed to study the effect of the biological control of the spread of the mealybugs in the plant field. The behaviour of the system in terms of stability, phase space and bifurcation diagrams are considered. The results obtained from different numbers of predators being released are compared. In particular we obtain thresholds of introduced-predator level above which the prey is driven to extinction. Future models will include age-structured multi-compartments for both the prey and predator populations.