Aphthona whitfieldi Bryant (Coleoptera: Chrysomelidae) is a major insect pest of Jatropha curcas L. (Euphorbiacae) in Burkina Faso and other countries in West Africa. The insect pest feeds on the roots and the leaves ...Aphthona whitfieldi Bryant (Coleoptera: Chrysomelidae) is a major insect pest of Jatropha curcas L. (Euphorbiacae) in Burkina Faso and other countries in West Africa. The insect pest feeds on the roots and the leaves of the plant. When the attacks are heavy, the plant may lose all its leaves and die off. Unfortunately, little information is available on the biology of this insect pest. A study was conducted on the biology of this insect pest in the Sissili province, South Burkina Faso and resulted in the knowledge of some of the biological features of the insect pest. Aphthona whitfieldi was reared from 13th July to 22th October 2015. Larvae and pupae were collected in J. curcas plantations near Léo, the capital city of the Sissili province, and brought to the laboratory for rearing. The insects were observed daily and the dimensions and the duration of each stage were recorded. We recorded two larval stages (1<sup>st</sup> and 3<sup>rd</sup>): a pre-pupa and a pupal stage. The pupa was free and white milk-like. Both the pre-pupa and the pupal stages lasted for five days. The 1<sup>st</sup> instar larva was smaller than the third one.展开更多
Aphthona whitfieldi Bryant (Coleoptera: Chrysomelidae) is a major insect pest of Jatropha curcas L. in Burkina Faso. This study aimed at evaluating the effect of the insect pest populations’ density on the growth of ...Aphthona whitfieldi Bryant (Coleoptera: Chrysomelidae) is a major insect pest of Jatropha curcas L. in Burkina Faso. This study aimed at evaluating the effect of the insect pest populations’ density on the growth of the plant. To achieve this purpose, 90-day aged single plants were caged in a randomized complete block design experiment with 5 treatments and 5 replicates. The treatments consisted of increasing numbers of adults of A. whitfieldi used to infest the caged plants: T0 (0 adult = check), T1 (100 adults), T2 (200 adults), T3 (300 adults), T4 (400 adults). All caged plants were infested 21 days after transplantation and the evaluation started 14 days later one on every 2-week basis from September 18, 2014 to February 19, 2015. The growth parameters of the plant were assessed. The results showed that the intensity of damage caused by A. whitfieldi on the growth of young plants of J. curcas varied according to the treatment (i.e., according to the number of adult individuals infesting the plant at the beginning). The higher the number, the heavier the level of damage caused by the pest. So, the growth of the J. curcas plant was inversely proportional to the number of A. whitfieldi infesting individuals. There was also a positive linear correlation between the defoliation rate and the height of the seedlings. The status of this insect pest was confirmed by the results of this study.展开更多
<i>Aphthona whitfieldi</i> Bryant (Coleoptera: Chrysomelidae) is a major insect pest of <i>Jatropha curcas</i> L. (Euphorbiacae) in Burkina Faso and other countries in West Africa. The insect p...<i>Aphthona whitfieldi</i> Bryant (Coleoptera: Chrysomelidae) is a major insect pest of <i>Jatropha curcas</i> L. (Euphorbiacae) in Burkina Faso and other countries in West Africa. The insect pest feeds on the roots and the leaves of the plant. When the attacks are heavy, the plant may lose all its leaves and die off. Unfortunately, little information is available on the biology of this insect pest. A study was conducted on the biology of this insect pest in the Sissili province, South Burkina Faso and resulted in the knowledge of some of the biological features of the insect pest. <i>Aphthona whitfieldi</i> was reared from 13th July to 22th October 2015. Larvae and pupae were collected in <i>J. curcas</i> plantations near Léo, the capital city of the Sissili province, and brought to the laboratory for rearing. The insects were observed daily and the dimensions and the duration of each stage were recorded. We recorded two larval stages (1<sup>st</sup> and 3<sup>rd</sup>): a pre-pupa and a pupal stage. The pupa was free and white milk-like. Both the pre-pupa and the pupal stages lasted for five days. The 1<sup>st</sup> instar larva was smaller than the third one.展开更多
Jatropha curcas L. is a non-edible oleaginous plant of Euphorbiacea family. Its seeds provide oil for industrial use, and when grown as a biofuel, J. curcas can be used to restore degraded soil by improving their fert...Jatropha curcas L. is a non-edible oleaginous plant of Euphorbiacea family. Its seeds provide oil for industrial use, and when grown as a biofuel, J. curcas can be used to restore degraded soil by improving their fertility and by controlling water and wind erosion. The plant also reduces CO<sub>2</sub> emission by carbon sequestration. However, J. curcas is attacked by many insect pests including C. panaethiopica, a polyphagous heteroptera of the Scutelleridae family. Larvae and adults of the insect pest feed on J. curcas flowers, fruit, and seeds, thereby causing quantitative and qualitative losses. Despite the economic importance of this insect pest, there is little known about its potential natural enemies. A survey of the natural enemies of C. panaethiopica was carried out from 3rd June 2013 to 29th May 2014 on three J. curcas production sites in the South-Sudanian zone of Burkina Faso. Three Hymenopteran egg parasitoids all belonging to the Scelionidae family were found. These included Trissolcus basalis (Wollaston), Psixstriaticeps (Dodd), and Gryon sp. Several predator species belonging to the Araneae, Tarachodidae and Mantidae families were also found. The egg parasitism increased progressively between June and September 2013, reaching a peak (43%) in September 2013. The number of spiders and mantises was higher between July and August 2013. The highest numbers of natural enemies associated with the insect pest were recorded in J. curcas monoculture plantations.展开更多
The efficiency of an aqueous extract of Azadirachta indica’s seeds and deltamethrin 12.5 EC was tested for the control of Calidea panaethiopica and Aphtona whitfieldi populations, two major insect pests of Jatropha c...The efficiency of an aqueous extract of Azadirachta indica’s seeds and deltamethrin 12.5 EC was tested for the control of Calidea panaethiopica and Aphtona whitfieldi populations, two major insect pests of Jatropha curcas L. in Burkina Faso. This study was conducted in 2013 during the dry season and in 2014 during the raining season. In the laboratory, tests of toxicity by contact on paper blotter and by ingestion on organs of the plant and their repulsive effect on paper blotter were performed in vitro on the insect pests adults caught on J. curcasplantations as compared with controls. The aqueous excerpts of neem seeds were prepared at different lengths of steeping (12 h, 24 h and 48 h) and the deltamethrin 12.5 EC was diluted at different doses (4 ml, 8 ml and 16 ml/L). The results of this experiment showed the evidence of the efficiency of the doses 8 ml/L and 16 ml/L of deltamethrin 12.5 EC, and those of 24 h and 48 h for the excerpts of neem seeds. These efficient doses were evaluated in the field in 2013 and 2014. The highest decreases of C. panaethiopica (0.327) and of A. whitfieldi (0.501) populations were recorded with the 16 ml/L dose of deltamethrin in 2014 raining season. During the 2013 dry season, more insect pests were recorded (0.389 for C. panaethiopica and 0.679 for A. whitfieldi) with that dose. But these results were not significantly different from those of 8 ml/L. Regarding the A. indica extracts, the best decrease of populations in the 1st year (0.36 for C. panaethiopica and 1.278 for A. withfieldi) was recorded with the 48 h maceration. But in 2014 because of the effect of rainfalls that dose was less effective than that of 24 h maceration with 0.399 for C. panaethiopica and 1.208 for A. whitfieldi. The efficiency interval of the tested insecticides was two to three weeks in low or no rainfall conditions and one to two weeks in rainy season conditions.展开更多
Jatropha curcas L., a biofuel tree, is attacked by several insect pests, including Pempelia spp. (Lepidoptera: Pyralidae). This insect pest feeds on the stem and the leaves of the plant and can inflict severe damage t...Jatropha curcas L., a biofuel tree, is attacked by several insect pests, including Pempelia spp. (Lepidoptera: Pyralidae). This insect pest feeds on the stem and the leaves of the plant and can inflict severe damage to the shrub. This is why we studied its biology. Pempelia spp. larvae were collected in J. curcas’ plantations in the Léo, Biéha, Silly and Niabouri communes in the Sissili province of Burkina Faso, West Africa and were bred inside transparent plastic boxes. Immerged adults were separated into boxes after pairing them and were bred until their death. The female deposits its eggs in batches on the apical parts of J. curcas. Newly laid eggs are white pale. The first instar larvae are tiny and white pale or yellow. The 2<sup>nd</sup> instar larvae have a light green coloration, with longitudinal stripes. The 3<sup>rd</sup> instar larvae are lightly green with dorsal longitudinal stripes. The 4<sup>th</sup> instar larvae have a black head and a grey body. The 5<sup>th</sup> instar larvae have a blackish brown head with a dark reddish or light reddish longitudinal body. The mean duration of an instar is 8 days. The pre-pupa stadium is a period during which the larvae surround themselves with a white web developed from their saliva secretion. The pupa lives within a dark red cocoon. Pempelia spp. adults are grey. Female adults have large abdomen whereas males show a cylindrical and slender abdomen. These findings are the first of their kind reported in Burkina Faso. They are discussed in this paper.展开更多
<i>Jatropha curcas</i> L., a biofuel tree, is attacked by several insect pests, including <i>Pempelia</i> spp. (Lepidoptera: Pyralidae). This insect pest feeds on the stem and the leaves of the...<i>Jatropha curcas</i> L., a biofuel tree, is attacked by several insect pests, including <i>Pempelia</i> spp. (Lepidoptera: Pyralidae). This insect pest feeds on the stem and the leaves of the plant and can inflict severe damage to the shrub. This is why we studied its biology. <i>Pempelia</i> spp. larvae were collected in <i>J. curcas</i>’ plantations in the Léo, Biéha, Silly and Niabouri communes in the Sissili province of Burkina Faso, West Africa and were bred inside transparent plastic boxes. Immerged adults were separated into boxes after pairing them and were bred until their death. The female deposits its eggs in batches on the apical parts of <i>J. curcas</i>. Newly laid eggs are white pale. The first instar larvae are tiny and white pale or yellow. The 2<sup>nd</sup> instar larvae have a light green coloration, with longitudinal stripes. The 3<sup>rd</sup> instar larvae are lightly green with dorsal longitudinal stripes. The 4<sup>th</sup> instar larvae have a black head and a grey body. The 5<sup>th</sup> instar larvae have a blackish brown head with a dark reddish or light reddish longitudinal body. The mean duration of an instar is 8 days. The pre-pupa stadium is a period during which the larvae surround themselves with a white web developed from their saliva secretion. The pupa lives within a dark red cocoon. <i>Pempelia</i> spp. adults are grey. Female adults have large abdomen whereas males show a cylindrical and slender abdomen. These findings are the first of their kind reported in Burkina Faso. They are discussed in this paper.展开更多
<i>Jatropha curcas</i> is subject to the attacks of many insect pests, including <i>Calidea panaethiopica</i> Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, f...<i>Jatropha curcas</i> is subject to the attacks of many insect pests, including <i>Calidea panaethiopica</i> Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, fruit and seeds of the shrub resulting in quantitative and qualitative losses;the shrub is also attacked by <i>Aphthona whitfieldi</i> Bryan (Coleoptera: Chrysomelidae) which feeds on the leaves causing complete defoliation in severe attack. Despite their economic importance, very little is known about the alternative host plants of these insect pests. The study of the ecology of these species is a pre-requisite for the development of appropriate control methods. The identification of alternative host plants of <i>C. panaethiopica</i> and <i>A. whitfieldi</i> was conducted from June 3rd 2013 to November 30th 2014 in the Sissili province, South Burkina Faso. During that period, four <i>J. curcas</i>’ plantations of six locations in the province were prospected for alternative host plants of the two insect pests. In each plantation, observations were done across a diagonal up to 500 m away from the plantation. Fallows in the vicinity of the <i>J. curcas</i> plantations were particularly examined. Potential host plants of the two insect pests were collected and bred in the laboratory in Léo where they were used to feed the insect pests. Only <i>Jatropha gossypiifolia</i>, a cousin of <i>J. curcas</i>, was found to be a common alternative host plant of both insect pests.展开更多
Jatropha curcas is subject to the attacks of many insect pests, including Calidea panaethiopica Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, fruit and seeds of the shrub resulting ...Jatropha curcas is subject to the attacks of many insect pests, including Calidea panaethiopica Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, fruit and seeds of the shrub resulting in quantitative and qualitative losses;the shrub is also attacked by Aphthona whitfieldi Bryan (Coleoptera: Chrysomelidae) which feeds on the leaves causing complete defoliation in severe attack. Despite their economic importance, very little is known about the alternative host plants of these insect pests. The study of the ecology of these species is a pre-requisite for the development of appropriate control methods. The identification of alternative host plants of C. panaethiopica and A. whitfieldi was conducted from June 3rd 2013 to November 30th 2014 in the Sissili province, South Burkina Faso. During that period, four J. curcas’ plantations of six locations in the province were prospected for alternative host plants of the two insect pests. In each plantation, observations were done across a diagonal up to 500 m away from the plantation. Fallows in the vicinity of the J. curcas plantations were particularly examined. Potential host plants of the two insect pests were collected and bred in the laboratory in Léo where they were used to feed the insect pests. Only Jatropha gossypiifolia, a cousin of J. curcas, was found to be a common alternative host plant of both insect pests.展开更多
The efficiency of an aqueous extract of <i>Azadirachta indica</i>’s seeds and deltamethrin 12.5 EC was tested for the control of <i>Calidea panaethiopica</i> and <i>Aphtona whitfieldi<...The efficiency of an aqueous extract of <i>Azadirachta indica</i>’s seeds and deltamethrin 12.5 EC was tested for the control of <i>Calidea panaethiopica</i> and <i>Aphtona whitfieldi</i> populations, two major insect pests of <i>Jatropha curcas</i> L. in Burkina Faso. This study was conducted in 2013 during the dry season and in 2014 during the raining season. In the laboratory, tests of toxicity by contact on paper blotter and by ingestion on organs of the plant and their repulsive effect on paper blotter were performed in vitro on the insect pests adults caught on <i>J. curcas</i>plantations as compared with controls. The aqueous excerpts of neem seeds were prepared at different lengths of steeping (12 h, 24 h and 48 h) and the deltamethrin 12.5 EC was diluted at different doses (4 ml, 8 ml and 16 ml/L). The results of this experiment showed the evidence of the efficiency of the doses 8 ml/L and 16 ml/L of deltamethrin 12.5 EC, and those of 24 h and 48 h for the excerpts of neem seeds. These efficient doses were evaluated in the field in 2013 and 2014. The highest decreases of <i>C. panaethiopica</i> (0.327) and of <i>A. whitfieldi</i> (0.501) populations were recorded with the 16 ml/L dose of deltamethrin in 2014 raining season. During the 2013 dry season, more insect pests were recorded (0.389 for <i>C. panaethiopica</i> and 0.679 for A. whitfieldi) with that dose. But these results were not significantly different from those of 8 ml/L. Regarding the A. indica extracts, the best decrease of populations in the 1st year (0.36 for <i>C. panaethiopica</i> and 1.278 for <i>A. withfieldi</i>) was recorded with the 48 h maceration. But in 2014 because of the effect of rainfalls that dose was less effective than that of 24 h maceration with 0.399 for <i>C. panaethiopica</i> and 1.208 for <i>A. whitfieldi</i>. The efficiency interval of the tested insecticides was two to three weeks in low or no rainfall conditions and one to two weeks in rainy season conditions.展开更多
文摘Aphthona whitfieldi Bryant (Coleoptera: Chrysomelidae) is a major insect pest of Jatropha curcas L. (Euphorbiacae) in Burkina Faso and other countries in West Africa. The insect pest feeds on the roots and the leaves of the plant. When the attacks are heavy, the plant may lose all its leaves and die off. Unfortunately, little information is available on the biology of this insect pest. A study was conducted on the biology of this insect pest in the Sissili province, South Burkina Faso and resulted in the knowledge of some of the biological features of the insect pest. Aphthona whitfieldi was reared from 13th July to 22th October 2015. Larvae and pupae were collected in J. curcas plantations near Léo, the capital city of the Sissili province, and brought to the laboratory for rearing. The insects were observed daily and the dimensions and the duration of each stage were recorded. We recorded two larval stages (1<sup>st</sup> and 3<sup>rd</sup>): a pre-pupa and a pupal stage. The pupa was free and white milk-like. Both the pre-pupa and the pupal stages lasted for five days. The 1<sup>st</sup> instar larva was smaller than the third one.
文摘Aphthona whitfieldi Bryant (Coleoptera: Chrysomelidae) is a major insect pest of Jatropha curcas L. in Burkina Faso. This study aimed at evaluating the effect of the insect pest populations’ density on the growth of the plant. To achieve this purpose, 90-day aged single plants were caged in a randomized complete block design experiment with 5 treatments and 5 replicates. The treatments consisted of increasing numbers of adults of A. whitfieldi used to infest the caged plants: T0 (0 adult = check), T1 (100 adults), T2 (200 adults), T3 (300 adults), T4 (400 adults). All caged plants were infested 21 days after transplantation and the evaluation started 14 days later one on every 2-week basis from September 18, 2014 to February 19, 2015. The growth parameters of the plant were assessed. The results showed that the intensity of damage caused by A. whitfieldi on the growth of young plants of J. curcas varied according to the treatment (i.e., according to the number of adult individuals infesting the plant at the beginning). The higher the number, the heavier the level of damage caused by the pest. So, the growth of the J. curcas plant was inversely proportional to the number of A. whitfieldi infesting individuals. There was also a positive linear correlation between the defoliation rate and the height of the seedlings. The status of this insect pest was confirmed by the results of this study.
文摘<i>Aphthona whitfieldi</i> Bryant (Coleoptera: Chrysomelidae) is a major insect pest of <i>Jatropha curcas</i> L. (Euphorbiacae) in Burkina Faso and other countries in West Africa. The insect pest feeds on the roots and the leaves of the plant. When the attacks are heavy, the plant may lose all its leaves and die off. Unfortunately, little information is available on the biology of this insect pest. A study was conducted on the biology of this insect pest in the Sissili province, South Burkina Faso and resulted in the knowledge of some of the biological features of the insect pest. <i>Aphthona whitfieldi</i> was reared from 13th July to 22th October 2015. Larvae and pupae were collected in <i>J. curcas</i> plantations near Léo, the capital city of the Sissili province, and brought to the laboratory for rearing. The insects were observed daily and the dimensions and the duration of each stage were recorded. We recorded two larval stages (1<sup>st</sup> and 3<sup>rd</sup>): a pre-pupa and a pupal stage. The pupa was free and white milk-like. Both the pre-pupa and the pupal stages lasted for five days. The 1<sup>st</sup> instar larva was smaller than the third one.
文摘Jatropha curcas L. is a non-edible oleaginous plant of Euphorbiacea family. Its seeds provide oil for industrial use, and when grown as a biofuel, J. curcas can be used to restore degraded soil by improving their fertility and by controlling water and wind erosion. The plant also reduces CO<sub>2</sub> emission by carbon sequestration. However, J. curcas is attacked by many insect pests including C. panaethiopica, a polyphagous heteroptera of the Scutelleridae family. Larvae and adults of the insect pest feed on J. curcas flowers, fruit, and seeds, thereby causing quantitative and qualitative losses. Despite the economic importance of this insect pest, there is little known about its potential natural enemies. A survey of the natural enemies of C. panaethiopica was carried out from 3rd June 2013 to 29th May 2014 on three J. curcas production sites in the South-Sudanian zone of Burkina Faso. Three Hymenopteran egg parasitoids all belonging to the Scelionidae family were found. These included Trissolcus basalis (Wollaston), Psixstriaticeps (Dodd), and Gryon sp. Several predator species belonging to the Araneae, Tarachodidae and Mantidae families were also found. The egg parasitism increased progressively between June and September 2013, reaching a peak (43%) in September 2013. The number of spiders and mantises was higher between July and August 2013. The highest numbers of natural enemies associated with the insect pest were recorded in J. curcas monoculture plantations.
文摘The efficiency of an aqueous extract of Azadirachta indica’s seeds and deltamethrin 12.5 EC was tested for the control of Calidea panaethiopica and Aphtona whitfieldi populations, two major insect pests of Jatropha curcas L. in Burkina Faso. This study was conducted in 2013 during the dry season and in 2014 during the raining season. In the laboratory, tests of toxicity by contact on paper blotter and by ingestion on organs of the plant and their repulsive effect on paper blotter were performed in vitro on the insect pests adults caught on J. curcasplantations as compared with controls. The aqueous excerpts of neem seeds were prepared at different lengths of steeping (12 h, 24 h and 48 h) and the deltamethrin 12.5 EC was diluted at different doses (4 ml, 8 ml and 16 ml/L). The results of this experiment showed the evidence of the efficiency of the doses 8 ml/L and 16 ml/L of deltamethrin 12.5 EC, and those of 24 h and 48 h for the excerpts of neem seeds. These efficient doses were evaluated in the field in 2013 and 2014. The highest decreases of C. panaethiopica (0.327) and of A. whitfieldi (0.501) populations were recorded with the 16 ml/L dose of deltamethrin in 2014 raining season. During the 2013 dry season, more insect pests were recorded (0.389 for C. panaethiopica and 0.679 for A. whitfieldi) with that dose. But these results were not significantly different from those of 8 ml/L. Regarding the A. indica extracts, the best decrease of populations in the 1st year (0.36 for C. panaethiopica and 1.278 for A. withfieldi) was recorded with the 48 h maceration. But in 2014 because of the effect of rainfalls that dose was less effective than that of 24 h maceration with 0.399 for C. panaethiopica and 1.208 for A. whitfieldi. The efficiency interval of the tested insecticides was two to three weeks in low or no rainfall conditions and one to two weeks in rainy season conditions.
文摘Jatropha curcas L., a biofuel tree, is attacked by several insect pests, including Pempelia spp. (Lepidoptera: Pyralidae). This insect pest feeds on the stem and the leaves of the plant and can inflict severe damage to the shrub. This is why we studied its biology. Pempelia spp. larvae were collected in J. curcas’ plantations in the Léo, Biéha, Silly and Niabouri communes in the Sissili province of Burkina Faso, West Africa and were bred inside transparent plastic boxes. Immerged adults were separated into boxes after pairing them and were bred until their death. The female deposits its eggs in batches on the apical parts of J. curcas. Newly laid eggs are white pale. The first instar larvae are tiny and white pale or yellow. The 2<sup>nd</sup> instar larvae have a light green coloration, with longitudinal stripes. The 3<sup>rd</sup> instar larvae are lightly green with dorsal longitudinal stripes. The 4<sup>th</sup> instar larvae have a black head and a grey body. The 5<sup>th</sup> instar larvae have a blackish brown head with a dark reddish or light reddish longitudinal body. The mean duration of an instar is 8 days. The pre-pupa stadium is a period during which the larvae surround themselves with a white web developed from their saliva secretion. The pupa lives within a dark red cocoon. Pempelia spp. adults are grey. Female adults have large abdomen whereas males show a cylindrical and slender abdomen. These findings are the first of their kind reported in Burkina Faso. They are discussed in this paper.
文摘<i>Jatropha curcas</i> L., a biofuel tree, is attacked by several insect pests, including <i>Pempelia</i> spp. (Lepidoptera: Pyralidae). This insect pest feeds on the stem and the leaves of the plant and can inflict severe damage to the shrub. This is why we studied its biology. <i>Pempelia</i> spp. larvae were collected in <i>J. curcas</i>’ plantations in the Léo, Biéha, Silly and Niabouri communes in the Sissili province of Burkina Faso, West Africa and were bred inside transparent plastic boxes. Immerged adults were separated into boxes after pairing them and were bred until their death. The female deposits its eggs in batches on the apical parts of <i>J. curcas</i>. Newly laid eggs are white pale. The first instar larvae are tiny and white pale or yellow. The 2<sup>nd</sup> instar larvae have a light green coloration, with longitudinal stripes. The 3<sup>rd</sup> instar larvae are lightly green with dorsal longitudinal stripes. The 4<sup>th</sup> instar larvae have a black head and a grey body. The 5<sup>th</sup> instar larvae have a blackish brown head with a dark reddish or light reddish longitudinal body. The mean duration of an instar is 8 days. The pre-pupa stadium is a period during which the larvae surround themselves with a white web developed from their saliva secretion. The pupa lives within a dark red cocoon. <i>Pempelia</i> spp. adults are grey. Female adults have large abdomen whereas males show a cylindrical and slender abdomen. These findings are the first of their kind reported in Burkina Faso. They are discussed in this paper.
文摘<i>Jatropha curcas</i> is subject to the attacks of many insect pests, including <i>Calidea panaethiopica</i> Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, fruit and seeds of the shrub resulting in quantitative and qualitative losses;the shrub is also attacked by <i>Aphthona whitfieldi</i> Bryan (Coleoptera: Chrysomelidae) which feeds on the leaves causing complete defoliation in severe attack. Despite their economic importance, very little is known about the alternative host plants of these insect pests. The study of the ecology of these species is a pre-requisite for the development of appropriate control methods. The identification of alternative host plants of <i>C. panaethiopica</i> and <i>A. whitfieldi</i> was conducted from June 3rd 2013 to November 30th 2014 in the Sissili province, South Burkina Faso. During that period, four <i>J. curcas</i>’ plantations of six locations in the province were prospected for alternative host plants of the two insect pests. In each plantation, observations were done across a diagonal up to 500 m away from the plantation. Fallows in the vicinity of the <i>J. curcas</i> plantations were particularly examined. Potential host plants of the two insect pests were collected and bred in the laboratory in Léo where they were used to feed the insect pests. Only <i>Jatropha gossypiifolia</i>, a cousin of <i>J. curcas</i>, was found to be a common alternative host plant of both insect pests.
文摘Jatropha curcas is subject to the attacks of many insect pests, including Calidea panaethiopica Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, fruit and seeds of the shrub resulting in quantitative and qualitative losses;the shrub is also attacked by Aphthona whitfieldi Bryan (Coleoptera: Chrysomelidae) which feeds on the leaves causing complete defoliation in severe attack. Despite their economic importance, very little is known about the alternative host plants of these insect pests. The study of the ecology of these species is a pre-requisite for the development of appropriate control methods. The identification of alternative host plants of C. panaethiopica and A. whitfieldi was conducted from June 3rd 2013 to November 30th 2014 in the Sissili province, South Burkina Faso. During that period, four J. curcas’ plantations of six locations in the province were prospected for alternative host plants of the two insect pests. In each plantation, observations were done across a diagonal up to 500 m away from the plantation. Fallows in the vicinity of the J. curcas plantations were particularly examined. Potential host plants of the two insect pests were collected and bred in the laboratory in Léo where they were used to feed the insect pests. Only Jatropha gossypiifolia, a cousin of J. curcas, was found to be a common alternative host plant of both insect pests.
文摘The efficiency of an aqueous extract of <i>Azadirachta indica</i>’s seeds and deltamethrin 12.5 EC was tested for the control of <i>Calidea panaethiopica</i> and <i>Aphtona whitfieldi</i> populations, two major insect pests of <i>Jatropha curcas</i> L. in Burkina Faso. This study was conducted in 2013 during the dry season and in 2014 during the raining season. In the laboratory, tests of toxicity by contact on paper blotter and by ingestion on organs of the plant and their repulsive effect on paper blotter were performed in vitro on the insect pests adults caught on <i>J. curcas</i>plantations as compared with controls. The aqueous excerpts of neem seeds were prepared at different lengths of steeping (12 h, 24 h and 48 h) and the deltamethrin 12.5 EC was diluted at different doses (4 ml, 8 ml and 16 ml/L). The results of this experiment showed the evidence of the efficiency of the doses 8 ml/L and 16 ml/L of deltamethrin 12.5 EC, and those of 24 h and 48 h for the excerpts of neem seeds. These efficient doses were evaluated in the field in 2013 and 2014. The highest decreases of <i>C. panaethiopica</i> (0.327) and of <i>A. whitfieldi</i> (0.501) populations were recorded with the 16 ml/L dose of deltamethrin in 2014 raining season. During the 2013 dry season, more insect pests were recorded (0.389 for <i>C. panaethiopica</i> and 0.679 for A. whitfieldi) with that dose. But these results were not significantly different from those of 8 ml/L. Regarding the A. indica extracts, the best decrease of populations in the 1st year (0.36 for <i>C. panaethiopica</i> and 1.278 for <i>A. withfieldi</i>) was recorded with the 48 h maceration. But in 2014 because of the effect of rainfalls that dose was less effective than that of 24 h maceration with 0.399 for <i>C. panaethiopica</i> and 1.208 for <i>A. whitfieldi</i>. The efficiency interval of the tested insecticides was two to three weeks in low or no rainfall conditions and one to two weeks in rainy season conditions.
