Pub Date : 2023-03-23DOI: 10.17159/2254-8854/2023/a13584
M. Buxton, C. Nyamukondiwa, M. Kesamang, RJ Wassweman
Spatial distribution of vector mosquitoes plays a critical role in the dynamics of associated diseases’ spread across diverse landscapes. In Botswana, six Districts are implicated as malaria endemic zones, one of which is the Central District comprising both malaria endemic and non-endemic sub-districts. Despite being the biggest in the country, mosquito diversity in this District is under-explored, more so in the malaria non-endemic sub-districts. Here, we thus sampled mosquito adults and larvae from the malaria endemic sub-district of Bobirwa and non-endemic sub-districts of Palapye and Serowe, to determine spatial mosquito abundance and diversity in the District. Overall, all the sub-districts had a representation of key mosquito taxa of medical and economic importance (Aedes, Culex and Anopheles), irrespective of malarial endemicity status. Bobirwa had the highest number of mosquitoes sampled (429) although the greatest species richness (0.8511) was observed from Palapye. Moreover, Palapye also recorded a species from another genus, Culiseta longiareolata, a known natural vector of avian malaria parasites. Given global climate shift projections for the region, there is a need for continuous area-wide surveillance for vector mosquitoes and associated parasites in curbing the risk of emerging and re-emerging infections. While the Anopheles-centric approach to mosquito control is still necessary, a holistic approach, incorporating other vector incriminated mosquito species is warranted, particularly given shifting climates and the presence of invasive disease associated vector mosquito species.
{"title":"Mosquito community composition in Central District, Botswana: insights from a malaria endemic to non-endemic gradient","authors":"M. Buxton, C. Nyamukondiwa, M. Kesamang, RJ Wassweman","doi":"10.17159/2254-8854/2023/a13584","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a13584","url":null,"abstract":"Spatial distribution of vector mosquitoes plays a critical role in the dynamics of associated diseases’ spread across diverse landscapes. In Botswana, six Districts are implicated as malaria endemic zones, one of which is the Central District comprising both malaria endemic and non-endemic sub-districts. Despite being the biggest in the country, mosquito diversity in this District is under-explored, more so in the malaria non-endemic sub-districts. Here, we thus sampled mosquito adults and larvae from the malaria endemic sub-district of Bobirwa and non-endemic sub-districts of Palapye and Serowe, to determine spatial mosquito abundance and diversity in the District. Overall, all the sub-districts had a representation of key mosquito taxa of medical and economic importance (Aedes, Culex and Anopheles), irrespective of malarial endemicity status. Bobirwa had the highest number of mosquitoes sampled (429) although the greatest species richness (0.8511) was observed from Palapye. Moreover, Palapye also recorded a species from another genus, Culiseta longiareolata, a known natural vector of avian malaria parasites. Given global climate shift projections for the region, there is a need for continuous area-wide surveillance for vector mosquitoes and associated parasites in curbing the risk of emerging and re-emerging infections. While the Anopheles-centric approach to mosquito control is still necessary, a holistic approach, incorporating other vector incriminated mosquito species is warranted, particularly given shifting climates and the presence of invasive disease associated vector mosquito species.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43394831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-24DOI: 10.17159/2254-8854/2023/a12791
K. Kaur, N. Vashishat, Devinder Kaur Kocher
The growing threat of vector- borne diseases and environmental pollution has prompted the nanotechnology based investigations. The present study aimed to use one of the nanotechnological applications with larvicidal potential against Aedes aegypti by preparing aqueous hybrid nanoemulsion of zinc sulfide nanoparticles and Eucalyptus globulus oil. The mean droplet size of prepared and most stable hybrid nanoemulsion (9.5 ppm) was found to be 60±10.00 nm with rectangular shape. The hybrid nanoemulsion exhibited LC50 and LC90 values of 7.63 and 9.22 ppm respectively against larval stages of Aedes aegypti. The findings obtained from the larvicidal assay were corroborated with SEM, histological and biochemical profiles of Aedes larvae after treating with hybrid nanoemulsion. Under simulated conditions, nanohybrid treatment demonstrated optimum larvicidal potency after 48 hrs of exposure. Further, biosaftey studies of hybrid nanoemulsion were carried out against Scapholebris kingi and this larvicidal concentration of nanohybrid was found to be non-toxic to this species. Thus, the following research explains the larvicidal efficacy of zinc sulfide based hybrid nanoemulsion of eucalyptus oil formulated during the present study is a step towards safe and efficient approach against dengue spreading vector mosquito, Aedes aegypti.
{"title":"Formulation of eucalyptus oil-zinc sulfide hybrid nanoemulsion and evaluation of its larvicidal potential against Aedes aegypti","authors":"K. Kaur, N. Vashishat, Devinder Kaur Kocher","doi":"10.17159/2254-8854/2023/a12791","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a12791","url":null,"abstract":"The growing threat of vector- borne diseases and environmental pollution has prompted the nanotechnology based investigations. The present study aimed to use one of the nanotechnological applications with larvicidal potential against Aedes aegypti by preparing aqueous hybrid nanoemulsion of zinc sulfide nanoparticles and Eucalyptus globulus oil. The mean droplet size of prepared and most stable hybrid nanoemulsion (9.5 ppm) was found to be 60±10.00 nm with rectangular shape. The hybrid nanoemulsion exhibited LC50 and LC90 values of 7.63 and 9.22 ppm respectively against larval stages of Aedes aegypti. The findings obtained from the larvicidal assay were corroborated with SEM, histological and biochemical profiles of Aedes larvae after treating with hybrid nanoemulsion. Under simulated conditions, nanohybrid treatment demonstrated optimum larvicidal potency after 48 hrs of exposure. Further, biosaftey studies of hybrid nanoemulsion were carried out against Scapholebris kingi and this larvicidal concentration of nanohybrid was found to be non-toxic to this species. Thus, the following research explains the larvicidal efficacy of zinc sulfide based hybrid nanoemulsion of eucalyptus oil formulated during the present study is a step towards safe and efficient approach against dengue spreading vector mosquito, Aedes aegypti.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42537081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-24DOI: 10.17159/2254-8854/2023/a13583
N. Magengelele, G. Martin
Schinus terebinthifolia Raddi (Anacardiaceae) (Brazilian pepper tree) is a tree native to subtropical South America that was introduced into South Africa as an ornamental plant. Globally, it is regarded as one of the world’s worst invasive trees. In South Africa the tree has acquired a native seed-feeding wasp, Megastigmus transvaalensis (Hussey, 1956) (Hymenoptera: Torymidae). The wasp’s native hosts are from the Searsia F.A. Barkley genus (Anacardiaceae), but it has expanded its host range to form a new association with both S. terebinthifolia and its close relative Schinus molle L. (Anacardiaceae). In order to quantify the seed predation by M. transvaalensis on S. terebinthifolia seeds, tree populations were surveyed across the Eastern Cape and KwaZulu-Natal provinces. The wasp was present at 99% of the S. terebinthifolia populations with an average of 22% of the seeds being destroyed. In the Eastern Cape province, the highest seed damage occurred at the start of the winter months, when about 35% of seeds were damaged. This fell to less than 12% in spring and summer when the plants were flowering. Megastigmus transvaalensis was found at nearly all the S. terebinthifolia populations in South Africa, but due to the limited number of predated seeds it is unlikely to reduce population sizes or curb the spread of the invasive alien tree in South Africa.
{"title":"Distribution and impact of the native South African wasp, Megastigmus transvaalensis (Hussey, 1956) (Hymenoptera: Torymidae) on the invasive Schinus terebinthifolia Raddi (Anacardiaceae) in South Africa","authors":"N. Magengelele, G. Martin","doi":"10.17159/2254-8854/2023/a13583","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a13583","url":null,"abstract":"Schinus terebinthifolia Raddi (Anacardiaceae) (Brazilian pepper tree) is a tree native to subtropical South America that was introduced into South Africa as an ornamental plant. Globally, it is regarded as one of the world’s worst invasive trees. In South Africa the tree has acquired a native seed-feeding wasp, Megastigmus transvaalensis (Hussey, 1956) (Hymenoptera: Torymidae). The wasp’s native hosts are from the Searsia F.A. Barkley genus (Anacardiaceae), but it has expanded its host range to form a new association with both S. terebinthifolia and its close relative Schinus molle L. (Anacardiaceae). In order to quantify the seed predation by M. transvaalensis on S. terebinthifolia seeds, tree populations were surveyed across the Eastern Cape and KwaZulu-Natal provinces. The wasp was present at 99% of the S. terebinthifolia populations with an average of 22% of the seeds being destroyed. In the Eastern Cape province, the highest seed damage occurred at the start of the winter months, when about 35% of seeds were damaged. This fell to less than 12% in spring and summer when the plants were flowering. Megastigmus transvaalensis was found at nearly all the S. terebinthifolia populations in South Africa, but due to the limited number of predated seeds it is unlikely to reduce population sizes or curb the spread of the invasive alien tree in South Africa.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46039782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-24DOI: 10.17159/2254-8854/2023/a13231
L. Scheepers, J. Allison, B. Slippers, E. Rohwer, Patrick M. Mc Millan, Jan E. Bello, Marc C. Bouwer
Nudaurelia spp. (Saturniidae) are sporadic pests of pine plantations in South Africa. Taxonomic uncertainty exists in South Africa with this group and represents an impediment to the development and implementation of pheromone-based management tactics. Populations from the Western Cape have been described as Nudaurelia cytherea while those from KwaZulu-Natal and Mpumalanga have been described as Nudaurelia clarki. We compared Cytochrome oxidase subunit I (COI) gene sequences from moths from the Western Cape, KwaZulu-Natal (KZN) and Mpumalanga regions. We also analysed female pheromone gland extracts with gas-chromatography electroantennographic detection (GC-EAD) and gas-chromatography-mass spectrometry (GC-MS) for moths from KwaZulu-Natal and Mpumalanga. COI gene barcoding sequences were identical for moths from the Western Cape, KwaZulu-Natal (KZN) and Mpumalanga regions providing preliminary evidence to suggest that these populations may be the same species. Based on the available literature, the morphology and origin of our samples suggests that pheromone analyses in this study were done on N. clarki. Male N. clarki antennae respond to two compounds in female extracts. One of these compounds was confirmed with a synthetic standard to be (Z)-dec-5-en-1-yl-3-methylbutanoate, the sex pheromone previously identified from N. cytherea. The identity of the second compound could not be confirmed. Both male and female antennae responded to four structurally related compounds in the synthetic pheromone standard. Field trials with custom-made traps confirmed attraction of N. clarki males to polydimethylsiloxane and polyisoprene lures loaded with synthetic (Z)-dec-5-en-1-yl-3-methylbutanoate.
{"title":"Pine Emperor moths from KwaZulu-Natal use the same pheromone component previously isolated from Nudaurelia cytherea (Lepidoptera: Saturniidae) from the Western Cape","authors":"L. Scheepers, J. Allison, B. Slippers, E. Rohwer, Patrick M. Mc Millan, Jan E. Bello, Marc C. Bouwer","doi":"10.17159/2254-8854/2023/a13231","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a13231","url":null,"abstract":"Nudaurelia spp. (Saturniidae) are sporadic pests of pine plantations in South Africa. Taxonomic uncertainty exists in South Africa with this group and represents an impediment to the development and implementation of pheromone-based management tactics. Populations from the Western Cape have been described as Nudaurelia cytherea while those from KwaZulu-Natal and Mpumalanga have been described as Nudaurelia clarki. We compared Cytochrome oxidase subunit I (COI) gene sequences from moths from the Western Cape, KwaZulu-Natal (KZN) and Mpumalanga regions. We also analysed female pheromone gland extracts with gas-chromatography electroantennographic detection (GC-EAD) and gas-chromatography-mass spectrometry (GC-MS) for moths from KwaZulu-Natal and Mpumalanga. COI gene barcoding sequences were identical for moths from the Western Cape, KwaZulu-Natal (KZN) and Mpumalanga regions providing preliminary evidence to suggest that these populations may be the same species. Based on the available literature, the morphology and origin of our samples suggests that pheromone analyses in this study were done on N. clarki. Male N. clarki antennae respond to two compounds in female extracts. One of these compounds was confirmed with a synthetic standard to be (Z)-dec-5-en-1-yl-3-methylbutanoate, the sex pheromone previously identified from N. cytherea. The identity of the second compound could not be confirmed. Both male and female antennae responded to four structurally related compounds in the synthetic pheromone standard. Field trials with custom-made traps confirmed attraction of N. clarki males to polydimethylsiloxane and polyisoprene lures loaded with synthetic (Z)-dec-5-en-1-yl-3-methylbutanoate.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":"15 6","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41256855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-10DOI: 10.17159/2254-8854/2023/a13244
Risuna Mavasa, Inam Yekwayo, T. Mwabvu, Z. Tsvuura
Savannahs are structurally complex ecosystems consisting of a diverse community of plants and animals such as arthropods. Arthropods are essential in many ecosystem processes that help maintain life on Earth. The anthropogenic conversion of natural landscapes into croplands, residential and industrial areas has a negative impact on surface-active arthropods that have limited dispersal abilities and narrow habitat preferences. This study investigated the effect of disturbance on assemblages of ants, beetles and spiders in the savannah vegetation in Mpumalanga province, South Africa. We compared species richness, abundance and composition of these three taxa between the pristine savannah and the savannah that is exposed to a variety of anthropogenic activities (disturbed savannah). Arthropods were collected using pitfall traps in 15 sites in pristine savannah and 15 sites in disturbed savannah. We found that disturbance affects species richness and abundance of these taxa differently. Disturbance did not affect species richness of spiders and abundance of beetles, while greater species richness of ants and beetles, as well as abundance of ants and spiders was in disturbed than in pristine savannah. Furthermore, the species compositions of all taxa were different between disturbed and pristine savannah. The disturbed savannah had twice more unique indicator species than the pristine savannah. Differences in assemblages of arthropods between pristine and disturbed habitats suggest that it may be important to consider habitats in and outside protected areas in the conservation of arthropods, particularly in areas with greater percentage of natural and semi-natural landscapes occurring outside protected areas.
{"title":"Response of ants, beetles and spiders to disturbance varies among taxa in a South African savannah biome","authors":"Risuna Mavasa, Inam Yekwayo, T. Mwabvu, Z. Tsvuura","doi":"10.17159/2254-8854/2023/a13244","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a13244","url":null,"abstract":"Savannahs are structurally complex ecosystems consisting of a diverse community of plants and animals such as arthropods. Arthropods are essential in many ecosystem processes that help maintain life on Earth. The anthropogenic conversion of natural landscapes into croplands, residential and industrial areas has a negative impact on surface-active arthropods that have limited dispersal abilities and narrow habitat preferences. This study investigated the effect of disturbance on assemblages of ants, beetles and spiders in the savannah vegetation in Mpumalanga province, South Africa. We compared species richness, abundance and composition of these three taxa between the pristine savannah and the savannah that is exposed to a variety of anthropogenic activities (disturbed savannah). Arthropods were collected using pitfall traps in 15 sites in pristine savannah and 15 sites in disturbed savannah. We found that disturbance affects species richness and abundance of these taxa differently. Disturbance did not affect species richness of spiders and abundance of beetles, while greater species richness of ants and beetles, as well as abundance of ants and spiders was in disturbed than in pristine savannah. Furthermore, the species compositions of all taxa were different between disturbed and pristine savannah. The disturbed savannah had twice more unique indicator species than the pristine savannah. Differences in assemblages of arthropods between pristine and disturbed habitats suggest that it may be important to consider habitats in and outside protected areas in the conservation of arthropods, particularly in areas with greater percentage of natural and semi-natural landscapes occurring outside protected areas.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49185121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-10DOI: 10.17159/2254-8854/2023/a12637
J. Abraham, Carlos Amissah, Felix Osei Kuffour, J. D. Abraham
Tephritid fruit flies, including Ceratitis ditissima, often invade citrus orchards. These flies cause economic losses to farmers and can prevent farmers from exporting their fruits to foreign markets. To detect the presence of fruit flies in citrus orchards, traps are baited with synthetic lures, which are often expensive for smallholder farmers. Farmers in developing or financially less-endowed countries have to import such synthetic baits, raising the cost of pest monitoring and control. Therefore, we evaluated the potential of palm wine and three other food-based mixtures for trapping C. ditissima and the proportion of non-target flies they trap. Transparent deli cup traps were baited with four different food-based baits, namely palm wine, sugarcane spirit-wine mixture, apple cider vinegar and yeast-sugar mixture. The traps were placed within a citrus orchard on fruit-bearing trees. The content of each trap was collected after one week and evaluated. This was repeated for eight consecutive weeks. Traps baited with palm wine captured more C. ditissima than those with the other baits. Furthermore, the proportion of non-target insects, Bactrocera dorsalis and Drosophila spp., in palm wine-baited traps was less than the other baited traps. This study indicates that palm wine, a cheap beverage across Africa, Asia and South America, could be used to monitor the presence of C. ditissima in citrus orchards. Smallholder farmers who cannot afford expensive synthetic baits could make use of palm wine to monitor fruit flies in their farms.
{"title":"Palm wine as a food-based bait for monitoring adult Ceratitis ditissima (Munro) (Diptera: Tephritidae) in citrus orchards","authors":"J. Abraham, Carlos Amissah, Felix Osei Kuffour, J. D. Abraham","doi":"10.17159/2254-8854/2023/a12637","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a12637","url":null,"abstract":"Tephritid fruit flies, including Ceratitis ditissima, often invade citrus orchards. These flies cause economic losses to farmers and can prevent farmers from exporting their fruits to foreign markets. To detect the presence of fruit flies in citrus orchards, traps are baited with synthetic lures, which are often expensive for smallholder farmers. Farmers in developing or financially less-endowed countries have to import such synthetic baits, raising the cost of pest monitoring and control. Therefore, we evaluated the potential of palm wine and three other food-based mixtures for trapping C. ditissima and the proportion of non-target flies they trap. Transparent deli cup traps were baited with four different food-based baits, namely palm wine, sugarcane spirit-wine mixture, apple cider vinegar and yeast-sugar mixture. The traps were placed within a citrus orchard on fruit-bearing trees. The content of each trap was collected after one week and evaluated. This was repeated for eight consecutive weeks. Traps baited with palm wine captured more C. ditissima than those with the other baits. Furthermore, the proportion of non-target insects, Bactrocera dorsalis and Drosophila spp., in palm wine-baited traps was less than the other baited traps. This study indicates that palm wine, a cheap beverage across Africa, Asia and South America, could be used to monitor the presence of C. ditissima in citrus orchards. Smallholder farmers who cannot afford expensive synthetic baits could make use of palm wine to monitor fruit flies in their farms.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47160778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-10DOI: 10.17159/2254-8854/2023/a13747
Privilege T Makunde, B. Slippers, S. Bush, B. Hurley
Spondyliaspis cf. plicatuloides (Froggatt) (Hemiptera: Aphalaridae) is native to Australia but was first detected outside its native range in 2014, in South Africa. It feeds on eucalypt species and thus has the potential to become a pest in commercial Eucalyptus plantations. Information on the basic biology of this insect, which is important for the development of surveillance and management strategies, is lacking. To investigate the life cycle and general biology of S. plicatuloides, the psyllid was reared under controlled glasshouse conditions on potted red-flowering gum, Corymbia ficifolia. The egg incubation period, number of nymphal instars and their developmental time, adult fecundity, adult longevity and duration of the life cycle were determined. The major diagnostic features used to differentiate the five nymphal instars were the number of antennal segments, wing pad development and body length. Females reached reproductive maturity 2.3 ± 0.47 (mean ± SD) days after eclosion and laid 16.2 ± 3.9 (mean ± SD) eggs on average. Reproduction was sexual. The first nymphal instar took 10.7 ± 1.2 (mean ± SD) days to hatch from the egg. The nymphal instars completed their development in 22.6 ± 1.4 (mean ± SD) days under the brown scalloped shelters they secrete. The insect's total life cycle lasted 37.37 ± 1.17 (mean ± SD) days from egg to adult death. Males and females lifespan is also reported. The study provides the first information on the basic biology of S. cf. plicatuloides that will be useful for future studies on surveillance and management strategies.
{"title":"\"Biology of the invasive shell lerp psyllid, Spondyliaspis cf. plicatuloides (Froggatt) (Hemiptera: Aphalaridae)\"","authors":"Privilege T Makunde, B. Slippers, S. Bush, B. Hurley","doi":"10.17159/2254-8854/2023/a13747","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a13747","url":null,"abstract":"Spondyliaspis cf. plicatuloides (Froggatt) (Hemiptera: Aphalaridae) is native to Australia but was first detected outside its native range in 2014, in South Africa. It feeds on eucalypt species and thus has the potential to become a pest in commercial Eucalyptus plantations. Information on the basic biology of this insect, which is important for the development of surveillance and management strategies, is lacking. To investigate the life cycle and general biology of S. plicatuloides, the psyllid was reared under controlled glasshouse conditions on potted red-flowering gum, Corymbia ficifolia. The egg incubation period, number of nymphal instars and their developmental time, adult fecundity, adult longevity and duration of the life cycle were determined. The major diagnostic features used to differentiate the five nymphal instars were the number of antennal segments, wing pad development and body length. Females reached reproductive maturity 2.3 ± 0.47 (mean ± SD) days after eclosion and laid 16.2 ± 3.9 (mean ± SD) eggs on average. Reproduction was sexual. The first nymphal instar took 10.7 ± 1.2 (mean ± SD) days to hatch from the egg. The nymphal instars completed their development in 22.6 ± 1.4 (mean ± SD) days under the brown scalloped shelters they secrete. The insect's total life cycle lasted 37.37 ± 1.17 (mean ± SD) days from egg to adult death. Males and females lifespan is also reported. The study provides the first information on the basic biology of S. cf. plicatuloides that will be useful for future studies on surveillance and management strategies.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43502014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-10DOI: 10.17159/2254-8854/2023/a12814
L. L. Mathulwe, A. Malan, N. F. Stokwe
Formulation of entomopathogens refers to the mixing of various inert ingredients, like clays and mineral oils, with the active ingredients which are the entomopathogens. Successful formulation enhances the survival of the entomopathogen and also eases their transportation, storage, preparation and application. The aim of this study was to develop a formulation to maintain the longevity and pathogenicity of the mass-produced conidia of local Metarhizium pinghaense and M. robertsii, for above-ground future commercial field application against Pseudococcus viburni. The objectives were to develop a cost-effective protocol for formulation of infective propagules and to test their effectiveness under laboratory conditions. The conidia of both isolates were formulated using four different oils (liquid paraffin, coconut, canola and olive oils) as liquid carriers, and diatomaceous earth as a mineral carrier. Conidial viability and pathogenicity were assessed over a period of eight weeks. In the study, it was observed that the conidia formulated in oil carriers maintained a high conidial viability and survival rate of >95 % over a period of eight weeks for both isolates, relative to when formulated in mineral carriers, or when stored as dry conidial powder. The conidia in all the oil formulations were also observed to induce high mortality, ranging between 60 % and 90 % for M. pinghaense, and between 70 % and 90 % for M. robertsii, when used against P. viburni. The ability of conidia of both isolates to maintain viability and pathogenicity, following storage in the oil formulations, increased the likelihood of the local isolates being successfully integrated as biological control agents for management of P. viburni under field conditions.
{"title":"Formulation of Metarhizium pinghaense and Metarhizium robertsii and the infection potential of the formulations against Pseudococcus viburni (Hemiptera: Pseudococcidae), after storage","authors":"L. L. Mathulwe, A. Malan, N. F. Stokwe","doi":"10.17159/2254-8854/2023/a12814","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a12814","url":null,"abstract":"Formulation of entomopathogens refers to the mixing of various inert ingredients, like clays and mineral oils, with the active ingredients which are the entomopathogens. Successful formulation enhances the survival of the entomopathogen and also eases their transportation, storage, preparation and application. The aim of this study was to develop a formulation to maintain the longevity and pathogenicity of the mass-produced conidia of local Metarhizium pinghaense and M. robertsii, for above-ground future commercial field application against Pseudococcus viburni. The objectives were to develop a cost-effective protocol for formulation of infective propagules and to test their effectiveness under laboratory conditions. The conidia of both isolates were formulated using four different oils (liquid paraffin, coconut, canola and olive oils) as liquid carriers, and diatomaceous earth as a mineral carrier. Conidial viability and pathogenicity were assessed over a period of eight weeks. In the study, it was observed that the conidia formulated in oil carriers maintained a high conidial viability and survival rate of >95 % over a period of eight weeks for both isolates, relative to when formulated in mineral carriers, or when stored as dry conidial powder. The conidia in all the oil formulations were also observed to induce high mortality, ranging between 60 % and 90 % for M. pinghaense, and between 70 % and 90 % for M. robertsii, when used against P. viburni. The ability of conidia of both isolates to maintain viability and pathogenicity, following storage in the oil formulations, increased the likelihood of the local isolates being successfully integrated as biological control agents for management of P. viburni under field conditions.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45610755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-10DOI: 10.17159/2254-8854/2023/a13944
L. L. Mathulwe, A. Malan, N. F. Stokwe
Entomopathogenic fungi (EPF) are cosmopolitan soil borne pathogens that cause epizootics in various insect orders. EPF isolates of Metarhizium brunneum and M. pinghaense have shown the potential for use as biological agents of important agricultural insect pests. The aim of the current study was to test for the persistence of M. brunneum and M. pinghaense on apple bark over a period of three weeks, under laboratory conditions. Apple bark was sprayed with conidial suspensions of both fungi, at a standard infective conidial concentration of 107 conidia/ml. The persistence, or survival, of the conidia on apple bark was measured using codling moth larvae (CM) (Cydia pomonella) and females of woolly apple aphid (WAA) (Eriosoma lanigerum) as indicator species. The results showed that conidia of M. pinghaense can induce mortality of insect pests through contact with an EPF-treated substrate, with mortality of 39% to 82% for WAA over a period of 10 days post application, and with mortality of 3% to 68% for CM over a period of 7 days, after application to apple bark. Further evaluation showed that the conidia of M. pinghaense persisted longer on apple bark, up to 63%, than did M. brunneum, up to 11%, three weeks post application of the conidial suspensions. The study provides insights into the potential persistence of fungal isolates on apple bark over time post application. Further evaluation of the persistence of the isolates on apple bark under both glasshouse and field conditions should be conducted.
{"title":"Infection of insects and persistence of Metarhizium (Hypocreales: Clavicipitaceae) species on apple bark","authors":"L. L. Mathulwe, A. Malan, N. F. Stokwe","doi":"10.17159/2254-8854/2023/a13944","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a13944","url":null,"abstract":"Entomopathogenic fungi (EPF) are cosmopolitan soil borne pathogens that cause epizootics in various insect\u0000orders. EPF isolates of Metarhizium brunneum and M. pinghaense have shown the potential for use as biological\u0000agents of important agricultural insect pests. The aim of the current study was to test for the persistence of\u0000M. brunneum and M. pinghaense on apple bark over a period of three weeks, under laboratory conditions. Apple\u0000bark was sprayed with conidial suspensions of both fungi, at a standard infective conidial concentration of\u0000107 conidia/ml. The persistence, or survival, of the conidia on apple bark was measured using codling moth\u0000larvae (CM) (Cydia pomonella) and females of woolly apple aphid (WAA) (Eriosoma lanigerum) as indicator\u0000species. The results showed that conidia of M. pinghaense can induce mortality of insect pests through contact\u0000with an EPF-treated substrate, with mortality of 39% to 82% for WAA over a period of 10 days post application,\u0000and with mortality of 3% to 68% for CM over a period of 7 days, after application to apple bark. Further\u0000evaluation showed that the conidia of M. pinghaense persisted longer on apple bark, up to 63%, than did\u0000M. brunneum, up to 11%, three weeks post application of the conidial suspensions. The study provides insights\u0000into the potential persistence of fungal isolates on apple bark over time post application. Further evaluation of\u0000the persistence of the isolates on apple bark under both glasshouse and field conditions should be conducted.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43675975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.17159/2254-8854/2023/a11734
M. Acheampong, E. Cornelius, V. Eziah, K. O. Fening, K. Ofori, C. Storm, N. Jessop, B. Luke, D. Moore, V. Clottey, O. Potin, P. Grammare
The larger grain borer, Prostephanus truncatus (Horn) and the maize weevil, Sitophilus zeamais Motschulsky continue to cause tremendous losses to stored maize. Research in the UK has identified Beauveria bassiana, IMI 389521 as a suitable control agent for grain storage pests in the UK. The pathogenicity of B. bassiana, IMI 389521 was evaluated against adult P. truncatus, S. zeamais and Teretrius nigrescens in Ghana. Fifty adults of each insect species were treated with 0.5 g dry conidia powder of this isolate at 8.65 × 108 conidia/g for 1 minute and mortality recorded daily for 14 days. The results indicated that B. bassiana, is pathogenic against P. truncatus and S. zeamais, inducing over 90% mortality by day 7. Teretrius nigrescens was, however less susceptible to the fungus with 30% mortality. To determine the most effective concentration of B. bassiana for the control of P. truncatus, a laboratory dose response experiment using four concentrations of B. bassiana (108–1011 cfu/kg maize) was also conducted. Maize grains (250 g) in separate jars were treated with the four concentrations of the product. Fifty adults of P. truncatus were placed into the jars containing the treated maize and mortality was assessed weekly for 3 weeks. The most effective dose was 1010 cfu/kg maize, which resulted in 96% and 100% mortality of P. truncatus after 2 and 3 weeks, respectively. This study shows that B. bassiana could effectively be integrated into bio-control programme of these two key pests of maize in Ghana after further field trials.
{"title":"Efficacy of Beauveria bassiana against adults of Prostephanus truncatus (Horn), Sitophilus zeamais Motschulsky and Teretrius nigrescens Lewis in stored maize","authors":"M. Acheampong, E. Cornelius, V. Eziah, K. O. Fening, K. Ofori, C. Storm, N. Jessop, B. Luke, D. Moore, V. Clottey, O. Potin, P. Grammare","doi":"10.17159/2254-8854/2023/a11734","DOIUrl":"https://doi.org/10.17159/2254-8854/2023/a11734","url":null,"abstract":"The larger grain borer, Prostephanus truncatus (Horn) and the maize weevil, Sitophilus zeamais Motschulsky continue to cause tremendous losses to stored maize. Research in the UK has identified Beauveria bassiana, IMI 389521 as a suitable control agent for grain storage pests in the UK. The pathogenicity of B. bassiana, IMI 389521 was evaluated against adult P. truncatus, S. zeamais and Teretrius nigrescens in Ghana. Fifty adults of each insect species were treated with 0.5 g dry conidia powder of this isolate at 8.65 × 108 conidia/g for 1 minute and mortality recorded daily for 14 days. The results indicated that B. bassiana, is pathogenic against P. truncatus and S. zeamais, inducing over 90% mortality by day 7. Teretrius nigrescens was, however less susceptible to the fungus with 30% mortality. To determine the most effective concentration of B. bassiana for the control of P. truncatus, a laboratory dose response experiment using four concentrations of B. bassiana (108–1011 cfu/kg maize) was also conducted. Maize grains (250 g) in separate jars were treated with the four concentrations of the product. Fifty adults of P. truncatus were placed into the jars containing the treated maize and mortality was assessed weekly for 3 weeks. The most effective dose was 1010 cfu/kg maize, which resulted in 96% and 100% mortality of P. truncatus after 2 and 3 weeks, respectively. This study shows that B. bassiana could effectively be integrated into bio-control programme of these two key pests of maize in Ghana after further field trials.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46537113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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