Pub Date : 2022-08-02DOI: 10.17159/2254-8854/2022/a11687
H. Elbrense, M. Shamseldean, W.S. Meshrif, A. Seif
The extensive use of chemical insecticides to control mosquitoes led to the development of insecticide resistance and environmental health hazards. This caused a surge in interest in eco-friendly biocontrol agents. The present study aimed to explore the susceptibility of different instar larvae of the common mosquito, Culex pipiens Linnaeus, 1758, to the mermithid nematode, Romanomermis iyengari Welch, 1964. Moreover, the effects of R. iyengari on the mosquito pupal developmental time, adult emergence, longevity, female fecundity, as well as egg-hatching rate were determined after larval treatment with an LC50 quantity of the nematode pre-parasites. Different instars of Cx. pipiens (1st–4th) were exposed separately to R. iyengari at concentrations of 1–6 pre-parasites/mosquito larva. Mortality rates of mosquito larvae were observed and the LC50 values were calculated. The estimated LC50 values for the 1st–4th larval instars were 3.18, 2.73, 3.79 and 4 pre-parasites/larva, respectively. Mean percent mortality of the 1st–4th larval instars ranged from 10–94%, 16–100%, 4–100% and 0–52%, respectively. The results indicated that exposure of 4th larval instar to the LC50 of R. iyengari pre-parasites significantly prolonged the duration of pupal development, reduced the percentage of emerged adults and reduced mosquito female fecundity compared with the control. In contrast, adult longevity and the egg-hatching rate did not differ between the control and the exposed group. In conclusion, this isolate of R. iyengari could be a promising biocontrol agent for Egyptian Cx. pipiens. Other trials are required to assess the biocontrol potential of this parasite in field conditions.
{"title":"The parasitic impact of Romanomermis iyengari Welch (Nematoda: Mermithidae) on the survival and biology of the common mosquito, Culex pipiens L. (Diptera: Culicidae)","authors":"H. Elbrense, M. Shamseldean, W.S. Meshrif, A. Seif","doi":"10.17159/2254-8854/2022/a11687","DOIUrl":"https://doi.org/10.17159/2254-8854/2022/a11687","url":null,"abstract":"The extensive use of chemical insecticides to control mosquitoes led to the development of insecticide resistance and environmental health hazards. This caused a surge in interest in eco-friendly biocontrol agents. The present study aimed to explore the susceptibility of different instar larvae of the common mosquito, Culex pipiens Linnaeus, 1758, to the mermithid nematode, Romanomermis iyengari Welch, 1964. Moreover, the effects of R. iyengari on the mosquito pupal developmental time, adult emergence, longevity, female fecundity, as well as egg-hatching rate were determined after larval treatment with an LC50 quantity of the nematode pre-parasites. Different instars of Cx. pipiens (1st–4th) were exposed separately to R. iyengari at concentrations of 1–6 pre-parasites/mosquito larva. Mortality rates of mosquito larvae were observed and the LC50 values were calculated. The estimated LC50 values for the 1st–4th larval instars were 3.18, 2.73, 3.79 and 4 pre-parasites/larva, respectively. Mean percent mortality of the 1st–4th larval instars ranged from 10–94%, 16–100%, 4–100% and 0–52%, respectively. The results indicated that exposure of 4th larval instar to the LC50 of R. iyengari pre-parasites significantly prolonged the duration of pupal development, reduced the percentage of emerged adults and reduced mosquito female fecundity compared with the control. In contrast, adult longevity and the egg-hatching rate did not differ between the control and the exposed group. In conclusion, this isolate of R. iyengari could be a promising biocontrol agent for Egyptian Cx. pipiens. Other trials are required to assess the biocontrol potential of this parasite in field conditions.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49067214","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}
Host-associated genetic differentiation in grasshoppers has received limited attention, due to a lack of information on grasshopper-plant associations. The bladder grasshopper, Bullacris unicolor (Linnaeus, 1758) (Orthoptera: Pneumoridae), is a phytophagous species that can occur on at least six host plants within its geographic range. However, the relationship between host plant association and genetic variation of bladder grasshoppers has not been studied before. In light of this, the present study examined host plant-related genetic [mitochondrial cytochrome oxidase 1 (CO1) and the internal transcribed spacer (ITS) gene regions] and morphological (antennal length, body length, head width, abdomen width, femur length, tibia length and pronotum length) divergence within a population of B. unicolor. We used two plant species, belonging to different families, namely Didelta spinosa (L.fil.) Aiton (Asteraceae) and Roepera morgsana (L.) Beier & Thulin (Zygophyllaceae), to evaluate variation between individuals collected on these two sympatric host plants at a single locality in the Northern Cape, South Africa. The results demonstrated non-significant host related genetic variation with very low values of FST, indicating a low level of variation. The phylogram strongly indicated that there are no host-associated genetic differences in B. unicolor by displaying limited genomic clustering, whereas some differentiation was observed between the morphological measurements of males and females among host plants. Further studies using microsatellite molecular markers may help to discern population genetic structure. In addition, significant host-associated morphological divergence highlights the need to examine the mechanisms by which host utilization affects morphological features.
{"title":"No evidence for host plant associated genetic divergence in a population of Bullacris unicolor (Linnaeus, 1758) (Orthoptera: Pneumoridae)","authors":"Rekha Sathyan, Vanessa Couldridge Vanessa C.K. Couldridge, Adriaan Engelbrecht Adriaan Engelbrecht","doi":"10.17159/2254-8854/2022/a12473","DOIUrl":"https://doi.org/10.17159/2254-8854/2022/a12473","url":null,"abstract":"Host-associated genetic differentiation in grasshoppers has received limited attention, due to a lack of information on grasshopper-plant associations. The bladder grasshopper, Bullacris unicolor (Linnaeus, 1758) (Orthoptera: Pneumoridae), is a phytophagous species that can occur on at least six host plants within its geographic range. However, the relationship between host plant association and genetic variation of bladder grasshoppers has not been studied before. In light of this, the present study examined host plant-related genetic [mitochondrial cytochrome oxidase 1 (CO1) and the internal transcribed spacer (ITS) gene regions] and morphological (antennal length, body length, head width, abdomen width, femur length, tibia length and pronotum length) divergence within a population of B. unicolor. We used two plant species, belonging to different families, namely Didelta spinosa (L.fil.) Aiton (Asteraceae) and Roepera morgsana (L.) Beier & Thulin (Zygophyllaceae), to evaluate variation between individuals collected on these two sympatric host plants at a single locality in the Northern Cape, South Africa. The results demonstrated non-significant host related genetic variation with very low values of FST, indicating a low level of variation. The phylogram strongly indicated that there are no host-associated genetic differences in B. unicolor by displaying limited genomic clustering, whereas some differentiation was observed between the morphological measurements of males and females among host plants. Further studies using microsatellite molecular markers may help to discern population genetic structure. In addition, significant host-associated morphological divergence highlights the need to examine the mechanisms by which host utilization affects morphological features.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41562598","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 : 2022-05-24DOI: 10.17159/2254-8854/2022/a11778
A. Melin, J. Colville
We describe the male of Rediviva steineri Kuhlmann, 2012; distinguished by the shape and the margin of the apical plate of the eighth sterna and the vestiture of metasomal terga two and three. Five males were collected at the type locality of the female (Farm Doornbosch, Western Cape, South Africa). We examined the types of three other closely related species (R. pallidula, R. brunnea and R. whiteheadi) and provide images of the eighth sterna for comparison with R. steineri and update Whitehead et al.’s (2008) identification key for the males of these species.
{"title":"Description of the male of Rediviva steineri Kuhlmann, 2012 (Hymenoptera: Melittidae), an endemic oil-collecting bee species from South Africa","authors":"A. Melin, J. Colville","doi":"10.17159/2254-8854/2022/a11778","DOIUrl":"https://doi.org/10.17159/2254-8854/2022/a11778","url":null,"abstract":"We describe the male of Rediviva steineri Kuhlmann, 2012; distinguished by the shape and the margin of the apical plate of the eighth sterna and the vestiture of metasomal terga two and three. Five males were collected at the type locality of the female (Farm Doornbosch, Western Cape, South Africa). We examined the types of three other closely related species (R. pallidula, R. brunnea and R. whiteheadi) and provide images of the eighth sterna for comparison with R. steineri and update Whitehead et al.’s (2008) identification key for the males of these species. ","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41709922","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}
The use of plant pathogens for biological control (biocontrol) of invasive alien plants in South Africa was reviewed in 1991, 1999 and 2011. In this review, subsequent progress and projects undertaken in the years 2011 to 2020, on both classical agents using exotic pathogens and inundative agents using indigenous pathogens, are detailed. We report on the impact of several previously introduced exotic fungi, monitored during this period. A significant highlight is the completion of 30 years of annual monitoring, from 1991 until 2020, of the impact of Uromycladium morrisii Doungsa-ard, McTaggart, Geering & RG Shivas (Raveneliaceae) on the density of Acacia saligna (Labill.) Wendel (Fabaceae), with declines of up to 98% recorded at monitored sites. Post-release monitoring also suggested that Entyloma ageratinae R.W. Barreto & H.C. Evans (Entylomataceae), introduced when Ageratina riparia (Regel) R.M.King & H.Rob (Asteraceae) still had a very limited invaded range in South Africa, has prevented the weed from realizing its potential as an invader. Uromycladium woodii Doungsa-ard, McTaggart, Geering & R.G. Shivas (Raveneliaceae) has been established on Paraserianthes lophantha (Willd.) I.C.Nielsen (Fabaceae), as has Puccinia xanthii Schwein (Pucciniaceae) on Parthenium hysterophorus L. (Asteraceae). Prospodium transformans (Ellis & Everh.) Cummins (Raveneliaceae) failed to establish on Tecoma stans (L.) Juss ex Kunth var. stans (Bignoniaceae), while efforts to release Puccinia lantanae Farl. (Pucciniaceae) on Lantana camara L. (Verbenaceae) are underway. Of the established exotic pathogens that are classical biocontrol agents, two are considered to cause extensive damage, two considerable damage, and two moderate damage, to their target weeds. Puccinia arechavaletae Speg. (Pucciniaceae), an adventive fungus that is established on Cardiospermum grandiflorum Sw. (Sapindaceae) following an unknown path of introduction, is proving to be a damaging agent and the implications of its presence in the country are discussed. Early season augmentation of Puccinia eupatorii Dietel (Pucciniaceae) on Campuloclinium macrocephalum (Less.) DC. (Asteraceae) was tested to determine whether damage could be increased, but no difference in the rust's incidence and severity was evident between augmented and naturally infected plants at the end of the growth season. The identity of the indigenous fungus registered as Stumpout®, for the control of coppice growth after felling of Acacia mearnsii De Wild. (Fabaceae), was confirmed as Cylindrobasidium torrendii (Bres.) Hjortstam (Physalacriaceae) rather than C. laeve (Pers.: Fr.) Chamuris, as previously thought. The application of another indigenous fungus, Colletotrichum acutatum J.H. Simmonds (Glomerellaceae), by means of helicopter flights has facilitated its establishment on Hakea sericea Schrad. & J.C. Wendl (Proteaceae), in inaccessible mountainous terrain. For registration purposes, toxicity testing (oral rat LD50) of thes
1991年、1999年和2011年审查了南非利用植物病原体对入侵外来植物进行生物控制（生物控制）的情况。在这篇综述中，详细介绍了2011年至2020年在使用外来病原体的经典制剂和使用本土病原体的淹没制剂方面的后续进展和项目。我们报告了在此期间监测的几种先前引入的外来真菌的影响。一个重要的亮点是，从1991年到2020年，完成了30年的年度监测，监测点记录了莫里斯尾枝藻Doungsa-ard、McTaggart、Geering和RG Shivas（Raveneliaceae）对唾液Acacia saligna（Labill.）Wendel（Fabaceae）密度的影响，下降幅度高达98%。释放后的监测还表明，当尖角藻（Regel）R.M.King和H.Rob（Astraceae）在南非的入侵范围仍然非常有限时引入的老年虫R.W.Barreto和H.C.Evans（钩虫科）阻止了这种杂草发挥其入侵者的潜力。Uromycladium woodii Doungsa ard，McTaggart，Geering&R.G.Shivas（Raveneliaceae。Prospordum transformans（Ellis&Everh。）Cummins（Raveneliaceae）未能在Tecoma stans（L.）Juss ex Kunth var.stans（Bignonaceae）上建立，同时努力释放兰塔普契尼。马鞭草科正在进行中。在已确定的作为经典生物防治剂的外来病原体中，有两种被认为对其目标杂草造成广泛损害，两种相当大的损害，以及两种中度损害。Puccinia are chavaletae Speg。（Pucciniaceae），一种在桔梗上建立的外来真菌。（Sapindaceae）的引入途径未知，被证明是一种破坏剂，并讨论了其在该国存在的影响。欧洲蒲草科（Puccinia eupatorii Dietel）在大角星（Campuloclinium macrochalum（Less.）DC上的早季扩增。（菊科）进行了测试，以确定损伤是否会增加，但在生长季节结束时，增强型和自然感染型植物之间的铁锈发生率和严重程度没有明显差异。注册为Stumpout®的本土真菌的身份，用于控制砍伐Acacia mearnsii De Wild后的矮林生长。（Fabaceae），被确认为Cylindrobasidium torrendii（Bres.）Hjortstam（Physalacriaceae），而不是之前认为的C.laeve（Pers.：Fr.）Chamuris。另一种本土真菌尖孢炭疽菌J.H.Simmonds（Glomerellaceae）通过直升机飞行的方式应用，促进了其在蚕桑Hakea sercea Schrad上的建立J.C.Wendl（蛋白质科），在人迹罕至的山区。出于注册目的，需要对这些本土真菌进行毒性测试（大鼠口服LD50）。torrendii Cylindrobasidium、C.acutatum和Pseudolagarobasidium acaciicola Gins（Phanerochaethaceae）的致死剂量，后者用于对抗Acacia cyclops G.Don。（Fabaceae），超过2000 mg kg–1体重，因此所有三种真菌都被认为是安全的。
{"title":"Plant Pathogens and Biological Control of Invasive Alien Plants in South Africa: A Review of Projects and Progress (2011–2020)","authors":"A. Wood, A. D. Breeÿen","doi":"10.4001/003.029.0983","DOIUrl":"https://doi.org/10.4001/003.029.0983","url":null,"abstract":"The use of plant pathogens for biological control (biocontrol) of invasive alien plants in South Africa was reviewed in 1991, 1999 and 2011. In this review, subsequent progress and projects undertaken in the years 2011 to 2020, on both classical agents using exotic pathogens and inundative agents using indigenous pathogens, are detailed. We report on the impact of several previously introduced exotic fungi, monitored during this period. A significant highlight is the completion of 30 years of annual monitoring, from 1991 until 2020, of the impact of Uromycladium morrisii Doungsa-ard, McTaggart, Geering & RG Shivas (Raveneliaceae) on the density of Acacia saligna (Labill.) Wendel (Fabaceae), with declines of up to 98% recorded at monitored sites. Post-release monitoring also suggested that Entyloma ageratinae R.W. Barreto & H.C. Evans (Entylomataceae), introduced when Ageratina riparia (Regel) R.M.King & H.Rob (Asteraceae) still had a very limited invaded range in South Africa, has prevented the weed from realizing its potential as an invader. Uromycladium woodii Doungsa-ard, McTaggart, Geering & R.G. Shivas (Raveneliaceae) has been established on Paraserianthes lophantha (Willd.) I.C.Nielsen (Fabaceae), as has Puccinia xanthii Schwein (Pucciniaceae) on Parthenium hysterophorus L. (Asteraceae). Prospodium transformans (Ellis & Everh.) Cummins (Raveneliaceae) failed to establish on Tecoma stans (L.) Juss ex Kunth var. stans (Bignoniaceae), while efforts to release Puccinia lantanae Farl. (Pucciniaceae) on Lantana camara L. (Verbenaceae) are underway. Of the established exotic pathogens that are classical biocontrol agents, two are considered to cause extensive damage, two considerable damage, and two moderate damage, to their target weeds. Puccinia arechavaletae Speg. (Pucciniaceae), an adventive fungus that is established on Cardiospermum grandiflorum Sw. (Sapindaceae) following an unknown path of introduction, is proving to be a damaging agent and the implications of its presence in the country are discussed. Early season augmentation of Puccinia eupatorii Dietel (Pucciniaceae) on Campuloclinium macrocephalum (Less.) DC. (Asteraceae) was tested to determine whether damage could be increased, but no difference in the rust's incidence and severity was evident between augmented and naturally infected plants at the end of the growth season. The identity of the indigenous fungus registered as Stumpout®, for the control of coppice growth after felling of Acacia mearnsii De Wild. (Fabaceae), was confirmed as Cylindrobasidium torrendii (Bres.) Hjortstam (Physalacriaceae) rather than C. laeve (Pers.: Fr.) Chamuris, as previously thought. The application of another indigenous fungus, Colletotrichum acutatum J.H. Simmonds (Glomerellaceae), by means of helicopter flights has facilitated its establishment on Hakea sericea Schrad. & J.C. Wendl (Proteaceae), in inaccessible mountainous terrain. For registration purposes, toxicity testing (oral rat LD50) of thes","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49310738","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}
C. Zachariades, L. van der Westhuizen, Fritz Heystek, N. Dube, A. McConnachie, S. Nqayi, S.I. Dlomo, P. Mpedi, Y. Kistensamy
Several weed species within the asteraceous tribe Eupatorieae, all with a neotropical origin, are invasive in South Africa. Three of these form the subject of this review paper: Chromolaena odorata (triffid weed), Campuloclinium macrocephalum (pompom weed), and Ageratina adenophora (crofton weed). The three species invade different habitats and regions, and all have biological control (biocontrol) agents established on them. Ageratina adenophora was the first of these weeds to be subjected to a biocontrol programme in South Africa, with two agents (an insect and a pathogen) released and established in the 1980s. Two biocontrol agents were established on C. odorata in the early 2000s, and a third one, first released in 2011, has persisted for at least eight years – all three are insects. One insect biocontrol agent was established on C. macrocephalum in 2013, although a pathogen had appeared on the weed several years earlier. Chromolaena odorata and A. adenophora are under substantial control in certain habitats, but negligible in others. The biocontrol agent on C. macrocephalum released in 2013 is causing significant damage to the plant where it has established well. Several other biocontrol agents have been released on C. odorata but have failed to establish. For all three weedy Eupatorieae, it is considered desirable to establish additional biocontrol agents, so as to increase the level of control of these priority targets in South Africa. An additional biocontrol agent has already been approved for release against C. macrocephalum, while one is close to being approved for C. odorata. There are several possibilities for additional biocontrol agents for A. adenophora.
{"title":"Biological Control of Three Eupatorieae Weeds in South Africa: 2011–2020","authors":"C. Zachariades, L. van der Westhuizen, Fritz Heystek, N. Dube, A. McConnachie, S. Nqayi, S.I. Dlomo, P. Mpedi, Y. Kistensamy","doi":"10.4001/003.029.0742","DOIUrl":"https://doi.org/10.4001/003.029.0742","url":null,"abstract":"Several weed species within the asteraceous tribe Eupatorieae, all with a neotropical origin, are invasive in South Africa. Three of these form the subject of this review paper: Chromolaena odorata (triffid weed), Campuloclinium macrocephalum (pompom weed), and Ageratina adenophora (crofton weed). The three species invade different habitats and regions, and all have biological control (biocontrol) agents established on them. Ageratina adenophora was the first of these weeds to be subjected to a biocontrol programme in South Africa, with two agents (an insect and a pathogen) released and established in the 1980s. Two biocontrol agents were established on C. odorata in the early 2000s, and a third one, first released in 2011, has persisted for at least eight years – all three are insects. One insect biocontrol agent was established on C. macrocephalum in 2013, although a pathogen had appeared on the weed several years earlier. Chromolaena odorata and A. adenophora are under substantial control in certain habitats, but negligible in others. The biocontrol agent on C. macrocephalum released in 2013 is causing significant damage to the plant where it has established well. Several other biocontrol agents have been released on C. odorata but have failed to establish. For all three weedy Eupatorieae, it is considered desirable to establish additional biocontrol agents, so as to increase the level of control of these priority targets in South Africa. An additional biocontrol agent has already been approved for release against C. macrocephalum, while one is close to being approved for C. odorata. There are several possibilities for additional biocontrol agents for A. adenophora.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44204076","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}
G. Sutton, A. Bownes, V. Visser, A. Mapaura, K. Canavan
Historically, invasive alien grasses have not been considered a major threat in South Africa, and as a result, very few resources are allocated to their management. However, there is an increasing awareness of the severe environmental and socio-economic impacts of invasive grasses and the need for appropriate management options for their control. South Africa has a long history of successfully implementing weed biological control (biocontrol) to manage invasive alien plants, however much like the rest of the world, invasive grasses do not feature prominently as targets for biocontrol. The implementation and early indicators of success of the few grass biocontrol programmes globally and the finding that grasses can be suitable targets, suggests that biocontrol could start to play an important role in managing invasive alien grasses in South Africa. In this paper, we evaluated the prospects for implementing novel grass biocontrol projects over the next ten years against 48 grasses that have been determined to represent the highest risk based on their current environmental and economic impacts. The grasses were ranked in order of priority using the Biological Control Target Selection system. Five grasses were prioritised – Arundo donax L., Cortaderia jubata (Lem.) Stapf, Cortaderia selloana (Schult & Schult) Asch. & Graebn., Nassella trichotoma (Hack. ex Arech.), and Glyceria maxima (Hartm.) Holmb., based on attributes that make them suitable biocontrol targets. Arundo donax has already been the target of a biocontrol programme in South Africa. We reviewed the progress made towards the biocontrol of this species and discuss how this programme could be developed going forward. Moreover, we outline how biocontrol could be implemented to manage the remaining four high-priority targets. While biocontrol of grasses is not without its challenges (e.g. unresolved taxonomies, conflicts of interest and a lack of supporting legislation), South Africa has an opportunity to learn from existing global research and begin to invest in biocontrol of high-priority species that are in most need of control.
{"title":"Progress and Prospects for the Biological Control of Invasive Alien Grasses Poaceae) in South Africa","authors":"G. Sutton, A. Bownes, V. Visser, A. Mapaura, K. Canavan","doi":"10.4001/003.029.0837","DOIUrl":"https://doi.org/10.4001/003.029.0837","url":null,"abstract":"Historically, invasive alien grasses have not been considered a major threat in South Africa, and as a result, very few resources are allocated to their management. However, there is an increasing awareness of the severe environmental and socio-economic impacts of invasive grasses and the need for appropriate management options for their control. South Africa has a long history of successfully implementing weed biological control (biocontrol) to manage invasive alien plants, however much like the rest of the world, invasive grasses do not feature prominently as targets for biocontrol. The implementation and early indicators of success of the few grass biocontrol programmes globally and the finding that grasses can be suitable targets, suggests that biocontrol could start to play an important role in managing invasive alien grasses in South Africa. In this paper, we evaluated the prospects for implementing novel grass biocontrol projects over the next ten years against 48 grasses that have been determined to represent the highest risk based on their current environmental and economic impacts. The grasses were ranked in order of priority using the Biological Control Target Selection system. Five grasses were prioritised – Arundo donax L., Cortaderia jubata (Lem.) Stapf, Cortaderia selloana (Schult & Schult) Asch. & Graebn., Nassella trichotoma (Hack. ex Arech.), and Glyceria maxima (Hartm.) Holmb., based on attributes that make them suitable biocontrol targets. Arundo donax has already been the target of a biocontrol programme in South Africa. We reviewed the progress made towards the biocontrol of this species and discuss how this programme could be developed going forward. Moreover, we outline how biocontrol could be implemented to manage the remaining four high-priority targets. While biocontrol of grasses is not without its challenges (e.g. unresolved taxonomies, conflicts of interest and a lack of supporting legislation), South Africa has an opportunity to learn from existing global research and begin to invest in biocontrol of high-priority species that are in most need of control.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42715547","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}
A catalogue of natural enemies considered and released as biological control (biocontrol) agents against invasive alien plants in South Africa has been maintained for many years, and is updated here to include the period 2011-2020. The current catalogue reorders and separates data for exotic natural enemies that have been approved as classical biocontrol agents, from those on exotic natural enemies that have been considered but not released, exotic natural enemies that have been inadvertently introduced into South Africa with host plants that include target weed species, and locally sourced natural enemies that have been considered as bioherbicides. Ninety weed species have been targeted for biocontrol, with 310 exotic natural enemies considered, 136 classified as de jure or de facto classical biocontrol agents, and 92 established in the field on 66 target weeds. Ten of these species were found to have established independently of being released while research on them was in progress. An additional six exotic species have been found established on target weeds, and 11 locally sourced natural enemies have been considered for inundative or augmentative biocontrol, of which two have been developed commercially. Of the exotic natural enemies deliberately established, 35% inflict extensive damage to their host plants. Insects make up the majority of biocontrol agents (90%), with the balance of 8% being fungi and 2%, mites. Both establishment rates and damage levels vary between taxa. Five biocontrol agents previously considered established, have not been found in the field for several years and their persistence is in doubt. Outcomes of biocontrol at a plant population level are indicated for 54 target weeds on which agents have been established for over a decade. The increase in numbers of target weeds considered, as well as biocontrol agents released, over the past decade, has been enabled by continued generous funding and an efficient release-approval process.
{"title":"A Catalogue of Natural Enemies of Invasive Alien Plants in South Africa: Classical Biological Control Agents Considered, Released and Established, Exotic Natural Enemies Present in the Field, and Bioherbicides","authors":"C. Zachariades","doi":"10.4001/003.029.1077","DOIUrl":"https://doi.org/10.4001/003.029.1077","url":null,"abstract":"A catalogue of natural enemies considered and released as biological control (biocontrol) agents against invasive alien plants in South Africa has been maintained for many years, and is updated here to include the period 2011-2020. The current catalogue reorders and separates data for exotic natural enemies that have been approved as classical biocontrol agents, from those on exotic natural enemies that have been considered but not released, exotic natural enemies that have been inadvertently introduced into South Africa with host plants that include target weed species, and locally sourced natural enemies that have been considered as bioherbicides. Ninety weed species have been targeted for biocontrol, with 310 exotic natural enemies considered, 136 classified as de jure or de facto classical biocontrol agents, and 92 established in the field on 66 target weeds. Ten of these species were found to have established independently of being released while research on them was in progress. An additional six exotic species have been found established on target weeds, and 11 locally sourced natural enemies have been considered for inundative or augmentative biocontrol, of which two have been developed commercially. Of the exotic natural enemies deliberately established, 35% inflict extensive damage to their host plants. Insects make up the majority of biocontrol agents (90%), with the balance of 8% being fungi and 2%, mites. Both establishment rates and damage levels vary between taxa. Five biocontrol agents previously considered established, have not been found in the field for several years and their persistence is in doubt. Outcomes of biocontrol at a plant population level are indicated for 54 target weeds on which agents have been established for over a decade. The increase in numbers of target weeds considered, as well as biocontrol agents released, over the past decade, has been enabled by continued generous funding and an efficient release-approval process.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48676969","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}
The Northern Temperate Weeds programme is a novel biological control (biocontrol) programme started in 2017, with the aim of reducing the impacts of northern temperate weeds that are common, widespread and problematic in the high elevation grasslands of South Africa. As these regions are the most important systems for water security, providing nearly 50% of all water run-off, it is surprising that these species were not targeted for biocontrol previously. Thus far, research has focused on biocontrol feasibility as well as ecological and socio-economic impact studies on several northern temperate weeds, including Pyracantha angustifolia (Franch.) C.K.Schneid, Rosa rubiginosa L., Cotoneaster spp., Rubus spp., (all Rosaceae) and Salix spp. (Salicaceae). In addition, research conducted in the USA and Europe on the natural enemies associated with two of these species, Robinia pseudoacacia L. and Gleditsia triacanthos L. (both Fabaceae and native to the USA), have provided South African researchers with the necessary foundation to initiate programmes against these weeds. Research in South Africa is currently focused on pre-release studies on R. pseudoacacia, using the leaf miner Odontota dorsalis Thunberg (Coleoptera: Chrysomelidae) and the black locust midge Obolodiplosis robiniae Haldeman (Diptera: Cecidomyiidae), and on G. triacanthos, using a seed bruchid, Amblycerus robiniae F. (Coleoptera: Chrysomelidae). Progress with these programmes and potential constraints that may limit success, are discussed.
{"title":"Prospects for the Biological Control of Northern Temperate Weeds in South Africa","authors":"G. Martin","doi":"10.4001/003.029.0791","DOIUrl":"https://doi.org/10.4001/003.029.0791","url":null,"abstract":"The Northern Temperate Weeds programme is a novel biological control (biocontrol) programme started in 2017, with the aim of reducing the impacts of northern temperate weeds that are common, widespread and problematic in the high elevation grasslands of South Africa. As these regions are the most important systems for water security, providing nearly 50% of all water run-off, it is surprising that these species were not targeted for biocontrol previously. Thus far, research has focused on biocontrol feasibility as well as ecological and socio-economic impact studies on several northern temperate weeds, including Pyracantha angustifolia (Franch.) C.K.Schneid, Rosa rubiginosa L., Cotoneaster spp., Rubus spp., (all Rosaceae) and Salix spp. (Salicaceae). In addition, research conducted in the USA and Europe on the natural enemies associated with two of these species, Robinia pseudoacacia L. and Gleditsia triacanthos L. (both Fabaceae and native to the USA), have provided South African researchers with the necessary foundation to initiate programmes against these weeds. Research in South Africa is currently focused on pre-release studies on R. pseudoacacia, using the leaf miner Odontota dorsalis Thunberg (Coleoptera: Chrysomelidae) and the black locust midge Obolodiplosis robiniae Haldeman (Diptera: Cecidomyiidae), and on G. triacanthos, using a seed bruchid, Amblycerus robiniae F. (Coleoptera: Chrysomelidae). Progress with these programmes and potential constraints that may limit success, are discussed.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43698895","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}
This special issue is the fourth decadal review of biological control of invasive alien plants (biocontrol of weeds) in South Africa, following those published in 1991, 1999 and 2011. Including this introduction, there are 24 papers covering the weed biocontrol programmes, or important developments in the science and practice, from the period 2011-2020. Seventy-two target weed species are covered, including 25 species on which projects were initiated during the past decade. Developments in regulations, mass-rearing and implementation, and community engagement are also reviewed. An updated catalogue of agents released, rejected and under consideration is presented and reflects the most recent methods of quantifying success in weed biocontrol. Key events over the last decade include the hosting of the XIV International Symposium on Biological Control of Weeds to celebrate 100 years of weed biocontrol in South Africa, as well as the establishment of the Centre for Biological Control at Rhodes University. The science and practice of weed biocontrol has expanded significantly in the past decade, with growth in the number of researchers and practitioners, increased funding, and an increased number of scholarly outputs. Unlike many other countries in the world, South Africa has largely avoided constraints due to restrictive and risk averse legislation and bureaucracy, and has continued to release new biocontrol agents at a similar rate to that in previous years. Much of the success of weed biocontrol in South Africa is due to the sustained and increasing support of the Natural Resource Management Programme of the Department of Forestry, Fisheries and the Environment (Working for Water Programme). However, gaps in funding, where no funds are available for months at a time, are a major concern as the weed biocontrol community loses human capital in these periods, and research programmes suffer significant set-backs. Weed biocontrol is an essential component of South Africa's strategy to reduce the negative impacts of invasive alien plants and has contributed significantly towards the protection of the country's ecosystems, indigenous biodiversity, water security, agricultural productivity, and society in general. If the trend of increasing support for weed biocontrol in South Africa continues, we can expect that the benefits for the country at large will increase substantially in the future.
{"title":"An Introduction to the Fourth Decadal Review of Biological Control of Invasive Alien Plants in South Africa (2011–2020)","authors":"I. Paterson, A. D. Breeÿen, G. Martin, T. Olckers","doi":"10.4001/003.029.0685","DOIUrl":"https://doi.org/10.4001/003.029.0685","url":null,"abstract":"This special issue is the fourth decadal review of biological control of invasive alien plants (biocontrol of weeds) in South Africa, following those published in 1991, 1999 and 2011. Including this introduction, there are 24 papers covering the weed biocontrol programmes, or important developments in the science and practice, from the period 2011-2020. Seventy-two target weed species are covered, including 25 species on which projects were initiated during the past decade. Developments in regulations, mass-rearing and implementation, and community engagement are also reviewed. An updated catalogue of agents released, rejected and under consideration is presented and reflects the most recent methods of quantifying success in weed biocontrol. Key events over the last decade include the hosting of the XIV International Symposium on Biological Control of Weeds to celebrate 100 years of weed biocontrol in South Africa, as well as the establishment of the Centre for Biological Control at Rhodes University. The science and practice of weed biocontrol has expanded significantly in the past decade, with growth in the number of researchers and practitioners, increased funding, and an increased number of scholarly outputs. Unlike many other countries in the world, South Africa has largely avoided constraints due to restrictive and risk averse legislation and bureaucracy, and has continued to release new biocontrol agents at a similar rate to that in previous years. Much of the success of weed biocontrol in South Africa is due to the sustained and increasing support of the Natural Resource Management Programme of the Department of Forestry, Fisheries and the Environment (Working for Water Programme). However, gaps in funding, where no funds are available for months at a time, are a major concern as the weed biocontrol community loses human capital in these periods, and research programmes suffer significant set-backs. Weed biocontrol is an essential component of South Africa's strategy to reduce the negative impacts of invasive alien plants and has contributed significantly towards the protection of the country's ecosystems, indigenous biodiversity, water security, agricultural productivity, and society in general. If the trend of increasing support for weed biocontrol in South Africa continues, we can expect that the benefits for the country at large will increase substantially in the future.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41540905","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}
J. Coetzee, A. Bownes, G. Martin, B. E. Miller, R. Smith, P. Weyl, M. Hill
Biological control (biocontrol) against invasive macrophytes is one of the longest standing programmes in South Africa, initiated in the 1970s against water hyacinth, Pontederia crassipes Mart. (Pontederiaceae). Since then, 15 agent species (13 insects, one mite and one pathogen) have been released against six weeds, most of which are floating macrophytes, with excellent levels of success. The release of the water hyacinth planthopper Megamelus scutellaris Berg (Hemiptera: Delphacidae) in particular, has improved biocontrol prospects for water hyacinth since 2018. In the last decade, however, a new suite of submerged and rooted emergent invasive macrophytes has been targeted. The first release against a submerged macrophyte in South Africa, and the first release against Brazilian waterweed, Egeria densa Planch. (Hydrocharitaceae), anywhere in the world, was achieved with the release of a leafmining fly, Hydrellia egeriae Rodrigues-Júnior, Mathis & Hauser (Diptera: Ephydridae). Yellow flag, Iris pseudacorus L. (Iridaceae) and Mexican waterlily, Nymphaea mexicana Zucc. (Nymphaeaceae), have also been targeted for biocontrol for the first time worldwide, and are in the early stages of agent development. Post-release evaluations, long term monitoring and controlled experiments have highlighted the need for a more holistic approach to managing aquatic invasive plants in South Africa, whose presence is largely driven by eutrophication, resulting in regime shifts between floating and submerged invaded states.
{"title":"A Review of the Biocontrol Programmes Against Aquatic Weeds in South Africa","authors":"J. Coetzee, A. Bownes, G. Martin, B. E. Miller, R. Smith, P. Weyl, M. Hill","doi":"10.4001/003.029.0935","DOIUrl":"https://doi.org/10.4001/003.029.0935","url":null,"abstract":"Biological control (biocontrol) against invasive macrophytes is one of the longest standing programmes in South Africa, initiated in the 1970s against water hyacinth, Pontederia crassipes Mart. (Pontederiaceae). Since then, 15 agent species (13 insects, one mite and one pathogen) have been released against six weeds, most of which are floating macrophytes, with excellent levels of success. The release of the water hyacinth planthopper Megamelus scutellaris Berg (Hemiptera: Delphacidae) in particular, has improved biocontrol prospects for water hyacinth since 2018. In the last decade, however, a new suite of submerged and rooted emergent invasive macrophytes has been targeted. The first release against a submerged macrophyte in South Africa, and the first release against Brazilian waterweed, Egeria densa Planch. (Hydrocharitaceae), anywhere in the world, was achieved with the release of a leafmining fly, Hydrellia egeriae Rodrigues-Júnior, Mathis & Hauser (Diptera: Ephydridae). Yellow flag, Iris pseudacorus L. (Iridaceae) and Mexican waterlily, Nymphaea mexicana Zucc. (Nymphaeaceae), have also been targeted for biocontrol for the first time worldwide, and are in the early stages of agent development. Post-release evaluations, long term monitoring and controlled experiments have highlighted the need for a more holistic approach to managing aquatic invasive plants in South Africa, whose presence is largely driven by eutrophication, resulting in regime shifts between floating and submerged invaded states.","PeriodicalId":7566,"journal":{"name":"African Entomology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46676899","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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