Relative contribution of biotic and abiotic factors to population fluctuations of Auchenorrhyncha community that could play a role in the Cape Saint Paul Wilt Disease (CSPWD) (lethal yellowing) pathosystem in Ghana.

As a major setback to the global coconut industry, lethal yellowing disease (LYD), caused by phytoplasmas, continues to threaten coconut palms in the Americas, the Caribbean, Africa, and Oceania. Despite its economic impacts, limited information exists on LYD vectors, which impedes the prevention and management of the disease. Using double-sided yellow sticky traps, we investigate the factors that influence the seasonal abundance and population dynamics of three sap-sucking insects of LYD, i.e., Diostrombus (Hemiptera: Derbidae) sp. and Patara sp. (Hemiptera: Derbidae), and Nedoptepa curta Dmitriev (Hemiptera: Cicadellidae), on five coconut genotypes (Sri Lanka Green Dwarf (SGD), Vanuatu Tall (VTT), SGD × VTT, Malayan Yellow Dwarf (MYD) × VTT, and West African Tall (WAT)) in the Western Region, and one (SGD) in the Central Region of Ghana from April 2019 to May 2021. The results showed that N. curta and Patara sp. were the most abundant species in the Western and Central Regions, respectively. There was a significant difference between the coconut cultivars and sap-sucking insects. The peak population development of the sap-sucking insects was recorded during the dry season on all the coconut genotypes at all sampling locations. A significant positive correlation was detected between temperature and the population of N. curta and Patara sp. In the Agona Nkwanta, VTT had the highest population of N. curta, whereas WAT had the highest population of Patara sp. and Diostrombus sp. These findings provide useful information for assessing the role of factors that could affect the Cape Saint Paul Wilt disease pathosystem.

Tamarixia radiata global distribution to current and future climate using the climate change experiment (CLIMEX) model.

The phloem-limited bacteria, "Candidatus Liberibacter asiaticus" and "Ca. L. americanus", are the causal pathogens responsible for Huanglongbing (HLB). The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the principal vector of these "Ca. Liberibacter" species. Though Tamarixia radiata Waterston (Hymenoptera: Eulophidae) has been useful in biological control programmes against D. citri, information on its global distribution remains vague. Using the Climate Change Experiment (CLIMEX) model, the potential global distribution of T. radiata under the 2050s, 2070s, and 2090s for Special Report on Emissions Scenarios A1B and A2 was defined globally. The results showed that habitat suitability for T. radiata covered Africa, Asia, Europe, Oceania, and the Americas. The model predicted climate suitable areas for T. radiata beyond its presently known native and non-native areas. The new locations predicted to have habitat suitability for T. radiata included parts of Europe and Oceania. Under the different climate change scenarios, the model predicted contraction of high habitat suitability (EI > 30) for T. radiata from the 2050s to the 2090s. Nevertheless, the distribution maps created using the CLIMEX model may be helpful in the search for and release of T. radiata in new regions.

Modeling climate change impacts on potential global distribution of Tamarixia radiata Waterston (Hymenoptera: Eulophidae).

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an efficient vector of "Candidatus Liberibacter" species, the causative agents implicated in citrus greening or huanglongbing (HLB). HLB is the most devastating citrus disease and has killed millions of citrus trees worldwide. Classical biological control using Tamarixia radiata Waterston (Hymenoptera: Eulophidae) against ACP has been successful in some regions. Climatic conditions are critical in determining suitable areas for the geographical distribution of T. radiata. However, paucity of information on climate change impacts on the global spread of T. radiata restricts international efforts to manage ACP with T. radiata. We investigated the potential global distribution of T. radiata using 317 native and non-native occurrence records and 20 environmental data sets (with correlation coefficients (|r| > 0.7)). Using the Maximum Entropy model, these data were analyzed for two shared socioeconomic pathways (SSPs) and two time periods (2030s and 2050s). We showed that habitat suitability for T. radiata occurred in all continents except Antarctica. However, the highly suitable areas for T. radiata were found in parts of the Americas, Asia, Africa and Oceania. The climate suitable areas would increase until the 2050s. The predictions showed that mean temperature of coldest quarter and precipitation of warmest quarter were the most important environmental variables that influenced the distribution of T. radiata. The model reliably predicted habitat suitability for T. radiata, which can be adapted in classical biological control programs to effectively manage ACP in an environmentally friendly manner.

First report on the presence of huanglongbing vectors (Diaphorina citri and Trioza erytreae) in Ghana.

As significant threats to global citrus production, Diaphorina citri (Kuwayama; Hemiptera: Psyllidae) and Trioza erytreae (Del Guercio; Hemiptera: Triozidae) have caused considerable losses to citrus trees globally. Diaphorina citri vectors "Candidatus Liberibacter asiaticus" and "Ca. L. americanus", whereas T. erytreae transmits "Ca. L. africanus" and "Ca. L. asiaticus", the pathogens responsible for citrus greening disease or Huanglongbing (HLB). Though HLB is a destructive disease of citrus wherever it occurs, information on the occurrence and geographical distribution of its vectors in Africa is limited. In recent surveys to determine if HLB vectors are present in Ghana, we observed eggs, nymphs, and adults of insects suspected to be D. citri and T. erytreae. Using morphological traits and DNA analyses, the identity of the suspected insects was confirmed to be D. citri and T. erytreae. Individuals of D. citri and T. erytreae were examined using qPCR for CLaf, CLam, and CLas, but none of them tested positive for any of the Liberibacter species. Herein we report, for the first time, the presence of D. citri and T. erytreae in Ghana (West Africa). We discuss the implications of this new threat to the citrus industry to formulate appropriate management strategies.

Mesh versus suture repair of primary inguinal hernia in Ghana.

Background: Most patients in Ghana undergo suture repair for primary inguinal hernia. Although there is strong evidence from high-income country settings to indicate superiority of mesh repair for inguinal hernia, the evidence to support the safety and effectiveness of mesh repair in the Ghanaian setting is limited. This study aimed to compare hernia recurrence rates following suture versus mesh repair in Ghana. Methods: Men aged 18 years or over presenting with symptomatic, reducible inguinal hernias were included. Over the first 6 months all consecutive patients were enrolled prospectively and underwent a standardized suture repair; an equal number of patients were subsequently enrolled to undergo mesh repair. The primary outcome was hernia recurrence within 3 years of the index operation. Multivariable analysis was adjusted for age and right or left side. Adjusted odds ratios (ORs) with 95 per cent confidence intervals are reported. Results: A total of 116 sutured and 116 mesh inguinal hernia repairs were performed. Three years after surgery, follow-up data were available for 206 of the 232 patients (88·8 per cent). Recurrence occurred significantly more frequently in the suture repair group (23 of 103, 22·3 per cent) than in the mesh group (7 of 103, 6·8 per cent) (P = 0·002). In multivariable analysis, suture repair was independently associated with an increased risk of recurrence (OR 4·51, 95 per cent c.i. 1·76 to 11·52; P = 0·002). Conclusion: In Ghana, mesh inguinal hernia repair was associated with reduced 3-year recurrence compared with sutured repair. Controlled dissemination across Ghana should now be assessed.

Size and shape analysis of Trioza erytreae Del Guercio (Hemiptera: Triozidae), vector of citrus huanglongbing disease.

BACKGROUND: The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae) is one of the most devastating pests of citrus with a well-known role as a vector of the phloem-limited bacteria (Candidatus Liberibacter africanus) associated with huanglongbing (citrus greening disease), currently considered the world's most serious disease of citrus. Although the pest can successfully develop and reproduce on non-citrus host plants, there is no documented information on the geometric morphometry of ACT. We determine the effect of host plants on ACT morphometry under controlled laboratory conditions using traditional and geometric analysis. RESULTS: ACT reared on C. limon and Citroncirus spp. was significantly larger than when reared on the other host plant species. ACT reared on C. anisata and C. tangelo was consistently smaller than that reared on M. koenigii and C. sinensis. Based on warped outline drawings, ACT reared on Citroncirus spp. and Murraya koenigii had narrower wings than when reared on C. anisata, C. limon, and C. sinensis with slightly broader wing patterns. CONCLUSION: This study clearly demonstrates that host plant species affect morphometric variation in ACT, which might have a direct impact on fitness parameters of the pest as well as its potential for dispersion. Wing shape and size appear to be useful in separating populations of ACT into different groups. © 2018 Society of Chemical Industry.