Scholarlink

<p><i>Milicia excelsa</i> (Welw.) C.C.Berg (Moraceae), a Near Threatened West and Central African hardwood of high commercial and ecological value, faces persistent regeneration failure attributable primarily to gall-forming psyllids of the genus <i>Phytolyma</i> Walker (Hemiptera: Psyllidae). Of 312 records identified through a PRISMA-compliant search of five databases, 25 primary studies met inclusion criteria and were synthesised narratively. These covered the biology of <i>Phytolyma fusca</i> Walker (Nigeria) and <i>P. lata</i> (Scott) (Ghana; Côte d’Ivoire). Two taxonomically distinct species treated as functionally comparable on the basis of shared host range, gall biology, and damage profiles; direct cross-species experimental validation of management responses remains limited; older Nigerian literature referred to the Nigerian psyllid as <i>P. lata</i> before taxonomic revision, and data from such studies are attributed to <i>P. fusca</i> accordingly. Nymphal salivary secretions induce sealed leaf galls, with infested seedlings recording stem biomass reductions of up to 68.9% and first-year plantation survival as low as 6.3% in unmanaged monocultures. The sealed-gall biology of the pest strongly limits chemical and biological control: botanical biopesticides achieve high adult mortality in the laboratory (80–100%) but attenuated efficacy in field conditions (50–70%), and indigenous parasitoids yield 4–16% parasitism rates, which are insufficient for population suppression. Physical exclusion by mosquito-net barriers achieved 0% infestation at nursery scale, and mixed-species planting with <i>Terminalia superba</i> reduced gall incidence across nine plantation years. Intraspecific variation in susceptibility, linked to foliar polyphenol oxidase (PPO) activity, provides a biochemical basis for resistance breeding. Based on evidence derived exclusively from Ghana and Nigeria, an integrated strategy combining nursery-scale physical exclusion, mixed-species silviculture, and PPO-anchored resistance breeding represents the most evidence-supported pathway to sustainable <i>M. excelsa</i> production in these regions, though multi-country validation across the broader species range remains a research priority.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Gall-forming psyllids as a constraint to regeneration of Milicia excelsa: a review

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年8月1日

查看全文
  • Ibitoye Oluwatosin,
  • Akinyemi Gabriel,
  • Arabambi Israel,
  • Kolejo Oluwatobi

摘要

Milicia excelsa (Welw.) C.C.Berg (Moraceae), a Near Threatened West and Central African hardwood of high commercial and ecological value, faces persistent regeneration failure attributable primarily to gall-forming psyllids of the genus Phytolyma Walker (Hemiptera: Psyllidae). Of 312 records identified through a PRISMA-compliant search of five databases, 25 primary studies met inclusion criteria and were synthesised narratively. These covered the biology of Phytolyma fusca Walker (Nigeria) and P. lata (Scott) (Ghana; Côte d’Ivoire). Two taxonomically distinct species treated as functionally comparable on the basis of shared host range, gall biology, and damage profiles; direct cross-species experimental validation of management responses remains limited; older Nigerian literature referred to the Nigerian psyllid as P. lata before taxonomic revision, and data from such studies are attributed to P. fusca accordingly. Nymphal salivary secretions induce sealed leaf galls, with infested seedlings recording stem biomass reductions of up to 68.9% and first-year plantation survival as low as 6.3% in unmanaged monocultures. The sealed-gall biology of the pest strongly limits chemical and biological control: botanical biopesticides achieve high adult mortality in the laboratory (80–100%) but attenuated efficacy in field conditions (50–70%), and indigenous parasitoids yield 4–16% parasitism rates, which are insufficient for population suppression. Physical exclusion by mosquito-net barriers achieved 0% infestation at nursery scale, and mixed-species planting with Terminalia superba reduced gall incidence across nine plantation years. Intraspecific variation in susceptibility, linked to foliar polyphenol oxidase (PPO) activity, provides a biochemical basis for resistance breeding. Based on evidence derived exclusively from Ghana and Nigeria, an integrated strategy combining nursery-scale physical exclusion, mixed-species silviculture, and PPO-anchored resistance breeding represents the most evidence-supported pathway to sustainable M. excelsa production in these regions, though multi-country validation across the broader species range remains a research priority.