How plants and honeydew-producing hemipterans affect ant species richness and structure in a tropical forest zone

Abstract

Extrafloral nectaries (EFNs) and hemipteran honeydew are often discussed as two alternative mechanisms encouraging ant visitation in mutualistic ant-plant relationships, but little is known about the processes that generate distribution pattern in species-rich insect communities. A case study on the interaction between ants, EFNbearing plants and hemipterans was investigated along a gradient of increasing disturbance from regenerated forest to mixed crop field. Ants, EFN-bearing plants and hemipterans sampling was conducted in these vegetations during the wet and the dry seasons in five locations. Results showed that partitioning of ant species between season and vegetation was significantly different from random. High specialization index was observed in hemipterans/plants and ant/hemipterans interactions. Low specialization index was observed between ants and EFN-bearing plants mainly in the mixed crop field. Ant species were mostly found in non-aggressive co-occurrence at nectar sources. At the species level, specialization index was high for Anoplolepis tenella (0.86 ± 0.06) and also for its associated hemipterans Stictococcus vayssierei (0.97 ± 0.02). This association is detrimental to food crop especially cassava. These results outline the effect of vegetation and food source on the structure of the ant assemblage and interaction in tropical forest zone.

Geographic distribution and abundance of the Afrotropical subterranean scale insectStictococcus vayssierei(Hemiptera: Stictococcidae), a pest of root and tuber crops in the Congo basin

“…Interestingly, the pest's most frequent ant trophobiont, A. tenella , was absent from this zone back in the 1990s (Dejean and Matile-Ferrero, 1996). There was strong association in the occurrence of the scale and the ant across the fields, as earlier reported (Dejean and Matile-Ferrero, 1996; Fotso et al ., 2015 c ), indicating a likely similar geographic distribution of these trophobionts. However, a negative association between A. tenella and other ants such as Myrmicaria opaciventris (Fotso, 2011) could constitute a limiting factor to their distribution.…”

“…With 3000–10,000 mm annual rainfall recorded in the coastal regions, high precipitation and soil moisture could constitute limiting factors to the long-term establishment of the scale or its attendant ants. Ant attendance is apparently vital for ARTS survival (Hanna et al ., 2015; Fotso et al ., 2015 c ). However, ARTS' occurrence on Mount Cameroon at mid-altitude in the coastal region is a puzzling counterexample.…”

Alien and native tree species having extrafloral nectaries as favorite hunting area for arboreal endemic Philippine tiger beetles (Coleoptera: Cicindelidae) in human‐disturbed habitat in Lanao del Sur Province, Mindanao, Philippines

“…Presence of extrafloral nectaries on mentioned above plants was not studied by us in details, but high number of insects, especially different ant species, was noted on all these trees checked in all study sites. Although we are not able to confirm whether these insects were using extrafloral nectaries of Spathodea campanulata , Hibiscus tiliaceus , Acacia mangium , Erythrina fusca , and/or Mangifera indica as food source, numerous examples from different regions of the world clearly show that high diversity and abundance of Formicidae on plant species having such structures is a typical phenomenon (e.g., Aguirre‐Jaimes et al., 2018; Fonseca‐Romero et al., 2019; Fotso et al., 2015; Giuliani et al., 2019; Sanz‐Veiga et al., 2017). As it was noted in the literature, ants collect food from extrafloral nectaries and at the same time they can protect the plant against herbivorous insects (Lin et al., 2018), so both partners of such mutualistic relationship have benefits.…”