Phenological phases of the host plant shape plant–treehopper interaction networks

Abstract

Several studies have recently focused on the structural pattern of plant–insect interaction networks. However, insects and plants have dynamic cycles and differ in their level of specialisation over time, space, and scales. Thus, it is expected that sap‐sucking insects, such as treehoppers, and plants will not share similar patterns of interactions in all phenological stages of the plants. It was postulated that phenological stages of the host plant could change the structure of plant–treehopper networks, which will be more specialised during the reproductive stage than during the vegetative stage, mainly because of high concentrations of toxic compounds in the flowers. Here, quantitative metrics derived from graph theory were used to describe, for the first time, the changes in the structure of plant–treehopper interactions during the phenological stages of the host plants in Brazilian Atlantic Forest. The results revealed high temporal turnover of plant–treehopper interactions, and high similarity in the treehopper composition between the phenological stages. In both phenological stages, plant–treehopper networks exhibited a modular and non‐nested pattern. However, during the reproductive stage, the results showed lower species richness of plants and treehoppers, and higher levels of network specialisation compared with the vegetative phase. These findings demonstrate that the organisation of the same ecological interaction can change throughout plant phenology. In short, it was shown that the phenological phases of the host plants can constitute a remarkable mechanism that shapes plant–treehopper interaction networks in a tropical rainforest.

Pest categorisation of non‐EU Cicadomorpha vectors of Xylella spp.

“…Adults eventually return to the original host plant species for oviposition. This also applies to the vectors in the two additional Cicadomorpha families (Novotny, ; Gadelha et al., ). This behaviour may explain why some cicadellids which are proven natural vectors of PD in California are rarely found feeding on grapes and they are most common in riparian habitats adjacent to vineyards (Redak et al., ).…”

“…Membracidae includes about 3,500 spp., (2-20 mm long, mostly under 12 mm long) and they are extremely diverse in tropical America, where they occur in rainforests, savannas and deserts. They typically feed in apical meristems and inflorescences of herbaceous and shrubby plants (Gadelha et al, 2017). Adults have cuticular expansions on the pronotum that often extend over the abdomen giving them the appearance of spines, horns, and other elaborate shapes (e.g.…”

Protocol for Membracidae inventory (Hemiptera, Auchenorrhyncha, Membracoidea): what are the ideal collection methods for the Atlantic Forest?

“…In addition, we highlight the fact that membracids were listed as good biological indicators of environmental changes, with broad possibilities of being employed in monitoring studies (Brown 1997). Recently, studies conducted in phytogeographical zones of rainforest (southern Brazil) on ecological networks involving these insects, their attendant ants (mutualistic interactions) and host plants (antagonistic interaction), were developed to better understand the role of these insects in the ecosystems (Gadelha et al 2016, Gadelha et al 2017.…”

Interacciones dentro del ensamble de parasitoides y depredadores de áfidos y su efecto sobre el control biológico en el cultivo de berenjena

“…La diversidad estructural, está determinada por las diferentes condiciones requeridas por los insectos para establecerse y persistir en los sistemas agrícolas, lo que representa su nicho fundamental (Hutchinson 1958). Los cultivos agrícolas ofrecen diferentes hábitats y recursos a lo largo del todo su ciclo, que incluye diferentes estados fenológicos, por lo que las comunidades pueden variar temporalmente en su estructura a través de los mismos (Atakan & Bayram 2011, Rocca & Greco 2011, Gadelha et al 2017. Además de esta variación temporal, la estructura de las plantas determina la efectividad de los enemigos naturales en la búsqueda y captura de presas (Dixon & Russell 1972, Evans 1976, Carter et al 1984.…”

“…influyen en el comportamiento de búsqueda de los depredadores (Lauenstein 1980, Kajita 1986, Kareiva & Sahakian 1990. Por otra parte, la estratificación vertical en las plantas suele afectar la distribución de los herbívoros y sus enemigos naturales, (Denno & Roderick 1991, Frank et al 2007) ya que la calidad de las hojas como recurso, así como la presencia de flores y frutos, varían entre estratos (Jandricic et al 2014, Gadelha et al 2017. En el caso particular del cultivo de berenjena, al tratarse de una planta arbustiva con tallo semileñoso, los estratos verticales pueden ofrecer distintos recursos para la reproducción, alimentación, y/o refugio de los insectos y generar variación espacial de la comunidad.…”