Feeding behavior and spatial distribution of two planthoppers,Megamelusscutellaris(Delphacidae) andTaosalongula(Dictyopharidae), on water hyacinth

Abstract

Megamelus scutellaris Berg (Delphacidae) and Taosa (Cuernavaca) longula Remes Lenicov (Dictyopharidae) are specialist planthoppers that feed and reproduce on the invasive aquatic weed, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae). They overlap geographically in several regions of South America and may, therefore, interact and compete for food and microhabitat. Preliminary observations indicated that both species do not feed on the same part of the plant. We hypothesized that they partition the resource; hence, we studied (1) the feeding mechanism at the tissue level and (2) the spatial distribution of both species on the water hyacinth plant. Salivary sheaths were detected through histological sections of plant tissues using light microscopy. The location of either planthopper species on the plant was recorded when in the presence or absence of the other species. Both species produced true salivary sheaths, mostly branched (M. scutellaris: 82%; T. longula: 84%), ending in phloem (M. scutellaris: 56%; T. longula: 52%), and xylem tissues (M. scutellaris: 24%; T. longula: 28%). They resided on different parts of the water hyacinth plant even when they did not coexist; nymphs of T. longula occurred primarily on the back side of the leaf laminas, while nymphs of M. scutellaris occupied the basal zone of the petioles. This study shows that these planthoppers complement each other and could be used in combination as control agents for water hyacinth. Further experimental studies and field observations are necessary to quantify interactions.

Microhabitat partitioning in seagrass mesograzers is driven by consistent species choices across multiple predator and competitor contexts

“…This type of organization is consistent with findings from several other types of arthropod communities in both terrestrial and aquatic systems. Tropical beetles, for example, are separated into discrete assemblages between different microhabitats (field surveys: Bhargav et al , Wardhaugh et al ), as are plant hoppers and spittlebugs that occupy different parts of shared host plants (Mcevoy , Hernàndez et al ). Field surveys have also found evidence for size‐mediated microhabitat partitioning in marine amphipods (Korpinen and Westerbom ).…”

“…However, this strategy requires that alternative microhabitats are available and not already occupied by additional species. In seagrass beds, where an abundant and much more diverse assemblage of beetles, for example, are separated into discrete assemblages between different microhabitats (field surveys: Bhargav et al 2009, Wardhaugh et al 2012, as are plant hoppers and spittlebugs that occupy different parts of shared host plants (Mcevoy 1986, Hernàndez et al 2011. Field surveys have also found evidence for size-mediated microhabitat partitioning in marine amphipods (Korpinen and Westerbom 2010).…”

“…As overlap in microhabitat use increases the likelihood of competition between epifauna (Schoener 1983), distinct differences in microhabitat use could be an important way for mesograzer species to coexist. Previous work on arthropod epifauna from terrestrial (Mcevoy 1986, Hernàndez et al 2011, Wardhaugh et al 2012) and aquatic systems (van Riel et al 2007, Korpinen and Westerbom 2010, Cothran et al 2013 shows that the partitioning of microhabitat use can reduce competition. If that competition for space among seagrass mesograzers has fitness consequences, having distinct microhabitat preferences could reduce costs and promote coexistence.…”

Descriptions of Immatures of the South American Plant Hopper,Taosa(C.)longula

“…E. crassipes is under study as a candidate for water hyacinth biocontrol (Hernández et al 2011a, b). The adults are characterized by the uniform green coloration with a pair of lateral small dark spots on the mesonotum, vertex subquadrate with a closed triangular facet well defined on apex, and a long anal segment.…”

“…In feeding tests on another species of Pontederiaceae, Pontederia cordata L., T. longula survived to fourth instar and were only able to develop to adults on water hyacinth. Nymphs and adults are sap feeders, mainly phloem feeders, producing true salivary sheaths (Hernández et al 2011a, b; Cabrera et al unpublished). The current study provides a description of the immature stages of T .…”