Survivorship of Immature Stages of Eurypedus nigrosignatus Boheman (Chrysomelidae: Cassidinae: Physonotini) in Central Panama

Abstract

Larvae of the leaf beetle Eurypedus nigrosignatus Boheman carry fécula and cast skins on their dorsa forming a protective device, commonly called a fecal shield. Survival from egg to adult eclosión, natural enemies, and relation to its hostplant, Cordia curassavica (Jacq.) Roem. and Schult. (Boraginaceae) were assessed. Overall survival was 2%; eggs and fourth instars were less susceptible to enemies than were early larval stages and pupae. Prédation accounted for the low survival of larvae, whereas parasitism for a low success rate of pupae. Six different predators including three spiders (Arachnida), a pentatomid, a reduviid (Heteroptera), and an ant (Hymenoptera) were observed. Reared parasitoids included a chalcidid (Hymenoptera) and a tachinid (Diptera). The fecal shield increases in size throughout larval development; however, the shield of prepupal individuals is partially lost. Shield chemical content very closely reassambles that of a particular host plant. Although the lower terpenoid concentration (per weight) in shields decreases with larval development, bigger shields as a unit contain larger amounts. Adults spend the Panamanian dry season buried in the ground directly under host plants. Eurypedus nigrosignatus is under intense selective pressures in Central Panama. ResumenLas larvas del escarabajo Eurypedus nigrosignatus Boheman acumulan heces y mudas sobre su dorso formando un artefacto defensivo lllamado el manto fecal. La sobrevivencia desde la deposición de huevos hasta la eclosión de adultos, los enemigos naturales, y su relation con su planta hospedera Cordia curassavica (Jacq.) Roem. and Schult. (Boraginaceae) fue evaluada. La sobrevivencia total fue de 2%; los huevos y el cuarto estadio fueron menos susceptibles a los enemigos que los estadios larvales más jóvenes y las pupas. La depredación fue el principal factor en la sobrevivencia baja de las larvas, mientras que el parasitismo por el bajo rendimiento de las pupas. Se observaron seis depredadores diferentes incluyendo tres especies de arañas (Arachnida), un pentatomido, un reduvido (Heteroptera) y una especie de hormiga (Hymenoptera). Los parasitoides criados en el laboratorio incluyen un chalcido (Hymenoptera) y un taquínido (Diptera). El manto fecal aumento de tamaño a través del desarrollo larvario; sin embargo, el manto se pierde en los estados prepupales. El contenido químico de los mantos es muy similar al de plantas hospederas particulares. Aunque la concentración (por peso) de terpenoids en los mantos disminuye con el desarrollo larvario, los mantos más grandes como una unidad contienen cantidades más altas. Los adultos pasan la temporada seca panameña enterrados en el suelo alrededor de las raíces su planta hospedera. Eurypedus nigrosignatus está bajo presiones selectivas intensas en Panamá central.Many Cassidinae are free-living on exposed plant parts (Windsor et al. 1992). Due to their preference for apical foliage, their presence tends to be predictable, and their vulnerability to enemies high (Jeffries and Lawton 19...

Importance of biotic predictors in estimation of potential invasive areas: the example of the tortoise beetleEurypedus nigrosignatus, in Hispaniola

“…Based in the field observations in Panama, adults of E. nigrosignatus appear to bury themselves around their host plants during dry season (January–April; Gómez, 2004). Then, over the first three subsequent months of the rain season, ovipositing adults and immature stages become abundant and conspicuous on the host plant.…”

“…Then, over the first three subsequent months of the rain season, ovipositing adults and immature stages become abundant and conspicuous on the host plant. Egg masses of 5–29 eggs are deposited on leaves, with average survival to adult eclosion of only 2% (Gómez, 2004; Świętojańska et al, 2018). Thus, populations of this species are usually low in number of individuals and not conspicuous on field.…”

Faecal case architecture in the gibbosus species group of Neochlamisus Karren, 1972 (Coleoptera: Chrysomelidae: Cryptocephalinae: Chlamisini)

“…Protection from ants is a well‐supported hypothesis for certain taxa (Wallace, 1970; Jolivet & Verma, 2002; Flinte et al ., 2003; Flinte & Macêdo, 2004a; Vencl et al ., 2005), although ants have never been observed to attack Neochlamisus specifically (despite abundant field observation by DJF). Predator deterrence through incorporation of host‐plant chemicals into faeces is highly possible, as there is growing evidence demonstrating this in other Chrysomelidae (Pasteels et al ., 1984; Olmstead & Denno, 1992; Olmstead, 1994, 1996; Gómez, 1997, 2004; Morton & Vencl, 1998; Gómez et al ., 1999; Müller & Hilker, 1999, 2001, 2003, 2004; Nogueira‐de‐Sá & Trigo, 2002).…”

Biology and Phylogeny of the Cassidinae Gyllenhal Sensu Lato (Tortoise and Leaf-Mining Beetles) (Coleoptera: Chrysomelidae)

“…Ecological research has been done on several Aspidimorpha species (Thompson, 1964;Baltazar, 1970;Hawkeswood, 1982;Verma and Shrivatava, 1985), several Cassida species (Kosior, 1975;Steinhausen, 1950;Olmstead and Denno, 1993;Obermaier and Zwö lfer, 1999;Ward and Pienkowski, 1978), two Conchylotenia Spaeth species (Olckers and Hulley, 1989;Heron, 1999), Gratiana spadicea Klug (Becker and Pires Friere, 1996), Octuroplata Uhmann species (Teixeira et al, 1999), Plagiometriona flavescens (Boheman) (Nogueira-de-Sá and Valverde de , Calyptocephala brevicornis (Moura, 1984), and Eurypedus nigrosignatus (Gó mez, 1997(Gó mez, , 2004.…”