The Effect of the Fruit Sepals on the Citrus Mealybug Population and on Its Parasite

Abstract

Grapefruit sepals were shown to provide a suitable site for feeding mealybugs, and good protection against its parasites. In this way the fruit sepals determine the size of the mealybug population. RÉSUMÉ EFFET DES SÉPALES DES FRUITS SUR LA POPULATION DE PLANOCOCCUS CITRI ET SUR SON PARASITE Les résultats montrent que les pamplemousses étaient plus infestés par P. citri que les oranges, les citrons et les citranges Troyer. Le remplacement des sépales de ces derniers par une structure artificielle unifiée a eu pour résultat une infestation uniforme des quatre espèces de fruits. D'autre part, l'enlèvement des sépales des pamplemousses a entraîné une diminution considérable de la population de P. citri et un niveau de parasitisme beaucoup plus élevé par rapport aux fruits intacts. On en a conclu que les sépales des pamplemousses offrent à P. citri un site convenable et une bonne protection contre ses parasites. C'est ainsi que les sépales des fruits déterminent la taille de la population de P. citri.

Novel Approaches for the Management of Mealybug Pests

“…Many of the species tend to establish themselves in protected sites, such as cracks and crevices in bark, leaf axils, root crowns, nodes of grass stems, under fruit sepals and within fruit navels, between touching fruits or fruits and leafs, and in tunnels bored by insect larvae in roots and stems (Franco et al 2000;Kosztarab and Kozár 1988). This cryptic behavior of mealybugs may originate a spatial refuge from natural enemies and harsh environmental conditions (Berlinger and Golberg 1978;Gutierrez et al 2008a). This type of plant colonization makes mealybugs practically invisible during the latent population phase.…”

INFLUENCE OF TEMPERATURE AND RELATIVE HUMIDITY ON SURVIVAL AND FECUNDITY OF PAURIDIA PEREGRIN A, A PARASITE OF MEALYBUGS AND ITS INTERACTIONS WITH PLANOCOCCUS CITRI

“…Groups of 12--20 grapefruits were infested as described by Berlinger & Gol'berg (1978), cut and put in plastic boxes with "honey paper". Groups of 12--20 grapefruits were infested as described by Berlinger & Gol'berg (1978), cut and put in plastic boxes with "honey paper".…”

“…Then the sepals were removed from the fruit and the mealybug population from under the sepals was examined as described previously (Berlinger & Gol'berg, 1978). The opening between the sepals and the skin of the fruit was measured to + 0.05 mm by means of wires with diameters ranging from 0.1 to 1.3 mm.…”

How a slow-ovipositing parasitoid can succeed as a biological control agent of the invasive mealybug Phenacoccus peruvianus: implications for future classical and conservation biological control programs

“…Several species seek refuge in vine bark crevices, sugarcane leaf sheaths or citrus sepals to escape parasitism and predation (Bartlett 1978;Berlinger and Golberg 1978;Daane et al 2006;Moore 1988). The role of the mealybugs' waxy cover in their interactions with natural enemies is not yet clear.…”