Egg cannibalism in Ascia monuste in the field; opportunistic, preferential and very frequent

Abstract

Newly hatched caterpillars of the specialist herbivorous species Ascia monuste (Lepidoptera, Pieridae) feed on egg chorion before ingesting plant material. They also ingest their exoskeletons and perform egg cannibalism in both the field and the laboratory. Females lay eggs on plants which already have conspecifics (eggs and/or caterpillars) leading to the observation of cannibalism in the field. Two favorable conditions are required for such an occurrence: (1) eggs laid close together on the same leaf, and (2) the finding by older caterpillars of eggs on the same plant. Oviposition preference experiments in cages showed that females do not avoid laying on plants with eggs. However, they do avoid laying eggs on plants predated by caterpillars. All instars perform cannibalism in the field and, in addition to this, the ingested eggs are healthy and cannibalism occurs in the presence of abundant food. The ingestion of eggs from their own clutch was more intense when the clutch was large. Contact with eggs is also important for cannibalism. Caterpillars ingested healthy eggs during three successive days. According to the results, it is possible to state that egg cannibalism in A. monuste is opportunistic, preferential and highly frequent and that there is a tolerance to a diet based on animal protein in this species. Since A. monuste obtains nutrients from both animal and vegetable resources, it is probably better to consider it as opportunistic omnivorous.

Kin recognition in immatures of Heliconius erato phyllis (Lepidoptera; Nymphalidae)

“…In other words, the objective was to avoid any other food resource than the eggs, in order to give the caterpillars a greater propensity toward cannibalism and consequently preference for kin or nonkin. The occurrence of egg cannibalism in caterpillars of Lepidoptera even in the presence of an adequate plant resource has been found in Helicoverpa zea (Noctuidae) (Joyner and Gould 1985), H. armigera (Sigsgaard et al 2002), and Ascia monuste (Pieridae) (Barros-Bellanda and Zucoloto 2005).…”

Intra-instar larval cannibalism in Anopheles gambiae (s.s.) and Anopheles stephensi (Diptera: Culicidae)

“…At an individual level, cannibalism has been suggested to have several benefits, the most important being nutritional [2, 16]. The additional food gained has been shown to increase development rate, survival and fertility of cannibals in several arthropod species [1, 3, 7].…”

“…The additional food gained has been shown to increase development rate, survival and fertility of cannibals in several arthropod species [1, 3, 7]. In the pierid Ascia monuste cannibal caterpillars showed higher survival rate and weight than noncannibal ones [16]. Likewise, in Drosophila melanogaster larvae, it was shown that an exclusively cannibalistic diet was sufficient for normal development from eggs to fertile adults [17].…”

Effects of sex, host-plant deprivation and presence of conspecific immatures on the cannibalistic behavior of wild Ascia monuste orseis (Godart) (Lepidoptera, Pieridae)

“…A single laying of these females may be as large as 60 eggs, which are usually distributed in many plants in nature (Catta-Preta & Zucoloto 2003). However, females may oviposit on plants which already have conspecifics (eggs and/or caterpillars) (Barros-Bellanda & Zucoloto 2005) leading to the occurrence of egg cannibalism. Egg cannibalism is observed in both field and laboratory and it may also occur in the presence of abundant food (BarrosBellanda & Zucoloto 2005).…”