Variation in Host Plant Usage and Diet Breadth Predict Sibling Preference and Performance in the Neotropical Tortoise Beetle Chelymorpha alternans (Coleoptera: Chrysomelidae: Cassidinae).

Specialized interactions between insects and the plants that they consume are one of the most ubiquitous and consequential ecological associations on the plant. Decades of investigation suggest that a narrow diet favors an individual phytophagous insect's performance relative to a dietary generalist. However, this body of research has tended to approach questions of diet breadth and host usage from the perspective of temperate plant-insect associations.

Structural and physical evidence for an endocuticular gold reflector in the tortoise beetle, Charidotella ambita.

Charidotella ambita offers a unique opportunity for unambiguously locating its gold reflector by comparing the structure of reflecting and non-reflecting cuticle of the elytron and pronotum. Using light microscopy and TEM, the reflector was located underneath the macrofiber endocuticle just above the epidermis. The reflector is a multilayer comprising up to 50 bilayers alternating high and low density layers parallel to the surface of the cuticle.

Cuticular extracts from Acromis sparsa (Coleoptera: Cassidinae) mediate arrestment behavior of the commensal canestriniid mite Grandiella rugosita.

Astigmatid mites in the family Canestriniidae are often closely associated with tortoise leaf beetles (Chrysomelidae: Cassidinae). For example, the survival of the commensal canestriniid mite Grandiella rugosita depends on dispersal to the cassidine beetle Acromis sparsa. Here, we tested whether the beetle cuticle provides chemical cues for host recognition for G.

Insect leaf-chewing damage tracks herbivore richness in modern and ancient forests.

The fossil record demonstrates that past climate changes and extinctions significantly affected the diversity of insect leaf-feeding damage, implying that the richness of damage types reflects that of the unsampled damage makers, and that the two are correlated through time. However, this relationship has not been quantified for living leaf-chewing insects, whose richness and mouthpart convergence have obscured their value for understanding past and present herbivore diversity. We hypothesized that the correlation of leaf-chewing damage types (DTs) and damage maker richness is directly observable in living forests.

Subsocial Neotropical Doryphorini (Chrysomelidae, Chrysomelinae): new observations on behavior, host plants and systematics.

A summary of literature, documented observations and field studies finds evidence that mothers actively defend offspring in at least eight species and three genera of Neotropical Chrysomelinae associated with two host plant families. Reports on three Doryphora species reveal that all are oviparous and feed on vines in the Apocyanaceae. Mothers in the two subsocial species defend eggs and larvae by straddling, blocking access at the petiole and greeting potential predators with leaf-shaking and jerky advances.

Two genera of Aulacoscelinae beetles reflexively bleed azoxyglycosides found in their host cycads.

Aulacoscelinae beetles have an ancient relationship with cycads (Cycadophyta: Zamiaceae), which contain highly toxic azoxyglycoside (AZG) compounds. How these "primitive" leaf beetles deal with such host-derived compounds remains largely unknown. Collections were made of adult Aulacoscelis appendiculata from Zamia cf.

Reverse color sequence in the diffraction of white light by the wing of the male butterfly Pierella luna (Nymphalidae: Satyrinae).

The butterfly Pierella luna (Nymphalidae) shows an intriguing rainbow iridescence effect: the forewings of the male, when illuminated along the axis from the body to the wing tip, decompose a white light beam as a diffraction grating would do. Violet light, however, emerges along a grazing angle, near the wing surface, while the other colors, from blue to red, exit respectively at angles progressively closer to the direction perpendicular to the wing plane. This sequence is the reverse of the usual decomposition of light by a grating with a periodicity parallel to the wing surface.

Switchable reflector in the Panamanian tortoise beetle Charidotella egregia (Chrysomelidae: Cassidinae).

The tortoise beetle Charidotella egregia is able to modify the structural color of its cuticle reversibly, when disturbed by stressful external events. After field observations, measurements of the optical properties in the two main stable color states and scanning electron microscope and transmission electron microscope investigations, a physical mechanism is proposed to explain the color switching of this insect. It is shown that the gold coloration displayed by animals at rest arises from a chirped multilayer reflector maintained in a perfect coherent state by the presence of humidity in the porous patches within each layer, while the red color displayed by disturbed animals results from the destruction of this reflector by the expulsion of the liquid from the porous patches, turning the multilayer into a translucent slab that leaves an unobstructed view of the deeper-lying, pigmented red substrate.

Dietary specialization influences the efficacy of larval tortoise beetle shield defenses.

Plant chemical defenses and escape from natural enemies have been postulated to select for dietary specialization in herbivorous insects. In field and laboratory bioassays, we evaluated the effectiveness of intact and chemically modified larval shield defenses of the generalist Chelymorpha alternans and the specialists Acromis sparsa and Stolas plagiata (Chrysomelidae: Cassidinae) against three natural predators, using larvae reared on two morning glory (Convolvulaceae) species. We assessed whether: (1) specialists were better defended than generalists when both were fed and assayed on the same plant; (2) larval shield defenses were chemical, physical, or both; and (3) specialists exploit chemistry better than generalists.

The distribution of Wolbachia in fig wasps: correlations with host phylogeny, ecology and population structure.

We surveyed for the presence and identity of Wolbachia in 44 species of chalcid wasps associated with 18 species of Panamanian figs. We used existing detailed knowledge of the population structures of the host wasps, as well as the ecological and evolutionary relationships among them, to explore the relevance of each of these factors to Wolbachia prevalence and mode of transmission. Fifty-nine per cent of these wasp species have Wolbachia infections, the highest proportion reported for any group of insects.

Dual chemical sequestration: a key mechanism in transitions among ecological specialization.

Platyphora leaf beetles form a vast group of tropical species each feeding on a restricted set of host plants and exhibiting bright coloration warning predators against their chemical protection. These beetles offer an exceptional opportunity for understanding the evolution of phytochemical sequestration. Indeed, qualitative studies of defensive secretions indicate that Platyphora species acquire toxicity via sequestration of plant secondary metabolites.