Bionomic data usually hold the key for understanding the life history of the target insect species. Here, we provide morphological characteristics of different larval instars of Acanthoscelides macrophthalmus (Schaeffer), a leucaena bruchine beetle species that is a potential biocontrol agent for the notoriously invasive plant Leucaena leucocephala. The scanning electron micrographs of the head capsule, antenna, clypeolabrum, maxilla, labium, leg, spiracle, and anus of the larval stage of A. macrophthalmus also are provided for the first time for this species, with most of the traits reflecting the taxonomic placement of A. macrophthalmus in the genus Acanthoscelides. Successive instars are determined accurately by using a model of the distribution of the width of the larval head capsule. Therefore, the data generated from this study represent baseline information for further biological control programs involving A. macrophthalmus.

While Wolbachia, an intracellular bacterial symbiont, is primarily transmitted maternally in arthropods, horizontal transmission between species has been commonly documented. We examined kleptoparasitism as a potential mechanism for Wolbachia horizontal transmission, using ant crickets and their host ants as the model system. We compared prevalence and diversity of Wolbachia across multiple ant cricket species with different degrees of host specificity/integration level. Our analyses revealed at least three cases of inter-ordinal Wolbachia transfer among ant and ant crickets, and also showed that ant cricket species with high host-integration and host-specificity tend to harbor a higher Wolbachia prevalence and diversity than other types of ant crickets. This study provides empirical evidence that distribution of Wolbachia across ant crickets is largely attributable to horizontal transmission, but also elucidates the role of intimate ecological association in successful Wolbachia horizontal transmission.