Morphology of the Ovary and Spermatheca of the Leafcutter Ant Acromyrmex rugosus Queens (Hymenoptera: Formicidae)

Abstract

The leafcutter ant Acromyrmex rugosus Smith (Hymenoptera: Formicidae) is considered a pest of several crops. In this study we investigated the morphology of the ovary and spermatheca of A. rugosus queens. The ovary is meroistic polytrophic with 12 ovarioles per ovary. Each ovariole has a short terminal filament, a germarium, and a long vitellarium with growth follicles. The nurse chamber near the germarium is larger than the egg chamber. The follicular cells surrounding the egg chamber are cuboidal, with a well-developed nucleus, whereas those surrounding the nurse chamber are flattened. The oocyte increases in volume along the ovariole toward the lateral oviduct. Oocytes have multiple accessory nuclei. Mature oocytes have cytoplasm rich in yolk granules. The reservoir epithelium of the spermatheca shows morphological differences, with both columnar and flattened cells. The spermathecal gland has elongated and acinus-like cells.