Tissues Involved in Sex Pheromone Production in Phyllophaga obsoleta (Coleoptera: Scarabaeoidea: Melolonthidae)

Abstract

Females of Phyllophaga obsoleta (Blanchard) (Coleóptera: Scarabaeoidea: Melolonthidae) perform "sexual calling" with their protractile genital chamber (PGC) exposed to release substances that attract males. Histological aspects of the PGC and accessory glands ( AGs) of P. obsoleta females were studied. Studies with light microscope and transmission electron microscope revealed exocrine tissue in the posterior section of the PGC, where it might be producing the attractants. This epithelial gland is formed by a basement membrane, a hypodermis for substance production, secretion, and transport (cells, nucleus, mitochondria, endoplasmic reticulum, Colgi complex, and presence of folds in the plasma membrane), as well as evidence of the substance to be secreted to the outside (connecting cuticular pores to plasma membrane). Histological similarities between AG types I and II were observed, although only the PGC had properties of class I cells. These results suggest that the posterior section of the P. obsoleta PGC is involved in sex pheromone production.

Attraction of Adults of Cyclocephala lunulata and Cyclocephala barrerai (Coleoptera: Scarabaeoidea: Melolonthidae) towards Bacteria Volatiles Isolated from Their Genital Chambers

“…For the monitoring and management of these beetle species, studies have been carried out to take advantage of the substances involved in intraspecific interactions [ 7 , 8 , 9 , 10 ], focusing on volatile organic compounds involved in attracting a partner for copulation, such as sex pheromones [ 11 , 12 ]. Bacteria have been observed in the reproductive system of females of Melolonthidae, specifically in the accessory glands and the genital chamber-structures associated with sex pheromones production [ 10 , 11 , 12 , 13 , 14 ]. Based on this evidence, it has been suggested that bacteria participate in the production of these chemicals, such as in the case of Morganella morganii found in the accessory glands of female individuals of melolonthid Costelytra zealandica beetles.…”

Reproductive Apparatus, Gonadic Maturation, and Allometry of Cyclocephala barrerai Martínez (Coleoptera: Melolonthidae: Dynastinae)

“…The reproductive apparatus of C. barrerai females has the general arrangement of the Melolonthidae [ 8 , 13 , 14 , 29 ]. The bursa copulatrix and the spermatheca connect to the genital chamber, storing and nourishing the sperm inside the female body until oviposition [ 52 ].…”

“…The presence of microorganisms in lab-reared females indicates that these might be transferred by the mother or acquired during the larval period and not transferred by the male during mating. The architecture of the genital chamber and the presence of microorganisms suggest that they are relevant during attractant production [ 14 , 30 ].…”

“…UU) stereoscopic microscope. Several papers [ 8 , 9 , 14 ] were used to identify the reproductive structures. Drawing and image processing were performed with Krita 4.4.2 software (Stichting Krita Foundation, Deventer, The Netherlands).…”

“…The female Melolonthidae reproductive apparatus typically has (A) two compound ovaries with six ovarioles each, (B) a common oviduct, (C) a bursa copulatrix , (D) a spermatheca with a spermathecal gland, (E) a genital chamber, (F) one or two accessory glands, and (G) ventral plaques [ 8 , 13 , 14 ].…”