Genital Chamber Research Articles

The timings of vitellogenesis and choriogenesis in the Henosepilachna vigintioctopunctata oocytes

In order to provide a biological basis for the development of population management strategies, a critical need is to better understand the reproduction of agricultural pests. In the current paper, we timed the previtellogenesis, vitellogenesis and choriogenesis processes in Henosepilachna vigintioctopunctata (Fabricius), (Coleoptera, Coccinellidae), a serious polyphagous defoliator damaging a wide range of crops in Solanaceae and Cucurbitaceae. The female reproductive system was comprised of two ovaries, two lateral oviducts, a median oviduct, a spermathecal sac and a genital chamber. Each ovary had an average of 28 (±0.4) telotrophic meroistic ovarioles. In the ovarioles of 4-day-old females, only previtellogenesis process was observed. The vitellogenesis occurred at 5 to 7 days after female emergence, while the choriogenesis took place at 8 and 9 days post eclosion. Copulation and oviposition occurred before and at 8 days post emergence. In order to confirm the observation, HvVgR and HvVg were identified and their expression was examined. HvVgR was abundantly transcribed in the ovary, whereas HvVg was richly expressed in the fat body. The temporal expression profiles showed that the high levels of HvVgR and HvVg were accompanied with the active accumulation of yolk proteins and the occurrence of intercellular spaces among follicle cells. Moreover, only one oocyte was observed per ovariole in active vitellogenesis. The observation demonstrates that oocytes are continuously matured and the oviposition persists in females from 8 days to at least 13 days post eclosion.

Mating- and oviposition-dependent changes of the spermatheca and colleterial glands in the pest termite Cryptotermes brevis (Blattaria, Isoptera, Kalotermitidae).

The spermatheca and colleterial glands of female insects are organs associated with the reproductive system, responsible for sperm storage and secretion of egg coverings, respectively. Here we compared the development, secretory activity, and chemical nature of the secretion in the spermatheca and colleterial glands of different-aged females of the drywood termite Cryptotermes brevis. We also provide the ultrastructure of these organs in alate females. These structures have been poorly investigated in termites when compared to other eusocial insects (Hymenoptera) and termite-related dictyopterans (mantises and cockroaches). The spermatheca of C. brevis comprises a cone-shaped structure, connected to the genital chamber by a short duct. The colleterial glands, in turn, are divided into anterior and posterior tubules, each showing a basal trunk, and join into a common duct. Histological and histochemical analyses showed that the secretion of proteins and polysaccharides by the spermatheca takes place before pairing, but increases as females mate and store sperm. Colleterial glands of alates showed non-synchronous secretory activity, but the synthesis of products increased in egg-laying queens, together with the epithelium height. Ultrastructure of the spermatheca and colleterial glands revealed epithelia composed of class III secretory cells. Richness of mitochondria and electron-dense secretion in the spermatheca indicates synthesis and transport of content. Presence and absence of colleterial gland secretion in different individuals may reflect variable maturation stages of the females and secretory cells. Assuming that termites are iteroparous, the development and secretion of the spermatheca and colleterial glands play a crucial role for C. brevis queens.

First description of the male genitalia in a short-tailed whipscorpion (Arachnida: Schizomida), description of the female, and comments on pygidial glands and cuticular ultrastructure of Surazomus algodoal Ruiz & Valente, 2017.

The male genitalia of Surazomus algodoal Ruiz & Valente, 2017 are described. Since this is the first attempt to describe male genitalia in the schizomids, we propose new terminology to describe the sclerites of the male genital chamber in the order. We believe that the male genitalia may provide a large set of characters for taxonomic research in schizomids, as the female genitalia have proven to do. The setae and other cuticular structures were investigated using light and scanning electron microscopy (SEM). The female of S. algodoal is described for the first time, including the genitalia, and we highlight the sexual dimorphism present in the species. We also present descriptions of: 1) microtrichia, with respect to their presence/length/distribution, 2) cuticular sensilla, glandular openings and other cuticular structures, proposing new terminology, 3) setae of the pedipalpal trochanter and tarsus. Some changes on the terminology of setae of pedipalpal tibia are also given. These advances may be useful for description in other schizomids. The pygidial glands, mostly ignored in modern papers, were assessed and commented upon.

Are males just passive? Coupling mechanism of the Brazilian cave insects with inverted genitalia.

Species of the Brazilian cave barklouse genus Neotrogla (Psocodea: "Psocoptera": Trogiomorpha: Prionoglarididae: Sensitibillini) are known to have a "female penis (gynosome)" that functions as an intromittent organ inserted into the membranous pouches in the simple male genital chamber during copulation to receive semen. However, the functions of other male and female genital structures and the copulatory processes of Neotrogla were completely unknown to date. Based on µCT observation of the male and female postabdomen and connected muscles both before and in copula, we clarified the functions of the male and female genital structures. In addition, based on the analyses of the established 3D models, we concluded that precise and rigid contact of multiple genital structures, and step-by-step releases of each holding mechanism achieved by the cooperation of both sexes are involved in the copulatory processes. The coevolution between the male and female genital structures in Neotrogla may provide a new example for the evolution of tolerance traits.

Functional Morphology and Development of the Colleterial Glands in Non- and Egg-Laying Females of the Pest Termite Coptotermes gestroi (Blattaria, Isoptera, Rhinotermitidae).

Colleterial glands of female insects are accessory glands responsible for producing secretions associated with egg-laying. Within Dictyoptera, they synthesize compounds of the ootheca. However, their morphology and role in termites are poorly understood. Here, we compared the morphology, development, and secretory activity of the colleterial glands between non- and egg-laying females of the pest termite Coptotermes gestroi under light and transmission electron microscopy. We also provide the first description of these glands for Rhinotermitidae. The glands are paired, divided into anterior and posterior units, which join in a common duct via basal trunks. They are highly developed within egg-laying females, especially the posterior gland, secreting glycoproteins to lubricate the genital chamber and/or stick the eggs together. Ultrastructure revealed glandular epithelia composed of bicellular units of Class 3, whose secretory activity varied between groups and units. Posterior gland of egg-laying females showed richness of mitochondria, rough endoplasmic reticulum, and secretory vesicles, including electron-dense secretory granules, indicating synthesis and transport of contents, especially proteins. The basal trunks were enfolded by muscles, supporting their role in conducting secretion. Morphophysiological modifications occur in the colleterial glands as females mature and lay eggs, and the mechanisms underlying the secretory cycle of the glands are discussed.

Morphology of the Female Reproductive System in Carpocoris mediterraneus Tamanini, 1958 (Heteroptera: Pentatomidae)

Carpocoris mediterraneus is a polyphagous vegetarian. Adult females of C. mediterraneus were collected in Aksu, Antalya, in June 2018. In this study, the morphological structures of female reproductive system of C. mediterraneus, which has not been studied before, was investigated under light and electron microscopies. The female reproductive system of C. mediterraneus was composed of a pair of ovaries, lateral oviducts, a common oviduct, accessory gland and spermatheca. Each ovary consisted of six telotrophic meroistic type ovarioles. Each ovariole consisted a terminal filament, germarium, vitellarium, and pedicel. In the germarium region, there was a trophic core, trophocytes, young oocytes and prefollicular cells. Vitellarium contained three oocytes at various stages of maturity (previtelogenesis, vitellogenesis, choriogenesis). The ovarioles were connected via pedicels to a pair of short lateral oviducts and subsequently to a common oviduct. The spermatheca of C. mediterraneus consisted a spermathecal bulb, a pumping region, the distal duct, dilation region, proximal duct and genital chamber. The spermathecal bulb was oval in shape and strongly chitinized. Its lumen typically contains a large number of spermatozoa.

Polishing Michael’s Shoe: The structure and variability in the genital chamber of Uropodina

Primary and secondary sexual characters of Mesostigmata are often used in species descriptions and phylogenetic analyses. The use of these characters has been focused almost exclusively on external structures such as the male chelicera and genital plates, while internal structures have only been utilized for lightly sclerotized species.

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

Simple SummaryCyclocephala barrerai larvae feed on the roots of ornamental and commercial grasses. Most of their biology is still unknown, and there are no tools to manage their populations. The objective of this work was to study the reproductive system, gonadic maturation, and allometry of C. barrerai. This is the first report into the Melolonthidae family that characterizes the reproductive apparatus, gonadic maturation of both sexes, and allometric relationships of virgin F1 specimens. Adults do not feed, so gonadic maturation depends on larvae reserves. Females present sclerotized accessory glands and a genital chamber with muscular fibers and bacteria. The morphology of the parameres and the antennae are under sexual selection. This is the first report of two main differences among sexes: females are heavier while males have longer antennae. Males and females exhibit allometric relationships that can be used to predict the bodyweight of field-collected specimens.The Order Coleoptera provides good examples of morphological specializations in the reproductive apparatus, gonadic maturation, and allometry differing between the sexes. The female and male reproductive apparatus has been modified to ensure reproduction between individuals of the same species. The genus Cyclocephala has more than 500 species distributed in America, and Cyclocephala barrerai Martínez is an economically important species in the central part of Mexico. The objective of this work was to study the reproductive system, gonadic maturation, and allometry of C. barrerai. We used light, scanning electron, and laser scanning confocal microscopy to describe the reproductive apparatus and gonadic maturation of females and males. The relationship between adult weight and different parts of the body was established by linear regression. Regardless, the reproductive apparatuses of C. barrerai are like those of other Melolonthidae: the genital chamber, the type II accessory glands, and the ventral plaques of the female and the ejaculator bulb and genital capsule of the males are specific to C. barrerai. The gonads are fully developed when 18 d old. The weight of adult C. barrerai has a positive linear relationship with distinct parts of its body, while the antennae of males are larger than those of the females.

Stenozygum coloratum (Klug, 1845) (Heteroptera: Pentatomidae)’un Spermateka ve Yumurta Morfolojisi

The spermathecae and egg morphology of Stenozygum coloratum (Klug, 1845) were examined with light and scanning electron microscopy, and their external morphology was characterized in detail (egg chorion surface, operculum, and aero-micropylar processes, and spermatheca morphology). Eggs barrel-shaped; operculum round and the hatching line can be easily distinguished in the scanning electron photograph. The egg batches usually consist of 12 eggs. Because of the thick egg chorion, embrionic development was not visible from the outside. The eggs of S. coloratum are usually laid in two rows and are glued to the Capparis spinosa (Capparacea) plants. The egg burster is highly sclerotized, thick and T shaped. It is clearly observed in the hatched egg. Egg-burster is remains attached with the inside lateral surface of the egg. The well-marked operculum intersects the ring of 18–20 short pipe shaped micropylar projections that are found between the tubercles around the hatching line. In S. coloratum, the spermathecae has a semi-oblong spermathecal bulb. The spermathecal duct, pumping region, dilation of spermathecal duct and distal and proximal ducts. The pumping region has distal and proximal flanges. The balloon-like median spermathecal dilation has sclerotized rod and is narrowed distally and tipped. The proximal area of the spermathecal duct is close to the vagina opening. Two V-shaped sclerites and two ring sclerites are localized on the genital chamber (vagina) wall in to which opens the spermathecae. Egg and spermathecae structures in insects differ from species to species. In this study, spermathecae and egg structures of this species, which have not been studied before, were examined in detail, and it was aimed to contribute to systematic and taxonomic studies.

The spermatophore of the black field cricket, Teleogryllus commodus (Walker, 1869) (Orthoptera: Gryllidae) – a stereoscopic investigation

The contribution includes the detailed investigation of the spermatophore produced by the male black field cricket with the help of stereoscopic visualization techniques. For this purpose, sperm capsules of selected crickets were isolated and prepared for light- and electronmicroscopic analysis. Production of stereoscopic semi-images and red-cyan anaglyphs was carried out by application of the formerly introduced object rotation method and, alternatively, by use of computer-aided object depth mapping (ODM), where three-dimensional information is obtained from a single photograph. As found by stereoscopic imaging, the spermatophore of the black field cricket consists of a spherical ampulla with a diameter of 0.5 mm, a tube measuring up to 3.5 mm in length, and an anchor plate serving for the fixation of the capsule at the aperture of the female genital chamber during copulation. Single spermatozoa are characterized by an organized arrangement within the ampulla, so that their release from the sperm vessel is significantly facilitated. The study clearly demonstrates that spatial imaging is not only useful for the purpose of presentation, but also for a more detailed analysis of diverse insect structures.

Structural and ultrastructural characters of the reproductive tract in females of the mint leaf beetle Chrysolina herbacea (Duftschmid 1825) (Coleoptera: Chrysomelidae)

AbstractIn this study, Chrysolina herbacea female reproductive system, differentiating stages of vitellogenesis, the egg chorion are examined with light and scanning electron microscopies. C. herbacea is chosen for this study because it is considered to be one of the most harmful insects that destroy mint plants, and it is an agricultural pest. Female reproductive system consists of a pair of ovaries, a pair of lateral oviducts, a common oviduct, spermathecae and a genital chamber. The ovary has 18 meroistic telotrophic ovariole. Each ovariole is divided into four regions: terminal filament, germarium, vitellarium and pedicel. Terminal filament is a long tubular structure. Germarium contains trophocytes (nurse cells), young oocytes and prefollicular cells. Vitellarium consists differentiating oogenic stages including developmental periods of previtellogenesis, vitellogenesis and choriogenesis. The ovarioles open into lateral oviduct by pedicel. The single spermatheca is located near the base of the common oviduct. Spermathecae consist of spermathecae reservoir for sperm storage and a short spermathecae duct. C. herbacea eggs are yellow and elongated. The structure of female reproductive system, the egg chorion and larva of C. herbacea are important to understand the outbreak of this insect pest and to biological control this harmful species.

An extraordinary new species of Psyllipsocus (Psocodea: 'Psocoptera': Psyllipsocidae) from the Biosphere Reserve Sierra de Huautla, Morelos, Mexico

The insect species Psyllipsocus stupendus spec. nov., living on rock outcrops, is described and illustrated from central Mexico (Morelos state). Although the general morphology is typical for a Psyllipsocus species, both male and female are characterized by very peculiar genitalia. In the male, the phallosome has a pair of long pointed claspers and, surprisingly, the basal struts are not anteriorly but posteriorly directed. In the female, the first and second ovipositor valvulae, usually much reduced in this genus, are well developed and strongly sclerotized, forming a tube-like structure together with the sclerotized wall of the proximal part of the vagina. The dorsal wall of the female genital chamber is transversally double-folded, resulting in a ventral main compartment and an eversible dorsal compartment. The opening of the spermathecal duct (spermapore) opens proximally into the dorsal compartment. A similar structure of the female genital chamber has never been observed in Psocoptera before. Some functional hypotheses are discussed and it is postulated that a special form of selective pressure, probably due to sexual selection, might have favoured the evolution of these unique genital structures.

Material heterogeneity of male genitalia reduces genital damage in a bushcricket during sperm removal behaviour

Sperm removal behaviour (SRB) is known in many animals, and male genital structures are often involved in the SRB, e.g. rubbing female genitalia vigorously. However, it remains unclear how those male genital structures function properly without severe genital damage during SRB. In the present study, we focused on the bushcricket Metaplastes ornatus and examined the biomechanics of male and female genital structures, involved in their SRB as a model case. During an initial phase of mating, males of this species thrust their subgenital plate with hook-like spurs and many microscopic spines into the female genital chamber. By moving the subgenital plate back-and-forth, males stimulate females, and this stimulation induces the ejection of sperm previously stored in females. We aimed to uncover the mechanics of the interaction between the subgenital plate and genital chamber during SRB. The genital morphology and its material composition were investigated using modern imaging and microscopy techniques. The obtained results showed a pronounced material heterogeneity in the subgenital plate and the genital chamber. The material heterogeneity was completely absent in that of a second bushcricket species, Poecilimon veluchianus, which does not exhibit SRB. Finite element simulations showed that the specific material heterogeneity can redistribute the stress in the subgenital plate of M. ornatus and, thereby, reduces stress concentration during SRB. This may explain why only a few examined males had a broken spur. We suggest that the observed structural features and material heterogeneity in M. ornatus are adaptations to their SRB.

Histoanatomy of Malpighian tubules and the digestive tract of adult of biocontrol agent Calosoma sycophanta L. (Coleoptera: Carabidae)

Calosoma sycophanta L. is a voracious predatory beetle that feeds on several important lepidopteran pests such as the gypsy moth (Lymantria dispar L.), the brown-tail moth (Euproctis chrysorrhoea L.) and the pine processionary moths (Thaumetopoea pityocampa). It is mass reared in laboratory breeding and released against forest pests. So, C. sycophanta are important predators with the potential to be used in the biological control in agriculture. Although some studies provide important data on the gut anatomy in Carabidae, they are limited to few species. In the present study, we investigated the structure of the Malpighian tubules and digestive tract by means of light and electron microscopies. According to the results obtained, in C. sycophanta, the digestive tract consists of 3 basic parts: foregut, midgut and hindgut. The foregut consists of the oral cavity, pharynx, esophagus, crop, and proventriculus. The esophagus is tubular and has a convoluted surface. Crop bulb-like is an enlarged channel. The proventriculus is connected to the mid-gut. The midgut extends from the foregut at the anterior end to the hindgut at the posterior end. Midgut surface is densely covered with crypts which is finger-shaped. The hindgut consists of the ileum, the colon and the rectum. The anterior end of ileum is marked by the entrance of the four Malpighian tubules. Malpighian tubules are surrounded by a monolayer cubic epithelium. Colon is located between the posterior end of the ileum and the anterior of the rectum. The rectum is lined lumen, intima, a single layer convoluted epithelium and a muscle layer. In addition, in this species, a pair of anal gland, anal gland reservoir and thin-long reservoir ducts are connected with the genital chamber. These data are discussed in comparison with the digestive tract in other Coleopteran species.

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

In the study of the chemical communication of adults of the Melolonthidae family, bacteria have been observed in the epithelium of the genital chamber; possibly, bacteria are involved in the production of sex attractants in their hosts. Therefore, it is important to identify the volatile organic compounds from bacteria (VOCsB) released by these microorganisms and study the biological activity stimulated by VOBCs in adults of Melolonthidae. In this study, bacteria were isolated from the genital chamber of Cyclocephala lunulata and Cyclocephala barrerai, from which VOCsB were extracted using static headspace solid-phase microextraction (SHS-SPME) and dynamic headspace Super Q solid-phase extraction (DHS-SPE) and analyzed using gas chromatography-mass spectrometry. The effect of VOCsB on the hosts and conspecifics was evaluated utilizing an olfactometer and electroantennography (EAG). Two species of Enterobacteria were isolated from the genital chamber of each female species, and VOCsB derived from sulfur-containing compounds, alcohols, esters, and fatty acids were identified. An attraction response was observed in olfactometry studies, and antennal responses to VOCsB were confirmed in EAG bioassays. With these results, new perspectives on the relationship between these beetles and their bacteria emerge, in addition to establishing a basis for management programs in the future.

New findings on the functional morphology of the male genitalia of the blood-feeding bug Rhodnius prolixus in the light of a different observation on living tissue

Among insect species, the male genitalia evolved many different anatomical features to ensure reproductive success. Males of primitive insects do not copulate but transfer sperm packaged in a spermatophore to the female, whereas males of the most advanced insects copulate and deliver free sperm to the storage organ, the spermatheca, in the female reproductive tract. Based on previous studies on several species of triatomine bugs (Rhodnius prolixus included), Triatominae are thought to use an intermediate form of sperm transfer in which the male genitalia have evolved to carry out both copulation and spermatophore formation. Previous observations on chemically fixed tissue of R. prolixus appear to show that the penis, the aedeagus, contains a much-folded internal cuticle which is a collapsed sac that everts from the aedeagus during copulation for the formation and delivery of the spermatophore directly to the female genital chamber. However, observations on living tissue of these structures in R. prolixus show that this internal cuticle functions as a tube through which male secretions pass through the aedeagus to the vagina. The organization of this cuticle in the context of the various anatomical structures of the aedeagus, its different morpho-functional meaning during sperm transfer in R. prolixus, the use of living versus chemically fixed tissue and a new understanding of previous observations are discussed.

Anatomical and histological studies of the alimentary canal of adult maize leaf weevil, Tanymecusdilaticollis Gyllenhal, 1834 (Coleoptera: Curculionidae)

In this study, ananatomical and histological study was conducted on the alimentary canal of Tanymecusdilaticollis (Coleoptera: Curculionidae), which is an economic polyphagous pest species, to study the relationship between the structure of the alimentary canal and the feeding habit. Therefore, the structure of the alimentary canal of T. dilaticollis was examined using light and electron microscopies. Results have shown that the alimentary canal in T. dilaticollis is consisted of three separate regions as foregut, midgut, and hindgut structurally between the mouth and the anus, which pass from head, thorax, and abdomen. The foregut consists of pharynx, esophagus, crop and proventriculus and in the crop part, expansion is seen compared to other foregut parts. Midgut of T. dilaticollis is the largest part of digestion system. The anterior region of midgut is twofolds wider than the posterior region. The posterior midgut extends tubularly and it is connected to eightgastric caeca. The hindgut of T. dilaticollis consists of fourparts as pylorus, ileum, colon, and rectum. Well-developed muscle layers are found near the rectum and genital chamber. These results contribute to further studies on the ecology and biological control agents of Coleoptera and to provide a broad comparison of alimentary canal of Coleoptera species.

Anatomy of male and female reproductive organs of stink bugs pests (Pentatomidae: Heteroptera) from soybean and rice crops

Abstract: Pentatomidae comprises a diverse group of stink bugs widely distributed in the Neotropical region. Many species are phytophagous and cause injuries to plants, and can thus be defined as agricultural pests. In this study, the anatomy of the female and male reproductive tracts of three important agricultural pests in Colombia is described: Piezodorus guildinii Westwood, 1837 and Chinavia ubicaRolston 1983, found on soybeans, and Oebalus insularis Stål, 1872, found in rice crops. For that, light microscopy techniques were used. The anatomy of the reproductive tract of sexually mature males of the three species studied consisted of a pair of testes, vas deferens, seminal vesicles, ejaculatory bulb, an ejaculatory duct that opens into an aedeagus, and paired accessory glands. The reproductive tract of females consisted of a pair of ovaries, each with seven telotrophic-meroistic ovarioles, a pair of lateral oviducts, common oviduct, spermatheca, and a genital chamber. Telotrophic ovarioles were comprised of terminal filament, tropharium, vitellarium, and pedicel. Differences in size, color, and position of structures along the reproductive tract were observed between the species examined. Reproductive biology of insects provides informative characters for behavioral and evolutionary studies, as well as useful data for pest control strategies.

Coevolution between male and female genitalia in Belostoma angustum Lauck, 1964 (Insecta, Heteroptera, Belostomatidae): disentangling size and shape

Sexual and natural selection mechanisms might drive variation in the genitalia of male animals. All aforementioned mechanisms are known to predict the coevolution of male and female genital morphology. Belostoma angustum is known to have subtle variation in the male and female genitalia of its members. In this species, phallosoma with dorsal arms and ventral diverticulum are assumed to be intromittent male genital traits that interact with the female genital chamber. We thus evaluated the existence of variation after disentangling the size from the shape of male genitalia in B. angustum. Body and genitalia dimensions and photographs of phallosoma with dorsal arms, ventral diverticulum and lateral views of the right paramere (the non-intromittent part) were obtained. Semi-landmarks and landmarks were used to capture phenotypic variation, by eliminating all non-shape variation with a Procrustes superimposition. Male and female specimens collected from the same location or immediate vicinity were grouped, and 12 groups originating from 12 locations were used to conduct two block-Partial Least Squares analyses (PLS). Group structures were also taken into account by adopting a multilevel approach. The male and female genital traits had similarly shallow static allometry slopes, as well as the dispersion values around the mean (i.e. coefficient of variation) and the standard error of the estimate. The correlation between the pooled within-locality covariance matrix of the symmetric component of phallosoma with dorsal arms and the female genital chamber was significant (r-PLS=0.37), as well as that with male body dimensions (r-PLS=0.36), even after controlling for allometry. Specimens with lower PLS shape scores had narrower phallosoma with dorsal arms, with poorly curved outer margins of the dorsal arms, whereas specimens with higher PLS shape scores had slightly shorter dorsal arms, with strongly curved outer margins. Lower shape scores were associated with narrower and especially shorter and narrower female genital chambers. Similar shallow allometric curves among sexes and the correlation between intromittent male parts and the female genital chamber, as well as male dimensions, suggest the coevolution of these contact structures in size and in shape.

Chemicals in the Genital Chamber of Two Mexican Species of Phyllophaga1

Phyllophaga ravida Blanchard and Phyllophaga opaca Moser (Coleoptera: Scarabaeoidea: Melolonthidae) are economically important in Mexico. An option for management of the insect pests is use of sex pheromones. To obtain the chemical profile of sex pheromones of both species the posterior section of the genital chamber of females was excised and macerated to release the contents. Eight compounds from P. ravida were identified by retention index and mass spectra: cyclohexane, 1,1′-(2-tridecyl-1,3-propanediyl) bis-; 10-methyl-eicosane; 5-butyl-hexadecane; 3-hexen-2-one; 3,3-diethyl-azetidine-2,4-dione; tetramethyl-oxirane; 3-methyl-2-pentanone; and 2-methoxy-2-methyl-butane. Seven compounds were identified for P. opaca: cholesta-4, 6-dien-3-ol; cholesterol; cholesta-3,5-dien; 2-methyl heptadecane; α-tocopherol succinate; 9,19-cyclolanost-24-en-3-ol, acetate; and lup-20 (29)-en-3-ol, acetate. Some identified chemicals, mainly 3,3-diethyl-azetidine-2,4-dione and 2-methyl heptadecane might be involved in sexual attraction of P. ravida and P. opaca, respectively. Several compounds probably are incorporated from plants into insects during feeding, and further transformed by metabolism.