A new structure on the frons of male adults of the Asian rice spittlebug Callitettix versicolor (Hemiptera: Auchenorrhyncha: Cercopidae)

Genomic and Transcriptomic Insights into the Genetic Basis of Foam Secretion in Rice Spittlebug Callitettix versicolor

Many animal species produce protective foams, the majority of which exhibit evolutionary adaptability. Although the function and composition of foams have been widely studied, the genetic basis of foam secretion remains unknown. Unlike most species that produce foam under specific situations, spittlebugs continuously secrete foams throughout all nymphal stages. Here, we capitalize on the rice spittlebug (Callitettix versicolor) to explore the genetic basis of foam secretion through genomic and transcriptomic approaches. Our comparative genomic analysis for C. versicolor and eight other insect species reveals 606 species-specific gene families and 66 expanded gene families, associated with carbohydrate and lipid metabolism. These functions are in accordance with the composition of foams secreted by spittlebugs. Transcriptomic analyses of malpighian tubules across developmental stages detected 3192 differentially expressed genes. Enrichment analysis of these genes highlights functions also revealed by our comparative genomic analysis and aligns with previous histochemical and morphological observations of foam secretion. This consistency suggests the important roles of these candidate genes in foam production. Our study not only provides novel insights into the genetic basis of foam secretion in rice spittlebugs but also contributes valuable knowledge for future evolutionary studies of spittlebugs and the development of pest control strategies for C. versicolor.

More than 80 years without new taxa: analysis of morphological variation among members of Mexican Aeneolamia Fennah (Hemiptera, Cercopidae) support a new species in the genus

The genus Aeneolamia includes eight described species and 32 subspecies widely distributed in America. In Mexico, two species (A.contigua and A.albofasciata) and one subspecies (A.contiguacampecheana) are recognized. In a recent study of Cercopidae in Mexico, a new species of Aeneolamia was noted from Oaxaca, Mexico based on body color and the ornamentation patterns of tegmen, without a formal taxonomic description. To test the hypothesis of an extant new taxon within the genus a comprehensive analysis of intraspecific morphological variation from 46 morphological features was performed, four related to tegmen color patterns in both sexes, six to male genitalia, and 36 continuous characters measured in specimens of both sexes of Mexican Aeneolamia from several geographical localities using traditional univariate, multivariate morphometric, and geometric morphometric methods. This is the first time that this approach has been used in Cercopidae. Aeneolamiadanpecki Castro, Armendáriz & Utrera, sp. nov. from Oaxaca showed pronounced morphological differences in tegmen coloration patterns, the shape of different elements of the male genitalia, and body measurements compared to the other Mexican members of Aeneolamia; therefore, it is described as a new species.

Morpho-functional Analysis of the Head Glands in Three Auchenorrhyncha Species and Their Possible Biological Significance

The Cicadomorpha Philaenus spumarius, Neophilaenus campestris, and Cicadella viridis are known transmitters of the bacterium Xylella fastidiosa. Here, we studied the ultrastructural organization of their cephalic glands. Our investigations with scanning, transmission, focused ion beam-scanning electron microscopes and light microscope revealed for the first time in Auchenorrhyncha the presence of two types of cephalic glands. Both belonged to the Class III epidermal glands, according to the Noirot and Quennedey classification. Type A glands were the most common, being mainly located around antennae, lorum, and gena. Moreover, these glands were observed also on the abdomen and thorax, always in association with sensilla trichoidea. The second type of glands (type B) were located exclusively at the apical part of the postclypeus in P. spumarius and N. campestris. The ultrastructural organization was similar in both types, being composed of a secretory cell and a conducting canal. Differences were observed in the width of the cuticular opening, being smaller in the type II glands. In addition, we have recorded the presence of a maxillary sensory pit in all species and described sensilla trichoidea ultrastructural organization. Finally, we discussed the ultrastructural organization of the glands and their potential biological role.

Behavioural and electrophysiological responses of Philaenus spumarius to odours from conspecifics

The meadow spittlebug, Philaenus spumarius L. (Hemiptera: Auchenorrhyncha: Aphrophoridae), is the main vector of Xylella fastidiosa subsp. pauca strain ST53, the causal agent of the Olive Quick Decline Syndrome. Philaenus spumarius and other Auchenorrhyncha are known to communicate via vibrations, whereas the possible occurrence of semiochemical communication has been poorly investigated so far. Through a chemical ecology approach, we provide evidence of intraspecific chemical communication in P. spumarius. In Y-tube olfactometer bioassays, males were attracted to unmated females as well as toward the headspace volatile extracts collected from unmated females. Conversely, females did not respond to unmated male volatiles or their extracts, nor did males and females respond to volatiles from individuals of the same sex. Electroantennography assays of unmated male and female headspace extracts elicited measurable responses in the antennae of both sexes. Male responses to body wash extracts from both sexes were stronger compared to female responses. Thus, suggesting the presence of compounds that are highly detected by the male's olfactory system. The female head seemed to be the source of such compounds. This is the first record of intraspecific chemical communication in P. spumarius and one of the very few records in Auchenorrhyncha. Possible biological roles are under investigation.

The complete mitochondrial genome of Eoscarta assimilis (Hemipera: Cercopidae) and phylogenetic analysis of Cercopidae

The complete mitochondrial genome (mitogenome) of Eoscarta assimilis (Uhler, 1896) was sequenced in the current paper. The total length of the mitogenome is 17,231 bp and it consists of 37 genes including 22 transfer RNA (tRNAs), 13 protein-coding (PCGs) and 2 ribosomal RNA (rRNAs). The 13 PCGs initiated with the start codon ATN, but ND4 started with TTG. All of the PCGs ended with TAA, apart from COX3 which terminated by incomplete TAG. A ML tree based on sequences of 15 complete mitogenomes (13 Cercopidae and 2 outgroup) suggests that E. assimilis is more closely related to the genus Callitettix. The phylogenetic analysis supports the monophyly of the family Cercopidae and the genus Cosmoscarta, and the paraphyly of the subfamily Callitettixinae. This mitogenome information for E. assimilis could facilitate future evolutionary studies to related insects.