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Identification, rearing, and distribution of stick insects of Madeira Island: an example of raising biodiversity awareness

Publication . Aguiar, António M. F.; Aguin-Pombo, Dora; Gonçalves, Ysabel M.

Two species of stick insects are currently known to be present in the Macaronesian archipelagos: Clonopsis gallica (Charpentier) (Phasmatodea: Bacillidae) on the Canary Islands and in the Azores and Carausius morosus (Sinéty) (Phasmatidae) in the Azores. Here, we provide the first reliable records of the presence and distribution of C. gallica and C. morosus on Madeira Island. Egg and adult stages are briefly described along with some notes on the life history of these species in captivity. Data on island-wide distribution are based on specimens donated by the public in response to an article published in a daily newspaper. This method of data collection raised great popular interest in stick insects. The role of newspapers as a means of communicating awareness in biodiversity issues is discussed.

2014Journal article

Open access

Parthenogenesis and sex-ratio distorting bacteria in Empoasca (Hemiptera: Cicadellidae) Leafhoppers

Publication . Aguin-Pombo, Dora; Rodrigues, Marilia C P A; Voetdijk, Betsie; Breeuwer, Johannes A J

Endosymbiotic bacteria can induce parthenogenesis in many haplo-diploid species, but little is known about their role in asexual reproduction in diplodiploids. Bacteria are essential for reproduction in the asexual lin eages of springtails and booklice, and possibly some weevils, but whether they are the causative agent of par thenogenesis remains to be proven. This would require comparing unisexual forms and their closely related bisexual species, but such model species are very rare. Empoasca leafhoppers from the Madeira Archipelago provide an excellent case to test whether bacterial infections can cause parthenogenesis. Here we examined the diversity of the sex-distorting bacteria, Wolbachia, Cardinium, Rickettsia, and Arsenophonus, in three apo mictic morphotypes (A, B, C) and three bisexual relatives of Empoasca. Wolbachia of group B was present in all unisexual and bisexual species. Rickettsia were the only bacteria restricted to the three unisexual forms, suggesting an association between infection and asexual reproduction. In addition, we found Asaia for the third time in the Cicadellidae, although this may have little to do with the reproductive mode of its host. Adult females of morphotype C reared on plants watered with tetracycline solution did not result in the production of male offspring. To our knowledge, this is the first study to suggest a possible association between bacterial infection and parthenogenesis in apomictic XO/XX diplodiploid bisexual species based on a range of sex ratio distorting bacteria.

2021Journal article

Open access

Comparative cytogenetics of Auchenorrhyncha (Hemiptera, Homoptera): a review

Publication . Kuznetsova, Valentina; Aguin-Pombo, Dora

A comprehensive review of cytogenetic features is provided for the large hemipteran suborder Auche norrhyncha, which currently contains approximately 42,000 valid species. This review is based on the analysis of 819 species, 483 genera, and 31 families representing all presently recognized Auchenorrhyn cha superfamilies, e.i. Cicadoidea (cicadas), Cercopoidea (spittle bugs), Membracoidea (leafhoppers and treehoppers), Myerslopioidea (ground-dwelling leafhoppers), and Fulgoroidea (planthoppers). History and present status of chromosome studies are described, as well as the structure of chromosomes, chro mosome counts, trends and mechanisms of evolution of karyotypes and sex determining systems, their variation at different taxonomic levels and most characteristic (modal) states, occurrence of partheno genesis, polyploidy, B-chromosomes and chromosome rearrangements, and methods used for cytoge netic analysis of Auchenorrhyncha.

2015Journal article

Open access

Differences in wing venation between parthenogenetic and bisexual species of Empoasca leafhoppers from Madeira Island

Publication . Aguin-Pombo, Dora; Valido, Lia; Sousa, Fábio; Arraiol, Anabela

Empoasca is a large worldwide distributed genus of about 400 species many of which are pests to agricultural plants. Species of Empoasca are bisexual but recently three parthenogenetic morphotypes (A, B and C) of various degrees of polyploidy have been reported from Madeira Island. Females of Empoasca are difficult to identify because they show insufficient morphological diag nostic characters. In this work, we evaluate the utility of wing venation pattern for the identification of the three bisexual and three unisexual taxa of Empoasca present in Madeira. Our main motivation is to test whether the wing venation pattern is a stable char acter and to assess whether it could be suitable to develop an identification key for females of taxa present in Madeira Island. We analysed 107 categorical characters of wing patterns and vein shape in the forewings and hind wings of 677 females. The results showed that wing venation may provide useful characters to identify species of Empoasca despite a considerable amount of in traspecific variation. The variation within each species in wing pattern was analysed and several modifications in vein number such as additional or missing veins and in vein shape as bifurcations or incomplete veins are reported.

2014Journal article

Open access

Evidence for TTAGG telomere repeats and rRNA gene clusters in leafhoppers of the genus Alebra (Hemiptera: Auchenorrhyncha: Cicadellidae)

Publication . KuzNnetsova, Valentina G.; Maryanska-Nadachowska, Anna; Anokhin, Boris; Aguin-Pombo, Dora

The leafhopper genus Alebra Fieber, 1872 comprises a complex of morphologically similar species. The chromosome complements (karyotypes) of five Alebra species, i.e. A. albostriella, A. coryli, A. viridis, A. wahlbergi and a new, yet undescribed species, provisionally named Taxon 1, were here investigated, three of these species (A. coryli, A. viridis, and Taxon 1) for the first time. The techniques applied included standard chromosome staining, fluorescence in situ hybridization (FISH) for mapping of 18S rDNA and telomeric repeats (in every species), C-banding, AgNOR-banding and CMA3 /DAPI- staining (in A. viridis). The species have a holokinetic type of chromosomes, as in other hemipterans. Karyotypes of all species are remarkably conserved with 2n = 22 + X(0)/XX (male/female), one large and 10 medium pairs of autosomes and the X chromosome similar in size to larger chromosomes within this group. In every species, FISH identified the “classical” insect telomere repeat of TTAGG and rRNA gene clusters located on the homologues of a medium-sized pair of autosomes, presumably number 5. Thus, speciation in Alebra has apparently not involved significant karyotypic changes. In A. viridis, rDNA sites were both Ag- and CMA3 -positive and were located at an interstitial position. C-banding revealed heterochromatic bands in the X chromosome and also in all but four pairs of autosomes, the bands were located at one telomere of a chromosome. C-bands were positive for CMA3 and negative for DAPI, suggesting that C-heterochromatin is mainly enriched in GC-pairs.

2015Journal article

Open access