Fine Morphology of Antennal and Ovipositor Sensory Structures of the Gall Chestnut Wasp, Dryocosmus kuriphilus

Dryocosmus kuriphilus is a gall-inducing insect, which can cause significant damage on plants of the genus Castanea Mill., 1754. Antennae and ovipositor are the main sensory organs involved in the location of suitable oviposition sites. Antennal sensilla are involved in the host plant location, while ovipositor sensilla assess the suitability of the ovipositional bud. On both organs, diverse sensillar organs are present. Here, the distribution and ultrastructural organization of the sensilla were investigated by scanning and transmission electron microscopy. The antennae of D. kuriphilus are filiform and composed of 14 antennomeres, with the distal flagellomere bearing the highest number of sensilla. On the antennae, 6 sensilla types were found; sensilla chaetica, campaniformia, coeloconica-I, coeloconica-II, trichoidea and placoidea. The sensilla placoidea and trichoidea were the most abundant types. On the external walls of the ovipositor, gustatory and mechanoreceptive sensilla were observed. Internally, the egg channel hosted two additional sensory structures. The putative functional role of each sensilla in the context of insect’s ecology is discussed as well as the ovipositional mechanism used by this insect.

Checklist of ascomycetous microfungi of the Nuratau Nature Reserve (Uzbekistan)

A checklist of ascomycetous microfungi of the Nuratau Nature Reserve (Nuratau Mountains, Uzbekistan) was compiled for the first time as a result of field research conducted in 2009–2017. In total, 197 species, 3 varieties and 51 forms of micromycetes belonging to 66 genera and 30 families have been identified. Among them 19 species (Asteromella tanaceti, Camarosporium achilleae, Diplocarpon alpestre, Diplodia celtidis, Hendersonia ephedrae, Mycosphaerella artemisiae, Neopseudocercosporella capsellae, Phoma hedysari, P. mororum, Phyllosticta prostrata, P. silenes, P. trifolii, Ramularia trifolii, Rhabdospora eremuri, Selenophoma nebulosa, Septoria cyperi, S. dauci, S. ranunculacearum, S. trifolii) and one form (Erysiphe cichoracearum f. tanaceti) were found for the first time for the mycobiota of Uzbekistan. 30 species of microfungi were recorded on 31 new host plants. The most abundant species are representatives of the cosmopolitan genera Ramularia, Septoria, Erysiphe, Leveillula, Mycosphaerella, Phoma, Cytospora, Sphaerotheca, Phyllosticta and Marssonina. The annotated checklist includes data on host plant, location, date and collection number of every species.

Electroantennographic Responses of Aromia bungii (Faldermann, 1835) (Coleoptera, Cerambycidae) to a Range of Volatile Compounds

Background: The red-necked longhorn beetle, Aromia bungii, is one of the most damaging pests of stone fruit trees. Native to the south-eastern Palearctic and Oriental regions, it invaded and is established to some extent in the Campania Region (Southern Italy). In several cerambycid species, volatile organic compounds (VOCs) have been shown to play a role in mate and host plant location. Methods: The electroantennographic (EAG) technique was employed to explore the antennal chemoreceptivity of male and female A. bungii antennae to 90 VOCs. Results: Increasing EAG amplitudes from the basal to the distal antennal segments were recorded in response to six selected plant volatiles. From the distal flagellomeres, the largest EAG responses (>0.8 mV) were elicited by 2-hexanol, octanal, sulcatone, guaiacol, sulcatol, 2,4-dimethyl-3-hexanol, 2,4-dimethyl-2-hexanone, heptanal, nonanal, (Z)-3-hexenol, and 1-heptanol in both sexes, and by linalool, (E)-2-heptenal, 1-octen-3-ol, (E)-2-octenal, 3-octanol, (E)-2-octen-1-ol, α-phellandrene, and α-terpinene in males. The olfactory system of both sexes proved to be sensitive to changes in stimulus concentration and compound structure. Conclusions: this study demonstrates the capability of A. bungii males and females to detect and discriminate among a wide range of VOCs and provides a basis for further olfactometer and field trapping experiments aimed at identifying behaviorally-active compounds useful for the implementation of semiochemical-based control strategies for this pest.