On the Affinities and Systematic Position of Lachnaeus Schoenherr and Rhinocyllus Germar in the Tribe Lixini (Coleoptera: Curculionidae: Lixinae) Based on the Morphological Characters of the Immature Stages.

Mature larvae and pupae of Lachnaeus crinitus Schoenherr, 1826 and Rhinocyllus alpinus Gültekin, Diotti and Caldara, 2019 and pupae of R. conicus (Frölich, 1792), belonging to the Lixini (Curculionidae: Lixinae), are morphologically described for the first time. They possess all the characters considered distinctive in the immature stages of this tribe and are distinguishable from all the related genera by a combination of some characters (e.g., presence of endocarina, shape of premental sclerite; the number of pds on the abdominal segments; size and presence of urogomphi). It is emphasized that the controversial tribe Rhinocyllini is not supported by the characters of the larvae and pupae of Rhinocyllus and that the two subgenera of this genus, Rhinocyllus s. str. and Rhinolarinus, are separable from each other not only by characters of the adult but also distinctive characters of the larvae and pupae. These results confirm that the morphology of the immature stages, which is usually overlooked, can be very important for the purpose of identifying new characters that are useful for clarifying taxonomical and phylogenetic complex situations based only on the study of the imagoes.

Cleonis pigra (Scopoli, 1763) (Coleoptera: Curculionidae: Lixinae): Morphological Re-Description of the Immature Stages, Keys, Tribal Comparisons and Biology.

Mature larvae and pupae of Cleonis pigra (Scopoli, 1763) (Curculionidae: Lixinae: Cleonini) are morphologically described in detail for the first time and compared with known larvae and pupae of other Cleonini species. The results of measurements and characteristics most typical for larvae and pupae of Cleonini are newly extracted and critically discussed, along with some records given previously. Keys for the determination of selected Cleonini species based on their larval and pupal characteristics are attached. Dyar's law was used for the estimation of a number of larval instars of C. pigra. Descriptions of habitats, adult behavior, host plants, life cycle, and biotic interactions are reported here. Adults and larvae feed on plants from the Asteraceae family only (genera Carduus, Cirsium, Centaurea, and Onopordum). Oviposition occurs on the base of the plant stem or the root neck. In the process of larval development, a fusiform gall forms. C. pigra and Cyphocleonus achates can coexist in the same locality. In open habitats, the weevils become the prey of carnivorous animals.

Velcro-Like System Used to Fix a Protective Faecal Shield on Weevil Larvae.

The last instar larva and pupa of Eucoeliodes mirabilis (A. Villa & G. B. Villa, 1835) (Curculionidae: Ceutorhynchini) are described using drawings and SEM images and are compared and keyed with already described larvae of 58 other ceutorhynchinae taxa. The larval body has an effective combination of morphological adaptations that assist a unique biological defensive strategy. All larval stages of E. mirabilis feed ectophytically on leaves of Euonymus europaeus L. (Celastraceae), and the larval body is covered with a thick faecal shield. The fixation of this protective shield on the larval back is performed by a peculiar dorsal microsculpture composed of a dense carpet of microtrichia on the thorax and abdomen, which serves effectively as a velcro system. Because of this strategy, macrosetae on the larval and pupal body of E. mirabilis are completely reduced. Larvae of E. mirabilis also have distinct morphological adaptations for protecting the spiracles against intrusion of faeces and avoiding occlusion of the tracheal system: a) microtrichia around spiracles are slightly shorter, distinctly stronger and are arranged with high-density and in clusters and b) spiracles are protected by an external safety valve. This strategy of E. mirabilis larvae is unique, although somewhat similar to that of Criocerinae and Blepharida-group leave beetles (Galerucinae) (both Coleoptera: Chrysomelidae), but with distinctly different morphological adaptations.

Do the rich get richer? Varying effects of tree species identity and diversity on the richness of understory taxa.

Understory herbs and soil invertebrates play key roles in soil formation and nutrient cycling in forests. Studies suggest that diversity in the canopy and in the understory are positively associated, but these studies often confound the effects of tree species diversity with those of tree species identity and abiotic conditions. We combined extensive field sampling with structural equation modeling to evaluate the simultaneous effects of tree diversity on the species diversity of understory herbs, beetles, and earthworms. The diversity of earthworms and saproxylic beetles was directly and positively associated with tree diversity, presumably because species of both these taxa specialize on certain species of trees. Tree identity also strongly affected diversity in the understory, especially for herbs, likely as a result of interspecific differences in canopy light transmittance or litter decomposition rates. Our results suggest that changes in forest management will disproportionately affect certain understory taxa. For instance, changes in canopy diversity will affect the diversity of earthworms and saproxylic beetles more than changes in tree species composition, whereas the converse would be expected for understory herbs and detritivorous beetles. We conclude that the effects of tree diversity on understory taxa can vary from positive to negative and may affect biogeochemical cycling in temperate forests. Thus, maintaining high diversity in temperate forests can promote the diversity of multiple taxa in the understory.

The morphology of the immature stages of two rare Lixus species (Coleoptera, Curculionidae, Lixinae) and notes on their biology.

The mature larvae and pupae of Lixus (Ortholixus) bituberculatus Smreczynski, 1968 and Lixus (Dilixellus) neglectus Fremuth, 1983 (Curculionidae: Lixinae: Lixini) are described and compared with known larvae of 21 other Lixus and 2 Hypolixus taxa. The mature larva and pupa of Lixus bituberculatus are the first immature stages described representing the subgenus Ortholixus. The larva of Lixus neglectus, in the subgenus Dilixellus, is distinguished from the known larvae of four species in this subgenus by having more pigmented sclerites on the larval body. All descriptions of mature larvae from the tribe Lixini, as do all known species from the tribe Cleonini, fit the diagnosis of the mature larva of the Lixinae subfamily. Furthermore, new biological information of these species in the Czech Republic, Slovakia and Romania is provided. For Lixus bituberculatus, a chicory, Cichorium intybus L. (Asteraceae), is identified as a host plant, and Lixus neglectus is found on dock Rumex thyrsiflorus Fingerh. (Polygonaceae). Both species are probably monophagous or oligophagous. Adults of Lixus bituberculatus often inhabit host plants growing in active, dry and sunny pastures with sparse patches without vegetation, being mostly active during the night in April/May and then again in September, when the highest activity levels are observed. Adults of Lixus neglectus inhabit dry grasslands on sandy soils with host plants, being active during the day from May to September, with the highest level of activity in May/June and September. The larvae of both species are borers in the stem and root of the host plant, and they pupate in root or root neck. Adults leave the pupation cells at the end of summer and do not hibernate in the host plants. Finally, Romania is a new geographic record for Lixus bituberculatus.

Biology and morphology of immature stages of Adosomus roridus (Coleoptera: Curculionidae: Lixinae).

Mature larva and pupa of Adosomus (s. str.) roridus (Pallas, 1781) (Curculionidae: Lixinae: Cleonini) are described and compared with ten other taxa of Cleonini with known larvae. This weevil is an oligophagous species on the Asteraceae family. From our observations in Slovakia, we found active adults from April to September in dry sunny places within extensively used or fallow vineyards and in ruderal vegetation with host plants. The weevil is a root borer--larvae, pupae and fresh adults were collected from the root necks and roots of Common Tansy (Tanacetum vulgare L.) and rarely from Mugwort (Artemisia vulgaris L.). Each plant was usually occupied by one larva, or more rarely with two or three larvae. The new generation of adult individuals appeared from early summer to autumn. Both larvae and some of the adults overwinter, which is quite unique within Cleonini.