Łukasz Depa

Abundance of Stomaphis graffii Cholod. (Hemiptera) on maple trees in Poland

The paper presents data on the remarkable abundance of S. graffii in the parks of the industrially transformed region of Upper Silesia, Poland. Ten new sites and 36 colonies were recorded, while only 6 sites were known so far from the whole territory of Poland. New host plant species and new ant species tending aphids were also recorded. The conclusion is that the abundance of Stomaphis species may be underestimated due to their cryptic life mode.

Life cycle of maple-tree aphid Stomaphis graffii Cholodkovsky, 1894 (Hemiptera, Aphididae)

Aphids tend to alter their life cycle and habitat range under the influence of changes in climatic conditions, which is especially relevant given that such species are often agricultural pests. Aphids of the genus Stomaphis are remarkable for their large body size, but due to their discreet feeding positions, knowledge of their biology remains fragmentary. Observations conducted during a period of two years were used to infer the life-cycle of Stomaphis graffii Cholod., an abundant species in parks and forest-stands in southern Poland. Observations indicate the occurrence of the first generation as early as at the end of April and the generation of alate females throughout July and August. Sexual generation occurs in late August and oviposition takes place from the end of September through to October. At the turn of October and November, apart from oviparous females, some larvae are still present in colonies. Meteorological data provided for the period of hatching of first larvae indicates correlation of this phenomenon with the phenology of the host plant rather than directly with the weather. Presented data are further compared with the biology of other representatives of the genus Stomaphis with reference to their habitat requirements.

Central European Acer- and Salicaceae-feeding aphids of the genus Stomaphis (Insecta: Aphidoidea: Lachnidae) -separate species or populations?

In Europe, there are three aphid species of the genus Stomaphis Walker that feed on trees in the genus Acer and one that feeds on trees in the family Salicaceae. Although these species are considered morphologically distinct, their uncertain host specificity and variation in morphological features has led to misidentifications or questionable attribution of subspecies status. The aim of the present study was to clarify the identity of the Central European representatives on the basis of morphological and molecular analyses. Our study is based on 42 samples from Central Europe and Northern Italy. Mitochondrial markers COXI and COXII were used to determine the molecular identity of the specimens studied. Our molecular analyses revealed the existence of three clades (two on Acer, one on Salicaceae) as defined by both molecular markers. Morphological analysis showed a broad range of variability of the key morphological features in all three clades. Despite significant differences in the mean values of morphometric traits, their range of variability strongly overlapped. Samples from COXI clades on Acer showed two different patterns of geographical distribution. Host specificity is recognized only at the level of host plant genera (Acer) and family (Salicaceae), excluding the possibility of the existence of separate subspecies on single host plant species.

New records of an alien aphid species Tinocallis (Sappocallis) takachihoensis from countries in central and northern Europe (Hemiptera, Aphididae, Calaphidinae)

Abstract The aphid genus Tinocallis Matsumura, 1919 (Hemiptera: Aphididae: Calaphidinae) in central and northern Europe is reviewed; it includes four species. The first records of the Asian elm aphid Tinocallis takachihoensis Higuchi, 1972 are reported from the Czech Republic, Denmark, and Poland. The record in Denmark is the first in Scandinavia. Alate viviparous females and nymphs of T. takachihoensis were collected from Ulmus glabra “Pendula” (the Czech Republic and Poland) and from U. minor (Denmark) in 2017. Tinocallis takachihoensis is the fourth Tinocallis species to be recorded from Poland and together with two other species from the subgenus Sappocallis, T. nevskyi and T. saltans, is a species of alien origin. The alate viviparous females are reviewed and re-described and their affinities and distribution in central and northern Europe are discussed. A key to the European species of Tinocallis based on the characters of live and slide-mounted specimens is also given.

Morphological description of the alimentary tract of Geoica utricularia (Passerini, 1856) (Insecta, Hemiptera, Eriosomatinae).

Existing literature data report the lack of stomach and crenated intestine in the aphid species Geoicasetulosa (Passerini, 1860), a representative of subfamily Eriosomatinae. This odd anatomical feature seemed remarkable, due to the presence of fully developed intestine in closely related genera and mutualistic relationship with ants of this genus. The study aimed at repeated anatomical research of Geoicautricularia (Passerini 1856), in order to confirm what seemed to be a generic feature. Standard histological methods were applied, with addition of oblique light microscopy, fluorescence microscopy and confocal laser scanning microscopy. The results indicated the existence of a fully developed intestine, with broad sac-shaped stomach and loops of the crenated intestine. The general anatomy of the alimentary tract of G. utricularia resembles that of other representatives of the tribe Fordini. Also well-developed rectal gland is present, most probably playing a role in modifying the carbohydrate composition of excreted honeydew.

Morphological and histological study of the forewing of Orthezia urticae (Linnaeus, 1758) (Hemiptera, Sternorrhyncha)

Abstract Wings of Orthezia urticae males were studied. Both ventral and dorsal surfaces of wings were examined under light and scanning electron microscopes. The structure regarded as vein cubitus anterior turned out to be a reinforcement element only. Two elements known as radius sector and media are almost transparent depressions in the wing membrane. Veins at the margin of the fold of the wing anal lobe were not confirmed. Studies indicated a row of sensilla cupola at the beginning of the subcostal ridge. Cross sections of the wing membrane showed a two-layered membrane. The presence of two veins was confirmed in a common stem – subcostal and radius. The change of common stem shape was described. Neither tracheae nor nerves were observed. This is the second paper on cross-sections of wing within Sternorrhyncha.

Aphids Playing Possum – Defensive or Mutualistic Response?

Paper presents the phenomenon of thanatosis or death-feigning in selected aphids species. This specific reaction was predominantly analysed on the example of aphid subfamily Lachninae. Individuals of this group were used in experiments, during which a thanatotic response was induced with various results. The response differed from prolonged thanatosis, lasting for several minutes (Eulachnus rileyi), through shrinking behaviour (e. g. in Stomaphis graffii) to non-responsive species such as Cinara (Schizolachnus) pineti. The large interspecies variation of observed responses can be linked to other defensive mechanisms existing in the studied species, as well as to their mutualistic relationship with ants. The behaviour of shrinking is hypothesized to be the mutualistic response, developed from thanatosis, and being adapted to transportation by ant workers.

First report of Smynthurodes betae (Hemiptera: Aphididae) on Phelipanche ramosa (Orobanchaceae)

Summary The bean root aphid, Smynthurodes betae Westwood (Aphididae: Eriosomatinae: Fordini) is reported for the first time feeding on haustoria of branched broomrape, Phelipanche ramosa, (Orobanchaceae) a cropparasitic plant. Field surveys conducted in Poland revealed infestations of P. ramosa by nymphs and adult apterous females of a secondary-host generation of S. betae in 1 locality in Sandomierz County, near Szewce, Poland. Numerous nymphs of S. betae fed on broomrape sap, resulting in poor growth or dead shoots, and 10 to 20% of the total population of broomrape was infested. Potential use of this insect as a biological control method for invasive broomrapes requires further study.

Sexual morphs of Pterocomma tremulae Börner, 1940 (Aphididae, Aphidinae) with description of male reproductive system

Abstract Paper presents the first description of the so far unknown sexual generation of Pterocomma tremulae (Aphididae, Aphidinae): oviparous female and alate male. It also provides detailed description of the male reproductive system. Discussion focuses on comparative analysis of male reproductive system with other aphid groups and possible importance of its structure in resolving phylogenetic interrelationships within the genus Pterocomma. A key is provided to the known males of European Pterocomma species.

Micromyzus platycerii sp. n. (Hemiptera, Aphididae) – a new fern-feeding aphid species from Thailand

Abstract A new fern-feeding aphid species, Micromyzus platycerii, collected in Sakaerat Research Station in Thailand, is described.