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.

Detailed description of antennal sensory organs of Leptoglossus occidentalis Heidemann, 1910 (Insecta: Hemiptera: Heteroptera: Coreidae) and a comparison with L. zonatus (Dallas, 1852) are presented. A novel approach that combines the advantages of field emission scanning electron microscopy (FE-SEM) and atomic force microscope (AFM) was used to detail micromorphological structures. A simplified classification system for sensilla that eliminates the subjective aspects of morphology, such as their shape, is proposed. Fourteen sensory organs have been classified into three main groups: (a) aporous sensilla with a flexible socket, (b) porous sensilla with a flexible socket and (c) porous sensilla with an inflexible socket. A large variety of sensory organs (nine types) with olfactory functions are described. The antennal sensory organs have been recognized as one of the factors responsible for the evolutionary success of Leptoglossus spp. and their status as important pests and invasive species.

Two new genera, each represented by a single new species, Cassisotropis aciformis Taszakowski et al. gen. et sp. nov. and Infernotropis madagascariensis Taszakowski et al. gen. et sp. nov. are described from Madagascar. Photographs and SEM micrographs of the male and female habitus, genital structures and selected morphological structures are presented. The first record of Fulvius anthocoroides (Reuter, 1875) in Madagascar and the checklist of Madagascan cylapines are also provided.

The first observations of the aphid Prociphilus fraxini (Fabricius, 1777) being involved in a mutualistic relationship with the ant Prenolepis nitens (Mayr, 1853) in Europe is documented. Mutualism of an aphid generation living with the ants Prenolepis nitens and Lasius brunneus (Latreille, 1798) is discussed in reference to the possible development of an overwintering parthenogenetic population of the aphid, persisting on the roots of its secondary host, Picea abies, due to coevolution of the aphid with ants.

A new species, Kohnometopus yasunagai sp. nov. (Hemiptera, Heteroptera, Miridae, Isometopinae, Gigantometopini), is described from Peninsular Malaysia. Habitus and SEM images of the holotype female and necessary morphological structures are presented. The structure of the female abdomen including the genitalia are also shown in detail. A key to all known Kohnometopus species is provided.

A new species of Fulvius Stål—F. attenboroughi sp. nov.—is diagnosed and described. Schmitzofulvius bigibber Gorczyca, 1998 is redescribed. Photographic images of habitus and genital structures, as well as scanning electron micrographs of selected structures of both species, are provided. Fulvius kerzhneri Gorczyca, 2000 is diagnosed. New records of a few plant bugs species (Collaria elsae Matocq, 2021, C. cf improvisa Reuter, 1893, F. kerzhneri, Linnavuoricoris madagascariensis Chérot, 2013, Malagasycoelum dracula Kim & Jung, 2020 and S. bigibber) from Madagascar and the checklist of Madagascan Miridae are also presented.