Identification and Expression Analysis of G Protein-Coupled Receptors in the Miridae Insect Apolygus lucorum

G protein-coupled receptors (GPCRs) are the largest and most versatile family of transmembrane receptors in the cell and they play a vital role in the regulation of multiple physiological processes. The family Miridae (Hemiptera: Heteroptera) is one of the most diverse families of insects. Until now, information on GPCRs has been lacking in Miridae. Apolygus lucorum, a representative species of the Miridae, is an omnivorous pest that occurs worldwide and is notorious for causing serious damage to various crops and substantial economic losses. By searching the genome, 133 GPCRs were identified in A. lucorum. Compared with other model insects, we have observed GPCR genes to be remarkably expanded in A. lucorum, especially focusing on biogenic amine receptors and neuropeptide receptors. Among these, there is a novel large clade duplicated from known FMRFamide receptors (FMRFaRs). Moreover, the temporal and spatial expression profiles of the 133 genes across developmental stages were determined by transcriptome analysis. Most GPCR genes showed a low expression level in the whole organism of A. lucorum. However, there were a few highly expressed GPCR genes. The highly expressed LW opsins in the head probably relate to nocturning of A. lucorum, and the expression of Cirl at different times and in different tissues indicated it may be involved in growth and development of A. lucorum. We also found C2 leucine-rich repeat-containing GPCRs (LGRs) were mainly distributed in Hemiptera and Phthiraptera among insects. Our study was the first investigation on GPCRs in A. lucorum and it provided a molecular target for the regulation and control of Miridae pests.

The Effect of Mirid Density on Volatile-Mediated Foraging Behaviour of Apolygus lucorum and Peristenus spretus

Plants would release herbivore-induced plant volatiles (HIPVs) to repel herbivores and attract natural enemies after being damaged by herbivores. In this study, after cotton plants were damaged by different densities of Apolygus lucorum, the behavioral responses of A. lucorum and Peristenus spretus to cotton plants volatiles were evaluated, and the quality and quantity of volatiles from cotton plants were analyzed. Only when cotton plants were damaged by four bugs did both A. lucorum and P. spretus show an obvious response to damaged cotton plants, which indicates that cotton defense is correlated with pest density. The collection and analysis of volatiles reveals that the increase in pest density results in the emission of new compounds and an increase in the total number of volatiles with an alteration in proportions among the compounds in the blend. These changes in volatile profiles might provide wasps and mirids with specific information on host habitat quality and thus could explain the behavioral responses of parasitoids and pests.

Bugs (Heteroptera) of treeless areas of Chukotka (Russia)

The article summarizes the data on bugs in the treeless areas of the Chukotka Autonomous Okrug (tundra zone and the elfin wood subzone). Taking into account the available literary sources, as well as new materials (obtained in 2010s), 62 species of Heteroptera from 41 genera and 12 families are known here; 18 species recorded for these landscapes for the first time and 11 — for the Chukotka AO as a whole. There are: Saldula fucicola (J. Sahlberg, 1970) (Saldidae), Acompocoris brevirostris Kerzhner, 1979 (Anthocoridae); Apolygus lucorum (Meyer-Dür, 1843), Leptopterna ferrugata (Linnaeus, 1758), Teratocoris saundersi Douglas et Scott, 1869, Plagiognathus obscuriceps (Stål, 1858), Plagiognathus pini Vinokurov, 1978, Psallus anticus (Reuter, 1876) (Miridae); Kleidocerys resedae (Panzer, 1797) (Lygaeidae); Aelia frigida Kiritshenko, 1926, Rhacognathus punctatus (Linnaeus, 1758) (Pentatomidae). The number of known Heteroptera species for the tundra region of Chukotka increased from 39 to 51; for the elfin wood subzone — from 10 to 32 species. Some distribution features of bug species within zonal and climatic gradients of Chukotka are revealed.