The brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae), is an invasive species in North America and Europe that damages many different host plants. Substantial work has been conducted on the genetic diversity and invasion pathways of H. halys in some of the countries where it has been found, based on mitochondrial sequences. The main objective of the present study was to further explore the genetic diversity of invasive populations of H. halys exploiting both mitochondrial and nuclear markers. We used two molecular markers: the mitochondrial Cytochrome Oxidase I (COI) gene, an ideal standardized molecular marker for distinguishing closely related species, and the ribosomal Internal Transcribed Spacer 1 (ITS1), because only a few sequences of H. halys exist to this point in global databases. We used specimens from eight populations from Greece, Italy, Canada, and the US. Among the 14 haplotypes retrieved based on the mtCOI gene, two of them (H162–H163) were detected for the first time. These two haplotypes were found in specimens from Canada, Italy, and the US. Concerning the ITS1 region, 24 haplotypes were identified, with 15 being unique for a sampled population. In Greece and the US, 14 and 12 haplotypes were found, respectively, with 7 and 6 of them being unique for Greece and the US, respectively. Our analysis of the nuclear genes of H. halys indicates high genetic diversity of the invading populations in North America and Europe.

Insects of the subfamily Typhlocybinae (Hemiptera: Cicadellidae) are pests of economically important agricultural and horticultural crops. They damage the plants directly or indirectly by transmitting plant pathogens, resulting in significant yield loss. Several leafhoppers of this subfamily use vines as hosts. Accurate and rapid identification is the key to their successful management. The aim of this study is to determine the Typhlocybinae species that exist in vineyards all over Greece and investigate the relationship between them. For this purpose, yellow sticky traps were placed, morphological and molecular data were collected, and phylogenetic models were analyzed. The mitochondrial marker Cytochrome Oxidase Subunit I (mtCOI) was applied for the DNA and phylogenetic analysis. The combination of morphological and molecular data resulted in identifying the existence of six different species all over Greece: Arboridia adanae, Asymmetrasca decedens, Hebata decipiens, Hebata vitis, Jacobiasca lybica and Zygina rhamni. Forty-eight different haplotypes were found to exist in the different regions of the country.

Whitefly species of Aleurocanthus spiniferus (Quaintance) and A. woglumi Ashby (Hemiptera: Aleyrodidae) are serious pests of citrus and other important fruit crops. The problem of citrus has initiated the successful introduction of several natural enemies for biocontrol programs in Hawaii and many other countries. Here, we summarized the history of infestation and biocontrol efforts of the two whiteflies in Hawaii for possible parasitoid importation into Greece. Two Platygasteridae (Amitus hesperidum Silvestri, A. spiniferus (Brethes), and three Aphelinidae (Encarsia clypealis (Silvestri), E. smithi (Silvestri), E. perplexa Huang, and Polaszek) were released in Hawaii for biocontrol of the citrus whiteflies during the period 1974–1999. The aphelinid Cales noacki Howard, purposely released for Aleurothrixus flococcus (Maskell) in 1982, was also reported to attack other whiteflies, including Aleurocanthus species, on citrus. An additional aphelinid parasitoid, Encarsia nipponica Silvestri, native to Japan and China, was accidentally introduced and found to attack both citrus whiteflies on the islands. Since the colonization of introduced parasitoids in infested fields on four Hawaiian Islands, no survey has been conducted to evaluate their potential impact. We conducted two short surveys during September–November 2022 on the islands of Kauai, Hawaii, and Oahu to introduce the dominant parasitoids to Greece for the biocontrol of A. spiniferus. Results showed that the infestation level was very low on Kauai, Hawaii, and Oahu Islands, with a mean infestation level range of 1.4–3.1 on Hawaii and Oahu Islands, mostly on pummelo and sweet orange, with no detection on the island of Kauai. The dominant parasitoid was characterized as Encarsia perplexa, using molecular analysis. Its parasitism rates ranged from 0 to 28% on the island of Hawaii and 11 to 65% on the island of Oahu. Emerged parasitoids have been reared in Greece for evaluation. This was the first field survey of Hawaii since the introduction and release of citrus whitefly natural enemies.

Citrus tristeza virus (CTV) is a vector-borne virus that poses a significant threat to citrus production worldwide, inducing a variety of symptoms. Therefore, a detailed knowledge of local aphids, identification of viruliferous species, and the development of new monitoring tools are necessary to improve CTV control strategies. Herein, a 2-year survey was conducted to assess the frequency of aphid species infesting several citrus pilot orchards. Plot findings based on morphological and molecular identification revealed Aphis spiraecola (ranged from 44–100%) as the most abundant aphid species, followed by A. gossypii (<50%). Toxoptera aurantii, Myzus persicae, and A. craccivora were present in low numbers, and A. citricidus was not detected. Due to the absence of CTV detection in aphids and citrus trees from the pilot orchards, a complementary survey was conducted in CTV-infected fields. Three aphid species were identified as CTV-positive by RT-PCR, suggesting that they may be viruliferous, with A. spiraecola as predominant, followed by A. gossypii and T. aurantii. Additionally, we developed a non-invasive procedure for identifying aphid species using wingbeat analysis. This method provides a faster alternative to traditional identification techniques by taxonomic keys based on morphological features or PCR, although its accuracy is lower (approximately 95% for the two species tested). Overall, this work provides a detailed study of aphid species composition in citrus orchards, identifies the predominant local putative CTV vector, and introduces a novel sensor for aphid monitoring, contributing to improved epidemic forecasting and sustainable disease management strategies.

Whiteflies of Aleurocanthus spiniferus and A. woglumi (Hemiptera: Aleyrodidae) are serious pests of citrus and other important fruit crops. The problem in citrus has initiated the successful introductions of several natural enemies for biocontrol programs in Hawaii and many other countries. Here we summarized the history of infestation and biocontrol efforts of the two whiteflies in Hawaii for possible importation into Greece. Two Platygasteridae (Amitus hesperidum Silvestri, A. spiniferus (Brethes) and three Aphelinidae (Encarsia clypealis (Silvestri), E. smithi (Silvestri), E. perplexa Huang and Polaszek) were released in Hawaii for biocontrol of the citrus whiteflies during the period 1974-1999. The aphelinid, Cales noacki Howard, purposely released for Aleurothrixus flococcus (Maskell) in 1982 was also reported to attack other whiteflies including Aleurocanthus species on citrus. An additional aphelinid parasitoid, Encarsia nipponica Silvestri, native to Japan and China, was accidently introduced and found to attack both citrus whiteflies on the islands. Since the colonization of introduced parasitoids in infested fields on four Hawaiian Islands, no survey was done to evaluate their potential impact. We made two short surveys during September-November 2022 on Kauai, Hawaii, and Oahu Islands to introduce the dominant parasitoids to Greece for the biocontrol of A. spiniferus. Results showed that the infestation level was very low on Kauai, Hawaii, and Oahu Islands with mean infestation level ranged 1.4 - 3.1 on Hawaii and Oahu Islands mostly on pummelo and sweet orange, with no detection on Kauai Island. Only was E. perplexa the dominant parasitoid with parasitism rates ranged 0 -28 % on Hawaii Island and 11-65% on Oahu Island. Starter colony of the parasitoids has been colonized in Greece for evaluation and approval for release. This was the first field survey on Hawaii since the introduction and release of citrus whitefly natural enemies.

The genus Physokermes (Hemiptera: Coccoidea: Coccidae) includes species that parasitize coniferous trees. They are considered both as pests of forests and as highly beneficial species in Apiculture when bees produce honey with specific physicochemical characteristics, using the honeydew excreted by these scale insects. The identification of these important species is based only on morphological characteristics. Genetic taxonomy on these species is lacking, thus the aim of the present study is the molecular taxonomy and the examination of the possible phylogenetic relationships of the Physokermes species in Greece based on mtDNA sequencing data. The sampling of adult females was conducted in several mountain places of Greece. Based on the recent key to female Physokermes species, all specimens were found to be Physokermes hellenicus. The sequencing of COI mtDNA gene segment produced 14 different haplotypes. Our data, based on mtDNA analysis on samples that belong to Physokermes genus, collected from different areas of Greece, show that the variability detected is not connected to the geographical origin. The average pairwise genetic distance detected, based on our obtained data, does not sufficiently document the existence of different species. Further research on a wider sampling is necessary to confirm the above conclusions. Taxonomía molecular del género Physokermes (Hemiptera: Coccidae) en Grecia basada en datos de secuenciación de ADN mitocondrial El género Physokermes (Hemiptera: Coccoidea: Coccidae) incluye especies que parasitan coníferas. Son consideradas como plagas en los bosques o como especies altamente beneficiosas en la Apicultura cuando las abejas producen miel con características físico-químicas específicas, explorando la excreción de melaza por estos insectos escamosos. La identificación de estas importantes especies se basa únicamente en características morfológicas. Falta taxonomía genética en estas especies, por lo que el objetivo del presente estudio es la taxonomía molecular y el examen de las posibles relaciones filogenéticas de las especies de Physokermes en Grecia basadas en datos de secuenciación de ADNmt. El muestreo de hembras adultas se realizó en varias zonas montañosas de Grecia. Basándose en la clave reciente de la especie hembra Physokermes, todos los especímenes encontrados son Physokermes hellenicus. La secuenciación del segmento genético COI mtADN produjo catorce haplotipos diferentes. Nuestros datos, basados en el análisis de ADN mitocondrial en muestras que pertenecen al género Physokermes, recogidas en diferentes zonas de Grecia, muestran que la variabilidad detectada no está relacionada con el origen geográfico. La distancia genética media por pares detectada, basada en nuestros datos obtenidos, no documenta suficientemente la existencia de diferentes especies. Se necesitan más investigaciones sobre un muestreo más amplio para confirmar las conclusiones mencionadas anteriormente.