AbstractAs walnut trees (Juglans spp.) are of high economic importance, considerable attention has been given to invasive pests of these trees in Europe. In 2016, Dryocoetes himalayensis Strohmeyer, 1908, an alien bark beetle originating from the Himalayas region of India, already present in several European countries, was confirmed to have attacked walnut trees in the Czech Republic. Within the present study, we (i) surveyed the current distribution of D. himalayensis in the Czech Republic, (ii) examined D. himalayensis phenology by rearing it in trap logs, and (iii) investigated tree level habitat preferences of the species in two study stands with 180 black walnut (Juglans nigra L.) trees and 66 common walnut (Juglans regia L.) trees sampled. The present study documented the species to be relatively widespread in some warmer lowland regions of the Czech Republic (42 localities found) and to reach high abundance locally. Almost 15 thousand D. himalayensis individuals reared from the trap logs showed the species emerging throughout the whole vegetation period with a distinctive peak in June. Even though the species is able to develop in thin stems (diameter <5 cm), it is most numerous in thicker trunk bases and also preferably attacks trees of higher diameters. The species preferred common walnut trees (its native host) with decreased vitality. In contrast, black walnut trees (North American species) were attacked regardless of their vitality, but the vitality of occupied trees successively decreased. Based on our results, D. himalayensis should be assumed as a considerable pest of walnut trees (particularly black walnuts), which might become of significant importance in its European invasive range in the future, and thus substantial attention should be given to it.

AbstractUnderstanding the cues used by insects to select their hosts is essential for developing sustainable control strategies, particularly for plant disease vectors. Pear psyllids (Cacopsylla pyri) are vectors of the bacterial disease pear decline caused by ‘Candidatus Phytoplasma pyri’. Yellow sticky traps are typically used to monitor pest insects, but they are non‐specific and capture many beneficial insects, too. Against the background of improving visual traps, this research aimed to investigate the colour choice behaviour of C. pyri. Our first approach was to screen insect colour preferences by performing choice assays with different LED colour wavelengths in a small‐scale choice arena under controlled conditions. Over six LEDs tested, there was a strong significant preference of C. pyri for green 1 (532 nm) followed by green 2 (549 nm). Yellow (576 nm), orange (593 nm), red 1 (619 nm) and red 2 (633 nm) were less attractive than green. Subsequently, the trapping of pear psyllids was tested in the field using newly developed traps covered with transparent‐coloured PVC sheets with a similar wavelength of the preferred LEDs. Red and completely transparent traps have been used as control and combined in randomized blocks in a pear orchard. Field trials revealed that green traps ranging from 525 to 537 nm attracted significantly more pear psyllids than longer wavelength green (543 nm), red and transparent ones. The construction of specific green‐coloured sticky traps seems promising for improving psyllid trapping, especially during an early infestation at low population densities. Thus, these visual traps should be considered in future and integrated into psyllid monitoring as part of integrated pest management.

AbstractThe application of fungal entomopathogens, such as Metarhizium brunneum, has the potential to continue to impact targeted host populations through secondary cycling. In the present study, we examined the horizontal transmission of M. brunneum conidia from conspecific mycosed cadavers or soil on which the cadavers sporulated to Agriotes obscurus beetles. Close contact between the susceptible hosts and sporulating cadavers or contaminated soil was required for increased mortality of hosts and subsequent production of mycosed cadavers.

AbstractOne of the major problems in orchards is the presence of Tephritidae fly maggots, especially in Mirtaceae species. Various biological control tools include the use of Hymenoptera parasitoids, which naturally control fly populations. However, identification of the host species of parasitoids is challenging, because only the puparium remains after the parasitoid hatches. Therefore, the aim of this work was to determine the host species of Hymenoptera parasitoids, through the puparium. Host species were identified by amplification and sequencing of cytochrome C oxidase subunit I (COI) of mitochondrial DNA. The results of the present study show that COI DNA sequencing was able to reliably identify host pupae to the genus level, allowing the identification of the Anastrepha genus in this study. This suggests that this method can be used to identify agriculturally relevant hosts through its puparium remains, since this genus has already been described as a pest of Campomanesia adamantium. Knowledge of the species that cause damage to crop is extremely important to study the biological and ecological aspects of these pests and their control. In this way, our results suggest that this method can be used to identify economically relevant host pupal species since the genus identified in this study has already been described as a pest of C. adamantium.

AbstractSunflowers (Helianthus annuus) are potential trap crops to attract the yellow peach moth (Conogethes punctiferalis) in orchards but the volatile compounds released from sunflowers and their effects on C. punctiferalis behaviour are not clear. Here we used solid phase micro‐extraction to collect volatiles released from flower disks of sunflowers, identified them by gas chromatography–mass spectrometry, and examined the attractiveness of some of the compounds to mated female adult C. punctiferalis moths in Y‐tube olfactometer choice tests. We detected nine volatile compounds (α‐Pinene, β‐Phellandrene, Camphene, β‐Pinene, 3‐Carene, D‐Limonene, Eucalyptol, γ‐Terpinen, and Valencene) with consistently large peak areas for α‐Pinene and β‐Phellandrene. Among tested volatiles, both α‐Pinene and β‐Phellandrene were attractive to C. punctiferalis in olfactometer tests but this was only significant for higher concentrations of β‐Phellandrene. This suggests that β‐Phellandrene may promote C. punctiferalis oviposition on sunflower disks. This study provides insights into volatile chemical mediated responses of insect herbivores to trap crops.

AbstractAgriculture remains a major source of subsistence for local communities in India. However, agricultural yield can be strongly affected by agricultural pest outbreaks. This can result in economic losses for small‐scale farmers who already experience socio‐economic challenges, such as lack of appropriate infrastructure and subsides. Sophisticated pest management techniques (e.g. sterile insect technique) are less accessible to small farmers in developing countries, and therefore, alternative cost‐effective approaches for pest management are needed. Here, we report our findings of a 3‐year field trial (2018–2020) in India, which was designed to test for the potential effectiveness of a novel, slow‐release formulation protein‐based trap, compared to standard Cuelure traps against melon flies Bactrocera cucurbitae (Diptera: Tephritidae). Protein‐bait traps can attract flies from both sexes (as opposed to male‐only, chemical traps), bearing the potential to have a greater long‐term impact on pest populations by decreasing future reproductive potential of trapped individuals. We found that, despite uneven sampling efforts, Cuelure had overall higher trapping performance, while protein‐bait traps, despite trapping at lower efficiency, were equally effective for trapping males and females. Simulations with our field data revealed that protein‐bait traps can have an ‘inclusive’ advantage by trapping females and thereby preventing future individuals. Overall, our study highlights the potential benefits of using this alternative trapping technique to supplement pest management in developing countries.

AbstractStudies of moth pests (Lepidoptera: Tortricidae) of pome fruit in Washington State, USA, evaluated the addition of low‐intensity light‐emitting diode (LED) lights to traps baited with sex pheromone or kairomone lures. Species included codling moth (CM), Cydia pomonella (L.), oriental fruit moth (OFM), Grapholita molesta (Busck), oblique banded leafroller (OBLR), Choristoneura rosaceana (Harris), and eye‐spotted budmoth (ESBM), Spilonota ocellana (Denis and Schiffenmüller). Lures included (E,E)‐8,10‐dodecadien‐1‐ol (codlemone) plus (E,Z)‐2,4‐ethyl decadienoate (pear ester) and acetic acid (AA) (Combo) and a blend of pear ester, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene, pyranoid linalool oxide, and AA (4K) for CM; a three‐component OFM sex pheromone ((E)‐8‐dodecen‐1‐yl‐acetate, (Z)‐8‐dodecen‐1‐yl acetate, and (Z)‐8‐dodecen‐1‐ol) plus codlemone and terpinyl acetate plus AA for OFM; and 2‐phenylethanol and AA for OBLR and ESBM. Traps baited with only LEDs were not attractive for any of these tortricids. The addition of a LED to lure‐baited traps increased male and female catches 2‐12‐fold across the four pest species. The proportional increase in CM catches with the LEDs was similar with both the Combo and 4K lures. Traps baited with the 4K lure caught significantly more CM with a UV LED than with either blue or green LEDs. The proportion of females caught in traps that were mated did not change with the use of the lights across species. Significantly more CM of both sexes were caught in the adhesive on the side of the liner nearest the LED. The addition of LEDs sometimes increased the by‐catch of minute insects, but liners' saturation was never a factor impacting targeted moth catch. Adding the LED light significantly increased the catch of ESBM in CM‐baited traps and CM in OFM‐baited traps, respectively. The development of inexpensive, dual‐modality traps that add a light stimulus to a kairomonal‐based lure may improve direct control of these key orchard pests via female removal.

AbstractBemisia tabaci is a group of cryptic and morphologically indistinguishable species able to cause severe damage to many agricultural and ornamental plants. Among the various species of this complex, the Mediterranean (MED) and Middle East Asia Minor 1 (MEAM1) species stand out as they are highly polyphagous, invasive, easily in acquiring resistance to many insecticides and reproduce quickly. Considering how (1) the geographic distribution of B. tabaci is changing with the ongoing global climate change and (2) no knowledge is presently available on phylogenetics of whitefly endosymbionts in Sicily, a population survey was conducted in the most important horticultural production areas of the island to assess the species composition within the B. tabaci complex, including their endosymbiont community and their geographic distribution. Our results show that the MEAM1 species and two mitochondrial variants of B. tabaci MED are present in pure or mixed populations, the MED Q1 presents the highest level of genetic variability within the MED populations in Sicily, having been found almost across the island and, MED Q2 was nearly exclusively detected in the Ragusa province. MEAM1 individuals were rare and exclusively detected in two localities in the Trapani province. The survey on endosymbionts community revealed the existence of a species specific composition, showing the lowest endosymbiont diversity in MED Q2 populations, typically characterized by only Rickettsia. Moreover, except for Portiera in MEAM1, no sequence variation was found within any endosymbiont sequence. Co‐infection patterns of different endosymbiont species are discussed in the context of their needs for host cell metabolites. The present study defines an updated distribution map of cryptic species and phylogenetic groups of the B. tabaci complex and the first status on the endosymbiont community in Sicily; but it also represents the first report of whitefly endosymbionts sequences not only from Sicily but from Italy as a whole.

AbstractTwo years after the first European record in Italy, we report the first occurrence of the parasitoid wasp Leptopilina japonica Novković & Kimura, 2011 (Hymenoptera: Figitidae) in Germany. The species is a larval‐pupal parasitoid of Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae), which is a widespread invasive and economically important pest of soft‐skinned fruit. In total, we found 29 specimens of L. japonica in five different locations in southern and western Germany in the years 2021, 2022 and 2023. We examined the specimens morphologically and generated their DNA barcodes for identification. In three of the locations, L. japonica was sampled from raspberries. In two locations, L. japonica was caught in two and three consecutive years, respectively, which indicates adventive establishment. As D. suzukii and L. japonica originate from the same region in Asia, the possible establishment of L. japonica could be a case of unintentional biological control in Germany. In addition to this first record in Germany, we present a diagnosis of L. japonica to distinguish the species from the rest of the European Leptopilina fauna.