Annette Herz

Recent technological advances allow for the large-scale acquisition of genetic and morphological data: high-throughput sequencing has transformed the field of genomics while synchrotron X-ray microtomography enables rapid, noninvasive 3D imaging. However, integrating these approaches for the same specimens is challenging because X-rays can fragment DNA, and DNA extraction damages internal morphology, particularly relevant for small bodied organisms, such as insects. We systematically tested multiple extraction protocols and irradiation conditions across three model insect species. We irradiated more than 1,000 specimens under varying conditions and tested DNA quality through DNA barcoding and UCE sequencing. Our results demonstrate that high-quality DNA and high-resolution tomograms can be obtained from the same individuals, provided that the parameters are carefully optimized and rapid SR-μCT scanning precedes DNA extraction. In this respect, our findings establish practical guidelines for combining genomics and phenomics, paving the way for comprehensive integrative digitization of biodiversity.

The parasitoid Leptopilina japonica Novković & Kimura (Hymenoptera: Figitidae) is a natural enemy of the invasive Drosophila suzukii Matsumura (Diptera: Drosophilidae), which is a significant pest in berry and fruit production. Both species originate from East Asia and after its initial detection in Europe in 2019, L. japonica has quickly spread and has established more northwards in several countries. Therefore, the potential of L. japonica for natural regulation of D. suzukii needs to be evaluated under various climatic conditions. This study is the first to examine the life history traits of L. japonica under fluctuating temperature and humidity conditions relevant in Central Europe, one of its new distribution areas and that from its main host D. suzukii . Average values for early (16.1°C–27.2°C) and late (12.3°C–23.9°C) summer days in Germany, during which host populations begin to increase or reach their peak, respectively, were simulated in the laboratory. Single pairs of wasps were mated and regularly provided with fresh hosts ( D. suzukii L2‐larvae) from emergence until death under the conditions of early and late summer in comparison to standard rearing conditions (permanent 23°C, 60% humidity). Parasitized hosts were further incubated under these conditions until emergence. The development rate did not differ between early summer and the control group, but was somewhat delayed under the cooler conditions of late summer. At this regime, however, the lifespan, lifetime fecundity, proportion of female offspring, and apparently also mating success were higher. These findings indicate the best performance of the parasitoid during the peak of its host's population density toward the end of the season and are also consistent with current observations that L. japonica is most common in late summer. In summary, analyses of thermal performance should account for fluctuating conditions in order to more reliably predict a parasitoid's field performance.

The occurrence of the native ragwort Jacobaea vulgaris and its relatives is a problem for grassland owners, due to the pyrrolizidine alkaloids being poisonous for livestock. Besides J. vulgaris , the invasive Senecio inaequidens is challenging and control measures in line with nature conservation goals are needed. To evaluate prospects of using the native and herbivorous Tyria jacobaeae as a biological control agent, we studied its performance on S. inaequidens in comparison to the native J. vulgaris and J. aquatica. We compared the egg-laying decision of 106 females (number and placement of eggs on the plant, in the surrounding or not laid at all) and performance of 50 larvae, reared in five treatments with different food supply (only leaves or leaves and flowers) of the three ragwort species. We found that females oviposited preferably on the plant when J. vulgaris and J. aquatica were available, whereas in the presence of S. inaequidens most eggs were retained and not laid. No differences were observed in larval weight, weight gain, or leaf area consumed when larvae were fed with J. vulgaris (leaves, leaves and flowers) or J. aquatica leaves. Furthermore, 90% of the larvae provided with these treatments pupated successfully. In contrast, larvae developed slowly when provided with S. inaequidens and none survived to pupation. Our results show that J. aquatica is a suitable alternative host for T. jacobaeae , whereas S. inaequidens is not. We therefore argue that T. jacobaeae has no biological control potential against S. inaequidens .

The box tree pyralid moth ( Cydalima perspectalis ), which originates from Asia and has been introduced to Europe in 2006, has now infested several countries and continents outside its natural distribution. This herbivore is specialized on Buxus spp. and has destroyed not only many ornamental plantings, which are often of historical value, but also boxwood in its natural range, where it is often part of certain forest types. To date, no effective natural enemies are known, and plantings can only be saved by frequent insecticide applications, while natural boxwoods are threatened or have already gone extinct after massive outbreaks of this pest. During a monitoring in 2025, we discovered a parasitoid population in one of the first infested natural Buxus spp. stands in Europe, the boxwood forest near Grenzach-Wyhlen, Germany. According to our data, this Campoplegine larval parasitoid, Eriborus sp., is not native, but may have been accidentally introduced in the years after the introduction of its host nearby.

The spotted‐wing drosophila, Drosophila suzukii , is one of the most damaging invasive fruit pests in the world. It infests a wide range of wild and crop host plants, impacting natural habitats and causing significant economic losses. Leptopilina japonica , a predominant larval parasitoid of D. suzukii in the native areas of the fly, is now spontaneously expanding into non‐native areas of its fly host. This study documents the presence and genetic structure of L. japonica collected from various wild and cultivated fruits across 11 sites in France in 2023. Leptopilina japonica emerged from 15% of fruit samples and was strongly positively associated with D. suzukii , showing parasitism rates of up to 38.5%, notably in Lonicera fruits. Despite this, D. suzukii remained dominant, indicating a limited current biocontrol effect, while native parasitoids were nearly absent from samples. Molecular analyses using COI markers revealed 10 distinct haplotypes of the L. j. japonica subspecies in France that clustered into three groups, suggesting multiple introductions and/or migration routes into France from Asia, North America and neighbouring European countries. The lack of nuclear diversity measured from ITS2 markers suggests that the colonization is recent and that the populations experienced a bottleneck process. Nevertheless, a more extensive sampling combined with the use of additional genetic markers would be needed to better understand the origin and spread of L. japonica and its consequences on the equilibrium of Drosophila communities.

The genus Leptopilina comprises species of parasitoid wasps that primarily attack early instar larvae of drosophilid species, some of which are well-known agricultural or nuisance pests. To unravel host-parasitoid interactions and to use parasitoids effectively in biological control, the correct taxonomic assignment is of crucial importance. In the course of the German Barcode of Life III: Dark Taxa (GBOL III: Dark Taxa) project, we assembled specimens of all seven species of Leptopilina of the Western Palearctic. Using CO1 barcode sequence analyses and morphological examination allows us to evaluate species limits in an integrative approach, to provide extended species diagnoses as well as an updated key to the species of the Western Palearctic. This work also summarizes current knowledge on Western Palearctic Leptopilina species, including their distribution, population parameters, habitats, flight periods, and hosts. We provide the first country records of three Leptopilina species for Belgium, including the non-native L. japonica , propose two species level synonymies and move one Western Palearctic species out of Leptopilina . Finally, to facilitate taxonomic research on Leptopilina in lesser-known regions, we provide a list of non-Western Palearctic species, including the moving of 13 species into Leptopilina . These changes also result in two new generic synonymies. In conclusion, Western Palearctic Leptopilina can be clearly diagnosed both morphologically and molecularly. Comparable ease of identification and cultivation, as well as the economic interest in potent biological control agents against drosophilid pests make them ideal organisms for basic and applied research.

Liotryphon caudatus, an ichneumonid parasitoid of codling moth (Cydia pomonella), is known to perform host-feeding on late-instar host larvae. In this study, we examine the relationship between host-feeding, parasitisation behaviour and nutritional requirements of L. caudatus females and the impact on oogenesis and parasitism success. Using a series of laboratory experiments, we demonstrate that female L. caudatus lacking access to hosts for host-feeding were not able to develop mature eggs. Females successfully attacked only the immobile stages of codling moth to either host-feed or parasitise. No major differences in host attack behaviour were observed between naïve and experienced females, as both performed host-feeding similarly. However, experienced females exhibited significantly greater parasitisation success. We also found that when fed honey, female longevity increased up to fivefold compared to having only host-feeding opportunities or to a pure water control. Additionally, success in killing host larvae through host-feeding or parasitism was significantly enhanced with the access to honey. Overall, our findings emphasize that the presence of a carbohydrate source (honey) and a suitable host for host-feeding (immobile larval stages) are essential for the effective parasitisation and host-feeding performance of L. caudatus, as well as for the prolonged survival of females. This study provides new insights into the nutritional requirements, host preferences, and behavioural strategies of L. caudatus and underscores the importance of host-feeding for the reproductive success and survival of this parasitoid.

Biological control is a recognized and well-implemented strategy to protect crops from pests and diseases, and there is an urgent need to expand biocontrol-based crop protection further, also in Germany. Specially, the use of invertebrate biological control agents (IBCA) is considered as a fundamental method in integrated pest management and organic farming. The objective of this article is to give an overview of the current commercially available and used IBCA species in Germany. Of those, individual non-indigenous species are critically examined for potential environmental risks. Furthermore, the current legal situation in Germany about the use of IBCA is described. Based on this information, this article clarifies the need for an environmental impact assessment for IBCA species that do not occur naturally in Germany. An outlook for their safe use in the future is discussed.