Hymenopteran parasitoids reared from European gall midges (Diptera, Cecidomyiidae).

We report the results of investigations 2010 through 2023 of hymenopteran parasitoids associated with gall midges in Europe. A total of 242 collections of gall midges were made, from each of which one to several parasitoid species emerged, resulting in ca. 200 recorded parasitoid species and 267 host-parasitoid interaction records. The parasitoid families involved were Eulophidae (63 species), Platygastridae (56 species), Torymidae (34 species), Pteromalidae (31 species), Ceraphronidae (5 species), Eupelmidae (4 species), Eurytomidae (2 species) and Encyrtidae (1 species). As many as 159 interactions are reported for the first time, significantly enlarging our knowledge of gall midge - parasitoid interactions on the species level. Even more interesting, 51 host records are for parasitoid species for which no host was previously known. Similarly, 28 species of gall midge are reported as host to named parasitoids for the first time. Additionally, 91 parasitoid records were the first for the country in question. Differences between the rearing methods applied and their suitability for recording species with contrasting life histories, are discussed.

Completing Linnaeus's inventory of the Swedish insect fauna: Only 5,000 species left?

Despite more than 250 years of taxonomic research, we still have only a vague idea about the true size and composition of the faunas and floras of the planet. Many biodiversity inventories provide limited insight because they focus on a small taxonomic subsample or a tiny geographic area. Here, we report on the size and composition of the Swedish insect fauna, thought to represent roughly half of the diversity of multicellular life in one of the largest European countries. Our results are based on more than a decade of data from the Swedish Taxonomy Initiative and its massive inventory of the country's insect fauna, the Swedish Malaise Trap Project The fauna is considered one of the best known in the world, but the initiative has nevertheless revealed a surprising amount of hidden diversity: more than 3,000 new species (301 new to science) have been documented so far. Here, we use three independent methods to analyze the true size and composition of the fauna at the family or subfamily level: (1) assessments by experts who have been working on the most poorly known groups in the fauna; (2) estimates based on the proportion of new species discovered in the Malaise trap inventory; and (3) extrapolations based on species abundance and incidence data from the inventory. For the last method, we develop a new estimator, the combined non-parametric estimator, which we show is less sensitive to poor coverage of the species pool than other popular estimators. The three methods converge on similar estimates of the size and composition of the fauna, suggesting that it comprises around 33,000 species. Of those, 8,600 (26%) were unknown at the start of the inventory and 5,000 (15%) still await discovery. We analyze the taxonomic and ecological composition of the estimated fauna, and show that most of the new species belong to Hymenoptera and Diptera groups that are decomposers or parasitoids. Thus, current knowledge of the Swedish insect fauna is strongly biased taxonomically and ecologically, and we show that similar but even stronger biases have distorted our understanding of the fauna in the past. We analyze latitudinal gradients in the size and composition of known European insect faunas and show that several of the patterns contradict the Swedish data, presumably due to similar knowledge biases. Addressing these biases is critical in understanding insect biomes and the ecosystem services they provide. Our results emphasize the need to broaden the taxonomic scope of current insect monitoring efforts, a task that is all the more urgent as recent studies indicate a possible worldwide decline in insect faunas.

Review of the genus Isolia Förster (Platygastroidea: Platygastridae: Sceliotrachelinae) with description of two new species from India.

Two new species of Isolia Förster viz. I. bhima Veenakumari and Buhl sp. n. and I. bandoola Veenakumari and Buhl sp.n. are described and illustrated from India. The generic concept of Isolia has been expanded with additional characters. Supplementary characters have been provided to the original descriptions wherever required. All species (except I. longistriata Alekseev), including the six Palearctic species (I. biroi Szabó, I. dobrogica Popovici Buhl, I. foersteri Szabó, I. hispanica Buhl, I. mongolica (Kozlov) and I. santosi García Pujade-Villar) and the two Oriental species (I. indica Buhl and I. kalingae Veenakumari Buhl) have been imaged. Isolia striatitergitis Szabó is transferred to the genus Fidiobia Ashmead, and the images are provided. Isolia kalingae is treated as a junior synonym of I. indica. A key is furnished to differentiate genera in the Isolia-cluster and the species of Isolia treated here.

A new species of Platygaster Latreille (Hymenoptera: Platygastridae) parasitizing Chilophaga virgati Gagné (Diptera: Cecidomyiidae).

Platygaster chilophagae, new species, is described from specimens reared from larvae of Chilophaga virgati Gagné collected and reared in eastern South Dakota. The host larva feeds on the basal meristematic tissues of the inflorescence of Panicum virgatum L. This new species seems to lack immediate affinities with any described Platygaster species in its combination of characteristics, and is compared to and discriminated from six other species. Polyembryony is suggested by the presence of cocoon clusters containing 4-14 pupae from each host larva.