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Wheat stem sawfly (WSS), Cephus cinctus (Hymenoptera: Cephidae), is a native grass-feeding insect and one of the most important pests of wheat in North America. Yield losses from WSS can be due to stem boring and/or stem cutting which causes plants to lodge. Current methods, such as solid stem varieties and insecticides, do not effectively control WSS. A better understanding of WSS emergence, population size, and related environmental factors is critical to building efficient and effective integrated pest management (IPM) strategies for this pest. In this study, wheat fields were sampled for adult WSS from mid-April to the end of June between 2011 and 2023 in several field sites in two locations in Colorado. This multi-year data created a phenology model that predicts adult WSS emergence and population peak based on growing degree-day (GDD). The inter-annual variability in emergence timing based on calendar date was substantially reduced when using a GDD model with a base temperature of 10°C, an upper threshold of 30°C, and a biofix of Jan 1. The model predicted initial WSS emergence at 148 GDD, population peak at 224 GDD, and decline at 354 GDD. We also modeled the effects of environmental factors on mean WSS populations at each field site, finding that higher WSS populations are associated with longer emergence periods, less precipitation before emergence, milder temperatures during emergence, and milder maximum temperatures before and during emergence. By analyzing multiple years of comprehensive phenology data, we provide robust models to guide adult WSS forecasting and monitoring for the first time. Further, this data will aid in decision-making related to timely and effective management strategies to suppress populations of WSS.

A new species of the genus Bicurta Sheng, Broad & Sun, 2012, is described and illustrated, B.hejunhuai sp. nov., from North and Northeast China. The new species was reared from the stem-sawfly Stenocephusfraxini Wei (Hymenoptera, Cephidae), which is the first host record for the genus Bicurta.

Cephus cinctus Norton (Hymenoptera: Cephidae), the wheat stem sawfly, is a well-established and important pest of wheat, Triticum aestivum Linnaeus (Poaceae), and its relatives in North America. Crop losses are caused directly by C. cinctus feeding inside wheat stems during larval development and indirectly when weakened plants lodge before being harvested. Understanding the factors that affect population dynamics of C. cinctus can help farmers to better manage it. Our study therefore explored how C. cinctus and natural enemy densities vary in space (southern Alberta, Canada) and over time. Five fields were sampled using an established protocol in fall 2019 and resampled in spring 2020; six additional fields were sampled in fall 2020 and resampled in spring 2021. Wheat stubs were dissected to record numbers of cut stems, C. cinctus larvae, and sources of larval mortality (i.e., parasitism, fungal infection). Densities of wheat stem sawfly and the impact of natural enemies varied between the sampled fields. No C. cinctus mortality was observed during the winter, indicating that C. cinctus population dynamics are not susceptible to mortality (abiotic or biotic) between years. Results of our study will be incorporated into new models to predict wheat stem sawfly phenology and risk to crop production.

Providing sugar resources for parasitoids is an important component of habitat management approaches to bolster biological control. We screened three flowering cover crop species, and one aphid species, for their potential to increase the longevity of the parasitoid wasp, Bracon cephi (Gahan) (Hymenoptera: Braconidae), an important biological control agent of the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae). We found that buckwheat and honeydew from the cereal aphid, Rhopalosiphum padi (Linnaeus) (Hemiptera: Aphididae), increased longevity of B. cephi females by over threefold, while longevity on sunflower and coriander was not significantly different from controls on wheat.The results suggest that incorporating buckwheat into cover crop mixes could enhance parasitoid performance. However, the finding that honeydew associated with a common aphid in wheat provides a suitable resource suggests that a better understanding of the varying quality, and spatial and temporal availability, of aphid honeydew will be a critical consideration in evaluating the potential benefits of managing floral resources for parasitoid conservation in this system.

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is a key pest of wheat in the northern Great Plains of North America, and damage resulting from this species has recently expanded southward. Current pest management practices are inadequate and uncertainty regarding geographic origin, as well as limited data on population structure and dynamics across North America impede progress towards more informed management. We examined the genetic divergence between samples collected in North America and northeastern Asia, the assumed native range of C. cinctus using two mitochondrial regions (COI and 16S). Subsequently, we characterized the structure of genetic diversity in the main wheat producing areas in North America using a combination of mtDNA marker and micro-satellites in samples collected both in wheat fields and in grasses in wildlands. The strong genetic divergence observed between North American samples and Asian congeners, in particular the synonimized C. hyalinatus, did not support the hypothesis of a recent Ameri-can colonization by C. cinctus. Furthermore, the relatively high genetic diversity both with mtDNA and microsatellite markers offered additional evidence in favor of the native Ameri-can origin of this pest. The genetic diversity of North American populations is structured into three genetic clusters and these are highly correlated with geography. Regarding the recent southern outbreaks in North America, the results tend to exclude the hypothesis of recent movement of damaging wheat stem sawfly populations from the northern area. The shift in host plant use by local populations appears to be the most likely scenario. Finally, the significance of these findings is discussed in the context of pest management.

Background Wheat stem sawflies (WSS) [ Cephus pygmeus (L.) and Trachelus tabidus (F.) (Hymenoptera: Cephidae)] are significant pests in wheat-growing areas of the Southeastern Anatolia region, Türkiye. These species pose a significant threat to wheat production in the region. Larval feeding within the stem leads to considerable yield losses. Natural enemies play a pivotal role in integrated management strategies for WSS. The present study determined the parasitoid species associated with WSS in wheat fields of the Southeastern Anatolia region, Türkiye. The wheat root samples (stubbles left after harvesting) infested with WSS were collected and reared from four provinces (i.e., Adıyaman, Diyarbakır, Mardin, and Şanlıurfa) during 2021–2022. Results Two parasitoid species, Ceratobracon stschegolevi (Telenga, 1933) (Hymenoptera: Braconidae) and Collyria coxator (Viller, 1789) =  Collyria calcitrator (Gravenhorst) (Hymenoptera: Ichneumonidae), were recorded associated with the WSS in the region. The most frequently recorded species was C. coxator . Adıyaman province recorded the highest parasitism rate, whereas Diyarbakır and Mardin demonstrated lower rates. The overall parasitism rate was 22.3%, with the highest percentage found for C. coxator (15.3%) followed by C. stschegolevi (10.5%). Conclusion Parasitism rates varied among provinces, likely due to varying pest management strategies aimed at other cereal pests. Therefore, wheat producers are advised to avoid the indiscriminate use of pesticides in order to promote parasitism rates and suppress WSS populations.

The wheat stem sawfly, (Cephus cinctus Norton) Hymenoptera: Cephidae, has been a major pest of winter wheat and barley in the northern Great Plains for more than 100 years. The insect's cryptic nature and lack of safe chemical control options make the wheat stem sawfly (WSS) difficult to manage; thus, biological control offers the best hope for sustainable management of WSS. Entomopathogenic nematodes (EPNs) have been used successfully against other above-ground insect pests, and adding adjuvants to sprays containing EPNs has been shown to improve their effectiveness. We tested the hypothesis that adding chemical adjuvants to sprays containing EPNs will increase the ability of EPNs to enter wheat stems and kill diapausing WSS larvae. This is the first study to test the ability of EPNs to infect the WSS, C. cinctus, and test EPNs combined with adjuvants against C. cinctus in both the laboratory and the field. Infection assays showed that three different species of EPNs caused 60-100% mortality to WSS larvae. Adding Penterra, Silwet L-77, Sunspray 11N, or Syl-Tac to solutions containing EPNs resulted in higher WSS mortality than solutions made with water alone. Field tests showed that sprays containing S. feltiae added to 0.1% Penterra increased WSS mortality up to 29.1%. These results indicate a novel control method for WSS, and represent a significant advancement in the biological control of this persistent insect pest.

While working on an identification guide to the sawflies of Fennoscandia, we encountered numerous taxonomic problems, for some of which we present solutions. Dicrostema Benson, 1952 is a new synonym of Phymatoceropsis Rohwer, 1916, and not congeneric with Paracharactus MacGillivray, 1908. Two species occurring in Europe are transferred to Phymatoceropsis . Dolerus aericepsellus Heidemaa and Mutanen sp. nov. and Heptamelus viitasaarii Liston, Mutanen and Prous sp. nov. are described from Finland. Abia brevicornis Leach, 1817 nom. rev. is the valid name of Abia nitens auct. nec Linnaeus, and Abia nitens (Linnaeus, 1758) is the valid name for what has recently been called Abia sericea (Linnaeus, 1767). Tenthredo haemorrhoidalis Fabricius, 1781 is treated as an unplaced species of Hymenoptera, possibly Ichneumonoidea. Calameuta variabilis (Mocsáry, 1886) is the valid name of the species recently generally called C. haemorrhoidalis . Claremontia confusa (Konow, 1886) sp. rev. and Claremontia brevicornis (Brischke, 1883) are distinct species. Dolerus coracinus (Klug, 1818) is the valid name for D. anthracinus auct. Dolerus anthracinus (Klug, 1818) is a valid species similar to D. nitens Zaddach, 1859. Dolerus coruscans Konow, 1890 sp. rev. is a valid species. Dolerus junci (Stephens, 1835) is the valid name for Dolerus cothurnatus auct. Dolerus timidus (Klug, 1818) sp. rev. is distinguished from the similar D. pratensis (Linnaeus, 1758). A neotype is designated for Astatus punctatus Klug, 1803. Lectotypes are designated for 39 nominal species. 29 species group names are new junior synonyms. We present data on some species recently collected for the first time in Finland, including first records for the Palaearctic and West Palaearctic.

Most barley cultivars have some degree of resistance to the wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae). Damage caused by WSS is currently observed in fields of barley grown in the Northern Great Plains, but the impact of WSS damage among cultivars due to genetic differences within the barley germplasm is not known. Specifically, little is known about the mechanisms underlying WSS resistance in barley. We characterized WSS resistance in a subset of the spring barley CAP (Coordinated Agricultural Project) germplasm panel containing 193 current and historically important breeding lines from six North American breeding programs. Panel lines were grown in WSS infested fields for two consecutive years. Lines were characterized for stem solidness, stem cutting, WSS infestation (antixenosis), larval mortality (antibiosis), and parasitism (indirect plant defense). Variation in resistance to WSS in barley was compared to observations made for solid-stemmed resistant and hollow-stemmed susceptible wheat lines. Results indicate that both antibiosis and antixenosis are involved in the resistance of barley to the WSS, but antibiosis seems to be more prevalent. Almost all of the barley lines had greater larval mortality than the hollow-stemmed wheat lines, and only a few barley lines had mortality as low as that observed in the solid-stemmed wheat line. Since barley lines lack solid stems, it is apparent that barley has a different form of antibiosis. Our results provide information for use of barley in rotation to control the WSS and may provide a basis for identification of new approaches for improving WSS resistance in wheat.

New taxonomic, biological and faunistic data are presented for some species of sawflies occurring in southern Europe and North Africa. Pamphilius mediterraneus sp. nov. is described from Italy (Sicily). It belongs to the alternans sub-group of the alternans species group. Pristiphora omalos sp. nov. is described from Greece (Crete). It belongs to the depressa species group. New junior synonyms are Calameuta tazzekae Lacourt, 1991 of Calameuta gaullei (Konow, 1896), and Emphytus leucostomus Costa, 1890 of Allantus cingulatus (Scopoli, 1763). Periclista rufiventris Zombori, 1979 is moved from the subgenus Periclista to the subgenus Neocharactus. Ametastegia (Protemphytus) persica Khayrandish, Talebi & Blank, 2015 is recorded for the first time in Europe, from Italy (Sicily), and a key to West Palaearctic Protemphytus species provided. Allantus enslini (Forsius, 1918) is more widespread in southern Europe than previously recorded. An identification key distinguishes it from its closer West Palaearctic relatives. New hostplant records are for Halidamia affinis (Fallén, 1807) ( Rubia peregrina ), Janus compressus (Fabricius, 1793) ( Sorbus torminalis ), and Macrophya albicincta (Schrank, 1776) ( Centranthus ruber ). New distribution records are given for a few other species.