Odorant Receptors Expressing and Antennal Lobes Architecture Are Linked to Caste Dimorphism in Asian Honeybee, Apis cerana (Hymenoptera: Apidae).

Insects heavily rely on the olfactory system for food, mating, and predator evasion. However, the caste-related olfactory differences in Apis cerana, a eusocial insect, remain unclear. To explore the peripheral and primary center of the olfactory system link to the caste dimorphism in A. cerana, transcriptome and immunohistochemistry studies on the odorant receptors (ORs) and architecture of antennal lobes (ALs) were performed on different castes. Through transcriptomesis, we found more olfactory receptor genes in queens and workers than in drones, which were further validated by RT-qPCR, indicating caste dimorphism. Meanwhile, ALs structure, including volume, surface area, and the number of glomeruli, demonstrated a close association with caste dimorphism. Particularly, drones had more macroglomeruli possibly for pheromone recognition. Interestingly, we found that the number of ORs and glomeruli ratio was nearly 1:1. Also, the ORs expression distribution pattern was very similar to the distribution of glomeruli volume. Our results suggest the existence of concurrent plasticity in both the peripheral olfactory system and ALs among different castes of A. cerana, highlighting the role of the olfactory system in labor division in insects.

Range-wide genetic analysis of an endangered bumble bee (Bombus affinis, Hymenoptera: Apidae) reveals population structure, isolation by distance, and low colony abundance.

Declines in bumble bee species range and abundances are documented across multiple continents and have prompted the need for research to aid species recovery and conservation. The rusty patched bumble bee (Bombus affinis) is the first federally listed bumble bee species in North America. We conducted a range-wide population genetics study of B. affinis from across all extant conservation units to inform conservation efforts. To understand the species' vulnerability and help establish recovery targets, we examined population structure, patterns of genetic diversity, and population differentiation. Additionally, we conducted a site-level analysis of colony abundance to inform prioritizing areas for conservation, translocation, and other recovery actions. We find substantial evidence of population structuring along an east-to-west gradient. Putative populations show evidence of isolation by distance, high inbreeding coefficients, and a range-wide male diploidy rate of ~15%. Our results suggest the Appalachians represent a genetically distinct cluster with high levels of private alleles and substantial differentiation from the rest of the extant range. Site-level analyses suggest low colony abundance estimates for B. affinis compared to similar datasets of stable, co-occurring species. These results lend genetic support to trends from observational studies, suggesting that B. affinis has undergone a recent decline and exhibit substantial spatial structure. The low colony abundances observed here suggest caution in overinterpreting the stability of populations even where B. affinis is reliably detected interannually. These results help delineate informed management units, provide context for the potential risks of translocation programs, and help set clear recovery targets for this and other threatened bumble bee species.

Measuring factors affecting honey bee (Hymenoptera: Apidae) attraction to soybeans using bioacoustics monitoring.

Soybean (Glycine max (L.) Merr.) is an important agricultural crop around the world, and previous studies suggest that honey bees (Apis mellifera Linnaeus) can be a component for optimizing soybean production through pollination. Determining when bees are present in soybean fields is critical for assessing pollination activity and identifying periods when bees are absent so that bee-toxic pesticides may be applied. There are currently several methods for detecting pollinator activity, but these existing methods have substantial limitations, including the bias of pan trappings against large bees and the limited duration of observation possible using manual techniques. This study aimed to develop a new method for detecting honey bees in soybean fields using bioacoustics monitoring. Microphones were placed in soybean fields to record the audible wingbeats of foraging bees. Foraging activity was identified using the wingbeat frequency of honey bees (234 ±â€…14 Hz) through a combination of algorithmic and manual approaches. A total of 243 honey bees were detected over 10 days of recording in 4 soybean fields. Bee activity was significantly greater in blooming fields than in non-blooming fields. Temperature had no significant effect on bee activity, but bee activity differed significantly between soybean varieties, suggesting that soybean attractiveness to honey bees is heavily dependent on varietal characteristics. Refinement of bioacoustics methods, particularly through the incorporation of machine learning, could provide a practical tool for measuring the activity of honey bees and other flying insects in soybeans as well as other crops and ecosystems.

Molecular identification of Hymenopteran insects collected by using Malaise traps from Hazarganji Chiltan National Park Quetta, Pakistan.

The order Hymenoptera holds great significance for humans, particularly in tropical and subtropical regions, due to its role as a pollinator of wild and cultivated flowering plants, parasites of destructive insects and honey producers. Despite this importance, limited attention has been given to the genetic diversity and molecular identification of Hymenopteran insects in most protected areas. This study provides insights into the first DNA barcode of Hymenopteran insects collected from Hazarganji Chiltan National Park (HCNP) and contributes to the global reference library of DNA barcodes. A total of 784 insect specimens were collected using Malaise traps, out of which 538 (68.62%) specimens were morphologically identified as Hymenopteran insects. The highest abundance of species of Hymenoptera (133/538, 24.72%) was observed during August and least in November (16/538, 2.97%). Genomic DNA extraction was performed individually from 90/538 (16.73%) morphologically identified specimens using the standard phenol-chloroform method, which were subjected separately to the PCR for their molecular confirmation via the amplification of cytochrome c oxidase subunit 1 (cox1) gene. The BLAST analyses of obtained sequences showed 91.64% to 100% identities with related sequences and clustered phylogenetically with their corresponding sequences that were reported from Australia, Bulgaria, Canada, Finland, Germany, India, Israel, and Pakistan. Additionally, total of 13 barcode index numbers (BINs) were assigned by Barcode of Life Data Systems (BOLD), out of which 12 were un-unique and one was unique (BOLD: AEU1239) which was assigned for Anthidium punctatum. This indicates the potential geographical variation of Hymenopteran population in HCNP. Further comprehensive studies are needed to molecularly confirm the existing insect species in HCNP and evaluate their impacts on the environment, both as beneficial (for example, pollination, honey producers and natural enemies) and detrimental (for example, venomous stings, crop damage, and pathogens transmission).

First record of Apanteles hemara (N.) on Leucinodes orbonalis Guenée and biodiversity of Hymenoptera parasitoids on Brinjal.

The brinjal fruit and shoot borer (BFSB), Leucinodes orbonalis Guenée (Lepidoptera: Crambidae), is a very detrimental pest that causes significant economic losses to brinjal crop worldwide. Infested brinjal fruits were collected from vegetable fields located at the ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India, during two consecutive seasons (2021-2022). The larvae of the pest were brought to the laboratory and reared under controlled conditions of 25 ± 0.5 °C and 70 ± 5% relative humidity, for the emergence of parasitoids. In addition, the survey of Hymenoptera parasitoids in brinjal was conducted utilizing a sweep net and yellow pan trap over the course of two seasons. The results reveal that five parasitoid species were emerged from L. orbonalis viz., Apanteles hemara Nixon, 1965, Bracon greeni Ashmead 1896 (Hymenoptera: Braconidae), Goryphus nursei (Cameron, 1907), Trathala flavoorbitalis (Cameron, 1907) (Hymenoptera: Ichneumonidae) and Spalangia gemina Boucek 1963 (Hymenoptera: Spalangiidae). Out of these, A. hemara and S. gemina were documented as new occurrences in Delhi. Additionally, A. hemara was recorded for the first time as a parasite on L. orbonalis. Trathala flavoorbitalis was observed during both seasons and exhibited higher parasitism reaching 15.55% and 18.46% in July and August 2022, respectively. However, the average parasitism (%) recorded by A. hemara, B. greeni, G. nursei, T. flavoorbitalis and S. gemina was 3.10%, 1.76%, 1.10%, 9.28% and 1.20% respectively. Furthermore, the findings showed a significant (p ≤ 0.01) strongly positive correlation between fruit infestation (%) by L. orbonalis and parasitism (%). The survey indicates the presence of a broad group (19 families and 60 species) of Hymenoptera parasitoids in the brinjal crop ecosystem in Delhi which could be valuable in biological control. In light of these results, this study revealed that A. hemara and other parasitoids identified in this study alongside T. flavoorbitalis would be ideal biocontrol agents within the integrated pest management (IPM) program of BFSB in Delhi.

New records of three parasitoids, Pteroptrix chinensis, Aphytis hispanicus, and Marlattiella prima (Hymenoptera: Aphelinidae) associated with an exotic scale, Lopholeucaspis japonica (Hemiptera: Diaspididae) in Tennessee.

A survey for parasitoids of Lopholeucaspis japonica Cockerell (Hemiptera: Diaspididae), an exotic scale of woody ornamentals, resulted in the discovery of 3 species of aphelinid parasitoid wasps, Pteroptrix chinensis (Howard), Aphytis hispanicus (Mercet), and Marlattiella prima Howard. This serves as the first report of these parasitoids reared from a host in the state of Tennessee, USA. Despite routine pesticide applications in the surveyed nursery and directed treatments of the infested plants to control the scale outbreak, the percentage of parasitized scale in privet and euonymus shrubs averaged 7.0% and 7.9%, respectively. These parasitoids may be useful in the natural or managed control of this pest in the United States, but additional research is needed to understand how these parasitoids contribute to the control of L. japonica in the landscape and how nursery production practices can be modified to promote parasitoid populations.

Effect of egg production dynamics on the functional response of two parasitoids.

Functional response describes the number of hosts attacked by a parasitoid in relation to host densities and plays an important role by connecting behavioral-level processes with community-level processes. Most functional response studies were carried out using simple experimental designs where the insects were confined to a plain and small arena with different host densities during a fixed period of time. With these designs, other factors that might affect the functional response of parasitoids were not analyzed, such as fecundity, age, and experience. We proposed a series of latent-variables Markovian models that comprised an integrated approach of functional response and egg production models to estimate the realized lifetime reproductive success of parasitoids. As a case study, we used the parasitoids Anagyrus cachamai and A. lapachosus (Hymenoptera: Encyrtidae), two candidate agents for neoclassical biocontrol of the Puerto Rican cactus pest mealybug, Hypogeococcus sp. (Hemiptera: Pseudococcidae). The tested species were assessed according to their physiology and prior experience. We estimated the number of mature eggs after emergence, egg production on the first day, egg production rate, the proportion of eggs resorbed, egg resorption threshold, and egg storage capacity. Anagyrus cachamai and A. lapachosus both presented a type III functional response. However, the two parasitoids behaved differently; for A. cachamai, the number of parasitized hosts decreased with female age and depended on the number of mature eggs that were available for oviposition, whereas A. lapachosus host parasitism increased with female age and was modulated by its daily egg load and previous experience. The methodology presented may have large applicability in pest control, invasive species management, and conservation biology, as it has the potential to increase our understanding of the reproductive biology of a wide variety of species, ultimately leading to improved management strategies.

Providing rigor in bee colony strength auditing methods.

The primary method used to audit honey bee (Apis mellifera Linnaeus, 1758 [Hymenoptera: Apidae]) colony strength for almond pollination services, Nasr et al.'s (1990) frame-top cluster count method, is a subjective visual audit that relies on an auditor's spot assessment and may lack rigor and repeatability. We created novel, open-source software for the analysis of frame-top cluster count photographic assessments to improve methodological rigor and repeatability. We evaluated 2 existing visual audit methods, created 3 novel audit method variations, and determined between-method conversion factors using linear modeling. The software has potential applications in apiological research, apiarist and orchardist colony auditing, as well as training future generations of apiarists in auditing techniques. The software enhances the rigor and repeatability of Nasr et al.'s (1990) frame-top cluster count population assessment. In this article, we introduce the novel open-source software and between-method regression equations and review the tested visual assessment methods and their application.

Small wasps, big muscles: Fore and hind leg modifications in chalcidoid wasps (Hymenoptera: Chalcidoidea).

A particularly conspicuous morphological feature in chalcidoid wasps are strikingly modified legs present in both males and females. It evolved convergently multiple times on either fore or hind legs implying strong evolutionary pressure and a prominent function in the wasps' life history. We investigate the external and internal morphology of the modified legs of five species of chalcidoid wasps representing four families (Ooderidae, Heydeniidae, Chalcididae, and Leucospidae), using light microscopy, scanning electron microscopy and micro computed tomography. We aimed to identify shared characteristics as well as differences between genera/species, leg pairs and sexes and to draw first conclusions about the shared or different functions. All species and sexes share the same general leg morphology, with enlarged femur, curved tibia and a huge flexor tibiae muscle. However, there are also genus/species-specific differences such as distinctive spine-like setae on the femur of Oodera spp., or leg pair-specific differences in the position of the extensor tibiae muscle. Shared characteristics imply a common primary function in which strong forces are required to pull the tibia against the femur while differences imply different secondary functions. Both primary and secondary functions have yet to be revealed beyond informed speculations.

Morphological phylogeny and revision of Sycophila and Ficomila (Hymenoptera: Chalcidoidea, Eurytomidae) associated with Afrotropical fig trees (Moraceae, Ficus).

Eurytomidae (Chalcidoidea) species associated with fig trees (Ficus) are still poorly documented. A phylogenetic analysis of 63 morphological characters was conducted to revise Afrotropical species of Sycophila Walker and Ficomila Bouek associated with fig trees. Based on our results, which also included Palaearctic species of Sycophila, three subgenera of Sycophila are proposed: Sycophila s. str., Tineomyza Rondani stat. rev. and a new subgenus, Ficorytoma subgen. n. Lotfalizadeh & Rasplus. Ficomila is maintained as a valid genus. Thirty-six species are also newly described by Lotfalizadeh & Rasplus, namely Ficomila artocarpoides sp. n., F. carolae sp. n., F. bouceki sp. n., F. comptoni sp. n., F. flava sp. n., F. gabonensis sp. n., F. gibba sp. n., F. guinensis sp. n., F. sinai sp. n., F. tanzanica sp. n., F. vannoorti sp. n., Sycophila (Tineomyza) beninensis sp. n., S. (T.) busseicola sp. n., S. (T.) glumosae sp. n., S. (T.) luteacola sp. n., S. (T.) maldesi sp. n., S. (T.) minuta sp. n., S. (T.) platygastra sp. n., S. (T.) risbeci sp. n., S. (T.) wiebesi sp. n., S. (T.) zebrogastra sp. n., S. (Ficorytoma) delvarei sp. n., S. (F.) persicae sp. n., S. (Sycophila) annae sp. n., S. (S.) bidentata sp. n., S. (S.) longiflagellata sp. n., S. (S.) chirindensis sp. n., S. (S.) ficophila sp. n., S. (S.) fusca sp. n., S. (S.) lasallei sp. n., S. (S.) macrospermae sp. n., S. (S.) meridionalis sp. n., S. (S.) nigra sp. n., S. (S.) nigriterga sp. n., S. (S.) suricola sp. n., S. (S.) zebra sp. n.. Seven described species of Sycophila are reclassified in the subgenus Tineomyza: Sycophila (Tineomyza) flaviclava Bouek, 1981; S. (T.) modesta Bouek, 1981; S. (T.) naso Bouek, 1981; S. (T.) punctum Bouek, 1981; S. (T.) ruandensis Risbec, 1957; S. (T.) sessilis Bouek, 1981 and S. (T.) setulosa Zerova, 2009. After this revision, Ficomila and Sycophila include 46 species associated with Afrotropical Ficus. Detailed morphological descriptions and illustrations as well as identification keys are provided for the subgenera, species-groups and species of Ficomila and Sycophila associated with Afrotropical fig trees; their host fig association and relative lack of host-specificity are also discussed.

The paper wasps (Hymenoptera: Vespidae: Polistinae) of Sri Lanka recorded from recent investigations.

Paper wasps of subfamily Polistinae Lepeletier have been studied in many countries of the world due to their importance as pest species, predators, model organisms in research and medical significance. Seven species have been well documented in Sri Lanka, of these five species represent genus Ropalidia Gurin-Mneville, and two species genus Polistes Latrielle. However, the species have not been studied systematically for many years and recent records are not available. In the present study investigations for wasps (Vespidae) were conducted in 28 locations of all provinces and climatic zones of the country. Five species of paper wasps were found in 15 of the locations investigated, four in the genus Ropalidia and one in the genus Polistes. Ropalidia marginata Lepeletier was the most abundant and widely distributed species, while the other species had more limited distribution. Polistes (Gyrostoma) olivaceus De Geer, previously recorded from Sri Lanka, was not recorded during the present study. All the species of paper wasps encountered in the present study showed changes in distribution from their historical locations, decline in distributional ranges and occurrence in new locations.

Two new species of Epirhyssa (Hymenoptera: Ichneumonidae: Rhyssinae) from Costa Rica.

As a result of continuing research on the ichneumonid wasps of Costa Rica, two new species of Epirhyssa (Rhyssinae) are described: E. leonoreae and E. lewisi. A key is provided for the identification of all 14 species now known to occur in the country.

Review of the subgenus Tarpheion of the genus Blacus Nees (Hymenoptera, Braconidae, Brachistinae) from China, with description of nine new species and eight new records.

An updated key to the currently known species of the subgenus Tarpheion van Achterberg, 1976 (Hymenoptera, Braconidae, Blacus) in China is provided. Nine new species are proposed, B. (T.) adelphius sp. nov., B. (T.) frontalis sp. nov., B. (T.) gilvus sp. nov., B. (T.) hainanensis sp. nov., B. (T.) parilis sp. nov., B. (T.) reticulatus sp. nov., B. (T.) sculptilis sp. nov., B. (T.) tanae sp. nov., and B. (T.) wuyishanensis sp. nov. Eight species, B. (T.) achterbergi Haeselbarth, 1976, B. (T.) albiventris van Achterberg, 1988, B. (T.) angichorus van Achterberg, 1988, B. (T.) antennalis van Achterberg, 1988, B. (T.) apicalis van Achterberg, 1976, B. (T.) artomandibularis van Achterberg, 1976, B. (T.) bicolor van Achterberg, 1988, and B. (T.) soror van Achterberg, 1988, are newly recorded from China.

Taxonomic notes on some neglected doryctine wasps (Hymenoptera: Braconidae) from Argentina described by J. Brthes and E. Blanchard.

The type specimens of Austrodolops eremitae Blanchard, Doryctes ridiaschinae Brthes, and Hormiopius ptericoptophagus Blanchard were studied and reclassified according to the current classification of the subfamily Doryctinae. The monotypic genera Austrodolops Blanchard and Hormiopius Blanchard are treated as junior synonyms of Allorhogas Gahan (syn. nov.) and Heterospilus Haliday (syn. nov.) respectively. Examination of the gall associated species D. ridiaschinae shows that it belongs in the genus Allorhogas. All species are redescribed and illustrated and the following new combinations are proposed: Allorhogas eremitae (Blanchard) (comb. nov.), Allorhogas ridiaschinae (Brthes) (comb. nov.) and Heterospilus ptericoptophagus (Blanchard) (comb. nov.). Lectotypes are designated for all studied species and the genus Doryctes is excluded from the currently known Argentine fauna.

Revision of the genus Cyrtolabulus van der Vecht in Madagascar (Hymenoptera: Vespidae: Eumeninae).

The species of the genus Cyrtolabulus van der Vecht, 1969 occurring in Madagascar are revised, with the description of three new species: Cyrtolabulus flavorufus sp. nov., Cyrtolabulus parvulus sp. nov. and Cyrtolabulus scrobalis sp. nov. Pseudonortonia madacassa Gusenleitner, 2012 is synonymized under Cyrtolabulus suboscurus (Giordani Soika, 1941) syn. nov., and a neotype is designated for Labus bekilyensis Giordani Soika, 1941. A comparison with the closely related genus Cyrteumenes Giordani Soika, 1991 and a key to the species are provided.

Review of the spider wasp genus Episyron Schidte, 1837 (Hymenoptera: Pompilidae) from India, with description of three new species.

The spider wasp genus Episyron Schidte, 1837 is reviewed, with five species recorded from various parts of India along with three new species described and illustrated from Kerala: E. keralaensis Anju, Girish Kumar & Thejass, sp. nov., E. nigrocalcarius Anju, Girish Kumar & Thejass, sp. nov., and E. rufotibius Anju, Girish Kumar & Thejass, sp. nov. Diagnosis of species occurring in India, comparisons of new species with congeners and a key to the Indian species also are provided.

Revision of the Afrotropical genus Zetheumenidion Bequaert (Hymenoptera: Vespidae: Eumeninae).

A taxonomic revision of the Afrotropical genus Zetheumenidion Bequaert, 1926 is presented. Four new species (Zetheumenidion abruptum sp. nov., Zetheumenidion concinnoide sp. nov., Zetheumenidion latum sp. nov. and Zetheumenidion minimum sp. nov.) are described; Zetheumenidion paeneplanum (Bequaert, 1926) stat. rev. is resurrected from synonymy with Z. pulchripenne (Cameron, 1910); Zetheumenidion femoratum flavissimum Giordani Soika, 1987 is raised to species level (Zetheumenidion flavissimum stat. nov.). A key to all known species is provided and the taxonomic placement of the genus is discussed.

Properhyssalus, a new fossil genus of braconid wasps close to the genus Rhyssalus Haliday (Hymenoptera: Braconidae: Rhyssalinae) from Baltic amber.

The new braconid genus and species from the subfamily Rhyssalinae, Properhyssalus szechowskii Belokobylskij, gen. et sp. nov., from late Eocene Baltic amber are described and illustrated. The differences between the new genus and the type species of Rhyssalus Haliday, 1833, Rh. clavator Haliday, 1833, are provided. The position of the previously described from Baltic amber species Rhyssalus brevicornis Brues, 1933 and Rh. rugosus Brues, 1933, as well as Palaeorhyssalus dubitosus Brues, 1933, are discussed.

A review of the subgenera Carinichelonus, Microchelonus, Parachelonus and Stylochelonus of the genus Chelonus Panzer (Braconidae: Cheloninae) with descriptions of twenty-one new species from China.

Three subgenera Microchelonus Szpligeti, 1908 s. str., Parachelonus Tobias, 1995 and Stylochelonus Helln, 1958 are newly recorded from China, 21 new species, viz., C. (M.) adiazetos sp. nov., C. (M.) aequus sp. nov., C. (M.) brachykeraiatus sp. nov., C. (M.) bullatus sp. nov., C. (M.) clivus sp. nov., C. (M.) crassitibialis sp. nov., C. (M.) cyclotus sp. nov., C. (M.) erugatus sp. nov., C. (M.) illatus sp. nov., C. (M.) leious sp. nov., C. (M.) linzhiensis sp. nov., C. (M.) maculovittatus sp. nov., C. (M.) melanochromus sp. nov., C. (M.) platyetrus sp. nov., C. (M.) recavus sp. nov., C. (M.) ruficorpus sp. nov., C. (M.) scirpophagae sp. nov., C. (M.) staurorhytis sp. nov., C. (P.) hirsutus sp. nov., C. (S.) acaretrus sp. nov., and C. (S.) punctulosus sp. nov. are described and illustrated. Also, eleven species are reported as new to China: C. (M.) alticinctus (Tobias, 1989), C. (M.) alveatus (Tobias, 1989), C. (M.) calcaratus (Tobias, 1989), C. (M.) flagellaris (Tobias, 1989), C. (M.) insidiatrix (Tobias, 1989), C. (M.) milkoi (Tobias, 2003), C. (M.) moskovitus (Tobias, 1997), C. (M.) semilunaris (Tobias, 2000), C. (M.) temporalis (Tobias, 1986), C. (M.) varus (Tobias, 2000) and C. (M.) zaitzevi (Tobias, 1972). Four new combinations are proposed: C. (P.) compressor (Chen & Ji, 2003) comb. nov., C. (P.) macrocorpus (Ji & Chen, 2003) comb. nov., C. (P.) polycolor (Chen & Ji, 2003) comb. nov. and C. (Baculonus) rubriventris (Tobias, 1988) comb. nov. The following new names are proposed: C. (M.) jiae nom. nov. for C. (M.) bimaculatus (Chen & Ji, 2003) and C. (M.) substernatus nom. nov. for C. (M.) tobiasi (Yuldashev, 2011). Microchelonus (Carinichelonus) cavifrons Tobias, 2000 is synonymized with C. (Ca.) tabonus Sonan, 1932. A key to the Chinese species of the subgenus Microchelonus is provided together with keys to the currently known species of the subgenera Carinichelonus, Stylochelonus and Parachelonus.

Two new species of Allorhogas (Hymenoptera, Braconidae, Doryctinae) from southeast Brazil reared from seed pods of Inga vera Willd. and Anadenanthera colubrina (Vell.) (Fabaceae).

Two new species of Allorhogas (Braconidae: Doryctinae), Al. lavraensis sp. nov and Al. margitae sp. nov., which were reared from seed pods of Fabaceae species, are described from southeast Brazil. Allorhogas lavraensis forms seed galls on Inga vera Willd., whereas Al. margitae predates on seeds of Anadenanthera colubrina (Vell.) without making galls. The latter represents the first report of seed predation by a species of Allorhogas on the genus Anadenanthera.