Brood Chamber Research Articles

Mistletoes benefit from initiating cascading effects in a cactus–stem borers–arthropods system: A positive feedback

Abstract Parasitic plants may indirectly modify arthropod community structure by inducing resistance/susceptibility in host plants. In the Atacama Desert, the mistletoe Tristerix aphyllus initiates cascading effects on its cactus host, Echinopsis chiloensis, inducing susceptibility to stem‐borer beetles, whose brood chambers are colonized by a diverse arthropod community. We evaluated whether those cascading effects initiated by Tristerix generate a positive or negative feedback loop on this parasitic plant. A positive or negative feedback loop would occur if the mistletoe‐elicited indirect effects on arthropod community result in increased or decreased mistletoe fitness, respectively. Specifically, by way of field sampling, experimental manipulation of number of brood chambers, and structural equation modelling, we assessed the indirect impact of number of brood chambers on Tristerix fitness mediated by its influence on the abundance of arthropod trophic guilds (omnivores, nectarivores, herbivores and predators). We found that the number of brood chambers had a positive indirect effect on mistletoe fitness, likely mediated by the increased abundance of nectarivores. The number of brood chambers was positively associated with the abundance of predators, nectarivores and herbivores. However, nectarivores were the only trophic guild showing a positive association with both number of brood chambers and Tristerix fitness. This positive feedback loop, together with the known pattern of specific disperser‐mediated cyclic reinfection of cacti by Tristerix, would indicate that mistletoe infection may ultimately threaten cactus survival.

Safety assessment of high doses of vaporized oxalic acid on honey bee worker health and queen quality

IntroductionThe honey bee ectoparasitic mite, Varroa destructor, is one of the main causes of honey bee colony loss worldwide. Synthetic acaricides are the most commonly used strategy for varroa control, however, resistance to these acaricides has emerged. Consequently, the use of organic acids for varroa control is gaining more interest among beekeepers. For example, oxalic acid (OA) is a natural compound that has been shown to be an effective acaricide against varroa mites, however, the potential toxicity of OA to adult bees and queens is poorly understood. The objective of the study was to evaluate the toxicity of incremental doses of vaporized OA on honey bee workers and queens.MethodsWe exposed 32 colonies to incremental doses (0, 5, 10 or 20 g per colony) of vaporized OA once per week over four consecutive weeks and we monitored the acute and long-term toxicity. We investigated the short-term effects of OA administration by evaluating adult bee mortality, brood production, and population size. Next, we evaluated the long-term effects of OA application on both worker bees and queens. Regarding workers, we investigated their ability to rear new queens. As for queens, we measured acceptance, performance, and sperm quality.ResultsWe found that colonies treated with 20 g OA (20 times the label dose) had a statistically significant increase in worker bee mortality, with a non-significant, 23% decrease in brood relative to controls. No significant differences were observed in queen performance nor sperm quality.DiscussionWe found that repeated application of vaporized OA, at up to 20 times the label dose, had no significant short-term nor long-term, negative effects on colony or queen health, with the exception of a short-term increase in adult bee mortality in the 20 g OA-treated group. The results of this study support the safety of higher-than-label doses of OA for honey bee colonies. The observed increase in adult bee mortality in the 20 g OA dose group in this study suggests that OA doses should be maintained below 20 g per brood chamber.

Flight activity behavior of stingless bee (Apidae: Meliponini) in an urban park outside their natural range: the influence of hive temperature

In South America, the movement of stingless bee colonies outside their natural location is a common practice and, in many cases, meliponiculture activities are conducted in urban or semi-urban areas. In this study, we used a temperature/relative humidity probe inside the hives to assess indicators of hive dynamics to explore the adaptation of Scaptotrigona jujuyensis colonies located in an urban park outside the species’ natural range. The temperature inside the hives was negatively correlated with environmental temperature and its range was narrower than in the empty box (control). These results suggest that the colonies regulate the internal temperature and form a microenvironment, with average values ranging between 29 and 21 °C in the brood chamber, and between 27 and 19 °C in the storage chamber. The number of bees involved in the three flight activities studied varied with the time of the day, through the season and colony. Nevertheless, between 10:00 and 15:00 h, all colonies showed high and continuous activity. The pattern of activity curves of S. jujuyensis tends to be similar to other Scaptotrigona. Finally, we fit Generalized Linear Models to assess the effect of abiotic variables on the flight activity of S. jujuyensis through a negative binomial model. Our results show that the temperature of the brood chamber, relative humidity and colony size best predict the collection of pollen and removal pellets into the hive. These results contribute to the management and conservation of this native species in a new scenario of geographic distribution.

Heritability and correlations for honey yield, handling ease, brood quantity, and traits related to resilience in a French honeybee population

There is growing interest in selective breeding of the honeybee, resulting in the emergence of new breeding projects, often with an emphasis on improving resilience traits, in particular toward brood diseases. Lately, feed autonomy is also gaining importance. Here, we use data from a small breeding nucleus in France to estimate genetic parameters for common bee breeding traits and a novel trait reflecting honey reserves in the brood chamber. Open-mated queens were produced each year from inseminated dams between 2019 and 2021, and ~330 colonies were phenotyped each following year at three periods during the entire beekeeping season. Genetic parameters were estimated using ReML with an animal model. Narrow-sense heritability estimates ranged from low (around 0.15) for calmness and total capped brood surface both measured in early summer, to moderate (0.30 to 0.40) for hygienic behavior in spring, honey yield, and phoretic V. destructor load in early summer. Honey reserves in the brood chamber showed an intermediate heritability throughout the season (around 0.25). Gentleness had a null heritability. Most correlations between phenotypes adjusted for environmental fixed effects were close to zero. Among exceptions, there were honey reserves in the brood chamber in early summer with honey yield (around −0.2) and with the total capped brood surface in early summer (around −0.3). These estimates, although uncertain due to the dataset size, suggest that selection for production and resilience will be effective, even though simultaneous selection for honey yield and feed reserves might be difficult due to a possible genetic antagonism between both traits.

Redescription of Manayunkia caspica Annenkova, 1929 and M. danubialis Băcescu, 1944 n. comb. (Fabriciidae, Sabellida, Polychaeta)

The spread of the subspecies M. caspica danubialis Băcescu, 1944, which has been found in the Danube since 1944, into the upper section of the Danube as far as Austria was the reason for describing the characters of this species and comparing it with the nominotypical subspecies M. caspica caspica Annenkova, 1929, which lives in the Caspian Sea. Both subspecies are similar in the most important diagnostic characters, such as the number of branches of the radioles and the presence and number of pseudospatulate chaetae on thoracic chaetigers. However, they differ in other, less conspicuous characters, such as the number of thoracic uncini and the length of chaetigers. But these characters vary depending on the size of the specimens. Both subspecies inhabit completely different habitats. Based on the ecological species concept, the spatially and ecologically separated populations are regarded as distinct species, M. caspica, and M. danubialis n. comb. The occurrence of transitional uncini in both species and the presence of a brood chamber in the females of M. caspica are described for the first time. The structure of the radiolar crown is also described for both species. A molecular barcode for M. danubialis n. comb., a 654 base pair fragment of cytochrome c oxidase I is presented, allowing a fast and simple identification of this species by using a robust PCR/sequencing approach.

Distribution of brood of the acorn ant Temnothorax crassispinus in artificial nests after forced migration

Nest sites are important for social insects, as they provide refuge against enemies and ensure optimal conditions for the brood development. In large nests, the different chambers can be used for different reasons; for example, for food storage or as a brood chamber. Acorn ants from the genus Temnothorax dwell in small cavities in acorns and wood; however, even such small chambers can have a high degree of spatial heterogeneity. During this study, the distribution of brood items of the acorn ant Temnothorax crassispinus inside artificial nest cavities composed of three chambers in a linear system was analysed. 29 ant colonies were photographed 13 times during a period of approximately one month: during three consecutive days, and after forced migrations. I found that the distribution of the brood inside the nest cavity was similar during the consecutive days; however, after the forced migration, the distribution typically changed. Almost all the brood items were kept farther from the entrance. Keeping the brood farther from the entrance could be explained as a safer option.

HIVE TEMPERATURE REGULATION BY HONEYBEES IN RESPONSE TO EXTREME CONDITIONS

Honeybees are considered the primary pollinators of agricultural crops. However, climate change, pesticide use, disease transmission and pests all have an impact on their survival. Temperature is an important consideration, especially when bees are subjected to harsh conditions as a result of the effort required to regulate them within their hives. The brood chamber should be kept between 33 and 35 °C. The recognized temperature thresholds are 6 and 38 °C; deviations above or below these values cause metabolic damage in honeybees; the larger the difference, the greater the stress. These eusocial insects have developed thermoregulating mechanisms in response to adverse environmental conditions; the colony compensates for this difference by either fanning their wings to create air circulation and cause evaporative cooling or raising the temperature by generating endothermic heat to raise the temperature of the breeding chamber. This review brings together the most important and updated references on how to improve colony thermoregulation and its relationship to climate change.

Multiple evolutionary transitions of reproductive strategies in a phylum of aquatic colonial invertebrates.

Parental care is considered crucial for the enhanced survival of offspring and evolutionary success of many metazoan groups. Most bryozoans incubate their young in brood chambers or intracoelomically. Based on the drastic morphological differences in incubation chambers across members of the order Cheilostomatida (class Gymnolaemata), multiple origins of incubation were predicted in this group. This hypothesis was tested by constructing a molecular phylogeny based on mitogenome data and nuclear rRNA genes 18S and 28S with the most complete sampling of taxa with various incubation devices to date. Ancestral character estimation suggested that distinct types of brood chambers evolved at least 10 times in Cheilostomatida. In Eucratea loricata and Aetea spp. brooding evolved unambiguously from a zygote-spawning ancestral state, as it probably did in Tendra zostericola, Neocheilostomata, and 'Carbasea' indivisa. In two further instances, brooders with different incubation chamber types, skeletal and non-skeletal, formed clades (Scruparia spp., Leiosalpinx australis) and (Catenicula corbulifera (Steginoporella spp. (Labioporella spp., Thalamoporella californica))), each also probably evolved from a zygote-spawning ancestral state. The modular nature of bryozoans probably contributed to the evolution of such a diverse array of embryonic incubation chambers, which included complex constructions made of polymorphic heterozooids, and maternal zooidal invaginations and outgrowths.

Cohabitation with aggressive hosts: description of a new microhisterid species in nests of a ponerine ant with ecological notes

A new clown beetle species, Bacanius neoponerae, is described from Mexican nests of the arboreal ponerine ant Neoponera villosa found in the tank bromeliad Aechmea bracteata. Adult beetles were found in brood chambers or inner refuse piles, but also outside the ant nests, in decaying organic matter between the bromeliad leaves. No direct interactions between ants and microhisterid beetles could be observed. Several lines of evidence suggest a close relationship either with the ants, specific microhabitats within the ant nests or the bromeliads. Sample site elevation, colony size, monthly rainfall and collecting site were the main variables predicting the association. Almost half of the N. villosa colonies were associated with the microhisterids, and larger colonies favored their presence, especially during the driest months of the year. Two specimens were found in a nest of another ant species, Camponotus atriceps, also inhabiting A. bracteata. The new species is the seventh of the genus Bacanius reported from Mexico. This is the second time a species of this genus is associated with ants, and the fourth record of a histerid beetle cohabiting with ponerine ants. The small size of these beetles and their very protective body structure may facilitate their cohabitation with such aggressive hosts.

An easy and fast method to estimate the number of frames with eggs, open brood, sealed brood, and bees in the brood chamber at the time of the inspection of a hive

When a beekeeper is inspecting a hive, he wants to have an idea of how many frames are occupied by eggs, open brood, sealed brood, bees and honey, to be aware of the hive’s immediate or near-future needs. This method has to do with how to estimate those variables relating individually and numerically to the surfaces they occupy on both sides of each frame.

Mechanistic Understanding toward the Maternal Transfer of Nanoplastics in Daphnia magna.

Nanoplastics induce transgenerational toxicity to aquatic organisms, but the specific pathways for the maternal transfer of nanoplastics remain unclear. Herein, laser scanning confocal microscopy (LSCM) observations identified the specific pathways on the maternal transfer of polystyrene (PS) nanoplastics (25 nm) in Daphnia magna. In vivo and in vitro experiments showed that PS nanoplastics could enter the brood chamber through its opening and then be internalized to eggs and embryos using LSCM imaging (pathway I). In addition, PS nanoplastics were observed in the oocytes of the ovary, demonstrating gut-ovary-oocyte transfer (pathway II). Furthermore, label-free hyperspectral imaging was used to detect the distribution of nanoplastics in the embryos and ovary of Daphnia, again confirming the maternal transfer of nanoplastics through the two pathways mentioned above. The contribution from pathway I (88%) was much higher than pathway II (12%) based on nanoflow cytometry quantification. In addition, maternal transfer in Daphnia depended on the particle size of PS nanoplastics, as demonstrated by using LSCM and hyperspectral imaging. Unlike 25 nm nanoplastics, 50 nm PS nanoplastics could enter the brood chamber and the eggs/embryos (pathway I), but were not detected in the ovary (pathway II); 100 nm PS nanoplastics were difficult to be internalized by eggs/embryos and could not enter the ovary either. These findings provide insight into the maternal transfer mechanisms of nanoplastics in Daphnia, and are critical for better understanding the transgenerational toxicity of aquatic organisms.

Eucera bees (Hymenoptera, Apidae, Eucerini) preserved in their brood cells from late Holocene (middle Neoglacial) palaeosols of southwest Portugal

AbstractThe c. 100 myr extensive fossil record of bee brood nests and cells (calichnia) in siliciclastic sedimentary deposits, or palaeosols, is virtually devoid of the presence of their producers. The absence of a more specific assignment to a producer of the different ichnogenera of the ichnofamily Celliformidae precludes their use in phylogenetic and palaeobiogeographic studies. Omission surfaces developed in incipient carbonate palaeosols during the late Holocene (middle Neoglacial), c. 2975 yr cal BP, on the southwest coast of mainland Portugal show insect calichnia in dense ichnofabrics dominated by shallow discrete cells (Palmiraichnus castellanosi) and cells at the terminus of vertical shafts. At Carreira Brava, one of the studied sites, bees ready to abandon their cells were found in an exceptional state of preservation inside the sealed brood chambers. The chambers also preserve the inner cell hydrophobic polymerized membrane and remains of the monospecific Brassicaceae‐type pollen provision. Although the cause of mass mortality remains a mystery, oxygen depletion due to sudden flooding of the nesting substrate and consequent or overnight temperature drop, just before emergence, are plausible causes. The anaerobic conditions and later rapid carbonate diagenetic lithification are the likely causes of the preservation of the bees and the inner cell organic membrane. The favourable climate conditions for the development of successive, dense ichnofabrics from an omission suite dominated by bee brood cells may be the result of slightly colder and higher‐precipitation winters during the Neoglacial interval.

Boring bryozoans: an investigation into the endolithic bryozoan family Penetrantiidae

An endolithic lifestyle in mineralized substrates has evolved multiple times in various phyla including Bryozoa. The family Penetrantiidae includes one genus with ten extant and two fossil species. They predominantly colonize the shells of molluscs and establish colonies by chemical dissolution of calcium carbonate. Based on several morphological characters, they were described to be either cheilostome or ctenostome bryozoans. For more than 40 years, neither the characters of species identity and systematics nor the problem of their phylogeny was approached. Consequently, the aim of this study is to reevaluate species identities and the systematic position of the genus Penetrantia by analyzing at least six different species from eight regions with the aid of modern methods such as confocal laser scanning microscopy and 3D-reconstruction techniques. This study demonstrates that the musculature associated with the operculum and brood chamber shows significant differences from the cheilostome counterparts and seems to have evolved independently. Together with the presence of other ctenostome-like features such as true polymorphic stolons and uncalcified body wall, this finding supports a ctenostome affinity. Operculum morphology reveals many new species-specific characters, which, together with information about gonozooid morphology, tentacle number, and zooid size ranges, will enhance species identification. It also revealed a probable new species in Japan as well as potential cryptic species in France and New Zealand. In addition, this study increases the known distribution range of the family and its substrate diversity. Altogether, the new information collated here provides the basis for future work on a neglected taxon.

On the nesting behaviour of Polyrhachis illaudata Walker, 1859 (Hymenoptera: Formicidae)

Polyrhachis illaudata Walker, 1859, is known to have variability in nesting locations ranging from nesting in the ground to nesting under the bark of tree trunks. Here I describe the brood chambers of P. illaudata from the nests encountered beneath the bark of Silver Oak (Grevillea robusta A. Cunn. ex R. Br.) and report the presence of pupal cocoons in this species.

Nest Architecture, Prey, and Body Size in the Grass-Carrying Wasp, Isodontia auripes, at two sites in New York (Hymenoptera: Sphecidae)

Isodontia auripes [Fernald] females nested in fourteen 12-mm diameter artificial trap nests at two locations in New York State (Geneseo and Rensselaerville). We report broods of up to 14 pupae in a single chamber with an average of 5.8 pupae per chamber (previously reported range 2 - 6 pupae/chamber). Nest architecture, with plugs of finely shredded, packed grass and coarse, wound grass stems, was similar to other reports of I. auripes nests, except that only one nest contained a grass partition on the back wall of the chamber (in a case where mud-nesting wasps had preceded I. auripes). All prey items that could be identified to species were either the non-native drumming katydid, Meconema thalassinum [DeGeer], or the narrow-winged tree cricket, Oecanthus niveus [DeGeer]; M. thalassinum accounted for 71% of identified prey and is a new prey record for this wasp. Nests contained an estimated average of 11 prey per pupa, with a strongly female-biased prey sex ratio. The 116 collected pupae suffered from high pre-emergence mortality (65.5%), mostly due to the presence of parasitic flies and chalcid wasps in many nests. Adult females were larger than males in body mass and head width but did not differ in emergence time. Both male and female wasps could be found within single brood chambers, though the population was male-biased (2.4:1) and individual nests strongly favored one sex. In general, pupal cases closest to the nest entrance within a chamber were smaller than those found furthest away, suggesting size-related fitness impacts for offspring based on the order of egg laying.

Brood chambers of a stem borer beetle modify arthropod functional diversity on its cactus host

Brood chambers of a stem borer beetle modify arthropod functional diversity on its cactus host

First record of Amobia quatei (Diptera: Sarcophagidae: Miltogramminae) from the Indian subcontinent as kleptoparasite of Anterhynchium flavomarginatum (Hymenoptera: Vespidae: Eumeninae)

Amobia quatei Kurahashi, 1974 was reared from the puparia collected from the brood chambers of mason wasp Anterhynchium flavomarginatum (Smith, 1852). The species is reported for the first time from Indian subcontinent. This is also the first host record for the kleptoparasite A. quatei. A redescription of the kleptoparasite supplemented with illustrations of habitus and genitalia, along with notes on the biology of the host are provided.

Photosensitivity of Dispersing Cryptic Date Stone Beetles Coccotrypes dactyliperda (Coleoptera, Curculionidae, Scolytinae)-A Pilot Study.

Simple SummaryDate stone beetles (Coccotrypes dactyliperda), which feed on the albumen inside palm seeds, are a major pest in date palm plantations in the Middle East and North Africa. While they spend most of their life cycle in darkness inside the brood galleries where they mate and reproduce, females emerge for a short period of time when the brood gallery has become too crowded or when the seed’s albumen has been exhausted. During this emergence they seek out fresh seeds, commonly by attacking unripe dates still on the palm. Previous work indicated that the beetles might prefer dark conditions (i.e., nighttime) when emerging from seeds, whereas anecdotal evidence suggested that the beetles might be attracted to light. The controlled experiments showed that the beetles, once in the open, are attracted by and move faster to a light source, but that the color of the surface (red, blue, green, black) has no influence on either direction or crawl speed.The date stone beetle, Coccotrypes dactyliperda, is a cryptic spermatophagus species that spends almost its entire life cycle inside the seeds of palms, esp. Phoenix sp. Only during dispersal, when the host seed has been largely eaten out, do females emerge for a short period of time in search of a fresh seed in which to establish new brood galleries. Previous work indicated that C. dactyliperda might be photophobic, preferring to emerge from seeds during night hours, whereas anecdotal evidence suggested that the beetles might be photophilic in terms of their movements post emergence. This paper examines the photosensitivity of the species under controlled laboratory conditions. The results show that C. dactyliperda, once removed from the brood chamber, is attracted by and moves faster to a light source, but that the color of the lit surface (red, blue, green, black) has no influence on either direction or crawl speed.

IDENTIFICACIÓN TAXONÓMICA DE Mocis latipes Guenée (LEPIDOPTERA: EREBIDAE) EN PASTOS FORRAJEROS DE VERACRUZ, MÉXICO

<p><strong>Background.</strong> Cultivation of forage grasses is an important component in the dual-purpose cattle production system; however, insect pests can decrease fresh material yields. <strong>Objective. </strong>To taxonomically identify the causal agent that damages the cultivars <em>Panicum maximum </em>(Jacq.) cv. Mombasa and<em> Panicum maximum </em>cv. Zuri. <strong>Methodology.</strong> In two locations in the central region of Veracruz, specimens of an insect in the larval and pupal stages were collected using the quadrant method in an area of 50 ha. Subsequently, in the laboratory, larvae were boiled for two minutes and preserved in 70% alcohol. Meanwhile, pupae were placed in a brood chamber with foliage to obtain adults and to extract their genitalia, which represents the most important morphological structure for the identification of a species. <strong>Results.</strong> The total number of collected larvae was 650, and 65 pupae, all reaching the adult stage. Based on the taxonomic morphology, the species <em>Mocis latipes</em> or striped grassworm was determined. Damage was estimated at approximately 40% per hectare.<strong> Implications.</strong> Correct identification of the pest insect allows the implementation of a strategy for proper management. <strong>Conclusion.</strong> The species<em> M. latipes</em> was identified in forage grasses <em>P. maximum</em> cv. Mombasa and <em>P. maximum </em>cv. Zuri in Veracruz.</p>

Exploring the effect of atrazine exposure on the reproductive capacity of Daphnia magna

Atrazine is an herbicide commonly used for weed control in crops and on turf, but environmental contamination with atrazine causes endocrine disruption leading to reproductive defects in humans and freshwater organisms. The molecular and cellular mechanisms causing these reproductive deficiencies remain largely unknown. Thus, the purpose of this study is to explore the reproductive consequence of atrazine exposure at the molecular and cellular level in the freshwater planktonic crustacean, Daphnia magna. Results show that exposure of D. magna to high atrazine concentration of 1000 or 2000 μg/L reduced the number of the first set of offspring born at least 5 days after atrazine exposure. D. magna exposed to these atrazine concentrations exhibited DNA fragmentation, nuclear condensation and fragmentation in the ovaries, and caspase-3 protein activation in both the ovaries and embryos in the brood chamber. No obvious DNA fragmentation, nuclear condensation and fragmentation, or caspase-3 activation was seen in other tissues. These findings suggest that high environmental concentrations of atrazine specifically induce apoptosis in reproductive tissues, which could account for the decline in the number of offspring in D. magna exposed to high concentrations of atrazine.