Positive selection analysis of Cyt proteins from Bacillus thuringiensis: a conservative trend driven by negative (purifying) selection.

Bacillus thuringiensis is a Gram-positive entomopathogenic bacterium that produces different pesticidal proteins: vegetative insecticidal proteins (Vpb1/Vpa2, Vip3, and Vpb4) during vegetative growth and δ-endotoxins (Cry and Cyt) during sporulation, which accumulate into parasporal crystals. Cyt proteins are the smaller subset of δ-endotoxins targeting Diptera species. While Cry and Vip3 proteins undergo positive selection, our analysis suggests that Cyt proteins evolve following a conservative trend driven negative (purifying) selection.

Kinematics and coordination of moth flies walking on smooth and rough surfaces.

The moth fly, Clogmia albipunctata, is a common synanthropic insect with a worldwide range that lives in nearly any area with moist, decaying organic matter. These habitats comprise both smooth, slippery substrates (e.g., bathroom drains) and heterogeneous, bumpy ground (e.g., soil in plant pots). By using terrain of varying levels of roughness, we focus specifically on how substrate roughness at the approximate size scale of the organism affects kinematics and coordination in adult moth flies. Finally, we compare and contrast our characterizations of locomotion in C. albipunctata with previous work of insect walking in naturalistic environments.

Trapped between food, heat, and insects: Movement of moose (Alces alces) and exposure to flies in the boreal forest of Alaska.

Moose (Alces alces) in the boreal forest habitats of Alaska are unlike other northern ungulates because they tolerate high densities of flies (Diptera) even though flies cause wounds and infections during the warm summer months. Moose move to find food and to find relief from overheating (hyperthermia) but do they avoid flies? We used GPS collars to measure the rate of movement (m⋅h-1) and the time spent (min⋅day-1) by enclosed moose in four habitats: wetlands, black spruce, early seral boreal forest, and late seral boreal forest. Fly traps were used in each habitat to quantify spatio-temporal abundance. Average daily air temperatures increased into July when peak biomass of forage for moose was greatest in early seral boreal forest habitats (424.46 vs. 25.15 kg⋅ha-1 on average in the other habitats). Average daily air temperatures were 1.7°C cooler in black spruce than other habitats, but fly abundance was greatest in black spruce (approximately 4-fold greater on average than the other habitats). Moose increased their movement rate with counts of biting flies (mosquitoes, black flies, horse and deer flies), but not non-biting flies (coprophagous flies). However, as air temperature increased (above 14.7°C) moose spent more time in fly-abundant black spruce, than early seral boreal forest, showing great tolerance for mosquitoes. Warm summer temperatures appear to cause moose to trade-off foraging in fly-sparse habitats for resting and dissipating heat in shady, wet habitats with abundant flies that adversely affect the fitness of moose.

The genome sequence of a hoverfly, Merodon equestris (Fabricius, 1794).

We present a genome assembly from an individual female Merodon equestris (hoverfly; Arthropoda; Insecta; Diptera; Syrphidae). The genome sequence is 873.0 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 15.95 kilobases in length.

Preserving morphology while extracting DNA: a non-destructive field-to-museum protocol for slide-mounted specimens.

Our study aimed to develop an optimised laboratory protocol ensuring the preservation of morphological structures and extraction of high-quality DNA sequences from Psychodidae (Insecta, Diptera) specimens. With 310 analysed specimens, we investigated the impact of distinct laboratory treatments by employing two shaking categories (constant and interrupted) with five different incubation periods (16, 12, 8, 4 and 2 hours) during the DNA extraction process. Notably, 80.65% of the specimens exhibited morphological changes during DNA extraction. Our results indicated no statistical difference between constant and interrupted shaking for the total of morphological structures lost. However, within each shaking category, the loss of structures was influenced significantly by the incubation period. Prolonged incubation correlated with increased structural losses, whereas shorter incubation periods caused minor alterations in structures lost. In addition, our results showed a significant difference between constant and interrupted shaking treatments for DNA concentration. Likewise, the incubation period showed differences within each shaking category. Successful COI sequencing was achieved in 89.6% of specimens, with negligible differences in DNA fragment lengths across treatments. Our findings underscore the importance of an optimised protocol and its potential in systematic research involving nematoceran dipteran specimens by balancing morphological integrity and DNA extraction efficiency.

Anaerobic treatment removing tetrabromobisphenol A and biota safety: How do tropical aquatic species respond to effluent toxicity over short- and long-term exposures?

Wastewater containing tetrabromobisphenol A (TBBPA), a commonly used flame retardant found in wastewater, can present significant toxic effects on biota, yet its impact on tropical freshwater environments is not well understood. This study explores the effectiveness of two independent anaerobic treatment systems, the acidogenic reactor (AR) and the methanogenic reactor (MR), for the ecotoxicity reduction of TBBPA-rich wastewater in four tropical freshwater species. Despite presenting good physicochemical performance and reduced toxicity of the influent for most species, AR and MR treatments remain acute and chronic toxicity. Overall, MR exhibited greater efficacy in reducing influent toxicity compared with AR. TBBPA bioaccumulation was observed in Chironomus sancticaroli after short-term exposure to 100% MR effluent. Multigenerational exposures highlighted changes in the wing length of C. sancticaroli, showing decreases after influent and AR exposures and increases after MR exposures. These findings underscore the need for ecotoxicological tools in studies of new treatment technologies, combining the removal of emerging contaminants with safeguarding aquatic biota. PRACTITIONER POINTS: Acidogenic and methanogenic reactors reduced the acute and chronic toxicity of wastewater containing tetrabromobisphenol A. Both treatments still exhibit toxicity, inducing short- and long-term toxic effects on four native tropical species. The aquatic species Pristina longiseta was most sensitive to effluents from acidogenic and methanogenic reactors. TBBPA concentrations recovered from Chironomus sancticaroli bioaccumulation analysis ranged from 1.07 to 1.35 µg g-1. Evaluating new treatment technologies with multiple species bioassays is essential for a comprehensive effluent toxicity assessment and ensuring aquatic safety.

A cell line derived from the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae).

Insect cell lines are effective tools used in industry and academia. For example, they are used in screening potential insecticides, in making certain proteins for biomedical applications, and in basic research into insect biology. So far, there are no cell lines derived from the black soldier fly, Hermetia illucens (BSF). This may become an issue because BSFs are employed in a range of industrial and household processes. BSFs are used in producing biodiesel, in developing cosmetics and skin creams, and in the production of some medicines and animal feeds. BSF larvae process waste streams from a variety of sources into food for some animals and are also used in household composting. Our BSF cell line, designated BCIRL-HiE0122021-SGS, was developed from eggs using the medium CLG#2 (50% L-15 + 50% EX-CELL 420, with 9% FBS and antibiotics), with many other media being tested. This cell line consists of attached cells with a variety of morphologies and its identity was authenticated using CO1 barcoding. A growth curve was generated and the resulting doubling time was 118 h. We quantified the fatty acid methyl esters (FAMES) and recorded the expected range of saturated, monounsaturated, and polyunsaturated FAMEs, with only trace levels of lauric acid being noted. The BSF cell line is available free of charge by request.

The genome sequence of a hoverfly, Syrphus vitripennis (Meigen, 1822).

We present a genome assembly from an individual male Syrphus vitripennis (a hoverfly; Arthropoda; Insecta; Diptera; Syrphidae). The genome sequence is 388.8 megabases in span. Most of the assembly is scaffolded into 5 chromosomal pseudomolecules, including the XY sex chromosome. The mitochondrial genome has also been assembled and is 18.33 kilobases in length.

The genome sequence of a hoverfly Eristalinus aeneus (Scopoli, 1763).

We present a genome assembly from an individual female Eristalinus aeneus (a hoverfly; Arthropoda; Insecta; Diptera; Syrphidae). The genome sequence is 495.4 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 15.97 kilobases in length.

The genome sequence of a muscid fly, Hydrotaea cyrtoneurina (Zetterstedt, 1845).

We present a genome assembly from an individual female Hydrotaea cyrtoneurina (muscid fly; Arthropoda; Insecta; Diptera; Muscidae). The genome sequence is 575.2 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 19.6 kilobases in length.

Diversity and distribution of chironomids in Central European ponds.

Ponds are common freshwater habitats in the European landscape that substantially contribute to local and regional biodiversity. Chironomids often dominate invertebrate communities in ponds but are usually disregarded in ecological studies due to relatively complicated taxonomy and identification issues. We present a comprehensive overview of the chironomid diversity in 246 ponds spanning a wide range of conditions extending from the Pannonian Plain to the Carpathians. Altogether, we recorded 225 taxa including 192 species from six subfamilies (Podonominae, Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae and Chironominae). However, the chironomid taxa inventory is far from complete and about 16% of the total diversity of pond-dwelling chironomids remains undetected. Chironomid alpha diversity showed a significant unimodal pattern along the elevation gradient with the highest number of taxa per pond expected around 790 m a.s.l. Gamma diversity also peaked in mid-elevations (600-800 m), and the common chironomid taxa partitioned the 2100-m long altitudinal gradient relatively evenly. The heterogeneity of chironomid communities among ponds measured as beta diversity was significantly higher in elevations below 800 m. Temperature and the proportion of surrounding forests significantly influenced alpha diversity of chironomid communities, while urban land cover and pond size had no significant effect. Ponds with a mean annual air temperature of approximately 4.8°C and a low proportion of surrounding forests are expected to harbour the most diverse chironomid communities. Our study showed that chironomids represent a very diverse and often exceptionally rich group of pond-dwelling macroinvertebrates. Given the high diversity and broad range of occupied niches, chironomids should not be overlooked in pond ecology studies. On the contrary, they should be considered a potential model group.

Insect floral visitors of thermo-Mediterranean shrubland maquis (Ajaccio, Corsica, France).

Background: The Mediterranean Region represents a biodiversity hotspot with a high rate of endemism. In its western part, Corsica Island is notable in terms of biodiversity due to its large surface and its large range of habitats from seaside to alpine biotopes. Amongst diverse groups, insects, notably the main orders of pollinators composed of Coleoptera, Hymenoptera, Diptera and Lepidoptera, represent a good part of the insular richness. New information: Our sampling effort focused on the insects from these four orders visiting flowers in a characteristic thermo-Mediterranean vegetation. Our database is an insight into the Corsican floral visitor biodiversity from three sites separated by a few kilometres in the region of Ajaccio during 13 months over two successive years. In total, 4012 specimens were sampled and 252 species or morpho-species identified from 133 genera and 47 families. Beetles were by far the most abundant order representing about 54% of the sampled specimens. The most diverse order was the Hymenoptera representing 39% of the species. Our continuous survey showed that these orders are temporally dynamic both between years and between seasons in terms of abundance and diversity.

The genome sequence of the parsley Cheilosia, Cheilosia pagana (Meigen, 1822).

We present a genome assembly from an individual female Cheilosia pagana (the parsley Cheilosia; Arthropoda; Insecta; Diptera; Syrphidae). The genome sequence is 354.1 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 16.76 kilobases in length.

The genome sequence of the spotted cranefly, Nephrotoma appendiculata (Pierre, 1919).

We present a genome assembly from an individual male Nephrotoma appendiculata (the spotted cranefly; Arthropoda; Insecta; Diptera; Tipulidae). The genome sequence is 1,138.0 megabases in span. Most of the assembly is scaffolded into 4 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 17.42 kilobases in length. Gene annotation of this assembly on Ensembl identified 17,753 protein coding genes.

Different Sensitivity of Flower-Visiting Diptera to a Neonicotinoid Insecticide: Expanding the Base for a Multiple-Species Risk Assessment Approach.

Insects play an essential role as pollinators of wild flowers and crops. At the same time, pollinators in agricultural environments are commonly exposed to pesticides, compromising their survival and the provision of pollination services. Although pollinators include a wide range of species from several insect orders, information on pesticide sensitivity is mostly restricted to bees. In addition, the disparity of methodological procedures used for different insect groups hinders the comparison of toxicity data between bees and other pollinators. Dipterans are a highly diverse insect order that includes some important pollinators. Therefore, in this study, we assessed the sensitivity of two hoverflies (Sphaerophoria rueppellii, Eristalinus aeneus) and one tachinid fly (Exorista larvarum) to a neonicotinoid insecticide (Confidor®, imidacloprid) following a comparative approach. We adapted the standardized methodology of acute contact exposure in honey bees to build dose-response curves and calculate median lethal doses (LD50) for the three species. The methodology consisted in applying 1 µL of the test solution on the thorax of each insect. Sphaerophoria rueppelli was the most sensitive species (LD50 = 10.23 ng/insect), and E. aeneus (LD50 = 18,176 ng/insect) the least. We then compared our results with those available in the literature for other pollinator species using species sensitivity distribution (SSD). Based on the SSD curve, the 95th percentile of pollinator species would be protected by a safety factor of 100 times the Apis mellifera endpoint. Overall, dipterans were less sensitive to imidacloprid than most bee species. As opposed to most bee species, oviposition and fecundity of many dipteran species can be reliably assessed in the laboratory. We measured the number of eggs laid following exposure to different insecticide doses and assessed the potential trade-off between oviposition and survival through the sublethal sensitivity index (SSI). Exposure to imidacloprid had a significant effect on fecundity, and SSI values indicated that oviposition is a sensitive endpoint for the three dipteran species tested. Future studies should integrate this information related to population dynamics in simulation models for environmental risk assessment.

The genome sequence of the drosophilid fruit fly, Drosophila phalerata (Meigen, 1830).

We present a genome assembly from an individual male Drosophila phalerata (drosophilid fruit fly, Arthropoda; Insecta; Diptera; Drosophilidae). The genome sequence is 223.9 megabases in span. Most of the assembly is scaffolded into 7 chromosomal pseudomolecules, including the X and Y sex chromosomes. The mitochondrial genome has also been assembled and is 16.14 kilobases in length. Gene annotation of this assembly on Ensembl identified 18,973 protein coding genes.

The genome sequence of a stiletto fly, Thereva unica (Harris, 1780).

We present a genome assembly from an individual female Thereva unica (a stiletto fly; Arthropoda; Insecta; Diptera; Therevidae). The genome sequence is 910.1 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 17.66 kilobases in length.

The genome sequence of a conopid fly, Myopa testacea (Linnaeus, 1767).

We present a genome assembly from an individual male Myopa testacea (conopid fly; Arthropoda; Insecta; Diptera; Conopidae). The genome sequence is 243.3 megabases in span. Most of the assembly is scaffolded into 5 chromosomal pseudomolecules, including the X and Y sex chromosomes. The mitochondrial genome has also been assembled and is 17.61 kilobases in length. Gene annotation of this assembly on Ensembl identified 25,472 protein coding genes.

The genome sequence of the Four-banded Bee-grabber, Conops quadrifasciatus De Geer, 1776.

We present a genome assembly from an individual male Conops quadrifasciatus (the Four-banded Bee-grabber; Arthropoda; Insecta; Diptera; Conopidae). The genome sequence is 210.4 megabases in span. Most of the assembly is scaffolded into 7 chromosomal pseudomolecules, including the X and Y sex chromosomes. The mitochondrial genome has also been assembled and is 18.07 kilobases in length. Gene annotation of this assembly on Ensembl identified 23,090 protein coding genes.

Black blow fly (Diptera: Calliphoridae) bacterial symbionts inform oviposition site selection by stable flies (Diptera: Muscidae).

Larval habitats of blood-feeding stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), overlap with foraging sites of black blow flies, Phormia regina (Meigen) (Diptera: Calliphoridae). We tested the hypothesis that bacteria in blow fly excreta inform oviposition decisions by female stable flies. In laboratory 2-choice bioassays, we offered gravid female stable flies fabric-covered agar plates as oviposition sites that were kept sterile or inoculated with either a blend of 7 bacterial strains isolated from blow fly excreta (7-isolate-blend) or individual bacterial isolates from that blend. The 7-isolate-blend deterred oviposition by female stable flies, as did either of 2 strains of Morganella morganii subsp. sibonii. Conversely, Exiguobacterium sp. and Serratia marcescens each prompted oviposition by flies. The flies' oviposition decisions appear to be guided by bacteria-derived semiochemicals as the bacteria could not be physically accessed. Oviposition deterrence caused by semiochemicals of the 7-isolate-blend may help stable flies avoid competition with blow flies. The semiochemicals of bioactive bacterial strains could be developed as trap lures to attract and capture flies and deter their oviposition in select larval habitats.