The World Health Organization suggests that 'one-step' type disposable chambers lack the accuracy and precision of the haemocytometer method for assessing sperm concentration. The purpose of this particular study was to compare sperm concentration measurements and motility using the Neubauer((R)) haemocytometer with those obtained using three 'one-step' methods: the Microcell((R)) slide, Leja((R)) slide and a plain glass slide with a 22x22 mm coverslip. A total of 200 sperm concentration measurements and 100 motility assessments were performed on all chambers. Paired comparisons showed enormous discrepancies between the counts, particularly between the Neubauer((R)) and other chambers (P < 0.0001). This discrepancy was less pronounced in oligozoospermic samples, and samples with low (<30% progression) motility but more pronounced in normozoospermic samples and those with good motility (>50% progression). In addition, concentration assessments from a fresh undiluted and unfixed semen sample on the Microcell((R)) slide were found to be significantly lower than both fixed counts on the same slide (P = 0.011) and the initial laboratory reading on the Neubauer((R)) chamber (P = 0.009). No differences were observed in progressive motility between the different chambers and a plain glass slide. There appears to be little comparison between the haemocytometer and either re-useable or disposable one-step chambers. The unfortunate consequence of this is that diagnostic semen analysis and guidelines for allocation of patients to appropriate treatment groups will vary from centre to centre, depending on the method used and may, on occasion, be erroneous.
Eleven species of billbugs (Coleoptera: Dryophthoridae: Sphenophorus spp. Schönherr) infest managed turfgrass in North America. However, the regional variation in species composition remains unresolved and the seasonal phenology of several species has not been well documented. The latter gap is largely due to the inability to identify the larval stage to species-a confounding problem with several sympatric insect species. We used field trapping (adults) and soil sampling (larvae and pupae) surveys along with a DNA-based life-stage association to characterize the biology of billbugs associated with turfgrass in the Midwestern United States. Pitfall trapping at four locations in Indiana revealed four billbug species: S. venatus Say, S. parvulus Gyllenhaal, S. minimus Hart, and S. inaequalis Say. Sphenophorus venatus was the most abundant species on warm-season turfgrass while S. parvulus was most abundant on cool-season turfgrass. Investigation of S. venatus seasonal biology revealed two overwintered life stages-larva and adult-which resulted in two overlapping cohorts and two larval generations. Degree-day models describing S. venatus activity were more accurate for first-generation adults and larvae than for overwintering life stages. Maximum-likelihood analyses provided the first molecular species identification of billbug larvae and direct evidence that S. venatus larvae are capable of overwintering above 40°N latitude. Findings clarify the utility of molecular markers (CO1, 18S, and ITS2) for describing billbug larval population dynamics and seasonal phenology in regions where several sympatric billbug species occur. These results support the development of sustainable management strategies based on billbug seasonal phenology in different regions of North America.
We understand very little about the timing and origins of bioluminescence, particularly as a predator avoidance strategy. Understanding the timing of its origins, however, can help elucidate the evolution of this ecologically important signal. Using fireflies, a prevalent bioluminescent group where bioluminescence primarily functions as aposematic and sexual signals, we explore the origins of this signal in the context of their potential predators. Divergence time estimations were performed using genomic-scale datasets providing a robust estimate for the origin of firefly bioluminescence as both a terrestrial and as an aerial signal. Our results recover the origin of terrestrial beetle bioluminescence at 141.17 (122.63–161.17) Ma and firefly aerial bioluminescence at 133.18 (117.86–152.47) Ma using a large dataset focused on Lampyridae; and terrestrial bioluminescence at 148.03 (130.12–166.80) Ma, with the age of aerial bioluminescence at 104.97 (99.00–120.90) Ma using a complementary Elateroidea dataset. These ages pre-date the origins of all known extant aerial predators (i.e. bats and birds) and support much older terrestrial predators (assassin bugs, frogs, ground beetles, lizards, snakes, hunting spiders and harvestmen) as the drivers of terrestrial bioluminescence in beetles. These ages also support the hypothesis that sexual signalling was probably the original function of this signal in aerial fireflies.
A new species of the genus Carpophilus Stephens is described from Australia. This species is currently placed in the subgenus Myothorax Murray, although the group is in need of formal revision. A diagnosis is given to distinguish the new species from all other species of Myothorax in Australia. Additionally, a discussion of type material from Carpophilus described by MacLeay is added with formal lectotype designations for Carpophilus aterrimus MacLeay and Carpophilus pilipennis MacLeay. Taxonomic notes are also given for Carpophilus aterrimus MacLeay, while Carpophilus planatus Murray is removed from synonymy and treated as a valid taxon.
Bioluminescence is found across life and has many functions. Yet we understand very little about its timing and origins, particularly as a predator avoidance strategy. Understanding the timing between bioluminescence and predator origins has yet to be examined and can help elucidate the evolution of the ecologically important signal aposematism. Using the most prevalent bioluminescent group, fireflies, where bioluminescence primarily functions as aposematic and sexual signals, the timing for the origins of both potential predators of fireflies and bioluminescence is explored. Divergence time estimations were performed using a genomic-scale phylogenetic reconstruction Lampyridae, and multiple fossil calibration points, allowing for a robust estimate for the origin of beetle bioluminescence as both a terrestrial and aerial signal. Our results recover the origins of terrestrial beetle bioluminescence at 141 mya and aerial bioluminescence at 133 mya. These ages predate the origins of all known extant aerial predators (i.e., bats and birds) and support the much older terrestrial predators (frogs, ground beetles, lizards, snakes, and hunting spiders) as the most likely drivers of bioluminescence in beetles.
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