Design and Analysis of Mechanical Microswimmers

The fascinating field in present civilization scenario at the edge of science is micro-swimmers, which is a combination of bio physics with self-propulsion mechanisms involving swimming strategies at low Reynolds number. These micro swimming robots offer many advantages in biomedical applications such as drug delivery to some specific locations in our human body and also conducting some surgical operations like opening of blocked arteries etc. In recent times, blocked arteries become a major case in the medical world. This is can be diagnosed by Angioplasty (is a minimally invasive, endovascular procedure to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis) method. So this is the main reason to choose the aorta as our domain for analysis purpose. This paper presents a micro-swimmer with three different heads they are spherical head, Capsule type head and Tapered cylindrical or elliptical head and modelled using SOLIDWORKS and analysis in ANSYS FLUENT.

Adult body size measurement redundancies in Osmia lignaria and Megachile rotundata (Hymenoptera: Megachilidae)

Metrics to assess relative adult bee body size have included both mass and morphometrics, but these metrics may not equally or reliably estimate body size for all bee species and in all situations, due to bee age, diet, and/or environment. Understanding the relationships between different metrics and possible redundancies in the information they afford is important but not always known. Body size measurements provide valuable data for interpreting research outcomes for managed solitary bees, including Osmia lignaria Say and Megachile rotundata F. (Hymenoptera: Megachilidae). Applied studies of these important and readily available U.S. crop pollinators focus on refining commercial management practices, and basic empirical studies in various scientific disciplines (from genomics to ecology) employ them as model systems to study solitary bees. To examine common metrics of body size, we measured head capsule width (HCW), intertegular distance (ITD), and fresh and dry weights of newly emerged adults of both species. Using linear and exponential models, we determined relationships between these body size metrics. For M. rotundata, linear models best described relationships between ITD and all other metrics, and between HCW and fresh and dry weights. For O. lignaria, linear models best fit relationships between all metrics except for fresh weight with both ITD and HCW, which were fitted better with exponential models. For both species, model fits were strongest when males and females were pooled. Depending on the study question, knowing that only one metric may reliably measure body size can simplify evaluations of O. lignaria and M. rotundata responses to artificial or environmental variables.

Characterizing Billbug (Sphenophorus spp.) Seasonal Biology Using DNA Barcodes and a Simple Morphometric Analysis

Billbugs (Sphenophorus spp.) are a complex of grass-feeding weevil species that reduce the aesthetic and functional qualities of turfgrass. Effective billbug monitoring and management programs rely on a clear understanding of their seasonal biology. However, our limited understanding of regional variation in the species compositions and seasonal biology of billbugs, stemming primarily from our inability to identify the damaging larval stage to species level, has hindered efforts to articulate efficient IPM strategies to growers. We used a combination of DNA barcoding methods and morphometric measures to begin filling critical gaps in our understanding of the seasonal biology of the billbug species complex across a broad geographic range. First, we developed a DNA barcoding reference library using cytochrome oxidase subunit 1 (COI) sequences from morphologically identified adult billbugs collected across Indiana, Missouri, Utah and Arizona. Next, we used our reference library for comparison and identification of unknown larval specimens collected across the growing season in Utah and Indiana. Finally, we combined our DNA barcoding approach with larval head capsule diameter, a proxy for developmental instar, to develop larval phenology charts. Adult COI sequences varied among billbug species, but variation was not influenced by geography, indicating that this locus alone was useful for resolving larval species identity. Overlaid with head capsule diameter data from specimens collected across the growing season, a better visualization of billbug species composition and seasonal biology emerged. This approach will provide researchers with the tools necessary to fill critical gaps in our understanding of billbug biology and facilitate the development of turfgrass pest management programs.

Seeking Alfalfa Resistance to a Rhizophagous Pest, the Clover Root Curculio (Sitona hispidulus F.)

Since the cancellation of broad-spectrum soil-active insecticides in alfalfa (Medicago sativa L.) production, clover root curculio (Sitona hispidulus F.) (CRC) larval root damage has increased. Current CRC management practices are limited in their ability to suppress larval feeding belowground. First, we field screened developmental alfalfa populations for CRC damage. Subsequently, we developed a soil-less arena to observe nodule feeding and development (head capsule width) of larvae in the lab. This method was used to evaluate five alfalfa populations (two CRC-susceptible (control) and three CRC-resistant populations) against larvae. Further, one CRC-resistant population paired with its genetically similar susceptible population were tested against adult leaf consumption and oviposition in the greenhouse. Field screening revealed that the alfalfa populations selected for little or no larval root feeding damage were more resistant to CRC larval feeding than their corresponding unselected cultivars and significantly more resistant than populations selected for susceptibility. The development of a soil-less arena provided a useful method for evaluation of root-larva interactions. Although larval development was similar across susceptible and resistant alfalfa populations, one CRC-resistant population (NY1713) displayed overall increased nodulation and, thus, had a significantly lower proportion of nodules consumed by larvae. Adult feeding and oviposition aboveground were similar across all populations tested. These results provide possible candidates and screening method for the development and evaluation of alfalfa cultivars that may reduce the impacts of larval feeding and that offer an additional option for CRC management.

Long-headed predators in Cretaceous amber—fossil findings of an unusual type of lacewing larva

Lacewing larvae (Neuroptera) are known to be fierce predators which are morphologically highly specialised for a raptorial lifestyle. Mandibular-maxillary stylets are characteristic for all larvae of this group; these stylets can be extraordinarily massive. Despite these distinct sucking-piercing stylets, also other extreme features occur in some ingroups, such as an extremely elongated neck. In larvae of thread-winged lacewings (Crocinae) the neck can reach up to about one third of the body length; they are also called ‘long-necked antlions’. Even though the larvae of living neuropteran species show a variety of conspicuous morphologies today, indeed 100 million years ago, in the Cretaceous, Neuroptera seems to have had an even more “experimental phase”. Several larval specimens are known so far especially in Myanmar, Spanish and Lebanese amber from the Cretaceous with unique and unusual character combinations not found in any group living today. We describe here ten new fossil findings of one of these types of larvae with elongated head capsule in Myanmar amber, previously only known from a single specimen. We compared the head shapes of the new specimens with those of 190 specimens of other lacewing larvae and discuss further implications of our findings, especially making functional comparisons with long-necked antlions.

Changes in the Morphological Diversity of Larvae of Lance Lacewings, Mantis Lacewings and Their Closer Relatives over 100 Million Years

Neuroptera, the group of lacewings, comprises only about 6000 species in the modern fauna, but is generally assumed to have been more diverse and important in the past. A major factor of the modern-day ecological diversity of the group, and supposedly in the past as well, is represented by the highly specialised larval forms of lacewings. Quantitative analyses of the morphology of larvae revealed a loss of morphological diversity in several lineages. Here we explored the diversity of the larvae of mantis lacewings (Mantispidae), lance lacewings (Osmylidae), beaded lacewings (Berothidae and Rhachiberothidae, the latter potentially an ingroup of Berothidae), and pleasing lacewings (Dilaridae), as well as fossil larvae, preserved in amber, resembling these. We used shape analysis of the head capsule and stylets (pair of conjoined jaws) as a basis due to the high availability of this body region in extant and fossil specimens and the ecological importance of this region. The analysis revealed a rather constant morphological diversity in Berothidae. Mantispidae appears to have lost certain forms of larvae, but has seen a drastic increase of larval diversity after the Cretaceous; this is in contrast to a significant decrease in diversity in adult forms.

Detecting the Conspecific: Herbivory-Induced Olfactory Cues in the Fall Armyworm (Lepidoptera: Noctuidae)

The fall armyworm, Spodoptera frugiperda (Smith), is a polyphagous pest whose larval feeding threatens several economically important crops worldwide with especially severe damage to corn (Zea mays L.). Field-derived resistance to several conventional pesticides and Bt toxins have threatened the efficacy of current management strategies, necessitating the development of alternative pest management methods and technologies. One possible avenue is the use of volatile organic compounds (VOCs) and other secondary metabolites that are produced and sequestered by plants as a response to larval feeding. The effects of conspecific larval feeding on fall armyworm oviposition preferences and larval fitness were examined using two-choice oviposition experiments, larval feeding trials, targeted metabolomics, and VOC analyses. There was a significant preference for oviposition on corn plants that lacked larval feeding damage, and larvae fed tissue from damaged plants exhibited reduced weights and head capsule widths. All larval feeding promoted significantly increased metabolite and VOC concentrations compared to corn plants without any feeding. Metabolite differences were driven primarily by linoleic acid (which is directly toxic to fall armyworm) and tricarboxylic acids. Several VOCs with significantly increased concentrations in damaged corn plants were known oviposition deterrents that warrant further investigation in an integrated pest management context.

Rugitermes ursulae (Isoptera, Kalotermitidae), a new drywood termite from the Caribbean coast of Colombia

Rugitermes ursulaesp. nov. is described from a sample collected inside a dead branch in a tropical dry forest of Colombia’s Caribbean coast using molecular information and external morphological characters of the imago and soldier castes. Rugitermes ursulaesp. nov. soldiers and imagoes are the smallest among all described Rugitermes species. The imago’s head capsule coloration is dark castaneous, while the pronotum is contrastingly pale yellow. Our description includes soldier characters, such as subflangular elevation and shape of the antennal sockets, that can help in identification of samples lacking imagoes.

Structural megadiversity in leaf litter predators - the head anatomy of Pselaphus heisei (Pselaphinae, Staphylinidae, Coleoptera)

The head anatomy of Pselaphus heisei (Pselaphitae) is described and documented. The structural features are evaluated in comparison with findings presented in earlier studies on the subfamily, with a special focus on correlations with predacious habits and the groundplan of Pselaphinae. We found the tentorium, labrum, maxillary palps, shape of head, and a system of dorsal pits and sulci highly variable within the subfamily, reflecting multiple transformations, including many homoplasious changes. The following major characters are identified as groundplan features of Pselaphinae: falciform mandibles; small mola; semiglobular neck; ventrolateral antennal articulation; steep clypeal region; setiform labial palpomere 3; tentorium with nearly vertical main branches and lacking laminatentoria; separation of tentorial bridge from tentorial arms; fusion of dorsal tentorial arms with the head capsule; large brain placed in the posterior third of the head; and a triple cluster of well-developed cephalic glands. The last feature supports a hypothesis that multiple and independent cases of adaptations to myrmecophilous habits observed in various lineages of Pselaphinae were possible by re-programming already existing glands to produce appeasement secretions. The cephalic muscle apparatus of P. heisei is similar to what is found in other staphylinoid groups, with some exceptions, whereas it is strongly modified in the myrmecophile Claviger testaceus. We propose that the unparalleled structural megadiversity in Pselaphinae is primarily linked with life in the upper soil layers combined with specialized carnivorous habits, with small and agile or mechanically protected arthropods as prey. Within the group, various specialized life habits have evolved, including myrmecophily, termitophily, and also life in deep soil or caves, each with unique morphological adaptations.