Comparative Material and Mechanical Properties among Cicada Mouthparts: Cuticle Enhanced with Inorganic Elements Facilitates Piercing through Woody Stems for Feeding.

Adult cicadas pierce woody stems with their mouthparts to feed on xylem, suggesting the presence of cuticular adaptations that could increase hardness and elastic modulus. We tested the following hypotheses: (a) the mouthpart cuticle includes inorganic elements, which augment the mechanical properties; (b) these elements are abundant in specific mouthpart structures and regions responsible for piercing wood; (c) there are correlations among elements, which could provide insights into patterns of element colocalization. We used scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to investigate mouthpart morphology and quantify the elemental composition of the cuticle among four cicada species, including periodical cicadas (Magicicada sp.). Nanoindentation was used to quantify hardness and elastic modulus of the mandibles. We found 12 inorganic elements, including colocalized manganese and zinc in the distal regions of the mandible, the structure most responsible for piercing through wood; nanoindentation determined that these regions were also significantly harder and had higher elastic modulus than other regions. Manganese and zinc abundance relates to increased hardness and stiffness as in the cuticle of other invertebrates; however, this is one of the first reports of cuticular metals among insects with piercing-sucking mouthparts (>100,000 described species). The present investigation provides insight into the feeding mechanism of cicadas, an important but understudied component of their life traits.

Arthropod entombment in weathering-formed opal: new horizons for recording life in rocks.

Animal fossils preserved in various geological materials, such as limestone, claystone, or amber, provide detailed information on extinct species that is indispensable for retracing the evolution of terrestrial life. Here, we present the first record of an animal fossil preserved in opal formed by weathering with such high-resolution details that even individual cuticle hairs are observed. The fossil consists of the exoskeleton of a nymphal insect belonging to the order Hemiptera and either the family Tettigarctidae or the Cicadidae. This identification is based on anatomical details such as the tibial and femoral morphology of the forelegs. The exoskeleton of the insect was primarily zeolitized during the alteration of the host rocks and later sealed in opal deposited by silica-rich fluids derived from the continental weathering of the volcanic host rocks. Organic matter is preserved in the form of amorphous carbon. This finding makes opal formed by rocks weathering a new, complementary source of animal fossils, offering new prospects for the search for ancient life in the early history of Earth and possibly other terrestrial planets such as Mars, where weathering-formed opal occurs.

An augmented wood-penetrating structure: Cicada ovipositors enhanced with metals and other inorganic elements.

Few insect species are as popular as periodical cicadas (Magicicada spp.). Despite representing an enormous biomass and numbers that exceed 370/m2 during mass emergences, the extended time period of the underground nymphal stages (up to 17 years) complicates investigations of their life history traits and ecology. Upon emergence, female cicadas mate and then use their ovipositors to cut through wood to lay their eggs. Given the ability to penetrate into wood, we hypothesized that the ovipositor cuticle is augmented with inorganic elements, which could increase hardness and reduce ovipositor fracturing. We used scanning electron microscopy and energy dispersive x-ray spectroscopy to evaluate the material properties of ovipositors of four cicada species, including three species of periodical cicadas. We found 14 inorganic elements of the cuticle, of which P, Ca, Si, Mg, Na, Fe, Zn, Mn, Cl, K, and S show the highest concentrations (%wt) near the apex of the ovipositor, where other structural modifications for penetrating wood are present. To the best of our knowledge, this is the first report of metal deposits in the cuticle of true bugs (Hemiptera, >80,000 described species).

Psychoactive plant- and mushroom-associated alkaloids from two behavior modifying cicada pathogens.

Entomopathogenic fungi routinely kill their hosts before releasing infectious spores, but a few species keep insects alive while sporulating, which enhances dispersal. Transcriptomics- and metabolomics-based studies of entomopathogens with post-mortem dissemination from their parasitized hosts have unraveled infection processes and host responses. However, the mechanisms underlying active spore transmission by Entomophthoralean fungi in living insects remain elusive. Here we report the discovery, through metabolomics, of the plant-associated amphetamine, cathinone, in four Massospora cicadina-infected periodical cicada populations, and the mushroom-associated tryptamine, psilocybin, in annual cicadas infected with Massospora platypediae or Massospora levispora, which likely represent a single fungal species. The absence of some fungal enzymes necessary for cathinone and psilocybin biosynthesis along with the inability to detect intermediate metabolites or gene orthologs are consistent with possibly novel biosynthesis pathways in Massospora. The neurogenic activities of these compounds suggest the extended phenotype of Massospora that modifies cicada behavior to maximize dissemination is chemically-induced.

The periodical cicada four-year acceleration hypothesis revisited and the polyphyletic nature of Brood V, including an updated crowd-source enhanced map (Hemiptera: Cicadidae: Magicicada).

The periodical cicadas of North America (Magicicada spp.) are well-known for their long life cycles of 13 and 17 years and their mass synchronized emergences. Although periodical cicada life cycles are relatively strict, the biogeographic patterns of periodical cicada broods, or year-classes, indicate that they must undergo some degree of life cycle switching. We present a new map of periodical cicada Brood V, which emerged in 2016, and demonstrate that it consists of at least four distinct parts that span an area in the United States stretching from Ohio to Long Island. We discuss mtDNA haplotype variation in this brood in relation to other periodical cicada broods, noting that different parts of this brood appear to have different origins. We use this information to refine a hypothesis for the formation of periodical cicada broods by 1- and 4-year life cycle jumps.

Beekeeping from Antiquity Through the Middle Ages.

Beekeeping had its origins in honey hunting-the opportunistic stealing of honey from wild honey bee nests. True beekeeping began when humans started providing artificial cavities within which the bees could build comb for the queen to lay her eggs and the workers could process honey. By 2450 BCE, the Egyptians had developed sophisticated apiculture, and, within two millennia, beekeeping with horizontal hives had spread throughout the Mediterranean. During Europe's Middle Ages, honey and wax became important commodities for trade, and beekeeping in skep, log, box, and tree hives flourished to meet the demand. Other species of honey bees contributed to the development and spread of beekeeping in Asia beginning around 300 BCE. Meanwhile, beekeeping evolved independently in Mesoamerica with the stingless bee Melipona beecheii, as documented by archaeological finds and written accounts that survived Spanish conquest.

Entomological reactions to Darwin's theory in the nineteenth century.

Charles Darwin first became interested in entomology during his childhood, and this interest grew into a beetle-collecting obsession during his college days. Following the voyage of the Beagle, his focus on insects shifted from collecting specimens to searching for insect observations that supported his theory of natural selection as proposed in On the Origin of Species. Initially, Darwin believed that entomologists were opposed to his views. Using Darwin's correspondence, I show that his perception was based, in part, on three reviews, including one that he erroneously attributed to an entomological critic, and that not all entomologists were opposed to his ideas. Henry Walter Bates, discoverer of Batesian mimicry, voiced his support of Darwin in his papers and during meetings of the (now Royal) Entomological Society. In America, entomologist Benjamin D. Walsh wrote to Darwin in 1864, expressing his support and promising to counter any anti-Darwinian attack, and by 1868, Darwin was enjoying significant entomological support on both sides of the Atlantic. After his death in 1882, Darwin's supporters gained influence in Britain and the United States, completing entomology's shift to a Darwinian perspective.