There is widespread interkingdom signalling between insects and microbes. For example, microbes found in floral nectar may modify its nutritional composition and produce odorants that alter the ...floral odor bouquet which may attract insect pollinators. Mosquitoes consume nectar and can pollinate flowers. We identified microbes isolated from nectar of common tansy, Tanacetum vulgare, elucidated the microbial odorants, and tested their ability to attract the common house mosquito, Culex pipiens.
We collected 19 microbial isolates from T. vulgare nectar, representing at least 12 different taxa which we identified with 16S or 26S rDNA sequencing as well as by biochemical and physiological tests. Three microorganisms (Lachancea thermotolerans, Micrococcus lactis, Micrococcus luteus) were grown on culture medium and tested in bioassays. Only the yeast L. thermotolerans grown on nectar, malt extract agar, or in synthetic nectar broth significantly attracted Cx. pipiens females. The odorant profile produced by L. thermotolerans varied with the nutritional composition of the culture medium. All three microbes grown separately, but presented concurrently, attracted fewer Cx. pipiens females than L. thermotolerans by itself.
Floral nectar of T. vulgare contains various microbes whose odorants contribute to the odor profile of inflorescences. In addition, L. thermotolerans produced odorants that attract Cx. pipiens females. As the odor profile of L. thermotolerans varied with the composition of the culture medium, we hypothesize that microbe odorants inform nectar-foraging mosquitoes about the availability of certain macro-nutrients which, in turn, affect foraging decisions by mosquitoes.
Severe combined immunodeficiency (SCID) is a life-threatening condition of newborns and infants caused by defects in genes involved in T cell development. Newborn screening (NBS) for SCID using the T ...cell receptor excision circle (TREC) assay began in Wisconsin in 2008 and has been adopted or is being implemented by all states in 2017. It has been established that NBS using the TREC assay is extremely sensitive to detect SCID in the newborn period. Some controversies remain regarding how screening positives are handled by individual states, including when to perform confirmatory flow cytometry, what is the necessary diagnostic workup of patients, what infection prophylaxis measures should be taken, and when hematopoietic stem cell transplantation should occur. In addition, the TREC can also assay detect infants with T cell lymphopenia who are not severe enough to be considered SCID; management of these infants is also evolving.
Cuticular hydrocarbons (CHCs) of social insects have typically been studied for their roles in reproductive signaling (i.e., fertility) rather than sexual signaling (i.e., interest in mating), ...resulting in little information about CHCs of males and virgin females. This dearth of information applies particularly to social wasps. We tested the hypothesis that CHCs differentiate sex, caste, and nest membership in each of four yellowjacket species (baldfaced hornets,
Dolichovespula maculata
; southern yellowjackets,
Vespula squamosa
; western yellowjackets,
V. pensylvanica; V. alascensis
). Cold-euthanized queens (21), gynes (81), workers (125), and males (77) from 35 nests were extracted with pentane, and each of the resulting 304 extracts was analyzed by gas chromatography (GC) and GC–mass spectrometry to identify and quantify CHC constituents (aliphatic alkanes and alkenes; mono-, di-, and tri-methyl-branched alkanes). To determine whether caste and sex differ in CHC profiles of wasps, linear discriminant analyses were performed, using
Z
-transformed relative CHC peak areas as predictor variables and sex and caste, or nest, as grouping variables. When caste and sex were used as a grouping variable, plots of the first two discriminant functions revealed that wasps from each of the four species clustered into their respective groups (queens, gynes, workers, males), with significant differences in group centroids, as measured by Wilks’ lambda. When nest was used as a grouping variable, plots of the first two discriminant functions revealed that workers from each of the four species and males from each of three species (insufficient sample size for
V. pensylvanica
) clustered according to nest. Diagnostic power calculations show greater inter-caste than inter-nest variation. Our data support the above hypothesis and inspire future studies to determine the definitive role(s) that gyne- and male-specific CHCs play in the context of sexual communication, from the perspective of both males and females.
Garlic (Allium sativum) and its essential oil have long been used for their distinct flavour, therapeutic effects and as a topical and systemic insect repellent. We tested the hypothesis that the ...yellow fever mosquito, Aedes aegypti L. (Diptera: Culicidae), responds electrophysiologically and behaviourally to specific components of the steam‐distilled essential oil of garlic. In coupled gas chromatographic‐electroantennographic detection analyses of garlic oil, antennae of female Ae. aegypti responded to 14 compounds. Seven of them diallyl disulphide, diallyl trisulphide, diallyl tetrasulphide, 2‐(2,3‐dithia‐5‐hexenyl)‐3,4‐dihydro‐2H‐thiopyran, 3‐(2,3‐dithia‐5‐hexenyl)‐3,4‐dihydro‐2H‐thiopyran, 6‐methyl‐4,5,8,9‐tetrathiadodeca‐1,11‐diene and 4,5,9,10‐tetrathiatrideca‐1,12‐diene were isolated or synthesized and tested for their ability to repel host‐seeking female Ae. aegypti. A solution of diallyl trisulphide and diallyl tetrasulphide applied to a human forearm provided protection from female mosquitoes significantly longer than the paraffin oil control. All compounds had mean protection times significantly shorter than an equivalent dose of the ‘gold standard’N,N‐diethyl‐3‐methylbenzamide. Understanding the common moiety in organosulfur compounds that causes repellence could lead to the design of analogues that are more effective than their natural counterparts in repelling mosquitoes.
We studied life history traits of Xenos peckii Kirby (Strepsiptera: Xenidae), a little-known parasite of the paper wasp Polistes fuscatus (Fabricus) (Hymenoptera: Vespidae) in North America. We ...field-collected 24 wasp nests in early July 2012, isolated parasitised wasps, tracked life history events of X. peckii, and recorded such behaviour as emergence of males and mating by normal-speed and high-speed cinematography. To emerge, males first cut the puparium with their mandibles along an ecdysial suture line, and then push aside the pupal cap during emergence. The endoparasitic females engage in active calling (pheromone release) behaviour by slowly inflating their cephalothorax, and then extruding it even farther out of, and tilting it away from, the host wasp abdomen. Seasonal and diel (afternoon) emergence periods of males coincide with seasonal and diel receptivity and calling periods of females. Males approach calling females in a swaying flight with smooth turns. They typically land on the anterior portion of the host wasp's abdomen, and then step backward until they make contact with the cephalothorax of the female. As soon as their mesothoracic legs contact the female's cephalothorax, they curl around it, and the male initiates mating. Thereafter, the female fully retreats and never re-mates. Nous avons étudié des caractéristiques du cycle biologique de Xenos peckii Kirby (Strepsiptera: Xenidae), un parasite mal connu de la guêpe à papier Polistes fuscatus (Fabricius) (Hymenoptera: Vespidae) en Amérique du Nord. Nous avons récolté 24 nids de guêpes en nature au début de juillet 2012, isolé les guêpes parasitées, suivi les étapes du cycle biologique de X. peckii et enregistré certains comportements, tels que l’émergence des mâles et l'accouplement, par cinématographie à vitesse normale et à haute vitesse. À l’émergence, les mâles coupent d'abord le puparium avec leurs mandibules le long de la ligne de déhiscence et poussent ensuite de côté la calotte de la pupe. Les femelles endoparasites entreprennent des comportements actifs d'appel (par émission de phéromones) en gonflant lentement leur céphalothorax, l'extirpant encore plus vers l'extérieur et le faisant pivoter loin de l'abdomen de la guêpe hôte. Les périodes d’émergence saisonnières et journalières (en après-midi) des mâles coïncident avec les périodes saisonnières et journalières de réceptivité et d'appel des femelles. Les mâles s'approchent des femelles en appel en un vol sinueux à virages en douceur. Ils se posent typiquement sur la partie antérieure de l'abdomen de la guêpe hôte et reculent jusqu’à ce qu'ils entrent en contact avec le céphalothorax de la femelle. Dès que les pattes mésothoraciques du mâle touchent le céphalothorax de la femelle, elles se replient autour de lui et le mâle commence l'accouplement. Ensuite, la femelle se retire totalement et ne s'accouple plus.
Paper wasps are diverse in Neotropical rainforests but the factors that affect their abundance are poorly understood. Army ants (Ecitoninae) are generally thought to have the greatest predatory ...impact on populations of social wasps, but there is emerging evidence that predatory birds could also be a significant source of colony mortality. Our objectives were to (1) identify the genera of wasps preyed upon by
Ibycter americanus
(Falconidae), a specialist predator of Neotropical social wasps, (2) quantify wasp nest predation by
I. americanus
, and (3) compare wasp nest predation rates by
I. americanus
with calculated rates of wasp nest predation by
Eciton burchellii
army ants. In 2008 and 2009, we video recorded chick provisioning at
I. americanus
nests in French Guiana and found that adult birds brought nests of at least ten genera of mainly swarm-founding wasps (Epiponini). In 2012, we noted that three of four sympatric
Eciton
species raided into trees and thus potentially preyed upon the brood of paper wasps at the same site. We quantified the population density of one
Eciton
species, calculated its rate of wasp nest predation, and compared this predation rate to that of
I. americanus.
We conclude that
I. americanus
rivals the predatory impact of
E. burchellii
army ants on some populations of Neotropical social wasps.
Ibycter americanus
and other diurnal vertebrate predators may exert strong selection on wasp defensive behavior, resulting in defensive adaptations that include selection of specific nest sites as well as physical fortification and visual crypsis of nests.
We evaluated an alternative to using hypodermic needles to implant passive integrated transponder (PIT) tags in the body cavities of juvenile salmonids. We used surgical techniques to place PIT tags ...into the body cavities of 3,037 age‐0 Atlantic salmon Salmo salar and then held fish under hatchery conditions for 9 months. Tag retention was 99.8% (six fish lost tags), and survival was 94.3% (174 fish died) after controlling for initial mortality (0.7%). A single tagger was able to tag 80–100 fish per hour. Surgically implanting PIT tags into the body cavities of age‐0 Atlantic salmon proved to be a viable alternative to using hypodermic needles.
Display omitted
▶ Sexual communication in lymantriid moths was known to be mediated by sex pheromones. ▶ We show that male moths at close range are attracted by sound from conspecific females. ▶ ...Females produce species- and sex-specific wing beat and associated click sounds. ▶ The males’ tympanate ears are tuned to frequency components of wing fanning females. ▶ Sound reception appears to have evolved not only to evade bats, but also to find mates.
Sexual communication of nun moth,
Lymantria monacha (L.), pink gypsy moth,
Lymantria mathura Moore, and fumida tussock moth,
Lymantria fumida Butler (all Lepidoptera: Noctuidae: Lymantriinae), is known to be mediated by pheromones. We now show that males are attracted by the sounds of conspecific females over short distances and that wing fanning male and female
L. monacha,
L. mathura and
L. fumida produce species- and sex-specific wing beat and associated click sounds that could contribute to reproductive isolation. Evidence for short-range communication in these lymantriines includes (i) scanning electron micrographs revealing metathoracic tympanate ears, (ii) laser interferometry showing particular sensitivity of tympana tuned to frequency components of sound signals from conspecifics, and (iii) phonotaxis of male
L. monacha and
L. fumida to speakers playing back sound signals from conspecific females. We conclude that tympanate ears of these moths have evolved in response not only to bat predation, but also for short-range mate finding and possibly recognition.
Analyses of pooled headspace volatiles from three commercial chili pepper, Capsicum spp., products by coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled GC-mass ...spectrometry (MS) revealed 10 compounds (β-pinene, γ-terpinene, linalool, 2-phenylethanol, cumin aldehyde, 1,3-menthadienal, eugenol, trans-β-caryophyllene, caryophyllene oxide, and an unknown compound which co-eluted with 2-phenylethanol) that elicited responses from the antennae of cigarette beetles, Lasioderma serricorne. The unknown compound was separated by silica fractionation and identified by MS and NMR spectroscopy as 2-hydroxy-2,6,6-trimethyl-cyclohexanone. In Y-tube olfactometer bioassays, beetles were attracted to the 10-component synthetic blend and to many six- and four-component blends, demonstrating widespread redundancy in bioactivity among the components. Eugenol was discounted as an attractant, whereas β-caryophyllene and linalool had previously been identified as kairomones for L. serricorne. The remaining seven compounds are novel host kairomones for L. serricorne, bringing the total of known host kairomones for this species to 18. The redundancy among host kairomones may enable L. serricorne to find and infest many highly variable stored products, any one of which may emit only a few of the known kairomones.
•Ten potential host attractants (kairomones) for the cigarette beetle were identified in the pooled captured volatiles from three commercial chili pepper products.•Seven of the 10 identified compounds are novel, bringing the total number of known kairomones to 18.•Blends of 6, 4 and 3 of the 10 synthetic compounds in various combinations were as attractive, indicating remarkable redundancy.•Ability to respond to many compounds may enable cigarette beetles to find diverse hosts, any one of which may emit only a few of the 18 known kairomones.
PDF
