Host location by the fruit fly parasitoid Diachasmimorpha krausii: role of fruit fly species, life stage and host plant

Chemosensory communication is essential to insect biology, playing indispensable roles during mate-finding, foraging, and oviposition behaviors. These traits are particularly important during speciation, where chemical perception may serve to establish species barriers. However, identifying genes associated with such complex behavioral traits remains a significant challenge. Through a combination of transcriptomic and genomic approaches, we characterize the genetic architecture of chemoperception and the role of chemosensing during speciation for a young species pair ofHeliconiusbutterflies,Heliconius melpomeneandHeliconius cydno. We provide a detailed description of chemosensory gene-expression profiles as they relate to sensory tissue (antennae, legs, and mouthparts), sex (male and female), and life stage (unmated and mated female butterflies). Our results untangle the potential role of chemical communication in establishing barriers during speciation and identify strong candidate genes for mate and host plant choice behaviors. Of the 252 chemosensory genes,HmOBP20(involved in volatile detection) andHmGr56(a putative synephrine-related receptor) emerge as strong candidates for divergence in pheromone detection and host plant discrimination, respectively. These two genes are not physically linked to wing-color pattern loci or other genomic regions associated with visual mate preference. Altogether, our results provide evidence for chemosensory divergence betweenH. melpomeneandH. cydno, two rarely hybridizing butterflies with distinct mate and host plant preferences, a finding that supports a polygenic architecture of species boundaries.

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Not Led by the Nose: Volatiles from Undamaged Eucalyptus Hosts Do Not Influence Psyllid Orientation

Insects ◽

10.3390/insects9040166 ◽

2018 ◽

Vol 9 (4) ◽

pp. 166 ◽

Cited By ~ 2

Author(s):

Kevin Farnier ◽

Noel Davies ◽

Martin Steinbauer

Keyword(s):

Host Plant ◽

Plant Pathogens ◽

Host Location ◽

Seasonal Migration ◽

Physiological Data ◽

Host Plant Volatiles ◽

Glycaspis Brimblecombei ◽

Host Plant Specificity ◽

Unexpected Findings

Psyllids (Hemiptera: Psylloidea) are small sucking insects with high host plant specificity. Despite the primitive olfactory system of psyllids, some species have been suggested to rely on host plant volatiles (HPVs) for seasonal migration between summer deciduous hosts and winter coniferous hosts. Similarly, enhanced attraction of psyllid vectors has been observed as a result of the manipulation of host odors by plant pathogens. As yet, there are no studies of olfaction in psyllids that utilize evergreen eucalypt hosts. We investigated the behavioral responses of adults of four Eucalyptus-feeding psyllids—Ctenarytaina eucalypti, C. bipartita, Anoeconeossa bundoorensis and Glycaspis brimblecombei—to their respective HPVs in Y-tube olfactometer bioassays. We also used existing physiological data for C. eucalypti to investigate potential olfactory tuning that may modulate the preference for morphologically juvenile leaves over morphologically adult leaves. Although adult C. eucalypti were consistently repelled by HPVs from damaged host leaves, none of the species exhibited positive chemotaxis to HPVs from undamaged leaves. Surprisingly, G. brimblecombei was repelled by HPVs from undamaged host leaves. Our findings provide little support for a significant role of olfaction in host location by Eucalyptus-feeding psyllids. We propose a number of ecological hypotheses to explain these unexpected findings.

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‘And all my children?’

10.1093/oso/9780198828556.003.0001 ◽

2018 ◽

Author(s):

Charlotte Scott

Keyword(s):

Early Modern ◽

Life Stage ◽

Early Modern Period ◽

Life Stages ◽

Cultural Imagination ◽

Modern Period

Beginning with an exploration of the role of the child in the cultural imagination, Chapter 1 establishes the formative and revealing ways in which societies identify themselves in relation to how they treat their children. Focusing on Shakespeare and the early modern period, Chapter 1 sets out to determine the emotional, symbolic, and political registers through which children are depicted and discussed. Attending to the different life stages and representations of the child on stage, this chapter sets out the terms of the book’s enquiry: what role do children play in Shakespeare’s plays; how do we recognize them as such—age, status, parental dynamic—and what are the effects of their presence? This chapter focuses on how the early moderns understood the child, as a symbolic figure, a life stage, a form of obligation, a profound bond, and an image of servitude.

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Natural Zeitgebers Under Temperate Conditions Cannot Compensate for the Loss of a Functional Circadian Clock in Timing of a Vital Behavior in Drosophila

Journal of Biological Rhythms ◽

10.1177/0748730421998112 ◽

2021 ◽

pp. 074873042199811

Author(s):

Franziska Ruf ◽

Oliver Mitesser ◽

Simon Tii Mungwa ◽

Melanie Horn ◽

Dirk Rieger ◽

...

Keyword(s):

Molecular Clock ◽

Time Window ◽

Fruit Fly ◽

Diel Activity ◽

Wild Type ◽

Statistical Measures ◽

Clock Mutant ◽

Full Complement ◽

The Right

The adaptive significance of adjusting behavioral activities to the right time of the day seems obvious. Laboratory studies implicated an important role of circadian clocks in behavioral timing and rhythmicity. Yet, recent studies on clock-mutant animals questioned this importance under more naturalistic settings, as various clock mutants showed nearly normal diel activity rhythms under seminatural zeitgeber conditions. We here report evidence that proper timing of eclosion, a vital behavior of the fruit fly Drosophila melanogaster, requires a functional molecular clock under quasi-natural conditions. In contrast to wild-type flies, period01 mutants with a defective molecular clock showed impaired rhythmicity and gating in a temperate environment even in the presence of a full complement of abiotic zeitgebers. Although period01 mutants still eclosed during a certain time window during the day, this time window was much broader and loosely defined, and rhythmicity was lower or lost as classified by various statistical measures. Moreover, peak eclosion time became more susceptible to variable day-to-day changes of light. In contrast, flies with impaired peptidergic interclock signaling ( Pdf01 and han5304 PDF receptor mutants) eclosed mostly rhythmically with normal gate sizes, similar to wild-type controls. Our results suggest that the presence of natural zeitgebers is not sufficient, and a functional molecular clock is required to induce stable temporal eclosion patterns in flies under temperate conditions with considerable day-to-day variation in light intensity and temperature. Temperate zeitgebers are, however, sufficient to functionally rescue a loss of PDF-mediated clock-internal and -output signaling

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