Chremistica+umbrosa

=//Chremistica umbrosa// (Hemiptera: Cicadidae) =



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Cicadas
Cicadas are synonymous with the noises that they produce. Literally.

The term 'cicada' in Latin means 'buzzer', or a tree cricket. It is no wonder how this name is derived, given that one would naturally associate cicadas to the sounds that immerse them in a forest. Indeed, cicadas are one of the primary perpetrators of forest noises, making one of the loudest songs (recorded to be up to 120dB in certain species-cite) among hexapods. Yet more often than not, they are heard but not seen. Not many of us in Singapore had seen a cicada in the wild before. Their short aboveground lifespan, in addition to their close to impeccable camouflage, allow these creatures to evade our detection. There have been interesting accounts of cicada life histories- them spending 17 years underground before emerging from the ground for a short few weeks to mate, and then die. While this romanticised account are certainly true for one taxa of cicadas (//Magicicadas// sp.), this should not be generalised to all cicadas. What many fail to understand is the wide diversity of this taxa, Cicadoidea.

media type="youtube" key="tjLiWy2nT7U" height="360" width="640" Video 1: //Magicicada// sp. is the species featured within the clip (Life in the Undergrowth, by BBC wildlife).

Cicada species are classified by many different factors: Geography, habitat, season, diurnal patterns of reproductive activity and songs (Moore, 1993). There is an estimated of 3000 species of cicadas worldwide (Cooley et al., 2012). One of the most well documented and researched cicada taxa is the Magicicada sp. These are one of the most charismatic groups, in terms of cicada life history due to their periodicity. Primarily found in North America species in this taxa have particularly long life histories They spend their nymphal years underground, then emerge synchronously from the ground every 13 or 17 years, depending on individual species. Another cicada species, found in India from the genus //Chremistica//, is known to emerge every four years (Mozgai, 2012), in synchrony with the FIFA World Cup (yes, even to the month). These above-mentioned cicadas are termed as 'periodic cicadas', in contrast to 'annual cicadas' that emerge yearly. In terms of size, they vary widely too. The largest cicada, //Megapomponia imperatoria// in the below picture, has a body length of about 7.5cm (AGR, 2010), while //Pacuella puella// spans less than 2cm.
 * [[image:M. imperatoria.jpeg width="496" height="394" align="left" caption="Picture 2. Megapomponia imperatoria in comparison to an adult palm. Photo: Yakovlev Alexey. "]] || [[image:Pacarina puella.jpeg width="488" height="359" align="left" caption="Picture 3. Pacarina puella in comparison to a finger. Photo: Paul Lenhart. "]] ||

Why do cicadas sing?
Since most of us have experienced their loud shrill songs, we sometimes question: what are their songs for? There are a few types of cicada songs: the free song (produced by undisturbed, free living males), protest song (produced when males are disturbed, injured or caught) and for some species, the courtship song (produced only in the presence of females) (Simmons & Young, 1978). The song that is normally encountered by people in the forests is the free song, or the courtship song. Male cicadas sing to attract females to mate. And because of that, the females don't sing. media type="youtube" key="M3_-26LaQHw" height="480" width="640" align="center"

Video 2: Protest calls of a captured cicada. In this video, the protest call resulted in its liberation! Video: sbtmko, Youtube.

Some cicada songs
Because cicada songs are species specific, one can usually identify cicadas to the species level just by listening to their songs. Even species within the same genus would have distinctly different songs. To faciliate comparisons between //Chremistica umbrosa// songs with other cicada songs, a few links are included below: <span style="font-family: Arial,Helvetica,sans-serif;">singing probably the most familiar cicada song in Singapore. || <span style="font-family: Arial,Helvetica,sans-serif;">media type="file" key="Purana usnani - Singapore.mp3" width="240" height="20" <span style="font-family: Arial,Helvetica,sans-serif;">Audio: Dr Leong T.M, from youtube. Click here <span style="font-family: Arial,Helvetica,sans-serif;">for the full video. || <span style="font-family: Arial,Helvetica,sans-serif;">Dominant frequency: 3.94kHz (Leong et al., 2011b) || <span style="font-family: Arial,Helvetica,sans-serif;">media type="file" key="Dundubia_vaginata_BTNR_18Mar2009.mp3" width="240" height="20" <span style="font-family: Arial,Helvetica,sans-serif;">(Permission for use granted by Dr Leong T.M) <span style="font-family: Arial,Helvetica,sans-serif;">This recording was taken in Singapore. || <span style="font-family: Arial,Helvetica,sans-serif;">Frequency range: 7.8kHz -11.9kHz. Peak intensity: 9.8kHz (Leong et al.,2011c) || <span style="font-family: Arial,Helvetica,sans-serif;">media type="file" key="Huechys_fusca_at_BTNR.mp3" width="240" height="20" <span style="font-family: Arial,Helvetica,sans-serif;">(Permission for use granted by Dr Leong T.M) <span style="font-family: Arial,Helvetica,sans-serif;">This recording was taken in Singapore. || <span style="font-family: Arial,Helvetica,sans-serif;">Frequency range: 4.09kHz - 5.46kHz. Peak intensity: 4.81kHz (Leong et al., 2011a) || media type="file" key="Chremistica umbrosa singing Labrador Park.mp3" width="240" height="20" This recording was taken in Singapore. Recording: Edwin Khoo || Dominant frequency: Broad band: 3.3kHz, Narrow band: 2.75kHz (Gogola & Trilar, 2004) || Click here to hear the song! (Gogola and Trilar, 2004) || Dominant frequency: 2.85kHz - 2.95kHz (Gogola & Trilar, 2004) || Click here to hear the song!(Gogola and Trilar, 2004) || <span style="font-family: Arial,Helvetica,sans-serif;">To listen to even more cicada tymbalisations, click here (for Southeast Asian cicadas), here (for North American cicadas), and here (for European cicadas)
 * //<span style="font-family: Arial,Helvetica,sans-serif;">Purana usnani, //
 * //<span style="font-family: Arial,Helvetica,sans-serif;">Dundubia vaginata //
 * //<span style="font-family: Arial,Helvetica,sans-serif;">Huechys fasca //
 * //<span style="font-family: Arial,Helvetica,sans-serif;">Chremistica umbrosa //
 * //Chremistica guamusangensis//
 * //Chremistica pontianaka//

<span style="font-family: Arial,Helvetica,sans-serif;">In general
<span style="font-family: Arial,Helvetica,sans-serif;">Sound producing system in cicadas consists of two coupled resonators: Firstly, the sound producing tymbal, and secondly, the Helmholtz resonator that consists of the abdominal air sac and tympana (Young & Bennet-Clark, 1995). The tymbals produce the sounds, the resonator radiates and amplifies the sounds produced. This is why sometimes, the singing of the cicadas is also known as tymbalisation.
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:taxo4254/Cicada tymbal section.gif caption="Illustration 1. Permission for use granted by The Robinson Library. "]]

<span style="font-family: Arial,Helvetica,sans-serif;">1. Ventral view of cicada. 2. Lateral cross section of cicada. 3. Antero-ventral section of of tymbal area. Note that there is one pair of tymbals. For more information, refer to The Robinson Library [|here]. || ====<span style="font-family: Arial,Helvetica,sans-serif;">In detail ==== <span style="font-family: Arial,Helvetica,sans-serif;">The pair of tymbals of cicadas, located dorsolaterally on each side of the first abdominal segment, are responsible for the sounds they produce. Tymbals are cuticular membranes that are strengthened by sclerotised, dorsoventrally oriented ribs (Claridge, 1985). A tymbal muscle is attached to the inner face of the tymbal. The contraction of the tymbal muscle buckles the tymbal, causing a loud click that makes up the basic unit of cicada calls. Most cicadas have synchronous tymbal muscles, meaning that they require a separate nervous stimulation for every contraction, as opposed to asynchronous muscles that respond to previous cycles of nervous stimulations (Claridge, 1985). Because of this, the frequency tymbal muscle contraction is limited, and rarely reaching observed calling frequencies. Frequency multiplication takes place to reconcile muscle contraction oscillation to observed calling frequencies (Michelsen & Young, 1974) : for a call which peaks at 4kHz (in //Cyclochila//), the oscillation of the tymbal muscles happens at a rate of only about 120Hz (Young & Bennet-Clark, 1995). This frequency multiplication is carried out by the tymbal ribs for //Cyclochila//, having the ribs vibrate at 4000Hz when tymbal muscle contraction oscillation is 120Hz.This is one way for the cicada to carry out modulation of their songs, which is to vary the pitch, timing, or amplitude. Another muscle, the tensor muscle, anterior to the tymbal, serves to modify the elastic and acoustic properties of the tymbal, which could also help in song modulation (Claridge, 1985). Abdomen positioning is yet another means of song modulation- some cicadas deliberately raise their abdomen during song making to increase the gap between its operculum and the abdomen, allowing for louder acoustics (Claridge, 1985). This could explain why some cicadas adopt special 'song making' postures during tymbalisation. ||

media type="youtube" key="9XYcnbFqgLQ" height="360" width="640" align="center"

Video 3. <span style="font-family: Arial,Helvetica,sans-serif;">Cicada tymbalisation, by //<span style="font-family: Arial,Helvetica,sans-serif;">Magicicada //<span style="font-family: Arial,Helvetica,sans-serif;"> sp. Video: Acejackalope, Youtube. The sound is made by the tymbal of the cicada, and is the protest song from this species. The vibrating part that can be seen Note that the mechanism of cicada calls (tymbalisations) is different from that used by most orthopterans, (stridulation), as tymbalisation does not involve the rubbing of one surface against another surface.

<span style="font-family: Arial,Helvetica,sans-serif;">Why don't cicadas go deaf?
<span style="font-family: Arial,Helvetica,sans-serif;">Interestingly, the tympana, which are used by the males as resonators for their song, are also used to detect sounds, both in the males and females. So, if the organ that is exposed to the loud and shrill songs, propagated through a forest, is also the organ that is supposed to receive sounds, could all male cicadas be deaf by the time they sing? <span style="font-family: Arial,Helvetica,sans-serif;">Hennig et al. in 1994 found that there were folds on the male tympana when cicadas were singing, but were not present when they were inactive. The folds conferred protection from 'deafness' caused by mechanical overstimulation of the tympana when cicadas were singing, reducing the cicada's sensitivity to noise by up to 20dB. A more recent study by Sueur et al. (2008) found that male cicadas of his study species had high sensitivity towards only selective frequencies, which was lower than their dominant calling frequency. Also known as frequency detuning, this allows male cicadas certain amount of sensitivity towards auditory signals, and at the same time prevent deafening. On the other hand, they found that the female tympanum was tuned very precisely to the species' dominant calling frequency, allowing optimal detection and recognition of the species specific song sung by the males. More studies could be conducted to determine if these findings can be generalised to all cicadas.

<span style="font-family: Arial,Helvetica,sans-serif;">Song making posture and song modulation
<span style="font-family: Arial,Helvetica,sans-serif;"> For //C.umbrosa//, their songs are very distinct and unmistakable. Able to be heard from a few hundred meters away, their songs are shrill and continuous, punctuated short periods of by coarse-sounding portions in between. To create the coarse sounding portions, //C.umbrosa// seems to change the position of its abdomen, as shown in the below video. media type="youtube" key="qYAtzjN5OI0" height="360" width="640" align="center"

<span style="font-family: Arial,Helvetica,sans-serif;">Video 4. C.umbrosa song modulation through repositioning of its abdomen. Note that whenever the 'coarse' region of the song is sung, this male moves its abdomen downards, towards the tree branch. Video: Edwin Khoo.

<span style="font-family: Arial,Helvetica,sans-serif;">When //C.umbrosa// is singing, it adopt a singing posture, forming a curved abdomen. This posture could possibly function to serve as protection against over-stimulation of its tympana and to increase the amplitude of its songs when it tymbalises. <span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;">Life stages
<span style="font-family: Arial,Helvetica,sans-serif;">Being hemimatabulous, all cicadas go through three main stages in their life cycle, comprising of the egg, nymph and adult.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Life stage || <span style="font-family: Arial,Helvetica,sans-serif;">How does it look like? || <span style="font-family: Arial,Helvetica,sans-serif;">Description ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">Egg || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:taxo4254/cicada egg 450.jpg caption="Picture 6. Cicada-made slits on twig." link="@http://www.batw.net/CicadaGenerations.html"]] || <span style="font-family: Arial,Helvetica,sans-serif;">A female cicada after mating, would deposit eggs, through its ovipositor, into small slits made by itself on the bark of a tree. ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">Nymph || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Cicada nymph 450.jpg caption="Picture 7: Doug Allison. " link="@http://emlado.com/cicada.htm"]] || <span style="font-family: Arial,Helvetica,sans-serif;">Cicada nymphs have body forms that look similar to the adult stage, only without wings. Upon hatching, the nymphs fall from the bark onto the ground. Using their fossorial front legs, the nymphs dig into the ground where they would feed and grow. They derive their nutrition from piercing their rostrum (their feeding mouthparts) into the xylem of roots, and taking in plant sap. As the nymph grows, ecdysis takes place multiple times. ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">Adult || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:cicada adult 450.jpg caption="Picture 8: Hectonichus, Wikimedia Commons."]] || <span style="font-family: Arial,Helvetica,sans-serif;">The last nymphal instar digs out of the soil at night and makes its way onto a vertical surface, which usually are tree barks. There, it carries out its last moult. Emerging as a winged adult, it leaves its moulted exoskeleton (exuvia) behind on the bark. Adults, too, feed on plant fluids through the xylem vessels. ||

<span style="font-family: Arial,Helvetica,sans-serif;">Diet
<span style="font-family: Arial,Helvetica,sans-serif;">//C.umbrosa//, like other cicadas, feed on xylem sap. Their distant relatives from the taxon Sternorrhyncha specialise on getting fluids from the phloem. The mouthparts comprise mandibles and maxillae modified to become needle-like structures, lying in a beak-like labium, forming a rostrum. These are adapted such that the cicada would be able to pierce through bark, into the xylem vessels to take up fluids. Xylem sap from contains a large proportion of water, and ions of potassium, sodium, calcium, magnesium, chlorides and phosphates (Cheung & Marshall, 1973). Trace amounts of sucrose and amino acids are also present. To derive sufficient nutrients from xylem sap, the cicada has to intake a high volume of xylem fluid. To avoid osmotic dilution throught the high amount of water intake, cicadas employ certain physiological adaptations:
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Presence of specialised structures known as filter chambers **

<span style="font-family: Arial,Helvetica,sans-serif;">Uptake of xylem fluid --> Fluid transported to filter chamber via the esophagus --> Water is removed rapidly from the fluids in filter chamber --> Removed water is directly transported to ileum --> Remaining fluids get channeled to mid gut, where absorption of solutes occur.

<span style="font-family: Arial,Helvetica,sans-serif;">The filter chamber allows water to directly take a shorter route through the digestive system of the cicada, reducing osmotic dilution, and to be excreted rapidly. Details of the mechanism of this process can be obtained in the paper written by Cheung and Marshall, 1973. || ||
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Rapid discharge of excess water as urine **

<span style="font-family: Arial,Helvetica,sans-serif;">According to the rate of uptake of xylem fluids, cicadas also have to excrete excess fluids in order to continue uptake at the given rate. On a day where high amounts of feeding take place, urine is quickly discharged as cicadas feed. Components in the urine are in about the same proportions as the xylem sap (Cheung & Marshall, 1973), but in lower quantities. By gently tapping its abdomen, manual discharge of cicada urine can be simulated. Urine is discharged from the anus as fine, discontinuous squirt.

<span style="font-family: Arial,Helvetica,sans-serif;">WARNING: <span style="font-family: Arial,Helvetica,sans-serif;">'Cicada rain' can occur as a result of numerous cicadas feeding simultaneously atop a tree. By having every individual discharging urine at intervals, the cumulative effect is that which is similar to rain. (It is therefore advisable not to be over-relieved when it suddenly rains under a tree on a warm day.) || <span style="font-family: Arial,Helvetica,sans-serif;">media type="youtube" key="aCUtlOTadc0" height="283" width="504" <span style="font-family: Arial,Helvetica,sans-serif;">Video 4. //Chremistica umbrosa// discharging urine atop a tree. Location: Labrador Park, Singapore. Video: Dr Leong, T.M. ||

<span style="font-family: Arial,Helvetica,sans-serif;">//Chremistica umbrosa// life history
<span style="font-family: Arial,Helvetica,sans-serif;">As with all cicadas, //C.umbrosa// is hemimetabulous. Yet, not much is known about the life history of //C.umbrosa// currently. While it has been observed that there have been mass emergence events during late March and early November for a few years since 2010 (Leong et al., 2011), more studies have to be carried out to better understand the periodicity of this species. While the periodicity of this species cannot be confirmed at the moment, there is speculation that this species is likely to be an annual or bi-annual cicada. There are also some suspicions that the abundance peak during the March mass emergence event is slightly higher than the November peak (Leong, unpublished). The populations of //C.umbrosa// decline about 20-30 days after the mass emergence events (Leong et al., 2011). Hence, the aboveground lifespan of the adult //C.umbrosa// is likely to be about one month. Long term observational studies are required to further ascertain this postulation.

<span style="font-family: Arial,Helvetica,sans-serif;">//Chremistica umbrosa// last moult
<span style="color: #808080; font-family: Arial,Helvetica,sans-serif;">Materials extracted from Leong et al. (2011), unless otherwise stated. Permissions for use granted by Dr Leong T.M. <span style="font-family: Arial,Helvetica,sans-serif;"> Cicadas moult (carry out ecdysis) throughout their nymphal stages. Moulting is the shedding of the exoskeleton, required such that the cicada body size can increase. The number of nymphal instars for //C.umbrosa// has yet to be determined, and could be a potential area of study. The below pictures document various stages of the final nymphal moult for //C.umbrosa// to reach adulthood (the imago) (Leong et al., 2011). The pictures were taken on 29 March, 2011, at Labrador Park. In this observation, it was noted that the whole moulting process (from the second picture onwards) took about 30 minutes. <span style="font-family: Arial,Helvetica,sans-serif;">Here is a supplementary video for those who cannot get enough of cicada moulting. Note the various stages in the video that had been mentioned in the photos above.
 * [[image:Moult 1.jpg align="center" caption="Picture 9. Nymph crawls out from the soil, where it had spent its' nymphal years. This is why it is coated with mud."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Moult 2.jpg caption="Picture 10. A split appears at the dorsal part of the thoracic exoskeleton, and the head of the cicada emerges after some struggling. "]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Moult 3.jpg caption="Picture 11. It removes the legs from the exoskeleton and starts to recline backwards. At this time, the legs are still relatively straight. The cicada vibrates its upper half and soon the deflated wings emerge."]] ||
 * [[image:Moult 4.jpg align="center" caption="Picture 12. Wings are still compressed, and tracheal threads can be seen."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Moult 5.jpg caption="Picture 13. The body of the cicada continues its recline downwards and backwards, until it is almost perpendicular to the exuvia. This movement helps in the extraction of the cicada from its exoskeleton. "]] || [[image:Moult 6.jpg align="center" caption="Picture 14."]] ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Moult 7.jpg caption="Picture 15. It flexes its body forward and upwards as the wings slowly inflate."]] || [[image:Moult 8.jpg align="center" caption="Picture 16."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Moult 9.jpg caption="Picture 17. It holds onto its exuvia with all 3 pairs of legs. "]] ||
 * [[image:Moult 10.jpg align="center" caption="Picture 18. Using the grip on the exuvia as leverage, it fully extracts the most posterior part of the abdomen from the moult."]] || [[image:Moult 11 Complete.jpg align="center" caption="Picture 19. The wings are fully elongated and inflated. This process of wing inflation takes about 10 minutes from start to end. The cicada would eventually fold its wings over its body as a roof like structure. This is not yet the final colouration of C.umbrosa. The colourations would appear some time after the moult."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Exuvia.jpg caption="Picture 20. The exuvia remaining on the bark of the tree. Note the dorsal split at the center of the thoracic area. "]] ||

media type="youtube" key="Y4TiY1Ji5Zk" height="360" width="480" align="center"

Video 5. C<span style="font-family: Arial,Helvetica,sans-serif;">icada moulting. Even though the cicada in the video is not //<span style="font-family: Arial,Helvetica,sans-serif;">C.umbrosa //<span style="font-family: Arial,Helvetica,sans-serif;">, one can easily notice the similarities in moulting chronology between this species of cicada and //<span style="font-family: Arial,Helvetica,sans-serif;">C.umbrosa //<span style="font-family: Arial,Helvetica,sans-serif;">. Video: Robert Vingsnes.

<span style="font-family: Arial,Helvetica,sans-serif;">Mating
<span style="font-family: Arial,Helvetica,sans-serif;"> This mating event of //Chremistica umbrosa// was witnessed and documented first hand in Labrador Park, Singapore. The male had been tymbalising discontinuously through for at least an hour, alone. At around 12.53pm, his persistence was rewarded.


 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0573.jpg caption="12:53pm: A female flies and lands noisily a few centimeters behind the male."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0575.jpg caption="Within a few seconds, it stops its tymbalisation."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0576.jpg caption="The male turns around slowly to face the female."]] ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0577.jpg]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0578.jpg]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:taxo4254/DSC_0583.jpg caption="He then walks towards her, until they are directly facing each other. It maintains this position for about 10 seconds."]] ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0584.jpg caption="It then starts to climb onto the female."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0586.jpg]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0587.jpg]] ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0588 - Version 3.jpg caption="Note the visible pygofer of the male."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0589.jpg caption="Mating takes place."]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:DSC_0597.jpg]] ||





<span style="font-family: Arial,Helvetica,sans-serif;">Generalised external anatomy of cicadas
<span style="font-family: Arial,Helvetica,sans-serif;">

=<span style="font-family: Arial,Helvetica,sans-serif;">//Chremistica umbrosa// (Distant, 1904) =

<span style="font-family: Arial,Helvetica,sans-serif;">Taxonomy
<span style="font-family: Arial,Helvetica,sans-serif;">Animalia
 * <span style="font-family: Arial,Helvetica,sans-serif;">Arthropoda
 * Insecta
 * Hemiptera
 * Cicadomorpha
 * Cicadoidea
 * Cicadallidae
 * Cryptotympanini Boulard, 1979
 * //Chremistica//Stål, 1870
 * Tridentigera (Bregman 1985)
 * //Chremistica umbrosa// Distant 1904

<span style="font-family: Arial,Helvetica,sans-serif;">Synonyms
<span style="font-family: Arial,Helvetica,sans-serif;">//Cicada umbrosa// Distant, 1904 <span style="font-family: Arial,Helvetica,sans-serif;"> //Rihana umbrosa// Distant, 1906 <span style="font-family: Arial,Helvetica,sans-serif;"> //Rihana pisanga// Moulton, 1923 <span style="font-family: Arial,Helvetica,sans-serif;"> //Chremistica pisanga// Metcalf, 1963

<span style="background-color: #ffffff; font-family: Tahoma,Geneva,sans-serif;">//Chremistica// Stål, 1870

 * [[image:Distribution of Chremistica globa 800l.jpg]] || <span style="font-family: Tahoma,Geneva,sans-serif;">//Chremistica// Stål, 1870, is a genus containing 49 extant species occurring throughout the Oriental Region (Southeast Asia, China, Taiwan, Sri Lanka) and 1 species from Madagascar. (Yaakop et al., 2005).

<span style="font-family: Tahoma,Geneva,sans-serif;">Blue waypoints indicate the following regions: <span style="font-family: Tahoma,Geneva,sans-serif;">Vietnam, Philippines, Kedah, Meghalaya, Taiwan, Kedah, Java, Borneo, Sumatra, Thailand, Singapore, Sri Lanka, Vietnam, China (Hainan, Yun Nan), Cambodia, Seychelles Island, Madagascar, Bangka Island.

<span style="font-family: Tahoma,Geneva,sans-serif;">At least 3 //Chremistica// species are found in Singapore: <span style="font-family: Tahoma,Geneva,sans-serif;">//Chremistica nesiotes// Breddin, 1905, //Chremistica pontianaka// (Distant, 1888) <span style="font-family: Tahoma,Geneva,sans-serif;">//Chremistica umbrosa// (Distant, 1904) ||

<span style="font-family: Tahoma,Geneva,sans-serif;">Worldwide:

 * [[image:Distribution of Chremistica umbrosa 800.jpg]] || <span style="font-family: Tahoma,Geneva,sans-serif;">Occurrence of this species has been recorded in southern part of the Malayan Peninsula, the eastern coasts of Sumatra, Banka Island, Borneo, and other islands in the southern part of the Strait of Malacca (including Singapore). (Yaakop et al., 2005; Leong et al., 2011; Salmah et al., 2005) ||

<span style="font-family: Tahoma,Geneva,sans-serif;">In Singapore:

 * [[image:C umbrosa Singapore 800.jpg]] || <span style="font-family: Tahoma,Geneva,sans-serif;">Individuals of this species have definitively been observed at least in Bukit Timah Nature Reserve, Labrador Park and Pulau Ubin (Leong et al., 2011)[|[4 ]], Mount Faber (Leong, unpublished) and Venus Drive. ||

<span style="font-family: Arial,Helvetica,sans-serif;">Description / Morphology
==<span style="font-family: Arial,Helvetica,sans-serif;"> == <span style="font-family: Arial,Helvetica,sans-serif;">
 * [[image:C umbrosa dorsal labelled final.jpg caption="Picture 22. Dorsal view of C.umbrosa on a leaf. Photo: Leong et al., 2011. Permission for use granted by Dr. Leong. "]] || <span style="color: #808080; font-family: Arial,Helvetica,sans-serif;">From Yaakop et al. (2005), unless otherwise stated.

<span style="font-family: Arial,Helvetica,sans-serif;">Body

 * <span style="font-family: Arial,Helvetica,sans-serif;">Body length: about 33mm- 35mm for males, about 20mm - 20.4mm for females
 * <span style="font-family: Arial,Helvetica,sans-serif;">Head is ground coloured
 * <span style="font-family: Arial,Helvetica,sans-serif;">Dorsal surface of thorax and abdomen are dark yellow to brown. A greenish tinge can sometimes be observed at that area.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Medial and lateral obconical fields usually open
 * <span style="font-family: Arial,Helvetica,sans-serif;">Lateral obconical fields enclose a ground coloured spot
 * <span style="font-family: Arial,Helvetica,sans-serif;">On the ventral part of the body, the lateral sides from the eyes to the 8th abdominal segment are covered with short fine white hairs (technically known as 'pilosity').
 * <span style="font-family: Arial,Helvetica,sans-serif;">Rostrum with black-brown tip reaching the hind coxae
 * <span style="font-family: Arial,Helvetica,sans-serif;">Central mesonotal fascia not connected with the spots in front of the cruciform elevation

<span style="font-family: Arial,Helvetica,sans-serif;">Genitalia
<span style="font-family: Arial,Helvetica,sans-serif;">
 * <span style="font-family: Arial,Helvetica,sans-serif;">Male genitalia is usually hidden in a cicada in its normal state. It can be slowly pried out from the pygofer region with an insect pin.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Uncus is broad in male genitalia, with rounded rectangular fused lobes
 * <span style="font-family: Arial,Helvetica,sans-serif;">Bundles of reddish bristles present at the lateral edges of uncus

<span style="font-family: Arial,Helvetica,sans-serif;">Opercula
<span style="font-family: Arial,Helvetica,sans-serif;">The opercula covers the tympana of cicadas. <span style="font-family: Arial,Helvetica,sans-serif;">(note: opercula = plural of operculum; tympana = plural of tympanum) <span style="font-family: Arial,Helvetica,sans-serif;"> ||

<span style="font-family: Arial,Helvetica,sans-serif;">Diagnosis

 * <span style="font-family: Arial,Helvetica,sans-serif;">Male genitalia As described in the genitalia portion.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Strongly diverging medial margins in the male opercula As illustrated in the opercula portion.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Patterns of spots on mesonotum Patterns of the paramedial and lateral obconical fields.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Dense white pilosity on lateral sides of ventral surface Very apparent from a lateral view.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Calling song This is the best way to distinguish this species from other species, because of its distinct calling songs.

<span style="font-family: Arial,Helvetica,sans-serif;">Distinguishing males from females

 * [[image:Male dorsal.jpg caption="Male dorsal view. Photo: Edwin Khoo"]][[image:C umbrosa male ventral labelled.jpg caption="Male ventral view. Photo: Edwin Khoo"]] || * <span style="font-family: Arial,Helvetica,sans-serif;">Male operculum strongly diverges from base (of operculum), females have simple operculum (Yaakop et al., 2005)
 * <span style="font-family: Arial,Helvetica,sans-serif;">Females have a M-shaped black marking on the dorsal surface abdominal segment 9, and not in males (Yaakop et al., 2005)
 * <span style="font-family: Arial,Helvetica,sans-serif;">Presence of ovipositor on the ventral side for females, absence for males
 * <span style="font-family: Arial,Helvetica,sans-serif;">Males tymbalise, females do not (Yaakop et al., 2005).
 * <span style="font-family: Arial,Helvetica,sans-serif;">Males have tympanic organs and tymbals while females have fully developed tympanic organs, but no tymbals.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Male tympana is much larger than female tympana.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Females have a sharp, pointed abdomen, while males have more rounded abdomen.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Males have a pair of white patches at the dorsal lateral sides of tergite 3, while females do not.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Females have dense short golden or coppery hairs, while males have less dense hairs || [[image:Female dorsal.jpg caption="Female dorsal view. Photo: Edwin Khoo"]][[image:C umbrosa female ventral labelled.jpg.jpg caption="Female ventral view. Photo: Edwin Khoo"]] ||

<span style="font-family: Arial,Helvetica,sans-serif;">Type information
The holotype of species is the single physical example of an organism that is used when the species was originally formally described. The first formally described //Chremistica umbrosa// (at that point known as //Cicada umbrosa//) is now stored in the British Museum of National History (Yaakop et al., 2005).

Why is //Chremistica umbrosa// nested within these groups?
<span style="color: #808080; font-family: Arial,Helvetica,sans-serif;">From Yaakop et al. (2005), unless otherwise stated. Species nested within **Crytotympanini** usually have large tymbal covers that reach laterally to the operculum, and anteriorly to the metathorax. Also, males usually have greatly enlarged tergites 2 and 3 which are bent to the posterior at the sides of the abdomen. Species placed within the **Tridentigera** group are characterised by arc-shaped claspers, long lateral pygofer lobes, and trilobate median black markings on the vertex connected with the black colouration around the eyes.
 * //Chremistica//** sp. can be differentiated from species within the abovementioned taxa by its triangular head, prominent post-clypeus, and well developed claspers with lateral and medial lobes.

Cicada higher classification
<span style="font-family: Arial,Helvetica,sans-serif;">Based mainly on Australian cicadas, Moulds (2005) carried out an phylogenetic analysis to review the taxonomy of cicada taxa. Cladistic parsimony is used as a tree search criterion to determine the monophyly of cicada taxa, using 117 morphological characters, accounting for 290 states. These morphological characters are identified from both the internal and external anatomy of the tested cicadas. Even though //<span style="font-family: Arial,Helvetica,sans-serif;">C.umbrosa //<span style="font-family: Arial,Helvetica,sans-serif;"> was not included in this study, some useful insights about its higher classification can be inferred from the produced tree. The area highlighted in grey indicates the tribe that //C.umbrosa// is nested within, and the species highlighted in green is nested within a sister genus of //Chremistica//. <span style="font-family: Arial,Helvetica,sans-serif;">

How to spot cicadas in Singapore
<span style="font-family: Arial,Helvetica,sans-serif;">Cicadas are more heard than spotted. So if you really want to see one, here are a few tips that would increase your cicada spotting chances
 * 1) <span style="font-family: Arial,Helvetica,sans-serif;">Bring binoculars, or cameras with telephoto lenses attached.
 * 2) <span style="font-family: Arial,Helvetica,sans-serif;">Go around the late morning or afternoon, in very warm weather!
 * 3) <span style="font-family: Arial,Helvetica,sans-serif;">Listen out to get an indication of their presence. If there are no cicada songs on a warm afternoon, they are probably not around.
 * 4) <span style="font-family: Arial,Helvetica,sans-serif;">If you hear them, use their songs to get to a more precise location --> walk towards the source of the songs
 * 5) <span style="font-family: Arial,Helvetica,sans-serif;">Narrow the source down to one or two trees. If singing stops when you're under a tree, remain quiet and still. The cicadas know you're there. So wait until they start singing again.
 * 6) <span style="font-family: Arial,Helvetica,sans-serif;">Start by looking at the tree trunks for odd protrusions, or peculiar wing like structures --> these could be resting females!
 * 7) <span style="font-family: Arial,Helvetica,sans-serif;">If possible, use your hearing to triangulate to a more precise location of the cicada on top of the tree, and use the binoculars to start searching.
 * 8) <span style="font-family: Arial,Helvetica,sans-serif;">If all these fail, try to locate the cicadas through cicada rain --> stand against the wind direction and look out for the fine purges of cicada urine. Where the cicada rain comes from, there the cicadas are.

Discussion
If you spot any interesting cicadas, or wish to add to or modify anything in this wiki, please feel free to share it with us in this comment area. Your comments are much appreciated! Alternatively, you send an email to elekhoo@gmail.com to do the same.

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<span style="font-family: Tahoma,Geneva,sans-serif;">Acknowledgements
Many thanks to the people who had made this wiki possible, both by willingly providing materials and by providing valuable advice. Special thanks to Dr Leong Tzi Ming, for the short but very productive interview, sharing his field experiences with //Chremistica umbrosa//. My sincere gratitude extends also to Dr Salmah Yaakop, Dr Max Moulds, Wiley-Blackwell, The Robinson Library, Paul Lenhart- these people made the experience of creating of this wiki page very enjoyable!

<span style="font-family: Tahoma,Geneva,sans-serif;">References
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