Argyrodes+flavescens

=Red Silver Spider = =//Argyrodes flavescens //**(Pickard-Cambridge) 1880 **=

How many spiders are there on the web? Look closely at the sides of the web! Are these red spiders the spiderlings of the big spider in the middle of the web? Are these spiders the male spiders instead?

Read on to find out more!



= = =1. Introduction of //Argyrodes flavescens// (Red silver spider) = These small red-brown spiders are not  the spiderlings nor  males of the host spider. They are instead another species of spiders that behave as kleptoparasites and lives on the web of a larger web building spider host (Commonly Nephila spp.). The term kleptoparasitism or cleptoparasitism originated from Greek root words kleptēs thief + parasite, which means [|parasitism] by [|theft] [10]. In terms of etymology, kleptoparasitism should refer to the generalized theft of any resource, not just food [11]. Therefore from the term itself, it describes //Argyrodes flavescens//' dependent relationship on the host spider for resources. An additional information is that within the spiders of the genus Argyrodes, all except //Argyrodes flagellum// live on the webs of the larger web building spiders [2]! toc

 In the Gif above (Figure 2), it showcases how small these kleptoparasite are as compared to the web building host spider. The host spider //Nephila pilipes// abdomen is approximately 5cm long while these small kletoparasites' abdomen are only approximately 3mm!

=2. Distribution =

<span style="font-family: Arial,Helvetica,sans-serif;">2.1 Local distribution
<span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes flavescens// are found in locations where the large web building host could be found. The common host would be the golden orb weavers which are found in secondary and primary forest in Singapore such as Pulau Ubin, Sungei Buloh Nature Reserve, Labrador Park etc. Refer to //Nephila pilipes// species page for the details of their local distribution.

<span style="font-family: Arial,Helvetica,sans-serif;">2.2 Asia distribution
<span style="font-family: Arial,Helvetica,sans-serif;"> <span style="font-family: Arial,Helvetica,sans-serif;">The distribution of //Argyrodes flavescens// reflected in Figure 3 above were based on occurrence reports by the Global Biodiversity Information Facility (GBIF) network as of 22nd July 2012. The distribution includes countries in Asia: Malaysia [3], Thailand, Lao People's Democratic Republic [4], South Korea [5]. However, the list is not exhaustive as throughout the years //Argyrodes flavescens// has been recorded in other parts of Asia:Japan [6], China [7], Taiwan [8] and Singapore [9] (Figure 4 below).

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=<span style="font-family: Arial,Helvetica,sans-serif;">3. Biology = <span style="font-family: Arial,Helvetica,sans-serif;"> = =

<span style="font-family: Arial,Helvetica,sans-serif;">3.1 Kleptoparasitism
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<span style="font-family: Arial,Helvetica,sans-serif;">As mentioned in the introduction, Kleptoparasitism or cleptoparasitism orginated from Greek root words kleptēs thief + parasite, means [|parasitism] by [|theft] [10]. In terms of etymology, kleptoparasitism should refer to the generalized theft of any resource, not just food [11].

<span style="font-family: Arial,Helvetica,sans-serif;">Kleptoparasitism is one of the most common form of exploitation between animals which involves stealing of already captured food items from another animal [12,13]. In the past, most kleptoparsitic studies focused mainly on birds but the prevalence of this behavior is widespread in many animal taxa [14].

<span style="font-family: Arial,Helvetica,sans-serif;">For the interaction to be termed kleptoparasitism, the kleptoparasite must incur a benefit and the host must be negatively affected by the loss of food [14]. In the case that the host does not incur any energetic cost via the loss of the resource, the interaction is not considered to be kleptoparasites [14]. In general, kleptoparasites do not injure the hosts in any direct way other than through loss of nourishment [14].

<span style="font-family: Arial,Helvetica,sans-serif;">3.1.1 Kleptoparasitism in web building spiders
<span style="font-family: Arial,Helvetica,sans-serif;">A spider web serves as a microhabitat to obligatory kleptoparasites and provides them with a variety of resources, such as captured prey, prey remains, and silk [9,15]. The Theridiidae spider, //Argyrodes flavescens//, is known to conduct nearly all their activities on webs of other spiders and is commonly associated to the large web-weaving spider from the genus //Nephila// [9,16]. Figure 6 showcases a few scenarios of the different behaviors of //Argyrodes// inhabitants on a //Nephila// web.

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<span style="font-family: Arial,Helvetica,sans-serif;">3.1.2 //Argyrodes-Nephila// Kleptoparasitism relationship
<span style="font-family: Arial,Helvetica,sans-serif;">Previous studies have shown that the presence of //A. flavescens// is **detrimental** to //N. pilipes// in terms of reduced weight gain, increased web damage, rate of web relocation and ultimately mortality [9].

**<span style="font-family: Arial,Helvetica,sans-serif;">3.1.2.1 Susceptibility of //Nephila// to kleptoparasitism **
<span style="font-family: Arial,Helvetica,sans-serif;">Although //Argyrodes// kleptoparasites are found to occupy other web building spiders, spiders from the genus //Nephila// are especially susceptible to kleptoparasites [18–20]. There exist a variety of reasons behind why //Nephila// webs are suitable or favourable for //Argyrodes// [17]. Factors such as the web being a relatively permanent fixture and having an extensive three-dimensional barrier web helps to provides ample shelter with a large carrying capacity for //Argyrodes// to live on [17] (Refer to Figure 7).The significance of barrier webbing for //Argyrodes// were also proposed by several researchers [21,22]. Moreover, the mesh of the //Nephila// web is very fine and able to trap even the smallest insects [17]. The capture area of the orb web is also large, extremely stiff, and has diverging radii rendering it difficult for //Nephila// to monitor [17].

<span style="font-family: Arial,Helvetica,sans-serif;">In Singapore, there are two //Nephila// species that are susceptible to kleptoparsities: //Nephila pilipes// and //Nephila antipodiana//. Readers can refer to the //Nephila pilipes// species page for other reasons on why the genus //Nephila// are susceptible to kleptoparasitism.

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**<span style="font-family: Arial,Helvetica,sans-serif;">3.1.2.2 Factors influencing //Argyrodes-Nephila// relationships **
<span style="font-family: Arial,Helvetica,sans-serif;">The //Argyrodes-Nephila// relationships are known to be influenced by many factors, such as life stage, web characteristics, prey availability and environmental conditions [9]. In general, larger webs (and hence sub adult- adult Nephila) are found to carry a higher load of kleptoparasites [9].

**<span style="font-family: Arial,Helvetica,sans-serif;">3.1.2.2.1 Abundance of //Argyrodes// **
<span style="font-family: Arial,Helvetica,sans-serif;">It is well known that the abundance of //Argyrodes// considerably varies within host species and web characteristics, web structure and occupancy of host webs [8,18,23,24].

<span style="font-family: Arial,Helvetica,sans-serif;">In the case of the golden orb weavers //[|Nephila clavipes]// (from Neotropics), the abundance of kleptoparasites on the clustered webs is entirely predictable based on the size of the host’s web. However, it has been shown that on the isolated webs of //N. clavipes//, there exists a considerable variation in the number of kleptoparasites and host web size is a poor indicator of the kleptoparasite load [36]. In Singapore context, previous studies have shown that the number of //A. flavescens// is positively correlated with body size, web size and ambient light intensity surrounding the webs of host spider //Nephila pilipes// [9].

**3.1.2.2.2 Host availability**
<span style="font-family: Arial,Helvetica,sans-serif;">A study in Japan have demonstrated the seasonal dynamics of //Nephila-Argyrodes// systems by showing that host availability influences the abundance and dynamics of kleptoparasites [25].

<span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes flavescens// in sub-tropical Japan were observed to prefer different hosts at different period of the year due to the availability of the host (Differing life stages of the two different //Nehpila// species) [25]. In August and November, //Nephila clavate// was preferred while //Nephila maculata// was preferred in July. This was attributed to the larger size of //Nephila maculata// than //Nephila clavate// in July [25]. A study by Grostal & Walter revealed a similar result that //Nephila spp//. were the preferred hosts for //Argyrodes antipodianus// [24].

**<span style="font-family: Arial,Helvetica,sans-serif;">3.1.2.2.3 Inter-specific competition **
<span style="font-family: Arial,Helvetica,sans-serif;">In the same study, the authors found out that the peak density of two //Argyrodes// (//A. flavescens// and //A. bonadea//) were different due to inter-specific competitions. The authors demonstrated experimentally, that in a small spatial scale, the number of individuals of //A. flavescens// removed from the group was positively correlated with the rate of increase in //A. bonadea// [25]. As of 2016, //A. bonadea// sighting has yet to be recorded in Singapore.

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<span style="font-family: Arial,Helvetica,sans-serif;">3.2 Feeding Behaviour (Foraging strategies)
<span style="font-family: Arial,Helvetica,sans-serif;">Kleptoparasitic spiders in the genus //Argyrodes// are known to form social groups around their host spider’s web [26]. It is potentially hazardous to forage as a kleptoparasite on the host web as the host spider itself is a potential predator [27]. Host spiders are known to readily eat //Argyrodes// [22] and often chase them away [21,28,29].

//<span style="font-family: Arial,Helvetica,sans-serif;">Argyrodes //<span style="font-family: Arial,Helvetica,sans-serif;"> spider not only utilise a range of kleptoparasitic foraging techniques to exploit host spiders, they are also known to utilise araneophagic techniques such as attacking the vulnerable hosts that are moulting or lunging at spiderlings [26]. Kleptoparsitic foraging techniques such as “feeding with the host” are riskier than the other tactics such as “silk stealing” and they are known to give the most benefit to the kleptoparasites [21].

<span style="font-family: Arial,Helvetica,sans-serif;">media type="file" key="Video 1 argyrodes feeding with host.mp4" width="300" height="300" <span style="font-family: Arial,Helvetica,sans-serif;">Video 1. //Argyrodes flavescens// feeding with hosts to exploit digested food (Copyright © 2009 Starmer, F.) ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes// are known to display the following foraging strategies: **
 * <span style="font-family: Arial,Helvetica,sans-serif;">1. Collect small prey which are apparently ignored by hosts or eat prey remains which were abandoned by hosts [8,9] (Refer to Figure 9) || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 7. Argyrodes flavescens consuming a small prey.png caption="Figure 9. Argyrodes flavescens consuming a small prey (Copyright © 2007 Starmer, F.)"]] ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">2. Steal freshly captured or freshly stored prey by hosts [9,30] (Refer to Figure 10) || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 8. Argyrodes flavescens stole a freshly captured or freshly stored prey by hosts.png caption="Figure 10. Argyrodes flavescens stole a freshly captured or freshly stored prey by hosts (Copyright © 2007 Starmer, F.)"]] ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">3. Feed with the host to exploit digested food [9,21,23,24,26] (Refer to Figure 11) || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Fig 9.jpg width="496" height="337" caption="Figure 11. Argyrodes flavescens feeding with hosts to exploit digested food (Copyright © 2009 Starmer, F.)"]]
 * <span style="font-family: Arial,Helvetica,sans-serif;">4. Silk stealing [9,31] (Tso & Severinghaus 1998; Koh & Li 2002) (Refer to Figure 12) || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 10. Argyrodes flavescens feeding on silk stealing silk.jpg width="443" height="298" caption="Figure 12. Argyrodes flavescens feeding on silk/ stealing silk (Copyright © 2009 Starmer, F.)"]] ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">5. Hunt for spiderlings of host or attack the moulting host [21,26,32] (Rarely observed) || <span style="font-family: Arial,Helvetica,sans-serif;">No image was found for this at the moment. ||

<span style="font-family: Arial,Helvetica,sans-serif;">3.4. Reproduction

 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 11. Close up image of how a male (top of the image) A.flavescens head fits into the female (bottom of the image) A. flavescens chelicerae during mating.jpg width="426" height="419" caption="Figure 13. Image of a male and female Argyrodes flavescens engaged in mating. The smaller sized male head is being grabbed by the larger sized female chelicerae (pair of appendages in front of the mouth). (Copyright © 2008 Starmer, F.)"]]

<span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes flavescens// conduct nearly all their activities on webs of their host spider, which includes reproduction.

<span style="font-family: Arial,Helvetica,sans-serif;">During mating, the adult female grabs the head of the adult male //A. flavescens// with her chelicerae while, the male repeatedly prod his pedipalp one at a time into the female sexual organ (epigynum) (Refer to video 2 and 3). During their mating process, the male and female relaxes and back off from time to time (Refer to video 2 and 3). There was no publication found on the consequences of mating on the host web or if it makes them more vulnerable to the host detection.

<span style="font-family: Arial,Helvetica,sans-serif;">There are also very limited publications on the exact time it takes for //A. flavescens// to reach sexual maturity but one publication mentioned that with the consistent high prey availability, spiderlings of //A. flavescens// are able to reach maturity and produce egg case in a month [25]. || <span style="font-family: Arial,Helvetica,sans-serif;">media type="file" key="Video 2 Mating.mp4" width="360" height="360" <span style="font-family: Arial,Helvetica,sans-serif;">Video 2. A male and female //A. flavescens// mating (Copyright © 2008 Starmer, F.)

<span style="font-family: Arial,Helvetica,sans-serif;">media type="file" key="Video 3 argyrodes mating.m4v" width="360" height="360"

<span style="font-family: Arial,Helvetica,sans-serif;">Video 3. A close up look of a male and female //A. flavescens// mating (Copyright © 2016 Su Yong-Chao) ||

<span style="font-family: Arial,Helvetica,sans-serif;">3. 4.1 Egg case

 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Eggcase of argyrodes flavescens.png caption="Fig 14. Egg case of Argyrodes flavescens (Copyright © 2016 Lim Zhi Yun)"]] || <span style="font-family: Arial,Helvetica,sans-serif;">As mentioned previously, //Argyrodes flavescens// is known to conduct nearly all their activities on webs of their host spider, which includes laying of egg case.

<span style="font-family: Arial,Helvetica,sans-serif;">In the wild, //A. flavescens// builds a small tent web away from the host web or use the abandoned portion of the host web to place their egg sac [33].

<span style="font-family: Arial,Helvetica,sans-serif;">The egg case of //A. flavescens// are pale white to light brown in appearance and spherical, suspended by a long stalk [33]. The upper part of the eggcase is cone shaped, rounded and tapers well into a point. Inside the egg sac, the eggs are loosely deposited into the middle of a little puff of flossy silk [33]. After hatching, the offsprings crawl through the hole at the bottom of the egg sac [33]. ||

<span style="font-family: Arial,Helvetica,sans-serif;">3.4.2 Life stages
<span style="font-family: Arial,Helvetica,sans-serif;">There are 4 instars stage in //A. flavescens// before the final moult to become the adult. The sex of the //A. flavescens// is only distinguishable at the third instar onwards. Notice the pedipalps on the third and fourth instar image (Figure 15).

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<span style="font-family: Arial,Helvetica,sans-serif;">3.5 Dragline and Locomotion

 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 14. Close up image of how the support web of A. flavescens in between the Nephila web.jpg width="513" height="347" caption="Figure 16. Close up image of the support web of A. flavescens in between the Nephila web (Copyright © 2009 Starmer, F.)"]]

<span style="font-family: Arial,Helvetica,sans-serif;">**Draglines** are important for //Argyrodes// as they have been observed to escape and run away from the attack of the host via its dragline [34]. Dragline are stiff strand of silk produced by spiders especially to form the framework of its web and as a means of lowering itself and returning to a height [54]. In addition, //Argyrodes// has been observed to swing from their draglines to get closer to the prey item [34].

<span style="font-family: Arial,Helvetica,sans-serif;">**Rotary probe movement** are also observed in //Argyrodes//, including //A. flavescens//. They perform investigative behaviors as “rotary probe” by rotating the first pair of legs, because the host web is an unknown environment to the invader [34]. (Refer to Video 4 to observe the rotary probe action and the dragline from their spinnerets.) || <span style="font-family: Arial,Helvetica,sans-serif;">media type="file" key="Video 4 dragline and rotary probing.mp4" width="450" height="450" <span style="font-family: Arial,Helvetica,sans-serif;">Video 4. //A.flavescens// pulling out dragline from its spinnerets and performing rotary probing (Copyright © 2009 Starmer, F.) || <span style="font-family: Arial,Helvetica,sans-serif;">Figure 6 from section 3.1.1 has showcased some but not all of the scenarios of //Argyrodes// behavioural activities on the host's web. To facilitate reader's experience, Figure 6 is inserted below this section for easy reference.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Locomotion **

<span style="font-family: Arial,Helvetica,sans-serif;">In general, eight behavioral activities of //Argyrodes// (Specifically //Argyrodes Ululans//) were recognized and recorded [30]: <span style="font-family: Arial,Helvetica,sans-serif;">“(1) Rotary probing (rotating the first pair of legs at the coxatrochanter joint);(Refer to video 4 above) <span style="font-family: Arial,Helvetica,sans-serif;">(2) Feeding (extracting food from prey); (Refer to Feeding behaviour section 3.2) <span style="font-family: Arial,Helvetica,sans-serif;">(3) Folded (resting or inactive position in which the spider remains motionless in the web with the legs folded up near the body; (Refer to Figure 6) <span style="font-family: Arial,Helvetica,sans-serif;">(4) Still (also an inactive state in which the spider sits in the web motionless with the legs outstretched, (Refer to Figure 6) <span style="font-family: Arial,Helvetica,sans-serif;">(5) Grooming (cleaning legs by passing them through the chelicerae); (Refer to Figure 6) <span style="font-family: Arial,Helvetica,sans-serif;">(6) Mating (courtship and copulation); (Refer to Reproduction section 3.4 ) <span style="font-family: Arial,Helvetica,sans-serif;">(7) Stealing behaviors (including leg waving, web shaking, and clearing silk); and (Refer to Feeding behaviour section 3.2) <span style="font-family: Arial,Helvetica,sans-serif;">(8) Walking (locomotion)” [30]

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=<span style="font-family: Arial,Helvetica,sans-serif;">4. Morphology = <span style="font-family: Arial,Helvetica,sans-serif;">This section describes the morphology of //A. flavescens//. There are limited detailed description or drawings on the morphology of //A. flavescens//, hence this section does not consist of full comparison between the male and female //A. flavescens//.

<span style="font-family: Arial,Helvetica,sans-serif;">4.1 Morphology of //A. flavescens// (Male and Female)

 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 16. Epigynum of female Argyrodes flavescens.jpg width="325" height="305" caption="Figure 18. Epigynum of female Argyrodes flavescens (Copyright © 2014 Taiwan Spider Picture Data)"]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 17. Pedipalps of male Argyrodes flavescens.jpg width="376" height="306" caption=" Figure 19. Pedipalps of male Argyrodes flavescens (Copyright © 2014 Taiwan Spider Picture Data)" link="https://taiwanspider.blogspot.sg/2014/10/argyrodes-flavescens.html?showComment=1478424382076#c5346597840167255291"]] ||

<span style="font-family: Arial,Helvetica,sans-serif;">4.1.1 Legs (Tarsus)
<span style="font-family: Arial,Helvetica,sans-serif;">Although most of the Theridiid ae family members have a "comb like structure" of serrated bristles on the last segment (Tarsus) of their fourth leg (Figure 20), a look under the dissection microscope shows that //Argyrodes flavescens// lack such structures or that it is indistinguishable (Figure 21). Only tarsal claws were distinctively found on their leg instead.
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 18. Drawings of Tarsal comb in spiders (Copyright © Brandeis University Field Biology Electronic Field Guides).jpg caption="Figure 20. Drawings of Tarsal comb in spiders (Copyright © Brandeis University Field Biology Electronic Field Guides) (Permission to publish image sought but not granted because author is uncontactable. Image will be taken down if the author requests to.)" link="@http://www.bio.brandeis.edu/fieldbio/Spiders_Savransky_Suhd_Brondstatter/Pages/Glossary.html"]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:taxo4254/Figure 19. Image of A.flavescens 4th tarsal under the dissection microscope (Copyright © 2016 Lim Zhi Yun).png width="265" height="287" caption="Figure 21. Image of A.flavescens 4th tarsal under the dissection microscope (Copyright © 2016 Lim Zhi Yun)"]] ||

=<span style="font-family: Arial,Helvetica,sans-serif;">5. Diagnosis =

<span style="font-family: Arial,Helvetica,sans-serif;">5.1 Male //Nephila// VS //Argyrodes flavescens//
<span style="font-family: Arial,Helvetica,sans-serif;">As //<span style="font-family: Arial,Helvetica,sans-serif;">A. flavescens //<span style="font-family: Arial,Helvetica,sans-serif;"> (Figure 22) and males //N. pilipes// (Figure 23) are commonly found on the same web of the host (female) //N. pilipes//,there is a need to know how to differentiate the two species. At first glance, they may be mistaken to be same species since both are much smaller than female //N. pilipes// host, of similar reddish brown colour and are commonly observed at the periphery of the web. However, they can be clearly differentiated in a few ways (Figure 24).
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 20. Male A. flavescens.jpg caption="Figure 22. Male A. flavescens (Copyright © 2016  Lim Zhi Yun) "]] || <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 21. Male N. pilipes.jpg width="448" height="592" caption=" Figure 23. Male N. pilipes (Copyright © 2016  Lim Zhi Yun)"]] ||

<span style="font-family: Arial,Helvetica,sans-serif;">than male A.flavescens || <span style="font-family: Arial,Helvetica,sans-serif;">rounded at its extremity with a black spot at the end of the <span style="font-family: Arial,Helvetica,sans-serif;">prominence region and one at the spinneret || <span style="font-family: Arial,Helvetica,sans-serif;">Conical shape and is uniformly colored ||
 * **<span style="font-family: Arial,Helvetica,sans-serif;">The following features **
 * <span style="font-family: Arial,Helvetica,sans-serif;">can be used to distinguish **
 * <span style="font-family: Arial,Helvetica,sans-serif;">between the two species: ** |||| <span style="font-family: Arial,Helvetica,sans-serif;">[[image:Figure 22. Male A. flavescens in Singapore.png caption="Figure 24. Male A. flavescens in Singapore and Male N.pilipes in Singapore (Copyright © 2009 Starmer, F.)"]] ||
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Size ** || <span style="font-family: Arial,Helvetica,sans-serif;">Approximately 2mm smaller than male N.pilipes || <span style="font-family: Arial,Helvetica,sans-serif;">Approximately 2mm larger
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Legs morphology: size and colour ** || <span style="font-family: Arial,Helvetica,sans-serif;">Slender, deep blackish brown hue and the extremity of the femora yellow || <span style="font-family: Arial,Helvetica,sans-serif;">Thicker and of reddish brown hue throughout. ||
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Legs morphology: spinations ** || <span style="font-family: Arial,Helvetica,sans-serif;">No spinations || <span style="font-family: Arial,Helvetica,sans-serif;">Visible spinations ||
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Pedipalps ** || <span style="font-family: Arial,Helvetica,sans-serif;">Smaller and less visible || <span style="font-family: Arial,Helvetica,sans-serif;">Larger and more visible ||
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Abdomen shape ** || <span style="font-family: Arial,Helvetica,sans-serif;">Extremity produced into a somewhat cylindrical prominence,
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Abdomen colour ** || <span style="font-family: Arial,Helvetica,sans-serif;">The distinctive silvery markings || <span style="font-family: Arial,Helvetica,sans-serif;">No silvery markings ||

<span style="font-family: Arial,Helvetica,sans-serif;">5.2 //Argyrodes miniaceus// VS //Argyrodes flavescens//


<span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes flavescens// and //Argyrodes miniaceus// are of similar coloration and both have silvery markings on their abdomen. Therefore //A.flavescens// closely resembles //A. miniaceus// but it can be distinguished by examining the structure of female genitalia and the shape of embolus of male palps [6] (Figure 26).

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=<span style="font-family: Arial,Helvetica,sans-serif;">6. Taxonomy = <span style="font-family: Arial,Helvetica,sans-serif;">The spider family Theridiidae, popularly known as comb-footed spiders, ranks as one of the most species-rich families of spiders [35]. One of the reason for the high species number in the Theridiidae is due the diversity of foraging and lifestyle strategies [35].

<span style="font-family: Arial,Helvetica,sans-serif;">The taxonomy of the subfamily Argyrodinae has always been challenging [36] [37]. The current spider subfamily Argyrodinae (family Theridiidae) comprises of 239 named species [38] in six genera, //Argyrodes, Faiditus, Neospintharus, Ariamnes, Rhomphaea,// and //Spheropistha// [35]

<span style="font-family: Arial,Helvetica,sans-serif;">Two montoypic genera, //Argyrodella// and //Deelemanella// were proposed by their authors to be members of the Argyrodinae [39][40]. There are limited information known about the biology of either species and the authors mentioned that their genitalia and other anatomical structures that are somewhat different from typical Argyrodines [39][40][41]. (Note that these two genera were not included in the phylogeny tree below.)

<span style="font-family: Arial,Helvetica,sans-serif;"> In 1894, Simon regarded the genera //Argyrodes, Ariamnes// and //Rhomphaea// as a group he named Argyrodeae [43]. Subsequently in 1962, the New World species was revised by Exline and Levi. //Argyrodes, Ariamnes// and //Rhomphaea// were lumped into a single genus, //Argyrodes// [36]. Within this genus, Exline and Levi recognised six species groups: //Argyrodes, Ariamnes, Cancellatus, Cordillera, Trigonum// and //Rhomphaea// [36]. In 1998, Tanikawa added //Spheropistha// to the genus //Argyrodes// [42].

<span style="font-family: Arial,Helvetica,sans-serif;">In 2001, Exline and Levi’s one genus system was elevated to the subfamily level (Argyrodinae) by Yoshida [44]. In this subfamily Argyrodinae, Yoshida retained the genus //Argyrodes// and resurrected the following genera: //Ariamnes, Rhomphaea// and //Spheropistha// [44]. In 2004, Agnarsson’s morphological phylogeny of Theridiidae strongly supported the monophyly of the Argyrodinae which also aligned to Yoshida’s genera [35][44]. A molecular phylogeny of the Theridiidae family showed similar result [45]. In 2004, Agnarsson also elevated the //Cancellatus// and //Cordillera// species groups to a single genus, //Faiditus//, and elevated the //Trigonum// species group to genus //Neospintharus// [35]. This then formed the modern six genus system of Argyrodinae (which excluded the consideration of the two monotypic genera //Argyrodella// and //Deelemanella// mentioned previously).

<span style="font-family: Arial,Helvetica,sans-serif;">The genera //Ariamnes// and //Neospintharus// utilise araneophagy as their main foraging strategy. //Rhomphaea// mainly utilises araneophagy and occasionally kleptoparasitism. The foraging strategies or habits of //Spheropistha// remain understudied. The genera //Argyrodes// and //Faiditus// use kleptoparasitism as their main foraging strategy [46][47].

<span style="font-family: Arial,Helvetica,sans-serif;">6.1 Phylogenetics
<span style="font-family: Arial,Helvetica,sans-serif;">In 2014, Su and Smith conducted the first study of group-living behaviour among kleptoparasitic spiders in a molecular phylogenetic context [16]. This is also the only paper (as of 2016) that included //Argyrodes flavescens// in the phylogeny tree of Argyrodinae as other authors worked mainly with Neotropical species. Their study included 41 species of Argyrodinae in their analyses: 23 species in //Argyrodes//, six species in //Faiditus//, five species in //Rhomphaea//, two species in //Neospintharus//, two in //Ariamnes// and three //Spheropistha// [16]. They also used published DNA sequence data from five species [45].

<span style="font-family: Arial,Helvetica,sans-serif;">The DNA was extracted from the legs and prosoma of the specimens. In their analyses, they utilised 2511 bp of DNA sequence data from two mitochondrial genes, cytochrome c oxidase subunit I (COI, 776 bp) and 16S rRNA (16S, 633 bp), two nuclear genes, 28S rRNA (28S, 777 bp) and histone 3 (H3, 325 bp) [16]. They used published data and personal observations to character code three behavioural characters – foraging strategy, sociality and size of host web used – into discrete character states [16]. They categorised foraging strategies into "kleptoparasitism", "araneophagy", or ‘typical’ predation using self-constructed webs.

<span style="font-family: Arial,Helvetica,sans-serif;">Su and Smith estimated the divergence time using the concatenated data matrix under a gene-tree framework using BEAST v. 1.8.0 [50]. In the concatenated analyses, the clock models and substitution rates of each gene was unlinked and the substitution models were set up in MrBayes. The oldest fossil occurrence for the Argyrodines, //Argyrodes parvipatellaris// [51][52], was used as the reference calibration time for the divergence time estimations. The phylogenetic trees constructed by Su and Smith were then inferred using a Bayesian method in MrBayes v. 3.2.1 [48] and maximum likelihood in GARLI v. 2.0 [49].

<span style="font-family: Arial,Helvetica,sans-serif;">In Figure 27, both Bayesian and maximum likelihood (ML) analyses of concatenated data strongly support monophyly of the Argyrodinae (Bayesian posterior probability = 1.00 and ML bootstrap support = 100; Figure. 27) [16]. Both analyses also show that three genera – //Ariamnes//, //Neospintharus and Rhomphaea// – are each supported as clades, while the other three – //Faiditus, Argyrodes and Spheropistha// – are not [16]. There are multiple well-supported species groups within the //Argyrodes + F. xiphias+ Spheropistha// clade (Fig. 27, consensus tree), but the relationships among these groups are not resolved in the ML analysis (refer to Figure. 28 for summary tree) [16].

<span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes flavscens// falls under one of this unresolved clade, Miniaceus clade, which is indicated by the consensus and summary trees (Figures 27 and 28); this clade contains seven species, including //Argyrodes flavescens// and three species currently in the genus //Spheropistha// [16]. However, due to the uncertainty in the placement of the //Spheropistha// species, this clade is not recovered in the maximum clade credibility tree illustrated in Figure. 29 [16].

<span style="font-family: Arial,Helvetica,sans-serif;">The Bayesian stochastic search variable selection (BSSVS) reconstruction of the foraging strategy (Figure. 29) indicates that the ancestral foraging strategy in Argyrodinae is araneophagy [16]. BSSVS allowed the authors to evaluate that a single origin of kleptoparsitism in the the //Argyrodes + Spheropistha + Faiditus + Ariamnes// clade with a secondary loss of kleptoparasitism in the genus //Ariamnes// is more likely as compared to two origins of kleptoparasitism, one in the genus //Faiditus// and one at the base of the //Argyrodes + F. xiphias + Spheropistha// clade [16].

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<span style="font-family: Arial,Helvetica,sans-serif;">6.2 Vernacular (Common) Names
<span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes flavescens// is commonly called the "red and silver spider" or "red and silver dewdrop spider" due to the their colouration and the shape of its' abdomen [2].

<span style="font-family: Arial,Helvetica,sans-serif;">6.3 Etymology
<span style="font-family: Arial,Helvetica,sans-serif;">There are limited resources online that explains the etymology behind the family “Theridiidae”. Many sources simply gave it the definition of “Theridiidae-a family of comb-footed spiders”[2].

<span style="font-family: Arial,Helvetica,sans-serif;">The genus name //Argyrodes// is derived from Greek where argyros represent "silver" and -odes represent "like" [55]. Although this "silver like" coloration does not match //Argyrodes flavescens's// reddish-brown colouration, it is likely named due to the other silvery //Argyrodes// species. In Latin, //flavescens// means ‎“become yellow” [56], which could be due to the yellow colouration on their femora or their reddish-brown colouration.

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<span style="font-family: Arial,Helvetica,sans-serif;">6.4 Type Specimen
<span style="font-family: Arial,Helvetica,sans-serif;">//Argyrodes flavescens// was first described by Pickard-Cambridge, O. in 1880 (Refer to Figure 28) [53]. The syntypes used in the description was from Sri Lanka, and preserved in British Museum of Natural History (BMNH) [6] There was no information found on the lectotypes.

=7. Conservation Status= This taxon has not yet been assessed for the IUCN Red List.

=8. Literature and References= 1. E. Sue Andersen 2014 Captive Breeding and Husbandry of The Golden Orb Weaver Nephila inaurata madagascariensis at Woodland Park Zoo. 2. Joseph K. H. Koh 2000 A Guide to Common Singapore Spiders. //BP Guid. to Nat. Ser. Publ. by Singapore Sci. Cent. Spons. by Br. Pet.// 3. Nasir, D. M., Su, S., Mohamed, Z. & Yusoff, N. C. 2014 New distributional records of spiders (Arachnida: Araneae) from the west coast of Peninsular Malaysia. //Pakistan J. Zool// **46**, 1573–1584. 4. Peter Jäger & Bounthob Praxaysombath 2011 Spiders of Laos part 3.pdf. 5. Namkung, J., Yoo, J. S., Lee, S. Y., Lee, J. H., Paek, W. K. & Kim, S. T. 2009 Bibliographic Check list of Korean Spiders (Arachnida: Araneae) ver. 2010. //J. Korean Nat.// **2**, 191–285. (doi:http://dx.doi.org/10.1016/S1976-8648(14)60055-4) 6. Tanikawa, A., Chida, T. & Kumada, K. 1996 New Records of A rgyrodes flavescens ( Araneae : Theridiidae ) from Japan. **45**, 47–52. 7. Song, D. X., Zhu, M. S. & Chen, J. 1999 The Spiders of China. //Hebei Univ. Sci. Techology Publ. House//, 640 pp. 8. Tso, I. M. & Severinghaus, L. L. 2000 Argyrodes fissifrons inhabiting webs of Cyrtophora hosts: Prey size distribution and population characteristics. //Zool. Stud.// **39**, 236–242. 9. Koh, T. H. & Li, D. 2002 POPULATION CHARACTERISTICS OF A KLEPTOPARASITIC SPIDER. //RAFFLES Bull. …// 10. In press. Definition of kleptoparasite in English. //Oxford Dict.// 11. Burger, L. W. 2000 Long-term effects of red-cockaded woodpecker cavity-entrance restrictors. 12. Rothschild, M. & Clay, T. 1952 Fleas, flukes and cuckoos. A study of bird parasites. //Fleas, flukes cuckoos. A study bird parasites.// (doi:10.1001/jama.1952.03680150102046) 13. Brockmann, H. J. & Barnard, C. J. 1979 Kleptoparasitism in birds. //Anim. Behav.// **27**, 487–514. (doi:10.1016/0003-3472(79)90185-4) 14. Iyengar, E. 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(doi:10.1080/002229300299390) 19. Whitehouse, M. 2011 Kleptoparasitic spiders of the subfamily Argyrodinae: a special case of behavioural plasticity. //Spider Behav. Flex. Versatility.(ME Herberstein, ed.). Cambridge Univ. Press. Cambridge, UK//, 348–386. 20. Robinson, M. H. & Robinson, B. 1973 Ecology and behavior of the giant wood spider. //Nephila maculata//, 1–76. 21. Whitehouse, M. 1986 The foraging behaviours of Argyrodes antipodiana (Theridiidae), a kleptoparasitic spider from New Zealand. //New Zeal. J. Zool.// **4223**, 37–41. (doi:10.1080/03014223.1986.10422658) 22. Whitehouse, M. E. A. 1997 The benefits of stealing from a predator: foraging rates, predation risk, and intraspecific aggression in the kleptoparasitic spider Argyrodes antipodiana. //Behav. Ecol.// **8**, 665–667. (doi:10.1093/beheco/8.6.665) 23. Whitehouse, M. E. a 1988 Factors influencing specificity and choice of host in Argyrodes antipodiana (Theridiidae, Araneae). //J. Arachnol.// **16**, 349–355. (doi:10.2307/3705921) 24. Grostal, P. & Walter, D. E. 1999 Host Specificity and Distribution of the Kleptobiotic Spider Argyrodes antipodianus (Araneae, Theridiidae) on Orb Webs in Queensland, Australia. //J. Arachnol.//, 522–530. (doi:10.2307/3706051) 25. Miyashita, T. 2002 Population dynamics of two species of kleptoparasitic spiders under different host availabilities. //J. Arachnol.// **30**, 31–38. (doi:10.1636/0161-8202(2002)030[0031:PDOTSO]2.0.CO;2) 26. Whitehouse, M. E. A. 2016 Sex-linked differences in learning to improve foraging techniques in the group-living kleptoparasitic spider Argyrodes antipodianus (Theridiidae). //New Zeal. J. Zool.// **422343**, 96–11. (doi:10.1080/03014223.2015.1127264) 27. Elgar, M. a 1993 Inter-specific associations involving spiders: kleptoparasitism, mimicry, and mutualism. //Mem. Queensl. Museum// **33**, 411–430. 28. Cangialosi, K. R. 1991 Attack strategies of a spider kleptoparasite: effects of prey availability and host colony size. //Anim. 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F. 2012 Notes on the behavior of the kleptoparasitic spider Argyrodes elevatus. //Rev. Etol.// **11**, 56–67. 35. Agnarsson, I. 2004 Morphological phylogeny of cobweb spiders and their relatives (Araneae, Araneoidea, Theridiidae). Zool. J. Linn. Soc. 141, 447–626. 36. Exline, H. & Levi, H. W. 1962 American spiders of the genus Argyrodes (Araneae, Theridiidae). Arañas americanas del género Argyrodes (Araneae, Theridiidae). Bull. Museum Comp. Zool. 127, 75–202. 37. <span style="font-family: Arial,sans-serif; font-size: 10pt;">Yoshida, H. 2001 A revision of the Japanese genera and species of the subfamily Theridiinae (Araneae: Theridiidae). //Acta Arachnol.// **50**, 157–181. <span style="font-family: Arial,sans-serif; font-size: 10pt;">38. Platnick, N. (2014). The world spider catalog, version 15 American Museum of Natural History. Retrieved November 23, 2016, from Available at http://research.amnh.org/iz/spiders/ catalog/ 39. Yoshida, H. (2003). A new genus and three new species of the family Theridiidae (Arachnida: Araneae) from North Borneo. Acta Arachnologica 52, 85–89. doi:10.2476/asjaa.52.85 40. Saaristo, M. I. (2006). Theridiid or cobweb spiders of the granitic Seychelles islands (Araneae, Theridiidae). Phelsuma 14, 49–89. 41. Saaristo, M. I. (1978). Spiders (Arachnida, Araneae) from the Seychelle islands, with notes on taxonomy. Annales Zoologici Fennici 15(2), 99–126. 42. Tanikawa, A. (1998). The new synonymy of the spider genus Argyrodes (Araneae: Theridiidae) and a description of a new species from Japan. Acta Arachnologica 47, 21–26. doi:10.2476/asjaa.47.21 43. Simon, E. (1892–1895). ‘Histoire Naturelle des Araignées. Second Edn.’ Volume 1 (section 3, published 10 October 1894), Librairie Encyclopédique de Roret, rue Hautefeuille, 12, Paris, pp. 496–503. 44. Yoshida, H. (2001). The genus Rhomphaea (Araneae: Theridiidae) from Japan, with notes on the subfamily Argyrodinae. 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Name: Lim Zhi Yun (Miss) Email: a0115015@u.nus.edu
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