vexedmuddler's Identifications

This Ladybug was seen on the TTC around 6:00PM. This Ladybug was seen climbing the glass of the window and the template of the frame as well. This Ladybug appears to have 8 black spots on their red wings as well as two dark spots on its neck. This Ladybug also appeared to have fuzzy legs that bent outwards to climb.

Black and yellow jacket, eating a piece of leftover food, out in the sun, on a table on campus next to G building, sunny weather, 27 degrees outside. It was flying around and would get up every 2 seconds and come back to the piece of food. It was loud with a buzzing sound.

1. Scientific & Common Names:
   The yellow garden spider was first published in 1833 by entomologist Hippolyte Lucas, giving it the scientific name of Argiope aurantia (Hammond, 2002). In addition to the yellow garden spider, other common names include: golden orb-weaver, writing spider, yellow garden orb-weaver and zipper spider.

2. Habitat & Geographic Range:
   A. aurantia is in a wide range of countries including: Southern Canada, the United States of America, Mexico and Central America (Hammond, 2002). A. aurantia prefers sunny habitats, residing on plants such as flowers, shrubs and tall plants. When determining a potential habitat, A. aurantia considers key features that could influence the quality of web-site (McReynolds, 2000). For example, the quality of a web-site is influenced by the type and height of a plant. Shrubs and trees provide a sturdy base which supports larger and stronger webs (McReynolds, 2000). Thus, allowing A. aurantia to capture larger and stronger prey. Furthermore, taller plants allow A. aurantia to form its web at a greater height giving them the ability to capture insects that using flying for motility (McReynolds, 2000). In addition, yellow garden spiders will tend to seek out habitats in which prey is located. For example, they will situate themselves near pollinating flowers where they know bee populations are abundant (Ellender and Howell, 1984).

3. Size/Weight & Lifespan:
   The size of females and males differ with females commonly becoming larger than males. The body length of females varies anywhere from 14 to 25 millimetres, 3 times larger than males which grow anywhere from 5 to 9 millimetres (Harwood, 1974). The weight of A. aurantia could not be determined due to thier small size. Differences in climate has a strong influence on the lifespan and longevity of A. aurantia. In moderate climates, both females and males tend to live a little over a year, with most mortality coming in the colder seasons the following year (Hammond, 2002). Conversely, in warmer climates, females in captivity can live up to several years. Whereas, males usually die after mating (Hammond, 2002).

4. Diet:
   No different to all spiders, the yellow garden spider is carnivorous. As mentioned earlier, web construction is a crucial factor on the diet of the spiders. Their ability to construct webs allows them to capture flying insects (Hammond, 2002). In shoreline habitats, dragonflies are major contributors to the diet of yellow garden spiders (Ellender and Howell, 1984). In comparison, bees were crucial for the diet of yellow garden spiders in grasslands. However, grasshoppers are consumed in both grassland and shoreline habitats (Ellender and Howell, 1984). Females will wait in the centre of their webs waiting for prey to be captured by the webs. Subsequently, the spider injects its venom to further immobilize and kill the prey, which is then wrapped up in a silk cocoon for later consumption (Milne, Milne and Rayfield, 1980).

5. Reproduction & Communication:
   Apparent in many species, mature males are required to leave their webs and search for a female to have reproductive success. Males locate females’ web and begin to pluck and vibrate the web to signal potential mating (Milne, Milne and Rayfield, 1980). A. aurantia are polygynandrous meaning both males and females have multiple mating partners during breeding seasons. After mating occurs, females produce one or more egg sacs which contains hundreds or thousands of eggs in which females will oversee for the duration of their lifespan (Hammond, 2002). Conversely, males experience a spontaneous, programmed death while mating. Due to the short lifespans of the parents, yellow garden spiders are often thought to be r-strategists. R-strategists are species that produce a large amount of offspring but have little to no parental involvement in the upbringing of the offspring. Consequently, the growth and lifespan of the offspring are affected.

6. Predation:
   As yellow garden spiders are relatively small in size, you can imagine that they have a variety of predators. A common predator of A. aurantia is the blue mud wasp (Hammond, 2002). In addition, yellow garden spiders are predated by birds, lizards and mice (Hammond, 2002). Spiderlings are also susceptible to predation by these species. An overwintering egg case provides some protection to spiderlings, however, most are still damaged by predators (Hammond, 2002). Furthermore, predation by larvae insect predators and ovipositors of parasitic insects is reduced by the wall layers of cocoons (Hammond, 2002).

7. Conservation Status:
   Fortunately, the yellow garden spider is among the most common spiders in the world. Therefore, there is no special conservation status. (Hammond, 2002).

8. Did You Know?
   An interesting characteristic of yellow garden spiders that has been studied intensively is web construction and decoration. Orb-weaver spiders like A. aurantia have a web decoration in the middle of their webs called stabilimentum. Stabilimentum is a conspicuous silk structure that tends to be constructed as a zig-zag pattern (Blackledge, 1998). There have been two major hypothesized functions of this web decoration: acts as a defence mechanism against predators and attracts prey leading to foraging success (Blackledge, 1998). There is controversy about the two hypothesized functions because they are seen as contradicting. The web decorations are conspicuous, meaning that they are easily visible by both predators and prey (Blackledge, 1998). Thus, it is contradicting because typically spiders would not want to be easily spotted by their predators even though the function is to serve as a defence mechanisms from predators (Seah and Li, 2001). A 1999 study by Todd Blackledge and John Wenzel observed these two hypotheses. Their results showed that spiders in webs without stabilimentum had higher prey capture rates than webs with stabilimentum (Blackledge and Wenzel, 1999). Therefore, there are still some uncertainties on the function of stabilimentum and that is why there continues to be a conduction of research on its function.

References:
Blackledge, T. A. (1998). Stabilimentum variation and foraging success in Argiope aurantia and Argiope trifasciata (Araneae: Araneidae). The Zoological Society of London, 246(1), 21-27. Retrieved from https://www.cambridge.org/core/journals/journal-of-zoology/article/stabilimentum-variation-and-foraging-success-in-argiope-aurantia-and-argiope-trifasciata-araneae-araneidae/CECE8D387852F84537B01A55ACA45330

Blackledge, T. A., & Wenzel, J. W. (1999). Behavioral Ecology Vol. 10 No. 4: 372–376 Do stabilimenta in orb webs attract prey or defend spiders? Behavioral Ecology, 10(4), 372-376. Retrieved from http://gozips.uakron.edu/~tab27/pdfs/behav_ecol_1999.pdf

Ellender, R. D., & Howell, F. G. (1984). Observations on growth and diet of Argiope Aurantia Lucas (Araneidae) in a successional habitat. The Journal of Arachnology, 12, 29-36. Retrieved from https://www.jstor.org/stable/3705100?seq=1#page_scan_tab_contents

Hammond, G. (2002). Argiope aurantia. Retrieved from http://animaldiversity.org/site/accounts/information/Argiope_aurantia.html

Harwood, R. (1974). Predatory Behavior of Argiope aurantia (Lucas). The American Midland Naturalist, 91(1), 130-139. Retrieved from http://www.jstor.org/stable/242451

McReynolds, C. N. (2000). The impact of habitat features on web features and prey capture of Argiope Aurantia (Araneae, Araneidae). The Journal of Arachnology, 28, 169-179. Retrieved from http://www.bioone.org/doi/abs/10.1636/0161-8202(2000)028%5B0169:TIOHFO%5D2.0.CO%3B2

Milne, L. J., Milne, M., & Rayfield, S. (1980). National Audubon Society field guide to North American insects and spiders. New York, NY: A.A. Knopf.

Seah, W. K., & Li, D. (2001). Stabilimenta attract unwelcome predators to orb-webs. The Royal
Society, 268, 1553-1558. doi:10.1098/rspb.2001.1709