science

Tisamenus spadix

Tisamenus spadix is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Tisamenus spadix rather than just read about it. In short: Tisamenus spadix is a stick insect species from the family of Heteropterygidae endemic to the Philippine island of Panay. Occurrence The type material of the species comes from the island of Panay in the Visayas Islands.

Key takeaways

Tisamenus spadix belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Tisamenus spadix to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Tisamenus spadix from memory before moving on to harder problems.

Reference excerpt

Tisamenus spadix is a stick insect species from the family of Heteropterygidae endemic to the Philippine island of Panay.

Occurrence The type material of the species comes from the island of Panay in the Visayas Islands.

Taxonomy James Abram Garfield Rehn and his son John William Holman Rehn described the species in 1939 as Hoploclonia spadix. The species name "spadix" means spade-shaped or thickened. An adult male from the collection of Morgan Hebard collected by Baker between May 18 and 24, 1918 in Culasi in the province of Antique in the northwest of the island of Panay was chosen as the holotype. Three other specimens collected by Richard Crittenden McGregor were also examined, including an adult female, which is referred to as the allotype. The other two specimens are a juvenile male and a juvenile female. All three are deposited as paratypes, together with the holotype, at the Academy of Natural Sciences of Drexel University in Philadelphia. Rehn and Rehn divided the Philippine species of the genus into different groups according to morphological aspects. They placed Hoploclonia spadix in the so-called Deplanata group. In addition to Hoploclonia deplanata (now Tisamenus deplanatus) and Hoploclonia spadix, they assigned to this group Hoploclonia cervicornis (now Tisamenus cervicornis), Hoploclonia armadillo (now Tisamenus armadillo), Hoploclonia tagalog (now Tisamenus tagalog) and Hoploclonia fratercula (now Tisamenus fratercula), relatively spineless species with a flat upper surface, which show no or hardly any spines except for the supracoxal spines on the edges of the thorax, but at most teeth. In 2004, Oliver Zompro transferred the species, along with all other Philippine species, to the genus Tisamenus and left only the species occurring on Borneo in the genus Hoploclonia.

Description According to the first description, Tisamenus spadix is very similar to Tisamenus fratercula. It differs from this and all other species of the so-called Deplanata group of Rehn and Rehn by the presence of a spine on the hind hip (metacoxa), the so-called metacoxale. The genus-typical triangle on the mesonotum is wider than it is long in females and longer than it is wide in males. It is clearly concave, more so than in Tisamenus tagalog. Males are about 37 millimetres (1.5 in) long, which is of average length for the representatives of the Deplanata group. Their overall shape is rather broad. The body surface is covered with scattered granules. The legs are relatively short, strong and clearly notched. The head is rectangular and slightly longer than wide, with clearly prominent, almost spherical eyes. The first antennal segment (base segment or scapus) is relatively long and triangular, the second (pedicel or stem segment) is quite short and barrel-shaped. All other segments are also short and cylindrical. On the head there are low keels (carinae), which end posteriorly in rather strong, supraorbital spines. The occipital spines and the medial and lateral coronal spines are recognizable only as flat tubercles. Behind the supraorbitals there is a pair of low warts. The pronotum is almost square and its triangular area is bordered by low carinae. Its front corners end in large, conspicuous, slightly forward-facing double spines. The mesonotum is elongated. Its genus-typical triangle is slightly longer than it is wide and reaches to the middle of the mesonotum. Behind it, starting from the rear corner of the triangle, there is a clear longitudinal keel that continues across the entire metanotum and the segments of the abdomen. Large, paired spines are located on the sides of tergites 2 to 4 of the abdomen. Adult females are about 49 millimetres (1.9 in) long. They are essentially similar to males, but more elongated and relatively broader. The triangle on the mesonotum is wider than it is long and does not reach the middle. Its edge is granulated. The longitudinal carina of the metasternum is not as pronounced. The abdominal tergites are broader and their posterior margins show a series of transverse nodes and a posteromesal node on tergites 2 to 6. The middle carina of the seventh to ninth tergites is raised posteriorly and vertically sloping at the posterior margin.

References

Illustrations

Worked examples

Example 1 — a first encounter with Tisamenus spadix

Start with the simplest possible case. Write down what Tisamenus spadix claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Tisamenus spadix before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Tisamenus spadix ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Tisamenus spadix

In research: Tisamenus spadix appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Tisamenus spadix in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Tisamenus spadix is common in secondary-school and first-year university syllabi. It links to neighbouring topics Insects described in 1939, Phasmatodea, Phasmatodea of Asia, so understanding it makes those chapters shorter.
In everyday life: Look for Tisamenus spadix outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Tisamenus spadix in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tisamenus spadix means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Tisamenus spadix out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tisamenus spadix in simple terms?

Tisamenus spadix is a stick insect species from the family of Heteropterygidae endemic to the Philippine island of Panay. Occurrence The type material of the species comes from the island of Panay in the Visayas Islands.

Why does Tisamenus spadix matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Tisamenus spadix?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Tisamenus spadix.