Tag Info

Hot answers tagged

29

Off the top of head as a medical professional I can imagine the following mechanisms (everything is just speculative reasoning): Insects don't have blood. Instead, they have hemolymph whose primary role is not oxygen transport (they have an additional tracheal system for this purpose), but rather that of nutrients. Thus they don't need (and don't have) an ...


22

Dickinson (2005) has a good review of insect flight, including behavior, biomechanics, electrophysiology, and neural control with links to more of the primary literature. What follows is a general summary thereof. The jagged trajectories you mention are called saccades in the insect flight literature. In Drosophila, saccades are ~90° turns accomplished in ...


19

There are instances of insect muscle growth in response to increased use. The flight muscles of the tsetse fly (Glossina morsitans) have been observed to grow at a faster rate when subjected to enforced exercise (Anderson and Finlayson, 1976). Also larger mandibular adductor muscles (which power the feeding apparatus), and associated head capsule have been ...


15

Holometaboly is believed to have evolved only once (Labandeira, 2011), but is arguably the most successful mode of development we know of in terms of species richness (Kristensen, 1999 - PDF link). Insects which have adopted this method are far more diverse than their hemimetabolous counterparts. A conservative estimate by Hammond (1992) is that ...


14

There will always be a tradeoff in terms of resource allocation between reproduction and self maintenance. Since worker ants forego reproduction to perform other roles (gathering resources, caring for young etc.) within the colony, it makes sense that this would favour a longer lifespan. This idea works for most animals (i.e. higher reproduction = lower ...


13

Studies of Deinococcus radiodurans, the most radioactively tolerant microorganism we know, show that it has many genes for DNA repair. In the case of the cockroach, I would assume that in addition to repairing genes, and maybe some antioxidants produced in the cells to quench free radicals produced by radiation, the fact that the roaches lay many, many ...


12

Insect flight muscle is capable of achieving the highest metabolic rate of all animal tissues, and this tissue may be considered an exquisite example of biochemical adaptation. Locusts, for example, may (almost instantaneously) increase their oxygen consumption up to 70-fold when starting to fly. In humans, excercise can increase O2 consumption a maximum ...


12

Certainly ants evolved from insects that could fly. All the earliest wasps (ants are specialized wasps) could fly. Building and maintaining wings is expensive in terms of energy. That's an obvious evolutionary advantage to not having wings. So if there's insufficient benefit from having wings then there's selective pressure against having wings.


9

I'm not 100% sure, but I think they look like scale insects (Coccoidea). In particular it looks at bit like a hermaphrodite cottony cushion scale insect (Icerya purchasi)... The white fluffy thing underneath the insects is the ootheca (egg case). The mature insect migrates to the main trunk of its host tree and attaches to the bark. It then secretes the ...


9

It's a larvae from a ladybird (or ladybug). Judging by the stripe pattern it is a Common Spotted Ladybird (wiki: Harmonia conformis) and from the body shape & size I'd also say 3rd instar. The one you have photographed, and the one on flickr, are larval forms of the ladybug, just like when a catepillar becomes a butterfly, the ladybugs also have a ...


9

The standard answer to this question is - it's down to the delivery of oxygen to respiring tissues. Insects depend upon a process that is essentially diffusion-driven (via spiracles and the tracheal system) whereas vertebrates have a circulatory system that allows oxygen absorbed in the lungs to be carried via the blood to peripheral tissues. And of course ...


8

The smaller an animal is the easier it becomes for it to fly. That is because surface area increases to the second power of the diameter of the animal whereas mass increases to the third. So the larger a thing is the more mass per surface are it has. And since insects tend to be small they tend to be good at flying. As for any other reason, I don't think ...


7

Quick search - Some articles that may interest you: 1) Random walk model of insect movements Kareiva P. M., Shigesada N. (1983). Analyzing insect movement as a correlated random walk. Oecologia 56(2-3) 234-238 2) Artificial life model of flying insects and its comparison to real insects navigation strategies. Dale K., Collett T. C. (2001). Using ...


7

The main difference between tracheal gas exchange, and other forms of gas exchange (except simple diffusion) is that it is generally a passive process. Organisms with lungs, gills, or other modified respiratory organs can actively pump the oxygen-containing medium (usually air or water) across their respiratory surface, and some also pump their blood across ...


7

The cocoon phase allows lepidopterans (and other holometabolous insects) to reorganize their body and undertake the dramatic metamorphosis from larvae to adult in a safe environment. Cocoons and pupae are typically attached to branches by silk (oftentimes after climbing high into the canopy), thereby removing them from many predatory interactions and ...


7

Wootton (1992) reviewed the anatomy and biomechanics of insect wings. Basically the wing is a lightweight but strong scaffolding of veins, supporting a thin membrane. The veins are composed by a sandwich of cuticle with a potential space in between. The membrane is also a double-layer but without the space. In the venous space are is circulating hemolymph ...


7

Insects and spiders have tremendous sexual dimorphism, with males often being much smaller than females. They are pretty much just sperm carriers and sometimes do not eat. Insects may have two or one sex chromosome, where males my have only one chromosome. As is pointed out in the comments, not all mantis' species display this dimorphism. Since such ...


7

The answer is more or less yes. Normally Firebugs (Pyrrhocoris apterus) go through 5 nymph instar stages (as do most Hemiptera), where they resemble the adults more and more as they grow. Only adults are winged and have have functional reproductive organs. This type of metamorphosis is called hemimetabolous or simple metamorphosis (in contrast to ...


7

From the pattern on the elytra (hard upper wings), it looks like you might have a beautiful male Polyphylla fullo. Compare your photos with the P. fullo in this illustration, or photos on the Wikipedia page. edit to fully respond to the comments: I suspect you're right that the antennae plates in your picture are just tightly closed up, giving a different ...


6

I don't think it's a silly question, but it is a common error to anthropomorphise animals. Insects respond to cues which they have evolved to respond to, and this is how they 'make decisions'. They do not have free will or any more complex decision-making process like common sense. This is evident is lots of insect behaviour: flying repeatedly at a closed ...


6

After seeing your question, I decided to do a bit of research on the topic. First Source: EurekAlert! http://www.eurekalert.org/pub_releases/2007-04/jws-mrt041607.php "Mosquito repellents that emit high-pitched sounds don't prevent bites" Some key-points from the webpage: A Cochrane Systematic Review of the use of electronic mosquito ...


6

Flies can and do evolve quickly thanks to a short generational time. However, your question seems to stem from a misunderstanding of what evolution entails. Evolution occurs when the genome mutates. Why it mutates isn't particularly relevant, but a gene (or genes) mutates and as a result of that mutation a characteristic of the organism changes. It doesn't ...


6

Building on Noah Snyder's answer… Having wings could also be expensive in other ways. For example, energy aside, maybe the growth of wings relies on some special nutrients, which were scarce in the environment of the first ancestors of modern ants. So the ant colonies that grew smaller wings (or no wing at all) thrived. Having wings could also cost them ...


6

I don't have a definitive answer, but I suspect Hymenoptera is "just a name," albeit a name that has lasted through the phylogenetic nomenclature revolution. Hymenoptera was erected by Linnaeus in the 10th edition of Systema Naturae (1758). The description of Hymenoptera (membrane wing; p. 553 [hope your Latin is better than mine]) follows that of ...


6

The sense of depth is required to us to orient ourselves in a 3D world. Insects do orient themselves in the exterior 3D world, thanks to the ability to detect the plane of sunlight polarization, that is used as a navigation compass in foraging expeditions and when coming back home. You can find a good review on Current Biology (Krapp 2007) and a lecture ...


6

I do not know of any solitary ants, but there are species that form very small colonies. One such species is Jerdon's Jumping Ant (Harpegnathos saltator). They usually live in colonies smaller than 100 individuals and workers may reproduce, so the colony can survive after the queen's death.


6

This is Crane fly, of the Tipulidae family. They don't bite humans, adults feed on nectar. Larvae prefer moist environments such as wet soil or decomposing vegetable matter and can consume roots and vegetation, damaging plants. Among others, bats and some Coleoptera are its predators. Further informations can be found in the Wikipedia article linked above.


6

Yes, sub- or satellite colonies are common in many species (see e.g. Hölldobler & Wilson, 1990; Debout et al. 2007), and these are then labelled as polydomous species. Subcolonies can either contain extra queens, but sometimes only contain foraging workers. The purpose can be both to expand foraging grounds or as a pre-stage for colony budding. The ...


6

That is a flour beetle, the two most common and likely types are the confused flour beetle and red flour beetle but to identify look at the antennae. I'd suggest it is the confused flour beetle because the antenna go from thin to fat quite gradually, though the pictures may not be good enough for that to be certain. Other commonly used names are tribolium ...


6

Nice pictures! From the back pattern, size, and antennae shape, I'd say this is very likely a Cicada Killer wasp (Sphecius speciosus), cf., for instance, this picture taken at a similar angle to yours. There are many good resources online about Cicada Killers, including this page from the MSU Extension Office, and the Wikipedia entry Sphecius speciosus. It ...



Only top voted, non community-wiki answers of a minimum length are eligible