HOW DO WE KNOW?FIG. 43.10To what extent are insects capable of learning?BACKGROUNDEuropean digger wasps, Philanthus triangulum, live in the sand. Thesewasps are sometimes called “bee wolves” because they hunt honeybees tofeed their developing young. After mating, each female digs a longburrow with a few chambers at the end where she lays her eggs. She thenforages for honeybees that she brings back to these chambers for herlarvae to eat. The wasp faces a navigational challenge: having capturedher prey, how can she find her way back to and recognize her nest? Aspart of his PhD studies in the early 1930s, Niko Tinbergen noticed thatwasps lingered briefly near a new nest before heading off to hunt; hehypothesized that they were learning local landmarks associated with thenest.HYPOTHESISWasps learn visual cues around their nests to help locate the nest upontheir return.2937METHODTinbergen recognized that a good test of the learning abilities of an insectshould take place in its natural environment. He combined his skills as anaturalist and as an experimentalist to devise an elegant demonstration ofthe way in which female wasps learn landmarks for navigation. He placeda ring of pine cones around the nest of a wasp (Fig. 43.10a); then, onceshe had left to hunt, he shifted them to a new location away from the nestentrance (Fig. 43.10b). If visual cues are key to the wasp’s ability to locatethe nest, the wasp should return to the displaced pine cone ring. Incontrast, if cues are, for example, olfactory, the wasp should returndirectly to the nest.2938RESULTSFemale digger wasps carried out a brief landmark-learning flight ondeparture from the nest. When the landmarks were displaced, the femalesreturned to the wrong location (Fig. 43.10b).CONCLUSIONFemale digger wasps learn and use local landmarks, such as theexperimental ring of pine cones, as cues to the nest location.SOURCE Tinbergen, N. 1958. Curious Naturalists. New York: Basic Books.This adaptive aspect of animal learning is also revealed by tasteaversion experiments, in which an animal typically learns to avoidcertain flavors associated with a negative outcome. Rats learn to avoidflavored water if consuming it is associated with nausea. However,they do not learn to avoid flavored water if it is associated with adifferent kind of negative reinforcement, such as a mild electric shock.This result indicates that rats can make some associations, but notothers. The ones they can learn are the biologically meaningful ones,those that favor survival. In the course of evolution, the rat’s ancestorsencountered poisoned food that resulted in nausea and the aversionresponse evolved. Until humans started doing experiments on them,however, rats had never encountered a meal that resulted in an electricshock. It is not surprising, then, that the ability to pair these twophenomena never evolved. These experiments also show that thespecific evolutionary history of the species in question matters whenanalyzing animal behavior.In addition to adaptive predispositions for what can be learned andnot learned, many species exhibit predispositions for when learning2939takes place. This is particularly evident in imprinting, a form oflearning typically seen in young animals in which they acquire acertain behavior in response to key experiences during a critical periodof development. In 1935, Austrian ethologist Konrad Lorenz madeimprinting famous by exploiting the observation that newly hatchedgoslings and ducklings rapidly learn to treat any sufficiently largemoving object they happen to see shortly after hatching as theirmother. Lorenz found that, if he was the first person the hatchlingssaw, they would follow him as though he were their mother (Fig.43.11).FIG. 43.11 Imprinting on (a) Konrad Lorenz and (b) an ultralight aircraft. Bymanipulating newly hatched birds’ first sight of a moving object, it is possible toinduce powerful attachments in the birds.This behavior is adaptive because the first being that a hatchlingusually sees is a parent; the resulting close parent–offspring associationensures that the parent can provide care and protection. This filialimprinting is most common in bird species whose offspring leave thenest and walk around while still young, such as ducklings. Bycomparison, filial imprinting is rare in species of birds whose youngstay in the nest until they are able to fly away.2940Experiments have shown that filial imprinting typically occursduring a specific, sensitive period in the animal’s life and that theresults are usually irreversible. After Lorenz’s baby ducks hadimprinted on him, they would not change their minds about who theirparent was even when presented with their real mother duck. Thetiming of the sensitive period varies from species to species. In somecliff-nesting sea birds, imprinting on auditory stimuli (such as the callof the parents) begins while the chick is still in the egg.

In a new experiment conducted by a team of neuroethologists from Kiel University in Germany, Caribbean box jellyfish (Tripedalia cystophora) were observed spotting and avoiding obstacles in their way despite their lack of a central brain. Head researcher Jan Bielecki hypothesized that the process of learning may not require a complex nervous system; in fact, learning capacity may simply be an inherent feature of nerve cells. These findings are the first evidence that jellyfish can mentally connect events and correct their behaviors, a discovery that could help scientists trace how animals evolved to learn.Which finding, if true, would most directly undermine Bielecki's hypothesis?Caribbean box jellyfish have been found to follow other marine creatures to navigate through particularly complex obstacles.eliminateOther species of jellyfish with similar nervous systems did not learn in a similar way when observed in a similar situation.eliminateCaribbean box jellyfish have a strong olfactory system within their tentacles, allowing them to "smell" particles in the water.eliminateOther species of jellyfish with more complex nervous systems have been documented avoiding obstacles in similar ways as the Caribbean box jellyfish.

Read the following passage carefully and answer the questions on it.The black ant is indisputably one of the smallest visible insects on earth Except with aid of a very powerful microscope, it is difficult if not impossible to locate the eyes, the mouth the nostrils (if it ever has any) or any other part of the body. An air of mystery surrounds the existence of this little creature.Have you ever taken time off your programme to watch these ants move in row? What gives them the sense of direction, we do not know. Indeed whoever sends them on an errand and how they even know their destination and the type of errand to run we are yet to be told. But they are an extremely well-organized lot.Certainly, there are no defined routes for them on walls or trees, yet they move in an orderly manner. almost in a straight line. The beautiful thing about these insects is that even when their line of movement is disorganized. they soon regroup and connect themselves again end to end. If in the process. one of them is killed. they quickly recognize that fact from their various positions. Then. one sees them running helter skelter with a seeming insistence on getting at the comrade to confirm its death.When this has been done, some of them run zigzag at a tremendous speed to alert the others on the route. Soon, they disappear completely. Later. as if everything were over and forgotten they reappear and form a new route and continue their movement transporting food or going on one errand or the other as before Bring your ears close to them and you hear nothing and you wonder what their means of communication could be. Perhaps, most surprising is their high sense of understanding the weather and the climate They are just like men in this area. They know when it is the rainy season and when the dry season comes. In fact, it is true to say that they prepare better for the future than man.During the dry season. they file out to different places gathering food which they store underground. At the slightest sign of the approach of the rainy season. they all get into the hole and seal it up. Surprisingly. they re-emerge when the dry season sets in. And whoever tells them that the dry season has come we do not know. You can now see the sense in the injunction, "Go to the ant, thou sluggard. learn her ways and be wise."(a) Why does the writer regard the black ant as one of the smallest insects on earth?(b) Give reasons why the writer thinks that the way ants live is ' interesting'?(c) (i) What is the writer's attitude towards the black ant? (ii) Quote an expression from the passage to support your answer.(d) When this has been done " What does 'this' refer to?(e) "The beautiful thing about these insects ..."(i) What grammatical name is given to this expression(ii) What is its function in the sentence?(f)What quality of the wins implied in the last sentence of the passage?(g) For each of the following words or phrases find another word or phrase that means the same and can replace it as it is used in the passage: (i) indisputably; (ii) row; (iii) helter skelter, (iv) a tremendous (v) area (vi) approac

How do honey bees communicate with each other regarding the location of food? (a) By dancing (b) By making sounds (c) By singing (d) None of these

Read the passage given below and answer the questions by clicking on the correct optionsBees make honey to survive. It is their only essential food. If there are 60,000 bees in a hive about one third of them will be involved in gathering nectar which is then made into honey by the house bees. A small number of bees work as foragers or searchers. They find a source of nectar, then return to the hive to tell the other bees where it is. Foragers let the other bees know where the source of the nectar is by performing a dance which gives information about the direction and the distance the bees will need to fly. During this dance the bee shakes her abdomen from side to side while running in circles in the shape of 8.The distance of the food from the hive is indicated by the length of time that the bee shakes her abdomen. If the food is quite near the bee shakes her abdomen for a short time. If it is a long way away, she shakes her abdomen for a long time.When the bees arrive at the hive carrying nectar they give this to the house bees. The house bees move the nectar around with their mandibles, exposing it to the warm dry air of the hive. When it is first gathered the nectar contains sugar and minerals mixed with about 80% water. After ten to twenty minutes, when much of the excess water has evaporated, the house bees put the nectar in a cell in the honeycomb where evaporation continues. After three days, the honey in the cells contains about 20% water. At this stage, the bees cover the cells with lids which they make out of beeswax.At any one time the bees in a hive usually gather nectar from the same type of blossom and from the same area. Some of the main sources of nectar are fruit trees, clover and flowering trees.Source: “Hum Sweet Hum”, National Foundation for Educational Research, 1993.GLOSSARYhouse bee: a worker bee which works inside the hive.Mandible: mouth-part.What is the purpose of the bees’ dance?*1 pointA. To celebrate the successful production of honey.B. To indicate the type of plant the foragers have found.C. To celebrate the birth of a new Queen Bee.D. To indicate where the foragers have found food.Based on the passage above, which option shows the three the main sources of nectar?*1 point1. Fruit trees, clover, flowering trees2.Flowering plants, cloves,fruits3. sunflower, roses, daffodils4. chrysanthamus, hibiscus,cloverHow does nectar differ from honey?*1 pointA. The proportion of water in the substance.B. The proportion of sugar to minerals in the substance.C. The type of plant from which the substance is gathered.D. The type of bee which processes the substance.In the dance, what does the bee do to show how far the food is from the hive?*1 pointA. The length of the time the bee shakes her abdomenB. By shaking the abdomenC. Both A and B aboveD. How fast the bee runs around in the figure 8

Using the infographic, explain why bees are classified as insects within the phylum Arthropoda.