Alfred Keller's Insect Models
The best works were created by Alfred Keller, a keen observer of nature, artisan, and inventor of innovative modeling techniques. Keller created works of a fascinating aesthetics that are at the same time scientifically highly accurate. The surviving models, mostly 30-40 cm in size, can still tell us engaging stories from the world of insects ...
The house fly belong to the order "Diptera" ("two-wingers"). In these insect, the forewings (left) are complete, whereas the hindwings are reduced to small club-shaped structures called "halteres". You can see them as light, club- dumbbell-shaped structures in the lower center. When flying, these structures move in the opposite direction of the forewings, stabilizing the flight.
Model of a maple aphid (Drepanosiphum) with a common red ant (Myrmica rubra). Aphids feed on plant sap, which is very rich in sugars, but has few proteins. The aphids remove the protein and release most of the sugars in the form of so-called "honeydew" secretions. When cars parked under trees become amazingly sticky: This was the action of the aphids, not the tree itself! Honey dew is the most important carbohydrate source of many ants. The relation between aphids and ants is often a mutualism: These ants protect the aphids against predators like ladybugs, even move them to new leaves, and actively milk the aphids by stroking them with their antennae.
Both the Nazis under Hitler and the communist German Democratic Republic claimed, the Americans would drop potatoe beetles from airplanes as a biological weapon. The famous German poet Bertolt Brecht did believe this and wrote: "Die Amiflieger fliegen, silbrig im Himmelszelt, Kartoffelkäfer liegen, in deutschem Feld (American planes fly, silver-colored in the sky, Potatoe beetles lie, in German fields)." However, there is no evidence that this ever happened. Instead, there are plenty of examples, how invasive species can effect similar damages without any such support. But the old propaganda message is still widely and stubbornly believed. We are probably more willing to believe in the powers of war machines than accept the power of nature itself!
Egg, larvae and adult of the Sloe Bug (Dolycoris baccarum). Whereas in some insect orders like beetles or butterflies larvae and adults are strongly dissimilar, and the larvae form a chrysalis to be fully transformed in a process called metamorphosis, the larvae of the true bugs (Heteroptera) and many other insect orders look immediately similar to the adults. They become more and more similar with each ecdysis (which occurs five times in the case of this species).
The Sloe Bug feeds on flowers and fruits of many species (especially from the rose family, like cherries or plums). Because when sucking plant saps it also injects saliva, the fruits often become unpalatable for humans.
An insect model of the wheat weevil (Sitophilus granarius) created by Alfred Keller. This weevil is a constant follower of humankind since the early stone age and one of the most feared pests of stored products.
The chewing mouthparts are at the tip of elongated snout. The females eat tiny holes into grain kernels, lay an egg, and close the hole with a secreted substance. The whole development of the larvae occurs inside the kernel, until finally the fully developed beetle emerges from the hollowed-out kernel.
Meal moths are frequent stored product pests. The larvae feed mainly on cereal products (flour, rolled oats, whole kernels, but also pasta). The adults can place several 100 eggs next to the tiniest of openings in packaging. Freshly hatched, the larvae are only 1 mm long and much thinner, being able to enter many resealable household packages through tiny openings that usually remain. After 40 days the larvae turns into a chrysalis, after another 10 the adult moth (which no longer feeds) emerges. (Model by Alfred Keller)
A human flea, (Pulex irritans). These wingless insects are at most 3 mm long. Relative to their size, they have amazing jumping capabilites (18 cm high and 30 cm wide). Their narrow build enables them to move between the hairs of their host.
As a result of improved living conditions of humans, the human flea has become relative rare. Today, flea bites on humans often are the result of animal fleas, especially cat fleas!
Insects are fascinating animals. Many strongly influence our lives in major ways. When we are enabled to study them in detail, they can tell us stories.
We consider Alfred Keller both as a talented and keen scientific observer and as an artist. He worked in close collaboration with another artist: Nature itself.
Text: Alice Chodura, Gregor Hagedorn (Museum für Naturkunde Berlin)
Photos: Carola Radke, Hwa Ja Götz (Museum für Naturkunde Berlin)
Contributors: Dr. Johannes Frisch, Linda Gallé (Museum für Naturkunde Berlin)