Insect Behavior Final

foraging

food-obtaining behavior, recognizing, searching for, capturing, eating food items

all animals

carbohydrates, fats, amino acids, minerals, and vitamins are essential for

cholesterol (cannot synthesize), sodium (particularly important to herbivores)

essential nutrients that are specific to insects

sweat bees feeding on human sweat for sodium and other minerals

an example of an insect feeding for sodium

puddling: insects gather at the edge of a puddle for salt and amino acids

an example of insects gathering nutrients

surface texture, visual cues, chemical cues

how do insects recognize and accept their food?

some wasps (Trichogramma evanescens) will only parasitize objects that are firm enough for it to walk on

example of surface texture recognition

proper positioning for egg laying, physical contact assists with host suitability, relying on walking to explore a host is very efficient for small insects

why use surface texture in foraging?

tsetse flies are drawn to their host using a combination of visual and chemical cues: movement, dark color, shape of large mammals, CO2, sweat, body odors, heat

example of visual cues in foraging

potato beetle lives on plant that contains toxic alkaloids, larvae have not adapted to the alkaloids yet, rely on olfactory receptors to detect harmful alkaloids, if receptors (palps and antennae) are removed, they will eat the harmful alkaloids

example of chemical cues in foraging

insects make “perfect” foraging decisions

to test if insects balance their diet, you must assume that

age, previous experience, nutritional needs, development stage, etc

what are some factors to consider when testing insect foraging?

choice experiment of different types of pollen (yes they can)

how to test if insects can balance their diet?

reduced competition, efficient, may provide protection from predators through plant toxins, plant-insect coevolution, the plant serves as mating site (drawbacks: what if host goes extinct? environmental changes?)

most insects are herbivores and specialists, why?

favored

specialization is _____ by natural selection

specialists

(foraging) most insects are

single host (parasitic wasps, leaf mining larvae)

extreme specialists are limited to a

mosquito larvae feed on plankton, adult female = blood, adult male = nectar

example of different feeding behavior throughout life stages

leaves in sugar are tied up in cellulose (strong connections btwn cellulose and glucoses), pollen and nectar limited to certain flowers/hours/seasons, plants may have defense mechanisms

challenges of herbivorous insects

gut microbes

digestion of cellulose requires specific enzymes that are acquired by having

by licking the anus of the adults

how do young termites acquire symbiotic microbes?

must find a way to capture prey, such as actively hunting in dragonfly larvae or ambushing

challenges in carnivores

relatively rare in insects, difficult lifestyle, example = ants, use cooperative hunting

challenges in omnivores