Interactions With Other Organisms – Insect Symbiosis and Plant-Insect Interactions (Vocabulary)

Vocabulary flashcards covering key terms on insect symbiosis, endosymbiosis in aphids and relatives, insect-fungal interactions, entomopathogenic fungi, tri-trophic interactions, ant-plant mutualisms, pollination, and plant chemical defenses.

Insect symbiosis

Interactions between insects and microorganisms living inside or on them, including mutualistic and parasitic relationships that influence nutrition, defense, reproduction, and ecology.

Wolbachia

A widespread intracellular bacterium transmitted through eggs that can bias host reproduction (e.g., female-biased sex ratios, parthenogenesis), kill males, and cause cytoplasmic incompatibility; explored for insect population control.

Vertical transmission

Transfer of symbionts from parent to offspring, typically via eggs in insects.

Parthenogenesis

Asexual reproduction by females without fertilization, which can be induced by certain symbionts like Wolbachia.

Cytoplasmic incompatibility

A reproductive barrier where infected males mate with uninfected females resulting in reduced offspring viability, promoting spread of the symbiont.

Endosymbiotic bacteria in aphids

Intracellular bacteria in aphids that synthesize essential amino acids missing from the aphid’s phloem diet.

Buchnera aphidicola

Primary endosymbiont of aphids providing essential amino acids, housed in specialized cells called bacteriocytes.

Mycetocytes

Specialized insect cells that permanently house intracellular microbial symbionts.

Bacteriome

An organ in some insects that houses symbiotic bacteria within bacteriocytes.

Sulcia muelleri

A Bacteroidetes endosymbiont in leafhoppers and spittlebugs that supplies essential amino acids.

Baumannia cicadellinicola

A gamma-proteobacteria symbiont of sharpshooters providing essential amino acids; located in the bacteriome.

Symbiotic bacteria functions beyond nutrition

Endosymbionts can also influence host traits such as heat tolerance and defense against parasitoids.

Insect-fungal interactions

Relationships between insects and fungi, including farming or cultivation (e.g., leaf-cutter ants) and symbiotic associations with fungi.

Ambrosia beetles

Beetles that cultivate fungi (ambrosia) as their primary food source for larvae.

Entomopathogenic fungus

Fungi that infect and kill insects; used as biological control agents against pests.

Entomophthora

A genus of entomopathogenic fungi that can alter host behavior to maximize spore dispersal.

Behavioral manipulation by fungi

Pathogens can modify host behavior (e.g., perching, mating) to enhance spore spread.

The fungus that entices male flies to mate with female corpses

A documented example of fungal manipulation where fungus-infected females attract males to their decomposing bodies.

Tri-trophic interactions

Interactions among plants, herbivores, and natural enemies (predators/parasitoids), often mediated by plant signals and volatiles.

Linalool

A plant volatile that can recruit predators or parasitoids to herbivore-damaged plants.

Systemic volatile release

Emission of plant volatiles throughout the plant to attract natural enemies of herbivores.

Jasmonate signaling

A plant defense signaling pathway (octadecanoid/jasmonate) activated by wounding or herbivory.

Extracellular nectaries

Plant structures that secrete nectar outside flowers to attract ants for protection.

Beltian bodies

Nutrient-rich lipid/protein bodies in Acacia leaves that feed mutualistic ants.

Hollow thorns

Plant spines or thorns that house ant colonies, contributing to protection mutualisms.

Ant-plant mutualism (myrmecophyte)

Plant species that provide shelter and food for ants in exchange for protection from herbivores.

Mutualism with ants (myrmecophytism)

A mutualistic relationship where ants defend plants in return for food or shelter.

Pollination mutualism

Mutualistic relationship where insects pollinate plants, benefiting both parties; orchids are notable examples with elaborate floral traits.

Orchid pollination

Orchid flowers often have specialized traits to attract specific pollinators.

Plant secondary metabolites

Chemical defenses produced by plants, including alkaloids, terpenoids, and flavonoids, that deter herbivores.

Azadirachtin

A terpenoid from the neem tree with potent insecticidal properties.

Cardenolides

Toxic compounds from milkweed latex that deter herbivores and can make plants sticky.

Morphine

An alkaloid from poppy latex that deters herbivores through toxicity.

Amygdalin

A cyanogenic glycoside from bitter almonds that releases cyanide when ingested.

Capsaicin

The spicy compound in chili peppers that deters some herbivores.

Tannins

Plant polyphenols that bind proteins, reducing nutritional value and digestibility for herbivores.

Glucosinolates

Compounds in cruciferous vegetables that deter herbivores and contribute to plant defense.

Herbivory

Feeding of insects on plants; more than half of insect species are herbivores.

Barriers to herbivory

Plant defenses including physical barriers (waxy surfaces, hairs, toughness) and chemical defenses (secondary compounds).