Updated: May 25, 2020
This post which explores interactions insects, plants, and other insects. Specifically the ones I have recently observed. I also used some pictures from other projects .(this project was released after project 8 so it has some of the photos from 8.)
Interactions between insects [and arthropods] and plants are an important factor in agricultural sciences, this section will explore direct relationships between insects and plants
I have recently observed lots of ant interactions including some between ants and plants. there are various reasons ants interact
Plants as nests
Ants interact with plants for various reasons, one being to nest in them, trees, logs, and nuts can all provide nests for ants.
A nest of Temnothorax sp. inside an acorn Temnothorax gets it's common name acorn ants from their affinity to nest in them, however they are not that picky when it comes to picking a nest.
Another example a plant used as a nesting site, this time with Camponotus novaboracensis using a log.
Plants as food
Another way insects interact with plants is by managing their seeds, this is common among ants like Pheidole and Pogonomyrmex who harvest seeds and store them in their nests. if the seeds germinate they remove the seedlings and bury them elsewhere.
A worker of Pogonomyrmex occidentalis removes a seedling from the nest. If the seedlings do grow, they often get extra light because of the constant pruning of other plants around the nest.
Ants like Dorymyrmex insanus and Myrmecocystus mexicanus can be seen pollinating flowers while drinking sap, they usually don't pollinate the plant well as they conserve distance travelled by only visiting a few flowers. Most species however don't interact with flowers as they can form other relationships with aphids that involve plants.
Dorymyrmex cf. insanus drink sap from a flower
Extrafloral Nectaries and Ants
Most species interact with plants and form other relationships involve plants. This comes in the form of extrafloral nectaries. An organ that plants develop to gain protection from pest insects like aphids. the plants have to create a balance of just the right amount of sugar for the ants to consume the aphids and not start tending them.
Extrafloral nectaries of a wild plum attract Crematogaster cf. emeryana ants.
Extrafloral nectaries sometimes will also produce lipids and protein for ants.
Its no surprise that bees and plants are highly dependant upon each other. Bees are the main pollinator for most flowering plants besides those with a really long flower like some trumpet vines.
Sweat bees are common pollinator in colorado, along with leaf cutter bees and bumble bees, they polinate most of our wildflowers.
A female sweat bee (left) drinks nectar from a flower while a males (right) flies up behind her.
Spiders and plants
Spiders and plants often don't have much relationships outside of the tropics, but spiders will live on plants looking for insects that may be attracted to them, sometimes this benefits the plant because the spider ends up eating pest insects like caterpillars
A Phidippus sp. jumping spider on a leaf
Termites and plants
Although they mostly consume wood as their primary plant relationship, termites (particularly subterranean ones) sometimes eat roots and other detritus, especially during founding stages.
Subterranean termites with a partially consumed root in their nest, the termites not only consume rotting wood, but they also eat roots of wood as well.
Relationships Between Insects
Insect Symbiosis between Insects is very common, and is truly a fascinating study. This section will also compare indirect plant insect relationships (like ants tending to aphids or scales).
Ant insect interactions
Ants and Sap Suckers (Aphids, Mealybugs, Scales, Leafhoppers)
One of the most common symbiotic relationship between ants and other insects is the one that exists between ants and aphids. Most ants will tend to various types of aphids, scales, and mealybugs. the ants supply protection and grazing grounds and in return they 'milk' the aphids for a sugary liquid called honeydew which the aphids produce to entice the ants.
Lasius cf. creightoni with root aphids
A close up of the ants shows that they cover the aphids when they are exposed, this is to help avoid predators
A different species, Lasius cf. coloradensis with a large colony of mealybugs or scales. the apids produce a waxy substance to help avoid drowning and make them easier to grab
Yet another species of Lasius, Lasisus cf. neoniger carries some mealybugs/scales to safety.
Often times aphids mate vía parthenogenesi, with females producing females until the ver end of summer when they produce males to help spread their genetics. Recently I encountered an interesting colony of Crematogaster which appears to have cull off the non productive adults and consumed them as food. interestingly this behaviour is usually only observed in mellisotarsus who farm shield bugs entirely for meat.
Other species of ants tend to aphids and care for them on plants. Sometimes ants will even care for leaf hoppers, or thorn bugs.
Ants and Caterpillars
Some ants (particularly Formica) tend to caterpillars of moth larvae this interesting relationship takes place in two forms. 1) caterpillars are parasitic and produce fake colony pheremones, so the workers tend to them as if they were larvae, or 2) the caterpillars function like an aphid and excrete sweet liquids. The first form is one of the most common
A Formica worker carries a butterfly caterpillar off to the nest. I'm not sure of what kind of larva it is.
Wasps sometimes take advantage of this relationship with caterpillars by entering the ant's nest, laying eggs inside the caterpillar and then the ants raise the wasp larvae instead of a caterpillar
Ants and other ants
Ants biggest predator is other ants, as they are one of the most successful insect groups, below are the several ant-ant interactions I have observed.
With the brood:
Tetramorium immigrans with worker larva
Tetramorium immigrans with alate larvae
Myrmica cf. lobifrons with brood
Myrmica cf. lobifrons with brood
Formica neogagates workers produce trophic eggs for consumption
With other colony members:
Workers of Pogonomyrmex occidentalis clear out debris from the nest that had fallen in over the winter
After their nest is exposed, a colony of the lestobiotic Solenopsis carolinensis scurries about to find a new nest.
Ants and queens:
Monomorium cf. minimum queen and workers
Myrmica cf. lobifrons queen and escort worker
To the left of this picture you can see two of the 5 queens in this Myrmica spatulata colony.
Queens of monomorium cf. minimum are revealed after flipping a rock.
Ants and Enemy Workers:
A Formica cf. dolosa worker drags a defeated Camponotus supermajor to the nest for consumption.
There are trillions of insect interactions every day, and this is not a complete record of the ones I have seen by any means, when studying ants you get to know about a LOT of different interactions, especially among eusocial insects. The week I am publishing this (week of 5/17/2020 [17/5/2020 for those who use international date format]) the entomology club theme is Insect Interactions so it worked out when it got published.
Thanks for Reading!