An online resource based on the award-winning nature guide

Ants

Black Bears Foraging

9-4-17 bear tree2 049A4107

This is the time of year when Black Bears are looking for every available source of food in order to bulk up before entering hibernation. During this period of gorging (hyperphagia) Black Bears consume large quantities of fruits, berries, nuts, grasses, roots and insects.

In particular, they favor the brood (larvae and pupae) of ants, due to their relatively high content of fat and protein. Black Bears find brood by detecting the pheromones and other chemicals such as formic acid that ants use for communication and defense. Research has confirmed that Black Bears will dig up as many as 200 ant colonies a day, flipping rocks, moss and leaf litter over and tearing apart logs, stumps and snags (such as the one pictured), using their canine teeth and claws to gain access to the ants. Once they have torn apart the stump or snag, they use their long, sticky tongues to gather brood. Anthills are avoided except for when Black Bears are extremely hungry, due to the fact that bears prefer not to get a lot of soil or sand mixed in with the brood they’re eating. (Thanks to Virginia Barlow for photo op.)

Advertisements

Ants “Milking” Treehoppers

9-18-15  Publilia concava 109Certain species of treehoppers (a type of true bug) release a sugary liquid called honeydew, made mostly from excess plant sap that they consume. Ants farm these treehoppers, much as they farm aphids, for their honeydew. An ant grasps a treehopper and strokes it with its antennae, causing a droplet of honeydew to appear at the tip of the treehopper’s abdomen, which the ant then consumes. Both insects benefit from this mutualistic arrangement. The ants get honeydew, and in return, provide protection for the treehoppers from predators. The plant indirectly benefits from the ants, as well, for if the ants were not there, the treehoppers’ honeydew would fall onto the plant, causing mold growth on fruits and leaves. Eggs, nymphs and adult treehoppers can usually all be found in one location. (Photo insert: a treehopper nymph on left, adult treehopper on right) To see a video of ants farming a type of treehopper called a thornbug, go to https://www.youtube.com/watch?v=HoeJn3Imss4.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Black Bears Seeking Protein

9-2 hornet nest torn by bear 083Although insects and animal matter make up less than 10% of the annual black bear diet, they are a crucial part of it. Black bears get most of their animal protein from ant brood, hornet larvae, tent caterpillars, march fly larvae, grubs (especially June beetle grubs), and snow fleas. Among the most preferred sources are bee and hornet larvae. Berries and other fruit don’t have a great amount of protein, but they do have some (blackberries = 2 grams of protein per cup). If the summer berry crops fail, insect brood is especially important, especially at this time of year, when bears are seeking protein, fats and carbohydrates, putting on as much as 30 pounds per week to sustain themselves through the coming months of hibernation.

When tearing apart a beehive, yellow jacket nest or bald-faced hornet nest (see photo), bears do get stung, particularly on their ears and faces (their fur is fairly impenetrable). Apparently the reward is worth the aggravation. After filling themselves with brood (and in some cases, honey) black bears shake vigorously in order to rid themselves of any insects that are caught in their fur.(Thanks to Alfred Balch for photo op.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate”
button.


Queen Ants Mating & Removing Wings

ant removing wings2  095Ants are social insects and live in colonies consisting of one or more queens, female workers and males. In most species the non-sexually mature female ants are wingless; only the males and the queen(s) possess wings. Periodically, often 3-5 days after a heavy rain, the winged ants emerge from the colony in large swarms in order to mate and create more colonies. Swarming behavior is usually synchronized with other nearby colonies, so large numbers (hundreds or thousands) of winged ants suddenly appear. After mating, the males die and the queens shed their wings and use the remaining wing muscles as a source of nutrients during the early stages of colony development. The shedding of wings is not a passive activity. The pictured ant is in the process of removing her fourth and final wing. She held each wing down with one leg while pulling it out with another. She then crawled off, leaving a pile of wings behind.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Myrmecochory: Seed Dispersal by Ants

8-6-14  myrmecochory 014As a dispersal mechanism, some plants have fatty structures called elaiosomes attached to their seeds’ coats which are very appealing to ants. After collecting a seed and carrying it back to its underground nest, the ant eats the elaiosome (or feeds it to ant larvae) and discards the intact seed in an area where waste and dead ant bodies are stored. Germination is highly likely in such an ideal environment, making myrmecochory a win-win situation. Trillium, bloodroot and violets are some of the thousands of plants that have elaiosomes attached to their seeds.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Carpenter Ants Huddling

11-14-13 carpenter ants 028Insects that live in northern New England have different strategies for surviving the winter. Carpenter ants live in the center of both dead and living trees, in galleries that they have chewed throughout their nest. Although wood is a good insulator, it still freezes during the winter. The ants tend to cluster together and enter a state of slowed metabolism called diapause. In addition, carpenter ants also produce glycerol, a compound which acts as antifreeze preventing destructive ice crystals from forming in their bodies.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Some Spiderlings Hatch in the Fall

antmiimic spider egg case 013Have you recently noticed a roundish, flat, papery, 1/4-inch diameter, metallic-looking structure adhering to the top of a rock? If it has tiny bumps in the center, chances are good that it’s a spider egg sac, most likely that of an antmimic spider (spiders resembling ants that often prey on ants), specifically one in the genus Castianeira. One would assume that the contents of the sac that were causing the bumps were eggs that were going to overwinter and hatch once warm weather arrives. This is true for a majority of spider egg sacs, but some, including those of Black-and-Yellow Argiopes and antmimic spiders, hold spiderlings that have already hatched and will remain in the sac throughout the winter. As long as the temperature stays cold, the spiderlings will be safe and secure until spring. If we have periods of cold interspersed with periods of warmer temperatures, or an exceptionally warm winter, the spiderlings will become active when the thermometer rises, and, not having any insects to eat, will be forced to devour each other.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.