Insects on Distant Hill
By Leaving a Dead Log Near Your Vegetable Garden?
It is hard to believe that leaving a log or downed tree in the woods might help you grow better vegetables, but it might just be true. It turns out that there are a number of parasitic wasps of the Superfamily Ichneumonoideathe, Braconid and Ichneumon, that are important parasites of other insects.
The adult female of the Ichneumon centrator wasp, shown above, hibernates for the winter under the bark of downed trees and logs on the forest floor. The females are impregnated before
hibernation and will develop eggs in the spring when warmer weather returns. This subfamily of wasp, Ichneumoninae, with over 120 species native to North America, are all parasitic and lay their
eggs in mature caterpillars - species of caterpillars that are often pests in the vegetable garden.
Charles Darwin was a bit repulsed by these parasitic wasps. In 1860 he wrote, "I own that I cannot see as plainly as others do, and as I should wish to do, evidence of design and beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars, or that a cat should play with mice."
A Very Useful Plant
Salidago, commonly called Goldenrod, is a genus of over 100 species of flowering perennial plants in the aster family. The majority are native to North America, with just a few species native to South America and Eurasia.
The pollen of Goldenrod is often unfairly blamed for causing hay fever in humans. However, the true culprit is the wind-dispersed pollen of Ragweed (Ambrosia sp.), which blooms at the same time as goldenrod. Goldenrod pollen is too heavy to be easily blown about, with the plants relying on insects for pollination.
The flowers of Goldenrod are an important source of fall nectar for bees, flies, wasps, and butterflies. The leaves are also used as a food source by the larvae of many butterfly and moth species
Humans have put Goldenrod to good use over the years. Native Americans used the seeds of some species for food. They also chewed the leaves to relieve sore throats and chewed the roots to relieve toothaches.
Solidago virgaurea, European Goldenrod, is used today as a kidney tonic by herbalists to treat inflammation and irritation caused by bacterial infections or kidney stones.
One of the more interesting uses of Goldenrod took place in the early 20th century, when Inventor Thomas Edison experimented with goldenrod to produce rubber. Edison created a fertilization and cultivation process to maximize the rubber content in each plant. His experiments produced a 12-foot-tall (3.7 m) plant that yielded as much as 12% rubber. The tires on the Model T given to Edison by his friend Henry Ford were made from goldenrod.
A“Little Basket” of Pollen
Bees in the family Apidae, made up in part by bumblebees, honey bees, stingless bees, and orchid bees, all posess pollen sacs. The corbicula, Latin for "little basket", is a cavity on the rear legs into which pollen is placed.
The corbicula is a cavity surrounded by a fringe of hairs, into which the pollen is placed; most other bees possess a slightly different structure for collecting pollen called the scopa. It is made up of a dense mass of branched hairs on the hind legs and/or the abdomen as opposed to a cavity.
To fill the corbicula a bee moistens the forelegs with its protruding tongue and brushes the pollen that has collected on its head, body and forward appendages to the hind legs. The pollen is transferred to the pollen comb on the hind legs and then combed, pressed, compacted, and transferred to the corbicula on the outside surface of the tibia of the hind legs. A single hair functions as a pin that secures the middle of the pollen load.
The bee then carries the pollen in the pollen basket back to the hive where it is mixed with honey or nectar to produce what is called bee pollen.
Bees collect the pollen as a protein source to raise their brood. An average bee colony will collect about 40 to 120 pounds (20 to 57 kg) of pollen a year.
Thanks to Wikipedia for much of the above information.
A Southern Species Moving North
The Giant Swallowtail (Papilio cresphontes) is the largest butterfly in Canada and the United States. Adults have a forewing span of 4 to almost 6 inches (avg. 5.5 inches) for males and a span of 5 to 7 inches (avg. 5.8 inches) for females. It is an uncommon stray in southern New Hampshire and Vermont, but we have had them here at Distant Hill Gardens for the past two years.
Is their presence in New England an example of climate change at work?
A paper published last year in Nature Climate Change seems to support that theory. They reported that many of the southern butterfly species in the US are packing up and moving north... "Our results suggest that a major, climate-induced shift of North American butterflies, characterized by northward expansions of warm-adapted and retreat of cold-adapted species, is underway."
The caterpillar of the Giant Swallowtail is as least as interesting as the butterfly. It looks exactly like a bird dropping, making it unappetizing to most insect-eaters. If it does happen to be threatened by a predator, a bright red, forked structure called an osmeterium emerges from its head, along with releasing a strong noxious odor.
The caterpillar has the nickname 'Orange Dog' due to preference for plants in the citrus family. It is very common in Florida and is considered a pest in the citrus groves throughout the State.
Here in northern New England, it will feed on Common Prickly Ash (Zanthoxylum americanum) or the Common Hop Tree (Ptelea trifoliata), if available. Both are native plants in the citrus family. Only the Prickly Ash can be found in this part of New Hampshire.
The only plant growing at Distant Hill Gardens that we have found Giant Swallowtail caterpillars feeding on is a Gas Plant (Dictamnus albus). It turns out that Dictamnus albus is in the same botanical family as
There is one other plant in the Rue family growing at Distant Hill Gardens, an Amur Corktree (Phellodendron amurense). We will have to keep an eye out for the Giant Swallowtail caterpillar feeding on its leaves.
Are ants a valuable pollinator?
Ants are shown here feeding on the nectar and possibly pollinating flowers of Spreading dogbane (Apocynum androsaemifolium). This native bushy perennial grows on the field edges at Distant Hill
I said "possibly pollinating" because scientists have discovered that many ants secrete a natural substance that acts as an antibiotic. This secretion protects ants from bacterial and fungal infections, but unfortunately this secretion also kills pollen grains rather quickly.
In addition, ants can actually reduce the likelihood of other pollinators visiting a plant because they are stealing the insect attracting nectar. Luckily, Spreading dogbane is also pollinated by flying insects and does not rely totally on ants. Hopefully they leave some nectar for the more efficient pollinators like bees.
Change is Good
- Simple metamorphosis: Grasshoppers, along with dragonflies and many other insects, go through simple metamorphosis. This is a 3 stage process: Egg to Nymph to Adult. The young nymphs usually look much like small wingless adults. The wings develop externally.
Here is a partial list of insects that use simple metamorphosis.
A Band-winged grasshopper in the Nymph stage of development. Note the short stubby wings.
A Band-winged grasshopper, in the Adult stage of its development. Note the long wings.
- Complex metamorphosis: Butterflies and moths undergo complex metamorphosis, in which there are 4 distinct stages: Egg to Larva to Pupa to Adult. With Complex metamorphosis, the immature insects and the adults have different forms, often live in different habitats, and may have very different behavior.
A Monarch caterpillar, the Larva stage of complex metamorphosis.
A Monarch chrysalis, the Pupa stage of complex metamorphosis.
A Monarch Butterfly, the Adult stage of complex metamorphosis.
Long Hairs on the Hill
Tussock moths Caterpillars are all members of the insect family Lymantriidae . The common name is derived from the hair tufts, or tussocks, found on most larval forms. The large larvae, or caterpillars, are hairy with many species having stinging hairs. Most feed on foliage of trees and shrubs. Some Lymantriidae caterpillars, such as the Gypsy Moth, are considered major forest pests. There are about 350 known genera and over 2,500 known species of Tussock Moths found all over the world, in every continent except Antarctica.
Notable Tussock Moth Species and Genera
- Brown-tail, Euproctis chrysorrhoea
- Yellow-tail, Euproctis similis
- Gypsy moth, Lymantria dispar
- Nun Moth, Lymantria monacha
- Pale tussock moth, Calliteara pudibunda
- Pine tussock moth, Dasychira plagiata
- Arctic woollybear moth, Gynaephora groenlandica
- Rusty tussock moth or Vapourer, Orgyia antiqua
- Western tussock moth, Orgyia vetusta
- White-marked tussock moth, Orgyia leucostigma
- Douglas-fir tussock moth, Orgyia pseudostugata
- Satin moth, Leucoma salicis
- Coca moth, Eloria noyesi
- Painted apple moth, Teia anartoides
This is a photo of a tobacco hornworm, the caterpillar of a Carolina sphinx moth (Manduca sexta) feeding on a tomato plant at Distant Hill Gardens. The tobacco hornworm, is closely related to, and often confused with, the very similar tomato hornworm. Both feed on plants in the Nighshade Family. The tomato hornworm is the caterpillar of the five-spotted hawk moth (Manduca quinquemaculata).
Note the Red horn at the tail end of the caterpillar, and the seven diagonal lines on its side. These identify this as a tobacco hornworm. The tomato hornworm has a Black horn, and eight V-shaped markings in place of the diagonal lines.
This is the same tobacco hornworm seven days later. It is covered with cocoons of Cotesia congregata, a species of parasitic braconid wasp. They lay eggs in the bodies of tobacco hornworms. The eggs hatch inside the hornworm and the larva feed internally, later to emerge from the body to spin their cocoons.
If you find a hornworm with these white cocoons, just let it be. Young wasps will soon emerge from the cocoons and lay their eggs in other unsuspecting tobacco hornworms.
Note: The insect on the body of the hornworm is not a braconid wasp. I'm working on getting a positive ID. Do you know what the insect is?
An Often Overlooked Butterfly
The Folded-wing Skippers are not very colorful, so they are often overlooked in the garden. But they are an interesting insect because of their unique and characteristic posture: they hold their wings partially open while resting, with the front wings and hind wings held at different angles.. All members of this group feed on grasses or grassy-like plants, like sedges and rushes, as caterpillars. Because of this fact, they are often called Grass Skippers.
Folded-winged Skippers, also called Banded Skippers, are butterflies of the family Hesperiidae. There are over 2000 species of Folded-winged Skippers, and 1500 other species in the
Skipper family. They are found worldwide.
Butterflies are a mainly day-flying insect of the order Lepidoptera, which is made up of the following superfamilies:
One Cool Dragonfly
Have you ever noticed that some Dragonflies point their tails up into the air at times, and wondered why? Well, a number of scientists have given it some thought, and have designed some experiments to answer the question. The research points to dragonflies attempting to cool off.
It has been dubbed "The obelisk posture" and has been observed in about 30 species of Dragonflies and Damselflies. A few species lower their tails instead of raising them, but for the same purpose - to keep cool.
More Amazing Dragonfly Facts
- A dragonfly can spot an insect moving 33 feet away.
- Dragonflies have six legs but cannot walk.
- A Dragonfly called the Globe Skimmer is thought to have the longest migration of any insect - 11,000 miles back and forth across the Indian Ocean.
Check this link for even more amazing 'Dragonfly Facts' from a past blog.
All That Glitters is Not Gold
A FOUR-SPOTTED SKIMMER
This beautiful dragonfly is found around the world in the northern hemisphere. It is known as the Four-Spotted Skimmer (Libellula quadrimaculata) in North America, and as the Four-Spotted Chaser in Europe and Japan.
Question: What is the state insect of Alaska?...
You guessed correctly... the Four-Spotted Skimmer.
Interesting Facts About Dragonflies From Wikipedia
- Some 5680 different species of dragonflies are known in the world today.
- Dragonflies are valuable predators that eat mosquitoes, and other small insects.
- Dragonflies are some of the fastest insects in the world. In general, large dragonflies have a maximum speed of 10–15 metres per second (22–34 mph).
- In some parts of the world dragonflies are a food source, eaten either as adults or larvae.
- In the United States Dragonflies and Damselflies are sought out as a hobby similar to birding and butterflying, known as oding, from the dragonfly's Latin species name, odonata. Oding is especially popular in Texas, where 225 different species of odonates have been observed.
A Pretty Pollinator
A Tricolored Bumblebee, Bombus ternarius, visiting an Erica carnea 'Springwood White', a variety of Spring Heath. This bee is also known as an Orange-belted Bumblebee, for obvious reasons. The name bumblebee refers to any member of the bee genus Bombus, in the family Apidae. There are over 250 known species, existing primarily in the Northern Hemisphere, with New Zealand and Tasmania being exceptions. Bumblebees are social insects that are characterized by black, yellow or orange body hairs often in bands.
Like their relatives the honey bees, bumblebees feed on nectar and gather pollen to feed their young. Bumblebees will also tend to visit the same patches of flowers every day, as long as they continue to find nectar and pollen.
What Makes Bees Buzz?
One common, yet incorrect, assumption is that the buzzing sound of bees is caused by the beating of their wings. The sound is actually the result of the bee vibrating its flight muscles. This is especially pronounced in bumblebees at low ambient temperatures.