This is a book to memorize, Creationists: Jessica Walliser's Attracting Beneficial Insects to Your Garden. |
My mother taught science and knew birds, mushrooms, wildflowers, moths, butterflies, and bugs. That is where I learned that most insects were beneficial and never to fear the rest of them. If we were out camping, she would trap a living bug and show us something.
After learning the microbial life of soil, the next most important part of gardening is bug life. Soil improvement is relatively simple - add mulch and the fungus, bacteria, nematodes, protozoa, and soil creatures will do the rest. When the weeds break through the mulch - add another layer of mulch.
Bugs are different. Like the birds, they have differing needs for shelter and food. Some bugs are voracious when hatched but need pollen and nectar as adults. Some bugs devour as babies and as adults - ladybugs and big-eyed bugs. Giving them the right plants will improve their ability to fight the damaging insects.
I am already thinking about three bugs I hardly knew existed, although I remember flower flies from childhood. I remember my mother saying about flower flies, "They look like little bees, but they aren't. They are good for the garden."
Two things kept me from using insecticide in the garden, starting in the 1980s. One was her advice to let beneficial insects do their job. The second was the cost of chemicals and the Dow chemists laughing about how overprices their products were.
I am just going to review some overlooked bugs, and I am sure you will start seeing them if you look closely at your plants outside.
Big-Eyed Bugs
Yes, they are small—measuring a mere 0.375 inch (10 mm) at maturity—but big-eyed bugs are also mighty. Each one is capable of consuming several dozen pests per day, making them among the most valuable natural enemies around. They are also among the most abundant. As generalist predators, they eat a protein-based diet including insect eggs, spider mites, aphids, cabbage worms, caterpillars, flea beetles, leafhoppers, thrips, lygus bug nymphs, corn earworms, whiteflies, and many, many others. One study revealed that big-eyed bugs consume sixty-seven different varieties of insects! These beneficials forage for pests on plants as well as on the soil, making these microhelpers incredibly important to gardeners.
Both the nymphs and adults of this amazing little insect are protein eaters. Slightly oblong with a broad head and distinctive wide-set bulging eyes (which help them spot their prey as well as their predators), the adults have clear wings that overlap and rest on their backs. They are brown, black, or gray in color. Females lay eggs on or near prey clusters to enable the hatching nymphs to find food quickly. Each female can lay up to three hundred eggs in her lifetime. Nymphs look much the same as adults except they’re a bit smaller and lack wings. Big-eyed bugs mature from egg to adult in about thirty days. Though their primary food source is other insects, big-eyed bugs also feed on nectar, sap, and small seeds to sustain themselves when prey are scarce. They spend the winter in garden debris and grassy areas [GJ - Aha. Keep the garden trash], and emerge in the spring to begin feeding on prey by piercing them with a specialized mouthpart and sucking out the internal organs (not a bad thought when you consider exactly whose guts they’re consuming!).
Walliser, Jessica (2014-02-26). Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control (Kindle Locations 647-660). Timber Press. Kindle Edition.
Ichneumon Wasps
Ichneumon wasps FAMILY Ichneumonidae NORTH AMERICAN SPECIES 3300
While many species of ichneumon wasps are extremely tiny, others are very large (up to 1.5 inches or 40 mm!). All are slender with long antennae. Many females have a highly noticeable ovipositor; it is sometimes longer than the insect’s body. Ichneumon wasps can be yellow to black or have patterns of various colors. They use caterpillars, the wood-boring grubs of various beetles, and other insects as hosts.
Walliser, Jessica (2014-02-26). Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control (Kindle Locations 1139-1144). Timber Press. Kindle Edition.
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"Cremastinae wasp" by Muhammad Mahdi Karim (www.micro2macro.net) Facebook Youtube - Own work. Licensed under GFDL 1.2 via Wikimedia Commons. |
http://www.scilogs.com/expiscor/10-facts-about-parasitoid-wasps-ichneumonidae/ -
The text below is copied verbatim. Note the many embedded links.
Parasitoid wasps are among the most amazing animals. They have the most unusual biology, are hyper-diverse, and are truly beautiful. These were my thoughts as continue with the 'ten facts about…' series on Expiscor, and my former post-doc Laura Timms kindly agreed to contribute a post on 'ichs' --> her favourite arthropod group, and one for which she is an expert.
From Laura:
Ichneumonidae is a family of parasitic wasps, and one of my particular research interests. If you’ve never heard of a parasitic wasp before, think chestburster from Alien, but for insects. A more scientific definition is that parasitoid wasps lay their eggs inside or on top of other insects; those eggs then grow and develop by feeding on their host’s tissue, resulting in the eventual death of the host. If you want to know more, this book has a lot of great information. In the meantime, here are ten facts about my favourite group of parasitoids.
1. Ichneumonidae is one of the largest families of organisms in the world – it contains an estimated 100,000 species, more species than all vertebrates combined. If you’re not impressed by sheer numbers, the thing that I find truly amazing about all that species richness is the amount of variation in life history that has come along with all that diversification.
2. For example, ichneumonids parasitize all kinds of hosts. Lepidopteran caterpillars and pupae are particularly common as hosts, but all sorts of others also make the list including beetles, flies, sawflies, spiders, caddisflies, scorpionflies, lacewings – and there are even reports of an ichneumonid being reared from a pseudoscorpion.
3. If you’re ever looking to find some ichneumonid wasps, try rearing some lepidopteran pupae that you found outside; it won’t take long before you find that a parasitoid pops out instead of the butterfly or moth. This is actually why I got into ichneumonids while studying forest caterpillars.
4. Some ichneumonids with crazy parasitoid lifestyles are the ectoparasitoids of spiders. Adult females of these species attack juvenile spiders and lay an egg on their body. After that egg hatches, the parasitoid larvae remains externally attached to the spider – even as the spider sheds its skin through various moults.
5. Another group with a very cool life history are the semi-aquatic ichneumonids. Species ofAgriotypus are ectoparasitoids of caddisfly pupae. Adult female Agriotypus crawl down plant stems to reach their hosts underwater. The wasps are covered with dense hairs that trap air around their bodies, allowing them to breathe and stay under for extended periods of time. The parasitoid larvae and pupae also have some interesting modifications for life underwater.
6. Don’t forget the hyperparasitoids – the parasitoids of parasitoids. Euceros species are ichneumonid hyperparasitoids with particularly complicated biology: 1) Adult female Euceros lay their eggs on pine needles near feeding sawfly larvae; 2) the parasitoid larvae hatches and grabs on to a passing sawfly; 3) the Euceros larva remains attached to the sawfly until the larva of a primary parasitoid emerges; and, 4) the Euceros then moves inside of the inside of the primary parasitoid and consumes it. Did you follow all that?
7. Some ichneumonids have an unusual latitudinal diversity gradient - their highest species richness occurs outside of the tropics. This finding doesn’t apply to every subfamily of Ichneumonidae, and there are still groups we don’t know enough about, but my own research indicates that it holds true for at least some subfamilies.
8. Although there are many very small ichneumonids, the biggest are the species in the subfamily Rhyssinae, parasitoids of wood-boring sawflies. You can sometimes spot these large wasps on tree trunks as they lay their eggs into their hosts – as you can imagine, it can take a long time to locate the host under the bark and then drill down far enough to get to it. Some great video footage ofMegarhyssa macrurus ovipositing can be seen here.
9. This quote by Charles Darwin: “I cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonidæ with the express intention of their feeding within the living bodies of caterpillars …” [from this letter to Asa Gray, 1860] is often brought up in discussions about how Darwin began to lose his faith while writing On the Origin of Species.
Don't judge me...I had to buy this book, so I ordered it on Kindle. |
10. Finally, there can’t be many books that feature ichneumonids, but The Snoring Bird by Bernd Heinrich is on that list. Bernd Heinrich is known for his work in comparative physiology and behaviour and also for his popular science writing. This book focuses on what it was like for Bernd to grow up with his father, Gerd Heinrich, an entomologist who devoted his life to the study of Ichneumonidae. I highly recommend this book for all sorts of reasons, not the least of which is that it paints a fascinating portrait of a man who really loved ichneumonids.
A BIG thanks to Laura for contributing to this series! You can follow her on twitter, here.
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Probably fewer than a dozen people had ever read any of these papers. Most people have never even heard of ichneumon wasps, and many of those who have would be likely to disparage them as “flies.” Ichneumons (“ ick-new-mons”) are mysterious and exotic wasps that are parasitic connoisseurs. Each specializes in one specific host (or a very few hosts). Ichneumons are delicately sculptured and patterned with almost infinite variety and subtlety...
Papa described more than 1,000 new species (many from museum specimens) during his lifetime, and all of us in the family who took up the net have been immortalized with a species of ichneumon wasp bearing our name that we had captured in the field.
Heinrich, Bernd (2008-12-24). The Snoring Bird (Kindle Locations 176-179). HarperCollins. Kindle Edition.
Flower Flies - Hover Flies - Syrphids
Syrphid flies, hoverflies, flower flies FAMILY Syrphidae NORTH AMERICAN SPECIES 890+
Members of this very important group of flies are frequently found hovering around flowers on bright, sunny days. The adults are significant pollinators that consume nectar, pollen, and honeydew. As with all true flies, they have one pair of wings; although at first glance some species may look superficially like small bees or wasps, their wing count is an easy way to separate the two (both bees and wasps have two pairs of wings). Syrphid flies can hover in midflight—hence their other common name of hoverfly. They are often brightly colored with stripes or other markings. Many species mimic bees in their coloration with various patterns of black and yellow, white and black, and occasionally gray or brown. Adults measure 0.16–1 inch (4–25 mm) long, with the majority of species falling somewhere in the middle and only a few at the extremes.
While the adults feed on flower products, their larvae are busy chowing down on various soft-bodied insects, including aphids, thrips, leafhoppers, scales, caterpillars, and others. Members of the subfamily Syrphinae all have predaceous larvae (called maggots—they are flies, after all). Larvae of other subfamilies may eat plant tissue, detritus, or even sewage and other waste. The larvae of predatory species are legless maggots 0.04–0.5 inch (1–13 mm) in length that taper to a point at the head end. They range in color from green to creamy white or brown and wriggle along swinging their heads from side to side until they bump into prey. Each maggot can consume several hundred insects during its three larval instars (life stages between molts) by nabbing the victim with its jaws and sucking it dry. Pupation lasts between one and two weeks or, at season’s end, continues through the winter. Many overlapping generations hatch each season.
Walliser, Jessica (2014-02-26). Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control (Kindle Locations 805-821). Timber Press. Kindle Edition.
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GJ - These are fascinating character sketches of the bugs I have just noticed in the garden this year. Now I bend over close to the roses to see what is happening. At night I check the roses by flashlight to see what is chewing on them. I also watch the slug population, since they prey on the tenderest shoots.
Readers who enjoy studying the interplay of insects, birds, and flowers in their yards will never run out of good material to read. What damaged Darwin's faith was the inability to grasp the purpose of Creation. We need these beneficial bugs to keep the damaging ones in line. And yet, the damaging insects feed the beneficials, since their attacks send up a chemical signal from plants, a 911 call that brings in the beneficial bugs.
I saw that when thousands of ladybugs attacked the cottony maple scale insects on our maple tree in Midland. The scientists were wrong about banding the tree with that gluey goop. That was no help and almost had to be surgically removed from my hand. But the ladybugs heard the call and swooped in to save the tree from additional damage.