Garden Food Webs: Lovely Lacewings

 

The flower flies, and ladybugs are not the only predators in my garden.  I occasionally see these green lacewings flying rather clumsily amongst the foliage and flowers.  Their eggs are rather remarkable:

 
 
Ants would carry the eggs away, but all they find is a thin stalk that they cannot climb.  The eggs hatch into hungry larvae - I call them 'alligators.'

 

Green lacewings comprise the insect family Chrysopidae, the Greek root words mean 'golden eye.'  They are rather beautiful and mesmerizing up close:

 

You are what you eat: the Small-eyed sphinx

Paonias myops blends in on Prunus serotina

The small eyed-sphinx, Paonias myops, is a moth in the family Sphingidae.  Many of the sphinx moths are specialists, and can only feed on a very limited range of host plant lineages.  This one feeds on black cherry Prunus serotina.  One of the advantages of specialization on a host is that insects can adapt cryptic coloration and behaviors that match the plant on which they are found.  This one has brown spots that appear to mimic the spots found on late-season cherry leaves.  It may be just enough camouflage to keep a hungry bird from noticing the caterpillar.

The small eyed sphinx is so named because of small eye-spot on it's hind wing (not visible in the photo below).

Two small-eyed sphinx moths on black cherry, shortly after leaving their underground cocoons

Leaflets three, wipe with me?

Toxicodendron radicans aka Poison Ivy

 Oh summer! Wonderful long days, firefly studded evenings, suntanned arms, and an itchy rash between my fingers all tell me that the entomology fieldwork season is under way.  I almost always have poison ivy on my fingers by the time the solstice comes around.  This is usually from reaching into poorly directed sweep nets, and tying bootlaces that have tromped through fields of this intresting (if inconvenient) native plant.

While it seems that the rash spreads itself up my arms, this is not the case.  Different parts of my arms and hands react at varying rates and severities to the same exposure to urushiol, the chemical that causes the allergic reaction.  Sometimes I get repeated exposures if I haven't washed everything that came in contact with the plant (typically my boot laces) but the oozing rash itself does not beget more rash.

This post was brought to mind when my wife brought home a new brand of toilet paper.  I'm all about sustainable products (especially when thay are actually eco-friendly and not just marketed as such) - but did this brand take 'going green' too far?  The graphic designer responsible is either having a good laugh, or they need to take botany 101.

hmmm.  Cause for concern?

Food webs in the garden: feasting flower flies

Syrphid fly and spiderwort

Most people are familiar with flower flies (also called hover flies), and even those who aren't have probably come across one of the 6000 species in the family Syrphidae.  Recognizing flower flies can be difficult, as many species mimic the yellow and black color patterns of bees and wasps.  Despite their warning colors, the pollen feeding adult flies are harmless.  The offspring of some species, however, are fearsome predators.  The are the stuff of nightmares, if aphids would have bad dreams:

This is what I think it would be like to be eaten by 'The Blob'

These maggots might be confused with caterpillars, as they crawl around on leaf surfaces looking for a meal.  Some species will slime their way through a group of aphids, turning around to consume the now stuck insects at a leisurely pace.  In combination with the ladybird beetles, these have really started to lower the populations of aphids on some of our plants.  Had I not planted a diverse garden that supports other aphids for they syrphids to eat, these predators would not have been around to keep the goldenglow aphids in check.

Not your compost's maggot!

 And for those of you that are feeling terrible about my little red plant-sucking friends, I want to ease your worries: I have reason to believe that aphids do not suffer from night terrors.

Food webs in the garden: ladybug beetles

Name that state insect?

The goldenglow aphids in our garden are under attack!  One of the predators that are most easily spotted are these seven-spot ladybird beetles Cocinella septempunctata.  These familiar insects are attracted not by the aphids themselves, but by chemicals that the plants release only when aphids have been feeding on them.  Both the adult and larval beetles are very efficient aphid predators, plucking them off the plant and chewing up their soft bodies with strong jaws.

Probably Coccinella septempunctata eggs

 Adult beetles lay clusters of eggs on leaves that look like clumps of yellow rice.  If you've ever been bitten by a ladybug larva, you know their jaws can deliver a strong pinch!

nom nom nom

 Cocinella septempunctata is not native to the Americas, but was introduced from Europe and by 1973 was established as part of a biological control program for pest aphid species.  This familiar insect was selected as the state insect of 6 states, including Delaware (I probably would have selected an insect more indicative of the region).  Another introduced coccinellid that I commonly find in our garden is the striking twice-stabbed ladybird beetle Chilocorus kuwanae.  There are native Chilocerus that look very similar but I have not yet seen one here.

Next up: fearsome flower flies!

Food webs in the garden

 Our Oxe-eye Sunflower Heliopsis helianthoides is about to bloom

Over the past several years Kiri and I have been furnishing our garden with plants native to Delaware.  We do this not only because we like these plants, but also to support local wildlife (especially insects of course).  While some pest insects can eat just about anything, most of our desirable insects can only feed on indigenous plant lineages that they co-evolved with.

As our summer flowers are gearing up for a brilliant June display, I have been spending more and more time checking  out the critters that have made their home in our yard.

Aphids give live birth

One of the most apparent visitors are these red aphids that are feeding on some plant stems.  Aphids can reproduce with or without sex, and they are viviparous - having live birth.  This helps them to increase in number very quickly, and sometimes an adult aphid can be seen with a whole row of it's clonal offspring feeding right behind it:

Goldenglow aphids Uroleucon rudbeckiae

Despite their sucking the juices out of our plants, these aphids are a welcome visitor, and I don't worry much about them killing my flowers.  Kiri noticed that while the aphids are host specific, feeding only on our Heliopsis, they do not feed on every plant of that species.  The different plants have slightly different genes, and the aphids prefer certain genotypes on which they are the most successful.  On the preferred plants, they have reached very high numbers, but they have also attracted large numbers of insect predators that attack aphids.

A battle is unfolding amongst our wildflowers as these predators go after the huge aphid colonies - I don't think it's going well for the squishy red plant-suckers.  More on that to follow!

Our garden provides wildlife habitat and a place for me to watch predators and prey!