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!

Fly Fly Again

Golden-backed Snipe Fly, Chrysopilus thoracicus

 I've been on a fly kick of late, and making a habit of punny post titles.  One of the most striking flies in our area is the Golden-backed Snipe Fly.  Although these rhagionids are rather common in early summer, they still turn my head every time I see them.  Like many flies, males are 'holoptic' with their eyes touching and covering most of their heads, while females eyes are spaced apart.  I presume that this is an adaptation for males identifying and following females on the wing.

Sexual dimorphism

Many rhagionids are predatory, but it is suspected that this species feeds only on nectar, if at all.  The genus 'Chrysopilus' means "golden hair." The scintillating thorax on these flies probably has something to do with my fascination with them...

Oooh so shiny!

Flies time

Self-portrait with Pangoniinae

I'm a big fan of the entomophagy movement but this post isn't about including insects in human diets, rather, it's the other way around.  I was pleased to see Morgan Jackson's post on deer flies; not only for the interesting read and beautiful flies, but also because it's nice to be reminded that there are other folks out there who are [insert adjective] enough to let an insect bite or sting them out of curiosity or for a nice portrait session.

I'm pretty sure that Morgan's photo was more painful than mine; as he mentions, most biting flies in the family Tabanidae use their serrated knife-like mandibles to painfully cut skin, and then drink up the blood.  Flies in the primitive subfamily Pangoniinae, however, are well adapted for feeding on nectar deep within flowers.  This one's long narrow proboscis inflicted little pain when it did bite.  Still, watching the fly work its far-reaching mouthparts into my knee was a little disconcerting:

This is the opposite of entomophagy

 One thing is clear from all these tabanid photos: The world is in need of some insect photographers with slightly less body hair.

Insect collecting 101 - Don't do this.

Kissable bug?

 I know this must happen to you all the time;  You're walking through the nation's capital when your spouse catches a cool membracid tree hopper.  Expecting a day of subways, pidgeons, and people you neglected to bring along anything to store your quarry in - will you ever learn?  As you consider a day of carrying the bug through museums in your sweaty hand, you have a flash of ingenuity.  You roll your chapstick all the way to the bottom of the tube, and pop the insect inside.  Brilliant!

Not until you return home to photograph your captive do you realize your folly.  Your jumping gem is well moisturized and coated in spf 25 'Nivea'.

I wanted to end with a hilarious joke that Kiri made about this chapstick slathered tree hopper, but neither of us can remember it.  Maybe something about Triatoma?  Any takers?

Eyelash Viper Revisited

In Costa Rica I took many photos of these golden vipers.  Here's another of my favorites.  The ridge over the eye gives the common name 'eyelash viper.'

Shenandoah NP Salamanders

Kiri and I took a few days off this week and went backpacking in Shenandoah National Park with good friends.  Rainy weather made for tough hiking and few photos, but the wildflowers were wonderful, and salamanders were abundant. To save weight and worry, I left my close up lens at home, but still got some shots with Kiri's help.