Wednesday, June 14, 2017

The Last Daffodil and What Eats It

This week temperatures have skyrocketed, but until recently it's been quite a cool (and sometimes downright chilly!) spring.  The last daffodil in my collection to bloom this year, Narcissus 'Actaea', flowered for over three weeks from mid-May through the end of last week.

Narcissus 'Actaea' - last daffodil bloom this year
The winding down of daffodil season, however, is when the fight to save my daffodils steps up.   In May and early June is when the critters that eat them come out to play.  And just what eats daffodils, the bulb that is impervious to almost every other garden pest around, you might wonder?



Frank from the garden blog Sorta Like Suburbia first told me about this fly, whose larvae burrows into the bulb and eats the middle of it, weakening or killing the plant.  After a quick google search, I knew I had seen this fly in my garden.  (Thank you, Frank!)  It's a good-sized fly whose various colorations mimic bumblebees, and when it flies it makes a distinctive whining sound.

Narcissus Bulb Fly
The adult flies emerge in late spring/early summer and live for 2 to 3 weeks.  I often see them around my flowers on sunny days this time of year, feeding on nectar and pollen.


After mating, the female flies lay anywhere from 40 to 100 eggs each at the base of suitable plants, one to three eggs per plant.  That's a lot of infested plants!  They usually lay eggs on daffodils, but they will also infest snowdrops, hyacinth, iris, lilies, amaryllis, and tulips, among others.

Narcissus Bulb Fly laying egg at base of daffodil leaves
After a few days the eggs will hatch and a larvae will wriggle down the outside of each bulb to feed on the basal plate that is on the bottom of the bulb.  It then bores into the middle of the bulb to feed on it, hollowing out the middle of the bulb as it grows larger and larger.  The larvae overwinters inside the bulb, and in early spring it pupates for a month or two (either inside the bulb or in nearby topsoil), finally emerging as an adult fly.


Of course, this usually spells disaster for the plant.  Sometimes the larvae's damage won't totally kill the bulb, and it will be able to send out small leaves and slowly recover over the next two or three years.  Unfortunately oftentimes the bulb is destroyed beyond recovery.


Thus I have been busy fighting these pests for the last weeks.  The Narcissus Bulb Fly is a tough fly to control.  Some people have luck using systemic insecticides, however I try to garden as organically as possible.  Daffodil growers often use hot water bath treatments to kill larvae from Bulb Flies and other pests.  To do this, after the leaves have died back, dig up bulbs that might be infested and submerge them in hot water that is 109° to 111° F (42°-44° C) for one hour.  The heat will kill the larvae; just make sure to avoid higher temperatures that cook the bulb!


I go for a slightly less complicated route - I become a Fly Hunter for the few weeks that they are out in the garden.  I am out gardening quite a bit this time of year, so I garden with a butterfly net handy.  I listen out for the familiar whine when gardening and often check the flowers that they particularly frequent.   When I see a Narcissus Bulb Fly, I swoop the net on top of it.  The fly usually flies straight up to the top of the net, so I then carefully gather the material around the fly and bring it somewhere I can stomp on and kill it.  So far this year I've killed about two dozen flies.


Here's hoping that it's enough to save most of my daffodils.


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Sunday, June 4, 2017

The Pink Spotted Ladybug

A couple weeks ago I had a very special visitor to the Red House Garden.

Pink Spotted Ladybug
On one of my miniature daffodils was a Coleomegilla maculata, also known as the Pink Spotted Lady Beetle or the Twelve-spotted Lady Beetle.

Coleomegilla maculata
Many cultures believe that ladybugs are a sign of good luck and prosperity, and I believe it about this particular ladybug.  What's so special about it?  It's the first ladybug I've seen in my garden that is actually native to this area.


While native ladybugs used to be quite common, they are now being outcompeted by non-native ladybugs.  If I see a ladybug here, it is usually an Asian Ladybug, aka Harlequin Ladybird.  Larger than most of our native species, the Asian Ladybug is known for its huge appetite and was repeatedly introduced to the US for the control of aphids starting in the early 1900's.  An established population of these beetles were found in the wild near New Orleans in 1988, and since then they have spread swiftly.  Their appearance is very variable, but they often have what looks like an 'M' on the backs of their heads. 

Asian Ladybug
Asian Ladybugs outcompete native ones due to their voracious nature, their high resistance to disease, and the fact that they carry a microsporidian parasite that infects and kills other ladybugs but which they are immune to.  They are often considered pests due to their tendency to swarm to light-colored buildings (including my porch) in fall and and try to come indoors to hibernate for the winter.  They also give off a noxious odor and stain when frightened or crushed. 


Pink Spotted Ladybugs such as the one in my garden are native to Northeastern North America, the Midwest, and the Southwestern United States.  Its color can range from pink to orange or red.  They prey on aphids and other small insects, but the Pink Spotted Ladybug is unusual in that pollen may make up to 50% of its diet.  It is attracted to areas with dandelions and other pollen-rich weeds (maybe that's why it ended up in my yard?)


 Either way, I consider myself fortunate to have one of our native ladybugs in my garden, and I hope it will be so lucky as to lead to more!


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