Mid-Summer 2020 Update

I've observed a grand total of 2 caterpillars. That's it. You read that right.

It's definitely hot and humid - which seems to be their favorite weather. We had a heat advisory over the weekend. I have triple the amount of leafy vine for them to eat, but where are the caterpillars?!

So, I have thought of 3 possibilities. One, the insect population has cycles that include "off" years in which the population is experiencing a decline after a previous population explosion. Cycles of nature at work. Two, there have been more birds frequenting my yard. Without a cat that is interested in frightening them off (my new cat would rather sleep all day on the cool retaining wall in the backyard), the Northern Mockingbirds have taken to landing on the trellis. There's also a tiny, brown bird who flits in and out of the bushes. He pays no attention to me in the yard and the mockingbirds could care less about my feeble attempts to scare them away. Very tolerant of human presence, these little guys are! I would guess that they fill their bellies with butterflies that attempt to lay eggs on the vines. Three, the overall population of pollinator insects is in decline all over the North American continent, and now I am seeing that here. Everywhere, people are clearing land, building houses and homesteads, putting down concrete parking lots and huge commercial buildings, and destroying the habitat that the insects rely on. People are growing lawns, which removes the flowering weeds that provide food year-round for insects. I had hoped that my home was far enough "in-the-middle-of-nowhere" (Pineywoods forest) that we would either not see this decline, or the survivors would come here for refuge.

My option of choice is number 1. A cycle of population explosions and sharp declines would mean that things are normal AND I could have the best of both worlds: caterpillars some years and delicious passionvine fruit other years.

For now, I'll tend the vines and my garden and see what happens. I suppose I could look at the interaction of stink bugs with caterpillars. The stink bugs have been attracted to the new garden plant that I am trying this year: tomatoes!

Oh! I should mention that March through June was the coronavirus/COVID-19 quarantine period. I spent an extra amount of time in the garden as a result of our voluntary lockdown. It has been expanded and includes a greater variety of edible plants. It was also a very wet spring, which allowed me to place more bamboo trellis poles in the soft ground. So, there has been an increased amount of human disturbance/presence near the vines and the new plant diversity may be attracting a greater diversity of insects and/or diseases - which could be predating on the butterflies, eggs, or larvae without my knowledge. I have to say that I have enjoyed my extra time outside in the spring weather. I am also researching local edible plants - "foraging" as it is called - as kind of a prepper hobby to go along with my "victory garden."

Posted on 15 de julho de 2020, 04:43 AM by redpenny redpenny

Comentários

Your tiny brown bird is likely a Carolina Wren

Publicado por lappelbaum mais de 3 anos antes

I just happened upon your page when trying to find out of Gulf Fritillary CATS will eat Passiflora aurantiaca b/c there are some passionflower they won't eat.
I keep reading your saying birds are eating the CATS and well, I think you're wrong. But I'm wondering if you've ever seen a bird eat one.
I've been growing passionflower for years & even have a "yellow passionflower" that just came up! Each year I wait with anticipation for the GF B'flies to lay eggs & then watch in excitement!

And everything I've read sez birds WILL NOT eat the CATS!
From the dirtdoctor.com ... LARVA: grows to approximately 3 inches in length and is bright orange and covered in rows of black spines on its head and back. The spines are soft to the touch and do not sting. The larva are poisonous if eaten. Their toxic flesh provides gulf fritillary caterpillars with excellent protection from predators. Birds avoid them. The larva feed exclusively on various species of passionflower such as maypop (Passiflora incarnata), the yellow passionflower (P. lutea) and running pop (P. foetida).

Publicado por chattykatz quase 2 anos antes

I did notice lots of missing caterpillars that I know were too young to pupate. I do have predation by Eastern Leaf-Footed Bugs and Assassin Bugs. I suppose I assumed that the birds were in on it too. I guess I underestimated how many caterpillars are eaten by predator bugs. Thank you for the correction.

Publicado por redpenny quase 2 anos antes

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