Category Archives: Insects

Parsley Caterpillar to Chrysalis

Black Swallowtail Butterfly

Black Swallowtail Butterfly

I’ve been noticing a lot of parsley caterpillars on my young carrot plants. As these are the larval stage of the black swallowtail butterfly and there are lots of these butterflies in the garden, I wasn’t surprised to see them.  I decided to take one and experiment to see if I could watch the process of metamorphosis.

In looking online I’d found that the 2″ green and black caterpillars were the final instar of the caterpillar’s growth. Earlier instars are small and often look like bird dropping – a great method of camouflage!

Parsley Caterpillar

Parsley Caterpillar

This final stage before metamorphosis has a little trick up its sleeve to protect it if it comes under attack. If the caterpillar is disturbed or threatened, a little yellow “forked tongue” called an osmeterium shoots out of the caterpillar’s head and can startle a bird or other threatening animal. In addition, it’s said to release a scent that can deter predators. It only took a couple touches to the caterpillar to cause it to use its osmeterium against me!

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Osmeterium

 

But back to my experiment…

I put the parsley caterpillar in a large jar with a number of parsley and carrot leaves. It spent the first day eating but the next day was very different. The caterpillar stayed on a branch of the parsley and didn’t move. It was bowed out slightly from the branch, attached by the two ends of the caterpillar. I wasn’t sure if it had died or if it was getting ready to form a chrysalis (cocoon).

Chrysalis

Chrysalis

The very next morning my question was answered. The bright green caterpillar was gone and in its place was a brown chrysalis. I’m amazed how quickly this all happened. Overnight the transformation occured.

 

Chrysalis in a Jar

Chrysalis in a Jar

I’ve trimmed off the leaves of the parsley stem that the chrysalis is on and placed it back in the jar. I’ll be looking for any changes along the way and hoping to see the emergence of a black swallowtail butterfly.

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Passion Flower and the Bees

I’ve never grown a passion flower plant before but at the end of the season, a local gardening center had the passion flower “Incense” at a great price so I decided to give it a try.

Passion Flower Incense

Passion Flower Incense

The plant didn’t do much for the first month; it just sat there in the garden, working to get established.

But now it’s starting to grow and is becoming filled with flowers.

Yesterday I noticed something about the way a bee interacts with a passion flower. It’s clear that the bee wants to get to the nectar and the nectar appears to be found in the center of the flower. But in making its way to the center, something interesting happens.

The male reproductive organ of the flower – the stamen – has two parts: the filament and the anther. The filament is simply the stalk that supports the anther. The anther is what produces pollen.

Passion flowers have five anthers and each of them open facing down. That means that when the bee crawls into the center of the flower, its back gets coated with pollen from the anthers.

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The female part of the flower is the pistil and the end of the pistil, the stigma, is where the pollen needs to land in order for the flower to be fertilized. The way the passion flower is set up makes it hard for the pollen to get to the stigma; that is, unless a bee is present.

After digging around in the center of the flower, the bee is coated in pollen. When the bee takes flight or lands on another passion flower, there’s a good chance that it might bump into one of the three stigmas of the flower with its pollen covered body. And when it does, fertilization takes place.

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I’m liking the passion flower plant. The flowers are interesting and seeing the bees pollination them is even more interesting!

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Social Media, the Allium Leaf Miner, the PA Department of Agriculture and Me

Last week I was scrolling through Facebook and noticed a post by Northeastern IPM (Integrative Pest Management) Center. In it, they described a new invasive insect named the allium leaf miner (Phytomyza gymnostoma). While this insect is common in Europe, it has now been detected for the first time in the Western hemisphere, with Lancaster county PA being the first reported case. Since this initial identification, the allium leaf miner has also been discovered in Lehigh, Chester, Dauphin and Delaware counties.

I though that this was interesting but I didn’t give it too much thought.

Three days later I was working in the garden and noticed that the onion plants looked strange. The leaves were wavy and they felt like they were wilted. Since we’ve been having so much rain I knew that they weren’t dry but I pulled one up to see if there was a problem with the roots. Maybe all of this rain had caused some kind of root rot.

Onions with Allium Leaf Miner Damage

Onions with Allium Leaf Miner Damage

When I pulled up an onion, it was clear that it had a healthy set of roots and there was no evident of root maggots. But I noticed that there were marks on the leaves and when I pulled the leaves apart and looked into the stem, there were a number of small maggots tunneling through it. Then I remembered the Facebook post and realized that this looked like the allium leaf miner and it was now in Lebanon county.

I pulled up all of the onions and used a few to take pictures. I didn’t want this pest to spread so I put the onions into the garbage instead of the compost bin.

Later, as I thought about it, I realized that I should let someone know about my discovery. If this new invasive insect was in another county, the authorities needed to know this. So I sent an email with pictures attached to the entomologist at Cooperative Extension and he instantly forwarded my email to the PA Department of Agriculture. I heard back from the gentleman there quickly; he thanked me for the pictures and asked some additional questions.

When you’re a gardener and an amateur entomologist, it’s exciting to be a part of the early stages of discovery of a new invasive insect. But there was one thing that I should have done that I didn’t think of at the time. Pictures are nice but for a confirmed identification, the Department of Agriculture needs a sample of the insect. I should have saved a few of the plants and delivered them to the local extension office for testing. Oops!

When I go out to the garden again, I’m going to see if the chives or garlic are showing signs of this insect. If they are, I’ll certainly be collecting samples. Also, in my next post, I’ll be describing this new (to the Western hemisphere) insect.

But for now, I’m just grateful for social media and the information it provided me about the allium leaf miner. I’m also happy to help provide information to those tracking this new insect pest.

 

Want Bees? Grow Lavender!

Everyone understands the importance of having pollinators in the garden. If you’re growing fruit trees, squash, cucumbers and other crops, you need insects to pollinate the flowers so that the fruit can set.

lav1I’ve never been very intentional about attracting pollinators to the garden. They always just seem to be there. But I’ve always noticed what plants seem to attract these insects. One of the best plants for bringing bees the to garden seems to be lavender.

This easy to grow perennial is a bee magnet. When the lavender is blooming, one plant can easily be swarming with over a dozen bees. The lavender plant that’s in bloom right now is especially attractive to bumblebees. While a nearby russian sage has honey bees flying around its blooms, the lavender has nothing but bumblebees visiting its flowers.

Lone Bee the Found the Borage!

Lone Bee the Found the Borage!

I also have a volunteer borage plant growing near the lavender. Borage is supposed to be a great plant for attracting bees but when there’s lavender nearby, the bees ignore the borage and head straight to the lavender!

Growing lavender is easy. While starting it from seed can be a challenge due to slow and sporadic germination, if you start with a small plant from a nursery, it’s hard to go wrong. Lavender likes full sun but doesn’t need a lot of fertilizer. It’s ignored by rabbits (yeah!) and the only thing it can’t tolerate is heavy, wet soil. If you want more plants, you can take cuttings and root them easily. And when the plant starts to bloom, you can cut some of the flowers and dry them for potpuorri or to use as dried flowers.

lav5After seeing how well the lavender has grown and how the rabbits leave it alone, I’ve planted a small bed of lavender near the front door. The location is warm and sunny and the plants should make an easy to maintain “hedge” that will draw in the bees.

I’m also thinking about taking some cuttings, rooting them and planting them in the vegetable garden. It certainly can’t hurt to have a few more bees working in the garden.

So if you want bees, try some lavender – it’s sure to bring them into your yard.

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Wheel Bug Babies – a.k.a First Instar Wheel Bug Nymphs

Here’s an example of why it pays to keep your eyes open when you’re working in the garden.

Wheel Bug Nymphs with Egg Case

Wheel Bug Nymphs with Egg Case

Yesterday I was thinning out some old lilac bushes when something caught my eye. On one of the branches, there was a group of small insects that were unlike anything I’d seen before. The head and thorax of this creature was black, but the abdomen was bright orange. They were also clustered around a honeycomb-like structure that I assumed was an egg case. They moved slowly and didn’t seem to want to leave the branch where I had found them.

I first thought these were some kind of spider but after taking a picture of them and looking at it more closely, what I thought were eight legs were really six legs and two really large antennae. Also, the antennae were orange at the tip.

Whenever I find an insect that I can’t identify, I go to my friend Google. I typed “black insect with orange abdomen” and the second image shown gave me my answer. This was the first instar of a wheel bug (Arilus cristatus).

Wheel Bug Nymph

Wheel Bug Nymph

I wrote about the wheel bug a few years ago when I saw my first one. (What the….. Oh, It’s a Wheel Bug.) I’ve seen adults over the past few years, but I knew nothing about what they look like as nymphs.

The wheel bugs I found were in their first instar, having just hatched from their egg cases. An instar is a developmental stage of a nymph in an insect that matures by way of incomplete metamorphosis. (Insects with incomplete metamorphosis have three stages: egg, nymph, and adult. Those with complete metamorphosis have four stages: egg, larva, pupa, and adult. Wheel bugs and grasshoppers mature by way of incomplete metamorphosis; butterflies and moths go through a complete metamorphosis.) Between each instar stage, the insect molts, shedding its exoskeleton to grow and/or take on a new form. Wheel bugs go through 5 instar stages before becoming sexually mature adults. At each molt, they change a little bit but it isn’t until the final molt that they take on the look of an adult wheel bug. It’s kind of hard to believe that this first instar nymph is the same insect as the adult!

 

Picture of Nymph and Two Mating Adults

Picture of Nymph and Two Mating Adults

I’m glad I had my eyes open and saw these wheel bugs when I was trimming. I was able to rescue them from the chipper since they’re beneficial insects. But maybe even more important, seeing them kept me from touching them which could have been a problem. You see, these nymphs, just like the adults, can give a painful bite. The nymphs might be cuter than the adults, but you want to leave both of them alone if you see them!

Movies for the Bees

I recently watched three different movies on Netflix and Hulu about bees. I’d heard about the colony collapse disorder but I didn’t know much about it. I also didn’t know a lot about how honey bees are raised and handled. While there’s still a lot more to learn, this movies gave me a good introduction to bees and what’s going on with the bees.

MTH_PLAKAT_RZ.inddThe first movie I saw was More Than Honey, a 2012 Dutch movie about bees. While I ran into a little trouble with some of the subtitles, this film was well made, moving all around the globe to show the state of bees in various countries. The most disturbing part was seeing workers in China hand pollinating trees because all of the bees in the area are dead. Only in China would there be enough labor forces to be able to do this.

queen-of-the-sun-what-are-the-bees-telling-us-movie-poster-2010-1020691200The next was Queen of the Sun, a 2010 release. When the movie started with a woman dancing with a swarm of bees on her torso, I almost stopped watching it. It looked like it might be a bit too “fringy” and not scientific enough for my taste. But when one of the people interviewed was Michael Pollan, I relaxed a little. I still have some question about some of the scientific claims of this movie but I’m glad I saw it.

Vanishing-of-the-beesThe final movie was Vanishing of the Bees, a 2009 movie. A bee keeper from this part of PA who first reported colony collapse was prominently featured and gave this movie a “hometown connection” for me. The cooperation of bee keepers around the globe was also shown which showed that this problem is being addressed from a variety of perspectives. It was a well made movie.

What I realized after watching all of these movies is that honey bees are facing a lot of stress. They’re shipped all around the country on the back of tractor trailers to pollinate crops in different areas of the country. They face an onslaught of diseases and mites. The queen bees are artificially inseminated and replaced in hives long before they need to be. Hives are “fed” high fructose corn syrup. And then there’s the use of neonicotinoid pesticides that seem to be affecting bee behavior and contributing to their death (I’m researching this for another post).

While all of the movies show the problems that bees are facing, there’s also some hope in each of them. The specific cause (if there is just one) of colony collapse is still being investigated but a lot has been learned about bee health because of this problem. Also some are finding ways to raise bees that addresses many of these issues and it appears to be working.

If you’re at all interested in bees and their current state of health or disease, these movies are a great place to start to learn about these amazing insects.

Asparagus Beetles

The vegetable garden has a small bed of asparagus that’s been growing for 20+ years. Asparagus is a perennial vegetable that takes a little time to get established but once it’s growing, it’ll last for decades.

I’ve never had any problems with the asparagus aside from keeping the rabbits from eating the young stalks as they emerge from the ground. However this year I noticed something I’d never seen before. On some of the spears there were little black rods that were attached in vertical rows.

I wasn’t sure what those black rods were. I initially thought that they might be some kind of insect frass (the entomologist’s term for insect droppings) but the orderly way that they were attached to the spears made me doubt that I was seeing frass. Insect eggs seemed like a more likely identification.

Asparagus Beetle Eggs

Asparagus Beetle Eggs

One quick Google search identified these mysterious rods: they’re the eggs of the asparagus beetle (Crioceris asparagi). The adult beetle overwinters in debris near or in an asparagus bed and then emerges in the spring. The beetles feed on the emerging spears and lay their eggs on the spears in straight vertical rows. The cycle from egg to adult is a quick one: the eggs hatch in about a week; the larvae feed on the spears and ferns of asparagus, going through four instars in about eight days; the larvae then pupate in the soil and emerge as adults in another week.

In reading about this beetle, I learned that it’s most active in the afternoon. To this point I’d seen the eggs but I had yet to see an adult asparagus beetle. All of that changed when I went to the asparagus bed on a warm afternoon. There were adult beetles everywhere, chewing on the spears and mating away.

Asparagus Beetles

Asparagus Beetles

If I were a commercial grower of asparagus I’d have to do something to control these beetles. Their chewing can cause the spears to be twisted or deformed and the eggs would make the spears unmarketable. But as a home gardener, I can be a little less aggressive in dealing with this insect. I don’t care if the spears of asparagus aren’t perfectly formed. The eggs can easily be wiped off of the spears and if I miss a few, I just see it as a chance to add a little insect protein to the asparagus!

The presence of these insect did get me thinking about why I’m noticing them this year. I think it all has to do with cultural practices. In years past I would mulch the asparagus in the summer with straw and then in the spring burn the mulch and the dried ferns to clear the bed. I didn’t know it at the time but while clearing the bed with fire I was also killing most of the overwintering beetles.

Mating Asparagus Beetles

Mating Asparagus Beetles

With changes in the neighborhood I’ve replaced the spring burning with mulching the bed with wood chips and cutting the ferns off in the fall. What this means is that I’ve started to provide a perfect environment for the adult beetles to overwinter.

This fall I plan to remove most of the mulch from the beds. I might leave the ferns in the bed and go back to burning them in the spring. The other option is to cut the ferns in the fall and then go over the bed in the early spring with a propane weed torch. This would burn off the bottoms of the old fern stalks and kill many of the overwintering beetles.

In the meantime I’ll be keeping a close eye on the asparagus bed. Harvest season is coming to an end and once the ferns have fully developed I’ll be making sure that they’re not being defoliated by the beetles. This could weaken the plants and ruin next year’s harvest. If it gets too bad, a little pyrethrin spray will help to keep the beetles in check.

While asparagus beetles can be a problem, now that I know about them and their life cycle, I think I can get them under control. Cleaning the bed in the fall and using a little fire in the spring should be all that’s needed to limit the number of asparagus beetles in the garden next year.