Springtime with awesome, beautiful and awe-inspiring insects

This spring of 2021 has offered some delightful chances to see interesting insect species, some of which I’ve noticed before and some that were new or gave me my first opportunity to observe them up close. While not many people aside from entomologists pay much attention to the “creepy crawlies,” they are certainly well worth watching in my view. Including insects in my nature observations greatly enhances my experience of appreciating the natural world.

male giant ichneumon wasp P5068000© Maria de Bruyn res (4)

ichneumon wasp P5067996© Maria de Bruyn res (2)

female giant ichneumon wasp P5068007 © Maria de Bruyn res (2)The month of May brought me two especially awe-inspiring events. The first was seeing long-tailed giant ichneumon wasps (Megarhyssa macrurus) preparing for reproduction on a nature trail in Chatham County. It was easy to distinguish the females (right) from the males (above) because they had very long ovipositors (a tubular organ through which a female insect lays stored eggs). In the species I saw, the ovipositor can be 4 inches long!’

female giant ichneumon wasp P5068028© Maria de Bruyn res (2)

There were several male and three female wasps flying about. None of them showed the slightest interest in the large human looming overhead. Even if they had, I needn’t have worried since these wasps don’t sting people. The females were busy pressing their antennae against a disintegrating hardwood log’s bark, aiming to detect vibrations inside.

ichneumon wasp P5068180© Maria de Bruyn res (2)

The mothers-to-be were “listening” for the best spots to lay their eggs by identifying where the larvae of the pigeon tremex horntail wasp (Tremex columba) were buried. Why you ask? The mother ichneumon paralyzes a horntail larva before laying an egg next to it. When her own offspring emerge from the eggs, they will eat those unfortunate horntail larvae while they prepare to overwinter until they emerge as full-grown ichneumon wasps in the spring.

ichneumon wasp P5068058 © Maria de Bruyn res (2)

 

The giant ichneumon’s ovipositor has three components. In the middle is the ovipositor proper, a filament with two interlocking parts that slide against one another; it is tipped with a cutting edge that can drill through wood. Some researchers have data indicating that the cutting edge may contain some ionized zinc or manganese.

ichneumon wasp P5068164© Maria de Bruyn res (2)

Two other thin filaments called valvulae sheath the central structure and their function is to protect the egg-laying organ. During egg-laying, they arc away from the ovipositor.

ichneumon wasp P5068171© Maria de Bruyn res (2)

While I watched one female wasp in particular, she sometimes had part of her ovipositor coiled up in a transparent expandable pouch at the end of her abdomen.

ichneumon wasp IMG_2003© Maria de Bruyn res (2) ichneumon wasp IMG_2002 © Maria de Bruyn res (2)

She would push out the ovipositor and appeared to smooth it out with her legs. The literature I read about the wasps did not explain this movement, but I thought she might be pushing eggs down the tube. Watch the video to see what you think! 

When she finished this smoothing movement and had found the right spots for her offspring, the protective lining filaments separated from the ovipositor itself and she inserted it into the log. It was a fascinating process to witness.

 

female giant ichneumon wasp P5068170 © Maria de Bruyn res (2)

female giant ichneumon wasp P5068109 (© Maria de Bruyn res (2)

Although ichneumon wasps are parasitic, various species are beneficial insects since their larvae feed on insects that harm food crops such as boll weevils, codling moths and asparagus beetles. The adults usually only live about 27 days and may only drink during that time. Their adult goal is to find a mate and then reproduce.

ichneumon wasp P5068014 © Maria de Bruyn res (2)

Another way in which the ichneumon wasps have contributed to human society is by serving as an example for the medical community. The STING Project at the Imperial College in London is investigating options for Minimally Invasive Surgery (MIS) to diagnose and treat various medical pathologies. The research team is now developing a flexible steerable probe that was inspired by the ichneumon wasp’s ovipositor!

cecropia moth IMG_0019 © Maria de Bruyn (2)My other exciting insect event involved a moth. Last fall, a cecropia moth (Hyalophora cecropia) positioned its cocoon on the door jamb of the women’s restroom at Cane Creek Reservoir. The reservoir’s manager feared that it would be damaged there and asked if I would be willing to care for it over the winter. I took the cocoon home and kept it safe during the fall, winter and much of this spring.

Cecropia moth larvae (caterpillars) are often found on maple, cherry and birch trees. Why this one chose a building as an overwintering site is a bit of a mystery. Since the pupa was going to be dormant all winter, I placed it upright in a large plastic container with a grate over the top and kept it on my screened-in porch.

cecropia moth IMG_0020© Maria de Bruyn (2)Periodically, I would check on it and it seemed to be ok. This was important as these moths are “univoltine” — they only have one generation of offspring per year. Out in nature, the caterpillars may fall victim to parasitic wasps and flies that lay their eggs on them. So it was fortunate that we were able to “rescue” this cocoon.

One evening at the end of May, I stopped working on my porch to go inside to watch the news. When I came back after about 20 minutes, I spotted a brilliant large moth on the screen. My youngest cat spotted it at the same time, so I shooed her inside. The cocoon scarcely had a hole in it; I really wish I’d seen how the huge moth got out.

cecropia moth IMG_0006© Maria de Bruyn (2) res

cecropia moth IMG_0003© Maria de Bruyn 2 res

The cecropia moth is North America’s largest moth with a wingspan up to 7 inches. The males and females look similar but the males like this one have larger, more feathery antennae.

cecropia moth IMG_0012© Maria de Bruyn (2) res

Female moths emit pheromones that the males can detect from up to a mile away. After mating, the female lays up to 100 eggs. Both sexes die after about two weeks as they lack functioning mouths and digestive systems and don’t eat.

cecropia moth IMG_0014 © Maria de Bruyn (2) res

 

The moth’s short adult lifespan must have made this guy anxious to get underway. Or seeing my cat and I hastened his development. One website reported that it takes the moth a few hours to dry before they can open their wings and fly.

cecropia moth IMG_0011© Maria de Bruyn (2) res

 

However, very soon (perhaps 10 minutes) after I removed him from my porch and took him outside (never touching him with my hands), he began vibrating his wings. In less than a minute, he launched himself upwards and flew towards the top of the nearby tall pine trees, setting off on his quest for a mate.

cecropia moth IMG_0016© Maria de Bruyn (2a) res

I suppose it is possible that the moth had emerged earlier and had crawled away to hide but that seemed unlikely. In any event, he looked like he could fly just fine, and I sincerely hope that he found a mate and that they were able to collaborate in ensuring a new generation of this stunningly beautiful species! And I was grateful for having agreed to overwinter the cocoon as it enabled me to contribute to the propagation of this wonderful moth. In any event, I was enthralled to see what a gorgeous creature he was. These moths are generally nocturnal so seeing him was a treat!

cecropia moth IMG_0017 © Maria de Bruyn (2) res

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Moth marvels

Some of the large moths, like the polyphemus (Antheraea polyphemus) and cecropia (Hyalophora cecropia, below) moths, definitely rival butterflies in their beauty and splendor. Before launching into a series on some Central American wildlife, I thought I’d share a couple recent moth-related spottings that I had.

The luna moth (Actias luna) is a large lepidopteran that entrances people and I recently saw one along a path in the Mason Farm Biological Reserve. Unfortunately, the insect had died but the cause was not apparent. Perhaps it was a parasitic fly that was originally introduced to help control invasive gypsy moths or perhaps it had simply reached the end of its life span.

This past year, I was fortunate enough to see the cocoons of both the polyphemus (left) and cecropia moths but I had not seen the large caterpillars associated with some large moths.

 

Then, just a few days before departing for a trip to Costa Rica, it was my good fortune to visit a garden that had two species of large hornworms. The tobacco hornworm is the immature form of the Carolina sphinx moth (also known as the tobacco hawkmoth; Manduca sexta). The tomato hornworm, the caterpillar of the brown and gray five-spotted hawkmoth (Manduca quinquemaculata) looks very similar except that it has a black or dark blue horn instead of the orange one sported by the tobacco hornworm.

The tomato hornworm is distinguished by v-shaped marks (right) while the tobacco hornworm has beautiful black-bordered straight white lines on its body. I find both species attractive but particularly like the tobacco hornworm caterpillars.

                    

They are so cute with their rounded heads and little suction-cup-like feet.

Both species of caterpillar can be found on either tomato or tobacco plants as they consume the foliage of various plants in the nightshade family. The presence of frass (insect larvae poop) alerts you to which plants may be hosting the hornworms.

These moth species originated in Central America and are now considered by some people to be garden pests, especially when they eat tomatoes. It seems that planting marigolds next to the fruit can repel the caterpillars, who eventually pupate and then overwinter underground where they have fallen off plants.

 

There are parasitic wasps that also prey on the hornworms. One species attacks the tiny hornworm eggs, which are laid on leaves; another wasp lays its eggs in the body of the caterpillars.

 

The Kingsolver Lab at the University of North Carolina (UNC) is researching the hornworms among other insects, examining how environmental changes caused by humans (agro-ecosystems, introduction of invasive species, climate change) are evoking responses in the caterpillars. It was a treat to see lots of these caterpillars at different stages of their development.

                

Next up: a blog on one bird species I’ve watched frequently this summer in NC and then a virtual trip to Costa Rica. 🙂

 

Venturing forth on overcast days

Our area has been inundated with rain for 9 days straight now – not a big deal if you live in a region with monsoon seasons but it is not really usual for us. We also had two hurricanes and several severe storms the past 5.5 months as well as other rainy periods and the ground – much of it clay – is just not absorbing all the water anymore. My yard (which I am fortunate to have, don’t get me wrong!) currently has patches that are simply sodden mud and clay with no vegetation to be seen. Paths in the nature reserves are slick and slippery. Still, if you’re a person who gets “spiritual sustenance” by going out into nature, you venture forth on those days that might have a few overcast but rain-free hours to see what is out and about. Though I haven’t seen beavers lately, I did see their tracks in one reserve. A father had brought his children out and they made plaster casts of the tracks – a wonderful outdoor nature lesson.

Because we have also had some unusually warm days for this time of year, the flowers began budding a bit earlier than other years. Daffodils, hyacinths and crocuses are blooming profusely and a few of my neighbors have lovely flowering quince (Chaenomeles).

 

 

A winter honeysuckle (Lonicera fragrantissima) at one park had some lovely blossoms.

 

 

 

 

 

At another reserve, an apple tree (Malus pumila) has lovely flowers emerging.

 

Unfortunately, the tree is right next to a grove of cedars that are laden with mature cedar apple rust galls (Gymnosporangium juniperi-virginianae). When they emit their spores, they will kill the apples. I used to have an apple tree in my yard but the nearby cedars also got apple rust and now the tree has died. I’ve planted a plum tree and hope that that one will thrive and survive.

With the leaves having fallen from most trees, it’s possible to see the cocoons of some of our larger moths. So far, I’ve found three cecropia moth cocoons, two polyphemus moth cocoons and several bagworm moth cocoons in three different places. The Chinese praying mantis (Tenodera sinensis) egg cases are also showing up better with little foliage to hide them.

Getting nice shots of birds is not easy on those dull and gray days. Many of the smaller birds were huddled in bushes and trees, puffing themselves up to trap some body heat as a means of coping with the cold and wet conditions.

 

Field sparrow (Spizella pusilla)

I tried to get close to a beautiful kestrel (Falco sparverius), who kept flying just a bit further away when I slowly approached it. As I was walking back to my car, it suddenly turned and flew right by me – I swung up my camera and got one shot, which was not perfect but still a bit of a reward.

 

A gorgeous great blue heron (Ardea herodias), on the other hand, deigned to entertain me with a protracted grooming session at a local pond. S/he first perched above a couple turtles and watched them until they plopped down underwater.

Then the bird began picking at its feathers, showing off how its long neck can be twisted to enable that long beak to reach where it wants.

Note where the beak is peeking through in the photo above right! Flexible neck!

The preening activities gave me a chance to get what I considered to be a series of nice portraits.

 

The weather forecasters predicted that the rain would end, it would get very windy and the sun would shine this afternoon – they were right! They also say we will have a week of sunny days coming up – I certainly hope that that’s the case so I can exchange my muck boots for regular walking shoes again. Hope you are enjoying some pleasant weather!