Azalea caterpillars hatching

Yesterday I found the first azalea caterpillars of the year. These tiny caterpillars had just hatched from the white eggs you see

Newly hatched azalea caterpillars. Notice white eggs on the leaves in the background. Photo: SD Frank

Newly hatched azalea caterpillars. Notice white eggs on the leaves in the background. Photo: SD Frank

in the background. You can scout for these bright eggs in August before the caterpillars hatch and remove them. I think these caterpillars are worth having though since they are very beautiful. Actually the caterpillars are prettier than azaleas tend to be this time of year and they will eat all the leaves stippled by lace bugs! You can read more about these caterpillars that feed on azaleas and blueberries in a post from last August.

SAVE THE DATE: LARVAE EXPECTED

This guest blog post is from four of our amazing undergraduate (or just-graduated!) Frank Lab Summer Employees: Nicole Bissonette (Zoology ‘15), Laura Daly (Horticulture ‘14), Karly Dugan (Animal Science ‘15) and Danielle Schmidt (Zoology ‘15). This blog is proof that even non-entomology majors can fall madly in love with bugs.

The expectant MOTHers in the Frank Lab.

The expectant MOTHers in the Frank Lab.

Once upon a lunch break, the four of us discovered a moth frantically flapping its wings beneath a

Rescued imperial moth

Rescued imperial moth

Southern Magnolia, unable to fly. We were concerned as she struggled to crawl up the tree and decided to bring her back to the Frank lab. Since our fellow coworkers were out in the field conducting research, we had to put on our entomology caps. After some intense googling, we discovered our lovely, large friend was an Imperial Moth.

 Going off our immensely extravagant base of insect knowledge (#sarcasm, #non-entomology majors), our observations lead us to believe that she was pregnant, not relieving herself as we had originally thought. Once brought into the lab, we noticed she stopped laying eggs, since she was probably getting cold due to the air conditioning. So, we relocated her to the balcony outside in the sun. Once warm, her ovipositor picked up speed, and was dropping eggs like ‘dey were hawt.’ We

Imperial moth eggs.

Imperial moth eggs.

decided to let her lay eggs all night in this plastic container as per suggestions on several other blogs. When we came into the lab the next morning, she had laid over 50 eggs! We have decided we are going to raise them as our own and document our experience. Save the date, cross your fingers, and check back for updates on our “MOTHerhood” duties!

 

 

 

 

 

Mimosa webworm

Mimosa webworms are active in Raleigh. I saw initial webbing just a week or so ago but

Small web in a mimosa tree. Photo: SD Frank

Small web in a mimosa tree. Photo: SD Frank

now they are in full swing. These are annual pests of mimosa trees which many people consider pests in their own right. However, if you are you of the many folks who love mimosa trees sans messy caterpillar webbing then it is time for action. The best way to prevent heavy infestations and extensive webbing is to prune out the nest when they are small. Moths overwinter as pupae attached to tree trunks, buildings, or other sheltered locations. The adults emerge in June or so to lay eggs on mimosa and honey locust trees. Caterpillars feed within the webbing for several weeks before pupating. There are multiple generations per year. Most insecticides available for caterpillar control will also control

Mimosa webworm. Photo: SD Frank

Mimosa webworm. Photo: SD Frank

mimosa webworm but remember that contact is difficult since they live in waterproof webs. In most cases mimosa webworms will not reduce the health or growth of their rapidly growing hosts. They also don’t seem to eat all the seedlings that pop up all over my yard from the tree next door. http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note07/note07.html

When fieldwork fails….

Musings on fieldwork by PhD student Emily Meineke who spends a lot of time in the field with her trees – and by ‘field’ we mean downtown Raleigh. When the equipment doesn’t cooperate she can still enjoy nature. 
Everything takes longer than I think it should– we all suffer from this, yes?– so when field

Bee digging for pollen. Photo: Emily Meineke.

Bee digging for pollen. Photo: Emily Meineke.

Beautifully patterned cricket. Photo: Emily Meineke.

Beautifully patterned cricket. Photo: Emily Meineke.

An unfortunate tussock moth covered in parasitoid pupae. Photo: Emily Meineke.

An unfortunate tussock moth covered in parasitoid pupae. Photo: Emily Meineke.

Tussock moth caterpillar sans parasitoids. Photo: Emily Meineke.

Tussock moth caterpillar sans parasitoids. Photo: Emily Meineke.

work this week dragged on but gave no results, I decided to stare at insects instead. Elsa Youngsteadt, a research associate in the Frank lab, and I set out to measure, as Elsa puts it, how well trees breathe, make food, and turn that food into tree. In other words, we’re measuring photosynthesis.

The measurements require a fancy machine, which is impressive in its fanciness but requires finessing. Elsa knows how to finesse it. I barely know how to look at it right. But we were both newly introduced to it and have spent the last 5 mornings from 7 am trying to make it tell us to what extent city trees are breathing.
Some small thing always goes wrong, and we’ve gotten exactly 0.00 measurements. This is not a complaint. It is a fact, one that we will try to remedy at 7 am again tomorrow (Sunday) morning with patience. But this morning, I had none left, so I took photos of a handful of the the many insects we’ve seen while waiting for the machine to “equilibrate” or “become happy again”. We’ve seen sand wasps stinging prey to take back to their nests, native bees, daddy long legs with red mites on their legs, ants, butterflies, crickets, termites, scale insects, trash bugs, bark lice, furry caterpillars, and the list goes on.
The patience required by this fancy machine and its temper tantrums has reminded me that if you just sit in one spot, a parking lot, a construction site, a back yard, the earth will rise in its many forms, to remind you (me) that things around you breath whether you measure it or not.

Baby bagworms

Bagworms have been hatching for the past week or so.  I found the first hatchlings at a hot

Newly hatched bagworms. Photo: AG Dale, NCSU.

Newly hatched bagworms. Photo: AG Dale, NCSU.

site on the south side of an NCSU building.  First instar bagworms quickly make tiny bags and begin feeding. The bags are held upright and look like little ice-cream cones until later instars when large bags hang below branches. You can scout for bagworms any time of year because the bags ‘hang’ around for a long time. Bagworms are relatively sedentary during their lifetime, most often remaining on the same tree until they pupate. Adult females are wingless and never leave the tree, while male bagworms pupate and develop into a small brown moth. Females lay eggs in the bags each fall that hatch in late spring (now!). So you know if you have bags you have eggs and thus new bagworms.

Bagworm bags that overwintered with eggs inside. Photo: SD Frank

Bagworm bags that overwintered with eggs inside. Photo: SD Frank

Heavy bagworm infestation like the one in this picture can defoliate evergreen foundation plants and privacy hedges making them not-so-private anymore.   One of the most effective, yet time consuming methods of treatment are hand-picking or cutting the female pupae bags off of the branches.  Since this may sometimes be impractical or impossible, there are other methods of treatment to be considered.  There are chemical control options available that should be applied during the early instar stages of the caterpillars since these are easier to kill and have not yet defoliated your plant.  As with many other pest insects, bagworms are susceptible to predation from parasitoids and birds which can also assist in their control.

Defoliation by many hundred bagworms. Photo: SD Frank

Defoliation by many hundred bagworms. Photo: SD Frank

More information in this note:

http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/ort081e/ort081e.htm

 

Two new cankerworm papers

Last week we had two papers published about cankerworms. Cankerworms are caterpillars that defoliate oaks and other tree species.  Cankerworms outbreaks have

Cankerworm larva. Photo: SD Frank

Cankerworm larva. Photo: SD Frank

become increasingly common in urban areas like Charlotte, Durham, and Raleigh. Damage can be extensive.  Many trees on campus were completely defoliated. In Charlotte we have seen entire neighborhoods defoliated. Trees can only tolerate two or three consecutive years of defoliation before their growth declines or they die. More about cankerworms here.

The first paper, published in Arboriculture and Urban Forestry, is “The effect of sticky bands on cankerworm abundance and defoliation in urban trees by Bobby

Bobby and Greg Bryant counting cankerworms on a sticky band. Photo: NCSU Bulletin, http://bulletin.ncsu.edu/2013/01/cankerworm/

Bobby and Greg Bryant counting cankerworms on a sticky band. Photo: NCSU Bulletin, http://bulletin.ncsu.edu/2013/01/cankerworm/

Chanthammavong who has worked in my lab for almost two years.  He conducted this research as an undergraduate during the cankerworm outbreak last year.  He wanted to test the efficacy of sticky bands, a non-insecticide management tactic, to help reduce cankerworm damage to campus trees. Sticky bands exploit an unusual aspect of cankerworm biology: the females moths are wingless. Therefore they have to climb up trees to lay eggs.  Sticky bands are wrapped around trees to capture the moths as they climb. If they never reach the canopy to lay eggs then you shouldn’t have cankerworms or damage come spring.  

Sticky bands worked fairly well and reduced cankerworm abundance in the trees but did

Maple partially defoliated by cankerworms. Photo: SD Frank

Maple partially defoliated by cankerworms. Photo: SD Frank

not reduce overall defoliation. Lots of cities including Charlotte and Durham, NC use sticky bands each year on hundreds or thousands of trees. Since the tiny caterpillars can float from tree to tree (entomologists call it ballooning) banding at a large scale probably works better than banding only a few of the trees in an area. Bobby was supported in part by an NCSU Undergraduate Research Grant. His work appeared in the Bulletin and Technician.

The second paper “Bad neighbors: urban habitats increase cankerworm damage to non-host understory plants” in Urban Ecosystems tests the hypothesis that cankerworm damage to plants is greater in urban settings than in forests.  Cankerworms often drop from host trees and land on understory plants or the ground.  We found that in urban settings where plant communities and habitat were simple (just shrubs and mulch in landscape beds) the shrubs below cankerworm infested trees were

Native dogwood damaged by cankerworms in an urban landscape. Photo: SD Frank

Native dogwood damaged by cankerworms in an urban landscape. Photo: SD Frank

defoliated more than the same species of shrubs in forests where plant communities were more  complex (shrubs, ground cover, leaf litter, etc).  There is a caveat though: cankerworms damage native plant species more than exotic, ornamental species. As cankerworm outbreaks become more frequent and severe in urban areas they will damage more than just their primary hosts but damage may be reduced by diversifying the plants and structure of urban landscapes. This work was funded in part by the Southeast Climate Science Center.

These papers address our goals of understanding the ecology of urban ecosystems, why pest damage is often more severe in urban landscapes, and developing management tools to protect urban trees.