Red headed flea beetle adults active in NC

Adult flea beetle feeding on hydrangea. Photo: SDF

I got reports from Area Specialized Agent Danny Lauderdale that red headed flea beetle adults are active in eastern NC. Danny has been monitoring these pests closely and found active larvae in early March. Now, at just over 500 GDD in eastern NC, nurseries are starting to report adults.

Adult red-headed flea beetles are small, shiny black, beetles with reddish to dark colored heads, and long antennae. If you try to get a closer look and a small black insect, 1/8 of an inch long, and before you can see the red head it is gone, it’s probably a flea beetle. As the name suggests they jump great distances when approached. There are at least two generations in the Mid-Atlantic region and probably more in the South.

Favorite host plants of red-headed flea beetles include roses, forsythia, salvia, joe-pye weed, azaleas, and hydrangeas. Red-headed flea beetles skeletonize leaves usually leaving thicker leaf veins behind.

Red-headed flea beetles seem remarkably tolerant of insecticide residue. In our research, even relatively effective insecticides, such as dinotefuran, acephate, and some pyrethroids, which killed almost 100% of beetles the first day after application killed very few just a week or two later.

Other posts from our site and a great set of resources from Danny including a scouting video and article could help you manage these pests.

April 17th, 2017|Categories: Uncategorized||

Cankerworms finally trickling out

Over the past week or so I have found cankerworms here and there. A few on a maple along the greenway. A couple dangling from a willow oak on campus. Today I found a small cankerworm tromping across some gloomy scales.

Cankerworms on a gloomy scale-infested red maple trunk. Photo: SDF

I past years I have seen cankerworms hatching in mid-March. In 2015 they hatched April 7 but even so they all hatched at once.

After a very early spring snow covered plants that had already started flowering and growing new leaves and shoots. Photo: SDF

I wonder if the snow we had on March 12 this year, around when I thought cankerworms would be hatching, might have killed some. Leaves and flowers on many trees and shrubs had already flushed and were damaged by the snow. Maybe cankerworms were about to hatch and were in a vulnerable state.

Cankerworms feeding on maple leaves. Photo: SDF

Alternatively, it could just be a low cankerworm year. Cankerworms live in New England and Canada so it is hard to believe a little snow would hurt them. I did not monitor adults this year but my friend Derek Johnson at VCU probably did. His lab just published a new threshold relating adult captures to likelihood of defoliation by larvae.

In any case, here they are we will see how the population develops.

April 6th, 2017|Categories: Uncategorized||

As Climate Shifts, So Do Pests: A National Forum and Assessment

With funding from the USDA National Institute of Food and Agriculture, the National Forum on Climate and Pests (NFCP) was convened at the National Academies in Washington DC on October 4–6, 2016. The NFCP brought together 26 scientists from the climate and pest science disciplines in front of a live Internet audience to provide the latest information on how climate change affects many aspects of pest biology and to discuss ways to create more resilient and productive agriculture and forestry ecosystems.

A summary of the discussions has been published in the Bulletin of the Ecological Society of America. You can also watch the presentations on the NFCP website. Each presentation is summarized in a paragraph. This paper is useful for those interested in the meeting and topic or for those looking for collaborators working in areas from climate modeling to pest physiology. I was quite a diverse set of disciplines.

Albert Einstein and attendees of the National Forum on Climate and Pests.

Of course I talked about scale insects, synthesizing work by Adam Dale, Emily Meineke, and Elsa Youngsteadt. Steve Young, Northeastern IPM Center director, put a ton of work into organizing the meeting and preparing this paper.

It is an open access article published in the Bulletin of the Ecological Society of America: http://onlinelibrary.wiley.com/wol1/doi/10.1002/bes2.1315/full

April 3rd, 2017|Categories: Uncategorized||

Monitor pine needle scales for egg hatch and crawlers

Pine needle scales are relatively easy to find and to monitor for crawler activity. Stare at the needles of any urban pine for a minute and you will see white flecks on the needles. These are the scales. You can flip the covers with a pin while looking at them with a hand lens.The females are purple blobs the eggs, if present , will spill out as tiny purple ovals.

Pine needle scale eggs. Photo: SDF

There is discrepancy, or really lack of knowledge, regarding pine needle scale life history. According to Armored Scale Insects of Trees and Shrubs (Miller & Davidson 2005) they have one generation per year in far northern states but 2 generations per year from Pennsylvania south. They over winter as eggs in the North but probably overwinter as eggs and as adult females in many places. There are mixed reports.

Pine needle scales. Photo: SDF

There is even discrepancy about the species itself. Pine needle scale, Chionaspis pinifoliae, is virtually indistinguishable from pine scale, Chionaspis heterophyllae. The difference, if there is one, is not really important for management since they look the same and have similar life history. Wait until crawlers hatch then use horticultural oil or if necessary something stronger like an insect growth regulator. Check the brand new Nursery and Landscape Pest Control Guide.

A paper from Iowa suggests eggs hatch around 150 GDD. We are well past that now (~360)  and am finding adults and eggs right now. Pine needle scale hosts include loblolly pine, scots pine, mugo pine, white pine, and and other conifers including Abies, Picea, Pseudotsuga, and Tsuga.

Every tree has a few so don’t worry about them. Some trees become very infested especially in urban settings where trees may be stressed and natural enemies in low abundance or diversity.

 

March 30th, 2017|Categories: Uncategorized||

Could your neighborhood use more trees? Apply for an NCUFC grant!

Street trees perform essential services like removing pollutants from air. Photo: EK Meineke

The North Carolina Urban Forest Council developed the Legacy Tree Fund to provide financial assistance to provide financial assistance

to communities across North Carolina for tree planting projects that help educate North Carolina citizens about the importance of trees.

Each year, the NCUFC awards grants to community groups, civic associations, block clubs, garden clubs, and other non-profit organizations for urban forestry for tree planting projects.

Apply for a grant OR make a donation. Trees are the answer.

March 24th, 2017|Categories: Uncategorized||

Don’t fret over (a few) dead bees

Dead carpenter bee. Photo: SDF

In spring carpenter bees, Xylocopa virginica, begin emerging from their winter hibernation. Many people are not concerned about dead bees but instead become alarmed when swarms of live carpenter bees are zooming around a wooden park bench or deck. Many young adult bees hibernate in a single burrow and a good structure may have many burrows. Male bees tend to come out first and swarm around waiting for female bees to come out. It can be intimidating but the males are harmless.

Other people worry about dead bees. Especially now since there has been so much

Dead bee below the fence where it spent the winter. Photo: SDF

press about pesticides, climate change, urbanization, and diseases that can threaten bee populations, a dozen or so dead bees on the ground could raise concern. This was the case yesterday when someone sent pictures of dead carpenter bees on their deck to a list serve I am part of. Dave Shetlar (Bugdoc Dave) from Ohio State University sent a quick response that is was natural for some bees to die over winter. The live bees just push them out onto the ground.

On the way home from work yesterday I found my own dead carpenter bee below a burrow in an old wooden fence. So I took some pictures and read up on carpenter bees in a great old review. Spring is here and carpenter bees are emerging from their burrows, dead or alive.

March 23rd, 2017|Categories: Uncategorized||

Get ready for oak felt scales

Oak eriococcin scale eggs spill out after removing the white cover. Photo: SDF

We have written before about felt scales on oak trees. Oak eriococcin scales, Eriococcus quercus, are one of the earliest scale insects to produce eggs, and thus crawlers, in Raleigh. The females become felted and swell in early spring. Now they are full of eggs. When the crawlers hatch from the eggs is when horticultural oil applications would be most effective. Not much is known about other control tactics for this pest. Just be careful. An important scale predator looks very similar to felt scales and mealybugs. Larvae of scale-eating lady beetles in a couple related genera including Hyperaspis spp. are white and waxy. However, they move. Since scales don’t move these lady beetle larvae have to crawl around looking for food. Sometimes thousands of lady beetles hatch at once so please do not confuse them with scales.

March 22nd, 2017|Categories: Uncategorized||

New paper – Drought and heat benefit tree pests

It’s not easy for trees to grow, much less, thrive in cities. Cities are warmer than natural areas where trees evolved. City soil is typically drier than natural soil too. Both of these problems – heat and drought – are caused in large part by impervious surfaces that absorb heat but deflect water.

Gloomy scales on a red maple branch. Photo: AG Dale.

In previous papers, we have shown that the urban heat island effect can increase pest abundance on trees. Oak lecanium scales become more abundant due to greater survival on hot trees. Gloomy scales become more abundant because on warm trees more of them survive and they produce three times as many eggs.

Adam measuring photosynthesis on a tree he has been watering with the green water bag around its trunk. Photo: AG Dale.

In a new paper, Adam Dale (former PhD student now at University of Florida), shows that

Gloomy scale embryos  that Adam counted to assess the effects of heat and drought on fecundity. Photo: AG Dale.

drought, in addition to heat, is also an important mechanism by which gloomy scale abundance increases on urban red maples. This is among the best evidence that heat and drought – two major consequences of urbanization and of climate change – combine to benefit pests and thus must be studied in concert. Read more about it in Adam’s blog post.

 

This article is published in the journal PLoS One. Find the entire article here: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173844

Also, a UF press release can be found here: http://news.ifas.ufl.edu/2017/03/gloom-and-doom-when-these-insects-are-on-hot-dry-red-maple-trees/

March 10th, 2017|Categories: Uncategorized||

Azalea caterpillars feeding now

Young azalea caterpillars feeding on a partially defoliated twig. Notice frass collecting below. Photo: SD Frank

Young azalea caterpillars feeding on a partially defoliated twig. Notice frass collecting below. Photo: SD Frank

Just a short post here to announce the arrival of azalea caterpillars for this year. Azalea caterpillars, Datana major, are among our most attractive caterpillar species. The feed primarily on Rhododendron spp. but I have also found them on blueberries. There is one generation of this pest each year. Adults lay eggs on the underside of azalea leaves where the small caterpillars feed gregariously. As they grow the caterpillars change from yellow with black stripes to black with yellow patches. Usually, these (and other caterpillars0 are noticed by the damage rather than by noticing the actual critters or eggs. Thus, by the time they are noticed azalea caterpillars may have consumed a lot of foliage. Scout for these caterpillars by scanning shrubs for bare twigs then look closer to investigate. You may also see collections of frass on leaves that indicate caterpillars feeding above. If you find a group of them just prune the branch out. In larger infestations or nurseries there are several insecticides active on caterpillars but any product works best on small stages. Find other posts on azalea and related caterpillars here.

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White azalea caterpillar eggs. Photo: SD Frank

September 3rd, 2015|Categories: Uncategorized||

A big caterpillar family or family of big caterpillars? Notodontids are big, beautiful, and flexible

There are many caterpillars in the family Notodontidae that feed on urban trees and shrubs. Several closely related Notodontids are among the most common late season defoliators of urban trees. These include the greenstriped mapleworm, (Dryocampa rubicunda) which feeds primarily on red maples and orangestripped oakworms (Anisota senatoria) that feed primarily on oaks. We have written about these critters on the blog, in Insect Notes, and in a free book so you can get your fill (maybe you already have).

Greenstripped mapleworm larva. Photo: AG Dale

Greenstripped mapleworm larva. Photo: AG Dale

Members of the genus Datana are among the most beautiful caterpillars ever to defoliate your plants. Around here these include azalea caterpillars (Datana major), and yellownecked caterpillars (Datana ministra). These two species are about the same size and have a defensive behavior someone should name a yoga pose after (Datan-asana?). When approached caterpillars arch their front and back ends to form a ‘C’ shape. This must be scary to some predator or they wouldn’t do it (neither would sawfly larvae). Perhaps it looks like a snake about to strike or maybe it is just unusual and visually arresting enough to make predators like birds think twice.

Late instar azalea caterpillar. Photo: SD Frank

Late instar azalea caterpillar. Photo: SD Frank

In host range azalea and yellownecked caterpillars are quite different. Azalea caterpillars feed almost exclusively on azaleas and occasionally on blueberry plants. Yellownecked caterpillars feed on a long list of species including oaks, maples, fruit trees, elm, hickory, beech, linden, and many others. Feeding habits and life histories of both species are similar to orangestripped oakworms. They hatch from clusters of eggs laid on the bottom of leaves in late summer. Young larvae feed gregariously defoliating one branch at a time. Larvae leave the plant to pupate underground until the next summer.

I found large yellownecked caterpillars on a willow oak last weekend. Azalea caterpillars come out later than yellownecked caterpillars or orangestripped oakworms. I have not seen any yet and usually find them around the end of August. Last year I found eggs hatching the first week in September.

 

Late instar yellownecked caterpillar on willow oak. Photo: SD Frank

Late instar yellownecked caterpillar on willow oak. Photo: SD Frank

Start monitoring for azalea caterpillar egg masses now by turning over leaves to look for egg masses. Also scan azalea shrubs and hedges for branch tips with skeletonized or missing leaves. This is the first sign of young caterpillar infestations and can be pruned to prevent more defoliation.

 

August 11th, 2015|Categories: Uncategorized||