Fall Armyworms in Yard

Howdy,

  Lately our office has been getting calls about lawn pests. A common pest in row crops, forages, pastures and lawns are armyworms. This insect lays eggs in clusters of about 50 eggs. Once the larvae hatch, they molt 5 times before pupating to the adult moth. The entire life cycle only takes about 28 days during warmer temperatures. The larvae cause damage to a variety of plants, and are commonly seen in lawns this time of year. Caterpillars tend to feed either in the late evening or early morning, so it's unlikely that you'll see the insect causing the damage. They feed on the foliage of the plants, chewing the green layer off the leaves. This leaves a "window pane" on the leaves. The first three stages the larvae goes through cause only minor damage, while the fourth and fifth stages cause much more damage, consuming up to 85% of their total foliage diet in these stages. A wide variety of predators consume armyworms. One of my most recent questions was on parasitoid wasps laying eggs in the armyworm egg masses. Ground beetles, other wasps, flies, and birds feed on them as well.

Fall Armyworm Egg Mass
Photo: Kate Harrell

Fall Armyworm Larva
Photo: Kate Harrell

   The photo above shows the four square spots on the back end of an armyworm larva. This is a good character to look at when trying to identify the insect.

Fall Armyworm Larva
Photo: Kate Harrell

  Armyworms can come in a variety of colors, even within one species, but look for the light colored "inverted Y" on the dark head capsule, as shown in the photo above.

  If the number of larvae becomes high and the damage in a yard is excessive, treatment may be necessary. Two insecticides, halofenozide (on small caterpillars), and spinosad are specific insecticides that are easier on beneficial populations. Bifenthrin, carbaryl, esfenvalerate, and permethrin are also commonly used to control armyworms.

  Feel free to email me or call our office if you have any questions or concerns.

Sincerely,

Kate Harrell

Cotton Update and Tropical Sod Webworm

Howdy,

  This last week has been rainier than most of us would've liked, but we're still getting the cotton out. Everything is still ginning okay. The seed quality is not great and the seed prices have gone down. We're still stressing that the cotton needs to be dry before picking, the seed quality is worse in modules that were wet. Not only is it hard on the seed, but the lint gets stained too. This year the lint has not been as bright white as it usually is. Below, you can see what some of the finished cotton is looking like when it gets packed into a bale and shipped off.

From left to right: cotton pulled from module, run through first set of cleaners, cleaned and ginned
Photo: Kate Harrell

Adult tropical sod webworm
Photo: James Kerrigan, University of Florida

  Tropical sod webworms are out and about right now. The caterpillars of these moths are a pest of turf. Feeding damage causes the grass to look ragged, and the spots will spread and get larger. To test an area for the caterpillars, sprinkle the grass with a solution of water and liquid dish detergent. The caterpillars will surface if they are present. I've seen the moths stirring while walking through grass.
  Give us a call or stop by the office if you have any questions. Keep picking and stay dry, everyone!

Sincerely,

Kate Harrell

From left to right: tropical sod webworm larval instars, pre-pupae and pupa
Photo: James Kerrigan, University of Florida

St. Augustinegrass residential lawn damaged by tropical sod webworm
Photo: Steven Arthurs, University of Florida

Cotton Update and Lovebugs

  This week has been a little drier than the past month, and cotton pickers are running. Cotton quality has been holding close to the same for most places, but has dropped a little in places that got the most rain in the area. The seed quality has been holding so far as well. I know this is a short update, but the gins have only been able to run a very short period of time compared to where they would like to be this time of year. Folks are running full time now though, and that is a good sign.
  This week's commonly questioned bug is the lovebug. The lovebug is actually a fly, and they usually appear in large numbers. The name comes from the tendency to find a pair of them rather than the single insect. The adults only live for 3-5 days, but the emergence lasts around 3-5 weeks. They are common during May and September in this area. The larvae are important decomposers, and the adults are pollinators. They do not bite, and aside from appearing in hordes, are not considered a pest species. The most efficient method for collecting these insects is with the front end of a  pickup moving at least 40 mph.

(Mostly) Lovebugs
Photo: Kate Harrell

Lovebugs
Photo: Aggie Horticulture

  Feel free to give us a call or stop by the office if you have any questions.

Sincerely,

Kate Harrell

Cotton Update and White-Tipped Black Moth

Howdy,

  This week several of you have been able to get into the fields. I know we've had spotty rainstorms all up and down our area, and some places still have not dried out (I'm looking at you, Danevang). The weather forecast for this weekend is not looking great for us either, but I'm hoping it won't rain on us. The gins are running, and the cotton they've gotten in has been going through so far. The big thing we need to watch for is making sure the lint and the seed are dry before picking (lint at 8% and seed below 12%). The wet seed sitting in a module could cause us issues down the road, as wet lint and seed can continue to degrade while sitting in a module. Cotton Incorporated developed an article on picker harvest recommendations that includes a section on timing a moisture considerations here. The southeastern U.S. dealt with a similar situation last year, take a look at those articles: Cotton Quality Affected by Late Rainfall and Seed Sprouting Observed. I know it looks bad in some places, but we really won't know for sure what everything will look like until we get it out and to the gins. Very little of the rained on cotton has been ginned and classed, so we have very little information on that for this year. To my knowledge, the seed quality and lint quality has been pretty good so far, given the situation.
  If you are looking at defoliating, or defoliating regrowth (again), recent harvest aid trials show bot Folex (6-8 oz/acre) and Ginstar (3-4 oz/acre) in combination with 1.6- 2.4 oz/acre Dropp have provided good control of young vegetative regrowth, but are less effective on mature leaves. The PPO products will work well on small regrowth and provide some drying down. Paraquat is the lest effective option for removing small regrowth, but is still an effective option for desiccating cotton prior to harvest.
  Gaylon Morgan's Row Crops Newsletter covers some of the information here as well as others, check it out here.

White-tipped black
Photo: Kate Harrell

  I've gotten several questions about the white-tipped black lately. This moth is out in abundance currently. The larvae feed on several plants, including Joseph's coat, snow bush, white sapote, snow on the mountain, Tahitian gooseberry tree, and foliage flower. The caterpillars are a colorful black and yellow inchworm with a distinct orange head, and the adults are a black moth with an orange head and thorax, and distinct white tipped wings. They are active during the day, and are often abundant in this area.

  As always, let me know if you have questions, and don't hesitate to stop by the office or give us a call. Have a good weekend, and I hope the cotton dries out.

Sincerely,

Kate Harrell

White-tipped black
Photo: Kate Harrell

White-tipped black caterpillar
Photo: Karen Anthonisen Finch
bugguide.net

Defoliation Trial