–by Dr. Raymond Cloyd
This year, throughout Kansas, we have seen an abundance and wonderful display of painted lady (Vanessa cardui) butterflies. The painted lady butterfly is one of the most common and widely distributed butterflies worldwide. Adults are distinct [and very different looking than the monarch butterfly (Danaus plexippus)] having wings that are mottled brown-yellow, white, brown, and black. There is a row of “small” eyespots on the underside of the hindwings (Figure 1).
Figure 1. Painted Lady Butterfly Adult (Author–Raymond A. Cloyd)
In addition, there is a white crescent on the front edge of the forewing (Figure 2).
Figure 2. Painted Lady Butterfly Adult (Author–Raymond A. Cloyd)
Painted lady adults feed on the nectar of many different plants in flower including sage (Salvia spp.), stonecrop (Sedum spp.) (Figures 3 and 4), butterfly bush (Buddleia spp.), and coneflower (Echinacea spp.).
Figure 3. Painted Lady Butterfly Adults Feeding On Stonecrop (Sedum spp.) Flowers (Author–Raymond A. Cloyd)
Figure 4. Painted Lady Butterfly Adults Feeding On Flowers Of Stonecrop (Sedum spp.) (Author–Raymond A. Cloyd).
The larvae are spiny and feed on the leaves of various plants including sunflower (Helianthus spp.), hollyhock (Alcea rosea), burdock (Arctium spp.), and thistle (Cirsium or Carduus spp.). The painted lady overwinters as an adult; however, most die during the winter (if we have a so-called winter). The painted lady adults migrate northward from the southwest from March through November with two flight periods. In fact, painted lady adults can fly >600 miles. It is possible that the front associated with Hurricane Harvey this year may have “pushed” more adults northward into Kansas. However, this is not the first time Kansas has experienced a plethora of painted lady butterflies. For instance, a migration flight in 1983 was so extensive that butterflies hitting windshields were a hazard to motorists. In addition, a single northward migration contained approximately 3 billion painted lady butterflies. So, just enjoy a wonder of nature…lots of painted lady butterflies.
–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Chinch bugs are numerous and very active throughout north central Kansas, and have been for at least the last month. The overwintering adults deposited eggs in wheat and oats, as far as our agricultural crops are concerned, and apparently the overwintering survival was relatively high because there have been huge numbers of chinch bugs migrating from these two crops. Fortunately, most of the corn and sorghum have developed enough to be able to withstand relatively large numbers of chinch bugs as they suck plant nutrients. Chinch bug populations sampled this past week consisted of 90% nymphs (both the very small reddish orange and larger gray nymphs, both of which have a transverse white stripe).
These nymphs, for the most part, are around the base of the plants feeding behind the leaf sheaths. These bugs will feed and develop for approximately another couple of weeks, then mature into adults. Mating and oviposition then will start another generation of chinch bugs that will continue to feed in corn and/or sorghum fields. With good growing conditions, most of this feeding will go unnoticed and have little effect on yield. However, if growing conditions deteriorate but bugs continue feeding, they can cause stalk lodging, which makes harvesting much more difficult. Spraying for chinch bugs at this stage of crop development is usually not effective as most bugs are relatively inaccessible to insecticides at ground level behind leaf sheaths.
–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Termite and ant colonies have been very active over the past week or so and are producing reproductives or ‘swarmers’. We have seen flying/fluttering individuals every place we have stopped throughout north central Kansas, as long as it was between about 10am and 4pm. Thus, we have received many calls regarding the differences between reproductive ants versus reproductive termites, in both cases often just referred to as ‘swarmers’. This swarming behavior seems to be initiated about the same time each year for both ants and termites as the same type of warm, wet weather evidently triggers both. Thus, it is imperative to be able to distinguish the two as they do very different kinds of damage and consequently require different management plans.
Termite reproductives, or swarmers, are dark brown to black, with transparent or translucent wings of equal size, and the dark body is cigar shaped, having no noticeable body divisions or waist. Termite antennae are straight and lack a club on the end. Ant reproductives, or swarmers, are also dark brown to black with transparent or translucent wings, but the fore or front wings are a little longer than the bottom or back wings. Ant antennae are elbowed, coming out perpendicular to the head then bending forward at a 90 degree angle.
For more information on ant identification, biology, and control, please visit: https://www.bookstore.ksre.ksu.edu/pubs/MF2887.pdf
For more information on termite identification, biology, and control, please visit: http://www.bookstore.ksre.ksu.edu/pubs/mf722.pdf
— by Dr. Raymond Cloyd
The fall webworm (Hyphantria cunea) is prevalent throughout Kansas with webs noticeable on certain trees and shrubs, which is the start of the second generation. Fall webworm nests are typically quite evident in August and September, with silk webbing enclosing the ends of branches and associated foliage or leaves (Figures 1 and 2).
Fig 1: Fall webworm nest on birch tree by Raymond Cloyd.
Fall webworm larvae (=caterpillars) are pale-green to yellow to nearly whitish in color with black spots (two per each abdominal segment).
Fig 2: Fall webworm nest and accompanying feeding damage (Raymond Cloyd)
The caterpillars are covered with long, white hairs (Figure 3). They feed on a wide range of trees, including: birch, crabapple, maples, hickory, pecan, and walnut. Fall webworm caterpillars, unlike eastern tent caterpillars, remain within the enclosed webbing and do not venture out to feed. Caterpillars consume leaves, resulting in naked branches with dirty webbing attached that contains fecal deposits (“caterpillar poop”). Although feeding by fall webworm caterpillars may ruin the aesthetic appeal of infested trees; the subsequent damage is usually not directly harmful to tree health because trees are primarily allocating resources for storage instead of producing new vegetative growth. The most effective means of dealing with fall webworm infestations is to simply prune-out the webs that enclose the caterpillars. Insecticide sprays may not be effective because the caterpillars remain in the webbing while feeding; thus reducing exposure to spray residues. If insecticides are too be used then be sure to use high-volume spray applications that penetrate the protective webbing or use a rake to disrupt or open-up the webbing so that the insecticide spray contacts the caterpillars.
I need to acknowledge Jeff Otto of Wichita, KS for bringing to my attention that fall webworm was active.
Fig 3. Close-up of fall webworm caterpillar (Raymond Cloyd)