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Extension Entomology

Category: Lawn and Garden

CARPENTER BEES

–Dr. Jeff Whitworth

A couple folks viewed last weeks carpenter bee photos and thought they were bumble bees. This is a great example then to point out just how important it is to take the best possible photos before sending them in to be ID’d. Please take several closeups from several angles and please place some object beside the specimen, i.e., a penny, pencil, ruler, etc, will work, so we can get an idea of size.  Also very important, where the specimen was found and what was it found on, and how many were at that location and what were they doing-feeding/crawling on the ground, etc. The specimens last week were collected from insulation in an old garage and seemed to have smooth abdomens. See figure 3 for side by side comparison between a carpenter bee vs bumble bee.

Figure 3 carpenter bee (on the left) vs bumble bee (on the right)

Also, for those interested in trapping carpenter bees-please see Dr Phil Sloderbeck’s carpenter bee trap (fig 4). Dr Sloderbeck retired ca.6 years ago as a KSU Extension Entomologist and Southwest Kansas Area Administrator. But, (fig 5)as you can plainly see–Dr Phil is still an entomologist at heart! Happy retirement, Dr Phil, and thank you for the pictures!

Figure 4  bee trap (P. Sloderbeck)

Figure 5  captured 17 carpenter bees (P. Sloderbeck)

 

Wheel Bug

–by Dr. Raymond Cloyd

If you have spent any time outdoors walking around, you may have noticed a very distinct, grotesque looking insect on trees, shrubs, or near homes. The insect is the wheel bug (Arilus cristatus), which is common, and widely distributed throughout Kansas. Wheel bugs, also called assassin bugs, are predators that feed on many insect pests. However, the nymphs and adult can inflict a painful bite if handled by human.

Fig 1. Wheel Bug Adults Mating. Male Is On Top Of Female (Auth–Raymond Cloyd, KSU)

Adult wheel bugs are 1 to 1-1/4 inches long, robust with long legs and antennae, and have a stout beak and large eyes on a narrow head (Figure 1). They are dark-brown to gray and possess a wheel or crest with 8 to 12 protruding teeth-like structures (tubercles) on the thorax that resembles a cogwheel; similar to the dinosaur—Stegosaurus (Figure 2). Wheel bugs have two long, slender antennae that are constantly moving or weaving around. Females are typically larger than males. Females lay eggs that resemble miniature brown bottles with white stoppers (Figure 3). Eggs are laid in clusters of 40 to 200. The eggs are glued together and covered with a gummy cement, which protects eggs from weather extremes and natural enemies (e.g. parasitoids and predators). Egg clusters are located on leaves, or the trunk or branches of trees or shrubs. Nymphs hatch (eclose) from eggs and are bright red with black markings (Figure 4). The nymphs do not have the wheel or crest. The life cycle, from egg to adult, takes three to four months to complete. Wheel bugs are active day and night, and are very shy, tending to hide on leaf undersides. The wheel bug overwinters as eggs with one generation per year in Kansas.

Wheel bugs are voracious predators feeding on a wide-variety of insects, including caterpillars (Figure 5), beetles, true bugs, sawflies, and aphids.

Fig 2. Wheel Bug Adult (Auth–Raymond Cloyd, KSU

 

Fig 3. Wheel Bug Eggs On Leaf Underside (Auth–Raymond Cloyd, KSU)

Fig 4. Wheel Bug Nymph (Author–BugGuid.Net)

 

Fig 5. Wheel Bug Adult Preparing To Attack A Caterpillar (Auth–Raymond Cloyd, KSU)

 

Unfortunately, wheel bugs will feed on beneficial insects such as ladybird beetles and honey bees. The mouthparts are red-brown and resemble a tube or straw that is located underneath the head. The mouthpart extends out when wheel bugs are ready to “stab” prey. Wheel bugs paralyze prey with their saliva that contains a toxic substance, which immobilizes prey within 30 seconds. In addition to feeding on insects, wheel bugs are cannibalistic, and will feed on each other if they cannot locate a food source (prey). What is there not to like about “bugs?” J.

 

Euonymus Scale

–by Dr. Raymond Cloyd

Now is the time year when euonymus scale, Unaspis euonymi, is noticeable on evergreen euonymus, Euonymus japonica, and Japanese pachysandra, Pachysandra terminalis), plants in landscapes. Euonymus scale overwinters as a mated female on plant stems. Eggs develop and mature underneath the scale, and then nymphs (crawlers) hatch from eggs over a two to three-week period. The nymphs migrate along the stem and start feeding near the base of host plants. Nymphs can also infest adjacent plants by being blown around on air currents, which results in infestations not being detected until populations are extensive and damage is noticeable. Leaves eventually become spotted yellow or white (Figure 1). Plants located near structures such as foundations, walls or in parking areas are more susceptible to euonymus scale than plants growing in open areas that receive sunlight and are exposed to air movement.

Fig 1. Euonymus Scale Infestation On Euonymus Plants Located Near Building (Auth-Raymond Cloyd, KSU)

Extensive infestations of euonymus scale can ruin the aesthetic appearance of plants, causing complete defoliation or even plant death. Females are dark brown, flattened, and resemble an oyster shell. Males, however, are elongated, ridged, and white (Figures 2 and 3). Males tend to be located on leaves along leaf veins whereas females reside on the stems. There can be up to three generations per year in Kansas.

Fig 2. Male And Female Euonymus Scale On Leaf (Auth–Raymond Cloyd, KSU)

Fig 3. Close-Up Of Euonymus Scale Female (Brown) And Male (White) (Auth–Raymond Cloyd, KSU)

Cultural practices such as pruning out heavily infested branches, without ruining the aesthetic quality of the plant are effective in quickly reducing euonymus scale populations, especially this time of year. Be sure to discard all pruned branches away from the area.

Insecticide applications should have been applied in May through early-June (now is really too late!) when the nymphs are most active, which will help alleviate problems with euonymus scale later in the season. Insecticide active ingredients recommended for suppression of euonymus scale populations, primarily targeting the nymphs, include acephate; pyrethroid-based insecticides such as bifenthrin, cyfluthrin, permethrin, and lambda-cyhalothrin; potassium salts of fatty acids; and petroleum, mineral, or neem-based (clarified hydrophobic extract of neem oil) horticultural oils. Always check plants regularly for the presence of nymphs, which will help time insecticide applications.

Three to four applications performed at seven to 10-day intervals may be required; however, this depends on the level of the infestation. Euonymus scale is a hard or armored scale, so, in most cases, soil or drench applications of systemic insecticides such as imidacloprid are not effective in suppressing euonymus scale populations. However, the systemic insecticide dinotefuran, due to its high-water solubility (39,000 ppm), may provide suppression of euonymus scale populations when applied as a drench to the soil.        Euonymus scale is susceptible to many different natural enemies (e.g. parasitoids and predators), including: braconid and ichneumonid wasps, ladybird beetles, green lacewings, and minute pirate bugs. However, natural enemies may fail to provide enough regulation to substantially impact extensive populations of euonymus scale. Furthermore, insecticides such as acephate; and many of the pyrethroid-based insecticides, including bifenthrin, cyfluthrin, permethrin, and lambda-cyhalothrin are very harmful to most natural enemies, so applications of these materials may disrupt any natural regulation or suppression.

 

For more information on how to manage euonymus scale and other scale insect pests

refer to the following extension publication:

Scale Insect Pests (MF3457 July 2019)

https://www.bookstore.ksre.ksu.edu/pubs/MF3457.pdf

 

ID to last week’s bug

–by Frannie Miller

 

Squash bug – Squash bugs use their piercing-sucking mouthparts to suck the sap out of plants leaves. This feeding can lead to the plants to wilt. These pests prefer to feed on zucchini, winter squash, and pumpkins, but will also attack members of the cucurbit family, such as cucumbers, cantaloupe and watermelon. It is important to detect the presence of these pests early, in order to try to control their population.

CARPENTER BEES

–by Dr. Jeff Whitworth

 

Carpenter bees (sometimes called mason bees) have been very active in northcentral /northeast Kansas over the last couple of weeks. These bees are not usually noticed for 51 weeks each year. But, then in late May to early July (depending upon the weather) , the adults (fig. 1) start emerging from holes in soft ,older wooden structures such as old barns, fences, decks, railings, eaves, etc., any wood that has been neglected, are the usual sites of carpenter bee nests.

Figure 1 Adult Carpenter Bees (pictures by Glenn Phelps)

 

The males most often emerge 1st and hover around the area waiting for females to emerge. These males have “bald” faces (female faces are all black) and it is these males that usually get people’s attention because they are very territorial and willing “dive bomb” any intruders into “their” area, including people and pets. However, these males are harmless as only the females can sting. Carpenter bees do NOT eat wood, the female’s just tunnel into it to hollow out cells for their young, which are grub-like (fig. 2).

Figure 2 Carpenter Bee Adults and Larvae (Glenn Phelps)

These larvae develop inside these little cells (fig. 3)–created and provisioned with food by the females in the summer/ early fall. These grubs develop throughout the rest of the fall/winter and spring until they pupate and then emerge as adults the following May-July to start the cycle all over again.

 

Figure 3 Cells created in the wood (Glenn Phelps)

Celebrate National Pollinator Week

–by Frannie Miller

 

Did you know that June 22 – 28, 2020 is National Pollinator Week. Fun fact is beetles pollinated the first flowers more than 140 million years ago. It is estimated that more than 200,000 animal species serve as pollinators. Insects pollinate our crops and help provide one in every three bites of food. Without them we wouldn’t have chocolate or many other vegetables, fruit such as strawberries, apples or grapes, seeds, and nuts.

What can you do to help make sure the pollinators are around to do their job? Examples may include:

*Create a backyard pollinator garden

*Volunteer to help create a pollinator garden at a local school

*Reduce or eliminate the use of pesticides

*Don’t spray directly on flowers

*Plant pollinator friendly plants such as natives or milkweeds

*Support local bees and beekeepers

*Give bees a nesting place

*Provide a water source for pollinators.

ID to last week’s bug

–by Frannie Miller

 

Golden dung fly – The golden dung fly is one of the most abundant and familiar flies. These flies can be found on the feces of large mammals, such as cattle, horses, sheep, deer, and feral hogs. They are extremely important in the natural decomposition of feces. These insects have a short life-cycle and are susceptible to experimental variables making them important to science.

Woolly Aphids on Maple Trees

–Dr. Raymond Cloyd

We have received numerous inquiries regarding insects feeding on maple trees including sugar (Acer saccharum), Norway (Acer platanoides), and silver (Acer saccharinum). These insects are woolly aphids. Woolly aphids are a group of aphids that feed on different types of trees, such as; maple (Acer spp.), elm (Ulmus spp.), alder (Alnus spp.), and apple (Malus spp.). Woolly aphids cover themselves with white waxy threads or filaments (Figure 1), which provides protection from natural enemies (parasitoids and predators).

Fig 1. Woolly aphids feeding on maple tree. Note the white waxy threads or filaments (Auth–Jesse Gilmore, Wildcat District)

Woolly aphids are typically found in large numbers feeding on the branches of trees (Figures 2 and 3). In addition, some species of woolly aphids develop initially on roots (e.g. woolly apple aphid, Eriosoma lanigerum) and then later on migrate upward from the soil to feed on plant stems and branches. Woolly aphids feed on plant fluids within the phloem sieve tubes. They withdraw large quantities of plant fluids resulting in the production of honeydew, a clear sticky liquid that serves as a substrate for black sooty mold.

Fig 2. Woolly aphids feeding on maple tree (Auth–Jesse Gilmore, Wildcat District)

Fig 3. Woolly aphids feeding on maple tree branch (Auth–Raymond Cloyd, KSU)

Young woolly aphids are all females (stem mothers) and can reproduce asexually (without mating). Winged and non-winged forms may be present simultaneously. The cornicles or tubes that protrude from the end of the abdomen may be substantially reduced compared to other aphid species (Figure 4).

Woolly aphids feed on mature maple trees and are not likely to cause significant plant damage. However, one of the easiest and quickest ways to remove woolly aphids from maple trees is to dislodge them using a forceful water spray. If done whenever woolly aphids are present, a forceful water spray will prevent populations from building-up. Although there are predators that will feed on woolly aphids including green lacewings, ladybird beetles, and syrphid fly larvae, in most cases, the predators do not provide sufficient regulation of woolly aphid populations.

Fig 4. Close up of woolly aphids feeding on maple branch. Note the reduced cornicles on the end of the abdomen (Auth–Raymond Cloyd, KSU)

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