–by Sharon Schroll
Q: What do you get if you cross a bee and a bunny?
A: A honey bunny!
Month: April 2021
Wheat Aphids
–by Jeff Whitworth — Field Crops
Wheat aphids, primarily bird cherry oat but with a few greenbugs mixed in, have been migrating into Kansas, especially the southern parts, over the last couple of weeks. Sampling a couple dozen fields throughout the central part of the state, however, over the last week (from I-35 to Hwy 77 west to east and from Hwy 24 north to Hwy 56 on the south) yielded very few aphids but also very few beneficials-which makes sense. However, in one field we did find one aphid — just as the only lady beetle we found in that field also found it and promptly gobbled it up (see fig 3). Most wheat was at least at the jointing stage. If aphid migrations increase significantly in the next couple of weeks, coupled with the lack of beneficials, these aphid populations could explode and thus cause some stress to the developing wheat. Thus, monitoring should continue — but please remember it takes approximately 20+ aphids/tiller throughout the field, with very few beneficials, to actually cause a negative effect on yield. Also, please remember adding an insecticide to an application of a fungicide to kill any insect pests, “just in case” is never a good idea.
Alfalfa Weevils
–by Jeff Whitworth — Field Crops
The only alfalfa weevils observed this week were relatively mature larvae (see fig. 1) and thus most feeding damage should be about finished. All alfalfa fields monitored had been treated, with one exception. This year’s overall alfalfa weevil infestations seemed considerably reduced compared to most of the past years. This, coupled with good growing conditions, allowed plants to keep up with alfalfa weevil feeding resulting in less defoliation then usual as seen in fig. 2 (The plant on the left was typical of an untreated field which was adjacent to a treated field from which the plant on the right was removed from).
Figure 1 Alfalfa weevil larvae (picture by Cody Wyckoff)
Figure 2 Alfalfa defoliation Left: untreated field Right treated field (Cody Wyckoff)
Insecticide Ear Tag use in Cattle
–by Cassandra Olds — Livestock and Veterinary
Insecticide impregnated ear tags can be a valuable tool for the control for flies and selected tick species in cattle. In this video we discuss how insecticide impregnated ear tags work and some tips to make them as successful as possible in your pest management program.
March Flies causing concern in Southwest Kansas
–by Anthony Zukoff–Southwest Research & Extension Center
March Flies (Bibio sp.) have begun emerging in large numbers in some areas of southwest Kansas. The synchronous nature of adult emergence in spring draws attention and concern as thousands of adults can show up almost overnight on structures and in cropland. These congregations of small (~6 mm), large-eyed flies are mating swarms and generally will be short lived as adults survive only a few days to a week. Another name for these flies is “Lovebug” since males and females will attach themselves at the end of their abdomens and remain like that at all times even while flying. After mating, females will excavate a small chamber in the soil, lay eggs and then die in the same chamber. Just as the adults congregate, so do the larvae. Dense pockets of hundreds of larvae can sometimes be unearthed. These larvae generally are detritivores, feeding on dead vegetation and other organic matter in the upper portion of the soil. However, some species are known to feed on living plant roots and are considered pests of various cereal, forage and vegetable crops. In 1891, entomologist Vernon L. Kellogg wrote of a new Bibionid fly emerging in large numbers in many wheat fields of seven western Kansas counties during the last week of April.
The large swarms of flies concerned farmers, but no evidence of damage by the flies was ever detected despite a large number of larvae being found in the soil weeks previous to adult emergence. Kellogg stated that the adults disappeared “suddenly and simultaneously”. Despite a large number of flies being detected in wheat and alfalfa this year, no unusual damage to these crops has been noted and the mating swarms should vanish in the coming week.
Bug Joke of the Week
–by Sharon Schroll
Q: What’s green and jumps a mile per minute?
A: A grasshopper with the hiccups!
Dr. Cassandra Olds – Dept of Entomology Extension Personnel
–by Dr. Cassandra Olds
Dr. Cassandra Olds has extension responsibilities in vector-pathogen-host interactions, specifically how these can be managed to reduce the negative impact of arthropod pests and their associated pathogens on animal health and wellbeing. Successful transmission of vector-borne pathogens is dependent on complex interactions between vector, pathogen and host. We research various aspects of tick vector competence to better understand endemic stability and immune responses of cattle to vector-borne pathogens. In addition, we also conduct studies investigating the role of filth flies in the spread of anti-microbial resistance.
Stable flies emerging as spring temperatures rise
–Dr. Cassandra Olds
Stable flies (Stomoxys calcitrans) are starting to emerge with the start of spring; you might even have seen a few around already! Stable flies are distinguishable by four black stripes on the thorax, black checkered spots on the abdomen and large, protruding mouthpart (Figure 1).
These flies are a common pest feeding primarily on cattle and horses but can also target other livestock species, pets (especially dogs) and humans. Both male and female adult flies are obligate blood feeders and their painful bite and feeding causes significant annoyance and blood loss. Stable flies can negatively affect cattle average daily weight gain, milk production and feeding efficiency. Each fly feeds once or twice a day for between two and five minutes each time. Stable flies are routinely found on the legs or underside of large animals such as horses and cattle, on dogs and small ruminants however, they are generally found around the head area. When not feeding, adult flies can be found resting on building surfaces or vegetation.
Sustainable stable fly control is best achieved through an integrated approach. In her lifetime, a single adult female can lay between 500 and 1000 eggs. Limiting resources available for egg laying and larvae development, especially in the spring and summer months is essential. Stable fly larvae develop in decaying plant matter, particularly those contaminated with animal waste. Hay bales are a great breeding site for stable flies (Figure 2),
elevating hay and straw off the ground when feeding animals prevents manure and urine contamination. Periodically clear feed storage and animal feeding areas of spilled hay, straw and feed. Large bales for herd feeding are especially able to promote fly populations, be sure to inspect and clean these areas regularly. Separate animal watering from feeding areas and protect stored feeds from weather and water runoff. For areas where straw bedding is used, frequently replace the bedding, spreading decomposing waste in thin layers, which allows waste to dry faster and be less attractive to female stable flies. Composting manure increases heat and dries out material making the environment inhospitable for developing fly larvae. If you have to store manure waste in piles, attempt to keep as little fibrous plant material/feed as possible in the pile. Insect growth regulators fed to animals as feed-throughs inhibit stable fly development during the pupal stage reducing adult fly numbers and are a great addition to an integrated pest management program. Adult stable flies can be controlled through insecticide application with both pyrethroid and organophosphate products being effective although resistance to both is increasing. For more information on specific products to use, search the VetPestX website for specific product information (https://www.veterinaryentomology.org/vetpestx).
Alfalfa Pests (pea aphids, alfalfa weevil pupa)
–by Dr. Jeff Whitworth
Alfalfa weevils have been actively feeding and developing quite rapidly throughout south central and north central Kansas during the last 7-10 days. However, infestation levels have not increased very much. The most significantly infested fields monitored during this period reached the 55% level, i.e. just over 1 larva/2 stems. Most fields were between 25-35% infested, with about 75% of the larvae at least in the late 1st- 3rd instar stage. Some fields have been sprayed and it seemed to provide good knockdown (see fig. 1 of dead larvae). All fields not treated had prepupae and pupae (see fig. 2). Alfalfa weevil larval sampling/monitoring should continue for at least another 10-14 days.
Pea aphid populations have decreased significantly in the last 7-10 days in the untreated fields.
Figure 1: Dead Larvae (photo by Cody Wyckoff)
Figure 2: Alfalfa Weevil Pupa (Photo by Cody Wyckoff)
Bug Joke of the Week
–Dr. Raymond Cloyd
Q: When do spiders go on their honeymoon?
A: After their webbing day!