Laura Ingwell

Entomology
Area(s) of Interest: Vegetable Pest Management, Protected Agriculture, Controlled Environment Agriculture, Urban Agriculture
I work on insect pest management and pollination in horticultural crop production. I specialize in high tunnel production systems, examining biological control and conventional pest management strategies and the impacts of agricultural inputs on crop pollinators with an emphasis on managed bumble bees. I am interested in evaluating organic and conventional pest management with an emphasis on sustainable practices for food production.

32 articles by this author

Article List

As the days grow shorter and those of you who adventure into winter production begin to prepare your seed starts, keep an eye out for unwanted invaders. Pests such as thrips, mites and aphids may be on the move as our field production dwindles, and nothing is tastier than a tiny new plant! In order to increase the success of winter production, be sure that you are starting with clean plants before you tuck them away under those cozy row covers! Controlling weeds, which can serve as alternative hosts to the aphid pests, will lessen problems of re-infestation. Scout with diligence for aphids, they can be one of the most damaging and hard to control pests during the winter months in high tunnels. The first step to managing aphids is to develop a scouting plan. Aphids reproduce clonally and develop quickly leading to very large population build-up in a short[Read More…]


The sweet corn variety plots at Pinney Purdue provide a good chance to observe sweet corn insects. In late July I observed two caterpillars that surprised me. The first was European Corn Borer (ECB), in the tassel where they are often found (Figures 1 & 2). It was a surprise because I have seen many fewer of these in the sweet corn plots in recent years. I understand from the entomologists that it is due to the widespread use of Bt field corn that has resulted in much lower populations of ECB. The week of Aug. 19 I observed an ECB egg mass on a flag leaf and a young larva on the ear (Figures 3 & 4). The second late July observation was a corn earworm (CEW)–the insect itself is not surprising, but it was in the tassel! (Figures 5-8). I have previously only seen them in ears. The[Read More…]


Recently we have received reports of swarms of hover flies (aka syrphid flies) around Indiana and wanted to take the opportunity to tell you a bit about this curious insect (Figure 1). Adult hover flies can sometimes be mistaken for bees or wasps, because they look a lot like them! Some people refer to hover flies as “sweat flies” or “sweat bees,” but these insects are actually quite different from bees. Hover flies belong to the Order Diptera, or the true flies. The most abundant group at this time of year belong to the genus Toxomerus, which feed on pollen (Figure 2) rather than other soft-bodied insects, like aphids. Hover flies are typically lighter in color, have a characteristic abdomen-bobbing behavior, and cannot sting at all – in fact, they are harmless. Sweat bees, on the other hand, are typically dark or metallic in color, smaller than common bees and[Read More…]


Winter squash – butternut, acorn, and kabocha – in our downy mildew sentinel plot at Pinney Purdue were showing some wilted and stunted plants by late July (Figure 1). They are easily pulled up, the stem breaking off at ground level, revealing a brown stringy decayed-looking stem base (Figure 2). Sometimes there is a little whitish or maybe pinkish mold on the stem. I cut open a kabocha squash to look for squash vine borer larva and found sap beetles that seemed to be feeding inside the stem, but no vine borer (Figure 3). The sap beetles were clearly taking advantage of an opportunity, but not the cause of the wilt. Perhaps a borer had already come and gone. I used scotch tape to pick up some of the mold and put it on a slide to look at under the microscope. At 100X and 400X I saw among the[Read More…]


whiteflies on cucumber leaf.

Here in Indiana, whitefly problems are rare, but when encountered it is most often in protected ag production (greenhouse or high tunnel) and less often in the field. However, this is the time of year that you may be seeing them in either environment. Whiteflies are not true flies, but rather Hemipteran insects, more closely related to aphids and plant hoppers. They are sap sucking insects that feed on the phloem of the plant, making them efficient vectors of plant pathogens. Whiteflies produce honeydew secretions which can attract other insects or host the growth of sooty mold on infested leaves. There are two main species of whiteflies that may be encountered in Indiana: the greenhouse whitefly (Trialeurodes vaporariorum) and the sweetpotato whitefly (Bemisia tabaci; Figure 1). They can be distinguished by the way in which they hold their wings when at rest on the plant: sweetpotato whiteflies hold their wings[Read More…]


The 2020 Indiana SFC is coming March 5-7, 2020, in Danville, Indiana. We are now accepting proposals for oral presentations, workshops, tours and posters. The deadline to submit is Friday, August 30, 2019. Attendees are interested in practical knowledge that can be applied to their operations to increase the environmental sustainability and economic viability of their businesses. This is the premier conference in Indiana where small farmers of all kinds have opportunities to network with fellow Indiana farmers and learn about advancements relevant to their operations, this is what makes the Indiana SFC special. We hope you’ll consider submitting a proposal to present next year and share your knowledge, passion, and innovation with others! This is an open call to farmers, educators, researchers, and other agricultural professionals or stakeholders in the small-farm space. Vegetable production, livestock (grazed, urban, etc.), food safety, marketing, value-added products, farm viability and land access are[Read More…]


Fig. 1 Corn earworm adult on silk. Photo courtesy John Obermeyer.

We have begun our state-wide trapping and monitoring program for corn earworm (Figure 1). The latest trap catch information can be found here. Traps have been placed at each of the eight Purdue Agricultural Centers throughout the state. Trap catches at the reporting farms are already in the double digits. Please refer to E-31 to learn more about corn earworm identification and management. Management and insecticide sprays target the eggs that are laid, preferably on fresh corn silk. If no field corn in the area is silking, which is true for most this year, use a threshold of 1-3 moths per night per pheromone trap. You only need to spray your sweet corn if it has silk present. When field corn begins to silk and green silk is present the threshold increases to 10 moths per night. Eggs are laid individually on developing silk. They hatch within 2-5 days and[Read More…]


Figure 3. Cucumber cultivar Taurus were grown in the front, cultivar Corinto was grown in the back.

Supported by NC SARE (LNC17-390), we are continuing research for improving high tunnel cucumber production. One of the biggest challenges for growing cucumbers in high tunnels in the summer is two-spotted spider mites. Dry and hot environments featured in high tunnels allow two-spotted spider mite populations to increase rapidly. The mites cause leaf yellowing, necrosis, and defoliation that interfere with plant photosynthesis. Yield can be significantly reduced. The pest also causes direct damage on cucumber fruit, resulting in a sandpaper-like texture to the rind (Figure 1). Early detection is the key for controlling two-spotted spider mites. As soon as two-spotted spider mites are detected, control efforts need to be taken. In the early stage, yellowish specks on the upper side of the leaves may be noticed (Figure 2). Turn the leaf over, on the other side of where the yellow specks are, you may find the presence of two-spotted spider[Read More…]


Figure 1: A cantaloupe plant surrounded by striped cucumber beetles that have died after feeding on a plant treated with an imidacloprid product.

I know this may not come as a surprise to most of you, but it is rare that we get to observe the effectiveness of insecticides in such a dramatic way as we encountered when visiting a melon grower in southern IN recently. And in this case, the decision to apply an insecticide at transplant was a good one. In the photo below (Figure 1), one can see an accumulation of dead striped cucumber beetles that have fed upon a cantaloupe seedling that was treated with an imidacloprid soil drench (Trade names include: Admire Pro®, Macho®, Midashe Forte®, Montana®) at transplant 14 days prior to the photo being taken. The beetles are dead because they fed upon the cantaloupe plant and ingested the imidacloprid. Therefore, the plants were protected from defoliation by the beetles, but what about bacterial wilt? Did the act of feeding, however brief, cause bacterial wilt to[Read More…]


Seed Corn Maggot in cucurbit stem. Photo credit John Obermeyer.

In addition to delaying much of our fieldwork, the cool set spring has wreaked havoc on some of the plants we have been able to squeeze in during brief dry periods. We have received reports of damage caused by seedcorn maggots (Figure 1) and wireworms (Figure 2). In preparation of this article I browsed the Vegetable Crops Hotline archives and came across eight articles published by Rick Foster. What do they have in common? Associations with weather and limited strategies for control. Capture LFR® remains the only product labeled and for wireworms only. Rick Foster did some work with this product and had some promising results. Seedcorn maggots typically lay their eggs in organic matter and feed on seed in the soil, however, they can also cause damage in cucurbit transplants. The adults are active in April and May laying eggs in the field. When soil temperatures reach 70°F the[Read More…]