Posts Tagged 'Lindorus'

Lindorus Kicks Christmas Trees Off Pesticide Treadmill

Lindorus eating pine needle scale

Lindorus eating pine needle scale

After years of spraying more pesticides and achieving less control, many of Ron Evans’ Christmas trees were left unfit to sell because of messy scale infestations. Farming for over 45 years, they began noticing pine needle scale 15 years ago. Scotch pine, red pine and Austrian pine were especially susceptible. In the mid 1990’s they used conventional pesticide spray based on monitoring and treating hot spots. Despite treatments, the scale crawlers spread and all trees with scale were eventually sprayed twice a year.

Within six years Evans reported, “Typically we were spraying all the fields three to four times per year. We tried to follow the recommendations found in pest control literature, but still found ourselves fighting a losing battle. Most of the literature recommends spraying scale when crawlers are present. Scale typically crawls for three days after hatching, and we logged as many as seven hatches the summer of 2000. The logistics of spraying 100,000+ trees in a three day window, three to four or more times per year became more than a nightmare.” Four E’s Trees was burning 1,500-3,000 trees every year that were ruined by scale pests. 

Evans called the University of Illinois Department of Entomology. Among their suggestions was a small black lady beetle Lindorus lopanthae as a scale predator. Ready to try something new, Evans cooperated in a test of Lindorus beetles. He put a small number of Lindorus in a remote patch on his farm during June 2002, while continuing with his conventional program everywhere else. In November, while they were harvesting (with difficulty because of scale damage), he walked back to the remote field, where five months prior he had released the Lindorus beetles and forgotten about them. To his surprise this patch of trees was the only area on the entire farm without a scale infestation!

Four E’s Trees released several thousand Lindorus beetles the following season. According to Evans, “The first year results were amazing. We had entire fields of marketable size trees that we could not sell in the 2002 Christmas season due to excessive infestations of scale. These same fields were scale free, healthy and salable for the 2003 season. In addition to reducing the scale infestations to manageable levels, we spent $3,000 less on pesticides and countless fewer man-hours with the Lindorus beetles than the spray program the previous year.” Lindorus must be released annually when there are enough scale to feed them, which is usually late spring to early summer.

In 2005 Rincon-Vitova Insectaries, recognizing that Four E’s was able to provide valuable technical support to expand the successful use of one of the organisms it grows, offered a dealership to Four E’s Trees to sell Lindorus to the Christmas tree industry. Evans writes and speaks to Christmas tree associations and supplies Lindorus to over 50 growers in 14 states. Four E’s helps customers assess the scope of the problem, the type of scale, the number of beetles needed and timing of release, other cultural practices to produce pest resistant trees, how to distribute the beetles and monitor results. Beetles are shipped overnight to Four E’s customers for them to make the releases. For more information about Lindorus for scale in Christmas trees, write to Ron Evans <FourEsTrees @> or call (217) 864-4704 and ask for Ron or Doug.


Use “Ant Trees” and Scale Hotspots to Grow Lindorus

Releasing Lindorus beetles on a mandarin tree for citrus scale control.

Releasing Lindorus beetles on a mandarin tree for citrus scale control.

Ant trees are what we call trees that ants pick out and work over more than most of the trees in the area so that they become chronic hotspots for homopteran and other pests including scale pests. Take advantage of a scale-infested ant tree by creating a barrier for the ants (see future posts about ant management) and release on the scale. They will produce Lindorus for the whole grove for the season and grow there if they don’t freeze or get disrupted by pesticides. You are unlikely to catch them in the act, but you can tell they’re working by the way they rip up the hard scale covers leaving raggedy edges where they got access to their prey. Green lacewing larvae leave similar signs but not as ragged.

Releases of Lindorus are especially valuable in a biological control programs against citrus red and yellow scale, and purple scale. You cannot afford not to do this when surplus beetles are available at deep discounts. Backgrounders about scale IPM programs are described at: IPM.ucdavis for both Red and Yellow and Purple Scale. Note that the University researchers writing these guidelines refer to Lindorus as Rhyzobius lopanthae. They are similar but distinct genera.

Red Scale on Mandarin (Photo by Dan Papacek)

Red Scale on Mandarin (Photo by Dan Papacek)

We especially appreciate Dan Papacek’s work in citrus. His excellent biocontrol tips and photos like this one can be found at

Florida wax scale on Indian Hawthorns could not be controlled with pesticides, but a report at U of Florida’s site includes Lindorus in an effective program. Check it out here.

Pseudaulacaspis pentagona white peach scale is also a good food for Lindorus. A classic report in the Florida Entomological Society (F.A. Collins and W. H. Whitcomb, 1975). In a more recent report in the same journal, the deleterious effect of “soft pesticides” on Lindorus. We are surprised that, “At one-half the field rate, R. lophanthae [Lindorus] had 43% mortality with insecticidal soap, 63% mortality with imidacloprid, and 46% mortality with fish oil. …the soap and oil were the least toxic of all pesticides tested.” See the full report here.

Product Availability: Week of Nov 17th

I am starting a report for the coming week about availability of organisms that sometimes have issues. Hopefully if you are planning an order of beneficials this will give you a heads up on what to expect in the next week or so.

Lindorus production here at Rincon-Vitova Insectaries has been in a puzzling slump the last two months or so, but I am happy to report that we have it back up. We had a summer intern who tended the culture and devised some ingenious techniques. After he left we gradually figured out that one of the techniques to boost egg laying just left us with hordes of hungry larvae eating up all the scale and not making it through the pupal stage. Our system wasn’t designed to feed so many predators! When it fell to me to fill orders without enough new adults coming on, it became a very rewarding experience helping those little beetles get their life cycle on. It’s a give and take situation, figuring out the right amount of food, and when to rotate said food, and how to not over collect. So when a customer gets shorted a vial or so, it’s now because there are lots of orders and we need to keep enough beetles laying eggs for future orders. There is now plenty to go around.

Brian at Applied Bio-Nomics (our Canadian supplier) reports his “Bad” Employee for the month of November is Atheta. “We have detected a parasitic mite (phoretic) and are re-culturing. This is a common problem with Atheta. We should be able to be back in business soon. This contamination is only apparent in the high densities of a commercial culture and does not affect their performance in the field…. We might be able to supply a little bit this month, but I can’t make any guarantees.”

Our Orius source remains unpredictable, so first come first serve works.

Check here every Wednesday for weekly updates or you can see a detailed list at the Product Availability Page at You can also call us for details at 800-248-BUGS.


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