Question
QUESTION: We live in Central Texas (near Dallas) and last year we had 3 cycles of web worms in our fruitless mulberry tree. Today (Apr. 25th) we noticed that this is beginning again - this is much earlier than last year. Short of removing the webs (and we've actually done some of that, but some branches are hard to reach) is there anything else that can prevent the continuation of these cycles? Thanks

ANSWER: Bt will work on young caterpillars as they eat the leaves. There are other insecticides that can be sprayed on the caterpillars for control (sevin etc.) Bayer Advanced Tree & Shrub Insect Control, is a systemic insecticide that is applied to the soil and the trees roots take it to the foliage killing any insect that feeds on the leaves. This will work for prevention of future infestations for up to 12 months. You should be able to get it at a nursery or garden type store.

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QUESTION: Not sure what the Bt is???? Also will insecticides be harmful to the birds?
Thanks for your earlier response
Mary

Answer
Bacillus thuringiensis (Bt) is an insecticide with unusual properties that make it useful for pest control in certain situations. Bt is a naturally occurring bacterium common in soils throughout the world. Several strains can infect and kill insects. Because of this property, Bt has been developed for insect control. At present, Bt is the only "microbial insecticide" in widespread use.

Bt acts by producing proteins (delta-endotoxin, the "toxic crystal") that reacts with the cells of the gut lining of susceptible insects. These Bt proteins paralyze the digestive system, and the infected insect stops feeding within hours. Bt-affected insects generally die from starvation, which can take several days. The most commonly used strain of Bt (kurstaki strain) will kill only leaf- and needle-feeding caterpillars.

The specific activity of Bt generally is considered highly beneficial. Unlike most insecticides, Bt insecticides do not have a broad spectrum of activity, so they do not kill beneficial insects. This includes the natural enemies of insects (predators and parasites), as well as beneficial pollinators, such as honeybees. Therefore, Bt integrates well with other natural controls.

Perhaps the major advantage is that Bt is essentially nontoxic to people, pets and wildlife. This high margin of safety recommends its use on food Crops or in other sensitive sites where pesticide use can cause adverse effects.

The soil applied insecticide (Bayer Advanced) once applied will not harm pets or birds. The spray type insecticide for the home owner will have not effect on the birds--they just kill insects. There are some insecticides that are restricted for professional use only that could harm birds or pets if not used correctly --these are not available for homeowners but are applied by Certified Pesticide Applicators. I only recommend insecticides that the home owner can apply safely.