Question
QUESTION: My 4 year old Meyer lemon tree has leaves that curl, get Spider webs and fall off.  It does not seem to affect the lemons themselves but the tree looks ugly.  I need something to spray on the tree and that will not harm the lemons as they develop.
Thanks,
Jimmye

ANSWER: Hi Jimmye,

Are these container grown lemons or are they grown in the ground?  There are many types of beneficial spiders that use the leaves as "nests".  Some use spider web silk to pull the leaves together to use as a type of nursery.

Do the leaves curl first, then you notice the spider webs?  Do you see any small insects? How big are the "fibers" of the web?  There are spider mites that produce these small webs.  When grown outdoors, natural predators keep these pests in check.  Indoors, especially in winter, the populations can explode.

Photos?  If so, send them to [email protected]



---------- FOLLOW-UP ----------

QUESTION: My lemon tree is planted in the ground.  We live in Houston, so the slight freezes we have do not really harm the tree.  I don't think these spiders are beneficial because the leaves eventually fall off.  From what I can tell, the leaves get the webbing and curl up and then fall off.  I could not see any little bugs. I really would like something that I could treat the tree with and not hurt the lemons and make them inedible.
Thanks,
Jimmye

Answer
When you say the leaves "curl up", do you mean that they are deformed leaves, or do you mean that they actually curl so that the opposite sides of the leaves join?  Thrips and aphids, among other insect pests, can cause the leaves to curl or deform. One common insect pest is Texas citrus mite which can cause deformed leaves and defoliation. Infestations are common in winter months, but as the climate changes, the natural predators control the populations.  

If the leaves are curled so that they join, then what you might be experiencing are "leaf rollers" which are related to butterflies (Lepidoptera, Hymenoptera, or Dioptera).  These insects actually entwine the leaves with the "web" and shape the leaves.  Unusually large infestations can completely defoliate a tree. Consult your local garden center to find which leaf rollers may be common pests in your area. There is the Omnivorus leafroller _Platynota stultana_ common from Florida to Texas, Arizona, and Southern California. These caterpillars feed within the rolled leaves, so they should be visible in some leaves.  Also, this is not the right time of year for this species to be producing young.

So, if I had to make a guess without any other information, I would speculate that you may have a Texas citrus mite infestation.  These mites are very, very small and difficult to see.

If you have an extension service office nearby, consult them.  Here is a website to find an office near you.

http://texasextension.tamu.edu/about/

Sorry that I can't be more specific.