Xtremehorticulture

Xtremehorticulture of the Desert

What is Causing the Webbing in My Desert Willow

2 Comments / desert willow has tents, hornworm, sphinx moth, web caterpillar, web tents, what is causing webbing in my desert willow /

Q. My desert willows in Kingman, Arizona, are being eaten up by worms. The web-like pods are all over the branches, but I have not found anything inside. I certainly do not want to spray as the trees are over one of my gardens and close to some windows. A. I did some quick checking but could not find this critter mentioned anywhere. How do you k now they were being eaten up? It is possible they have done their damage and now have moved on leaving their webbing behind. Sphinx moth found dead on sidewalk in May in Las Vegas. Desert willow is used in butterfly gardens but it is usually for the adult butterfly rather than the immature larva (worms) or caterpillar. If they are causing a great deal of damage then they should be controlled. Tent caterpillar webbing Worms or caterpillars that do cause damage to desert willow are the Sphinx moth larva or “worm” and relatives of tent caterpillars. The larva of the Sphinx moth is gigantic with the horn coming off of its rear end. You would’ve recognized that one if you had seen it. Sphinx moth to give you perspective on size of the moth. Bt formulation from Monterey The other caterpillar is much smaller, along the sizes you’re talking about, but they usually form a webbing one or 2 feet across and they feed inside this webbing or tent. That’s why they call these “tent caterpillars”. Tent caterpillars reproduce quickly and do a lot of feeding over a short period of time. My guess is that these critters will not last very long and be on their way for the season. The desert willow will respond and survive. But in the meantime that tree will have some damage. You could use a spray of BT, called usually either Dipel or Thuricide which is an organic control. It will only target “worms” that become moths or butterflies. Also Spinosad will work as well. This way you could avoid more poisonous conventional sprays.

What is Causing the Webbing in My Desert Willow Read More »

Large Worms Found Munching on Grape Vines

Leave a Comment / hornworm, hummingbird moth, sphinx moth, tomato hornworm /

Q. I am finding a large worm varying from 2 – 5 inches in length on my grape vines.  It is roughly 1/2 inch in diameter. The body color varies, green, pink, grey, and brown worms have been removed and destroyed.  Each worm has white diagonal stripes over the length of the segmented body. What is it, and how do I avoid it in the future? A. You will notice a stiff, semi-curved spine sticking up from its rump as well. This is the hornworm, this spine contributing to its name. The hornworm is commonly found on tomato so it is usually called the tomato hornworm but also damages peppers and eggplants as well. Not my picture and not from southern Nevada bud demonstrates the “spine” This is a larva or immature form of the hummingbird or sphinx moth which is a very beautiful large moth. The moth began laying eggs sometime in around March and April so the hornworms have been damaging garden plants since around April or May.             The hornworm is a voracious eater and can defloiate a plant making it leafless in a very short time. Because of their green color they are hard to see on garden plants even though they are large. On a windless day you can watch your garden for a few minutes and see the plant or leaves move because of their size and weight. This way you can identify their locations. You can also look for defoliation, entire leaves missing from plants, and that is also a very good sign they are present. Their excrement is large so seeing that is another way to identify their presence. If you have a blacklight that you used for “seeing” bark scorpions at night you can use this at night as well. Hornworms “fluoresce” or shine a different color at night from plants and can usually be easily found this way.             Control is fairly easy by handpicking when you see them and hunt them down or use the same biological spray that you use for grape leaf skeletonizer or tomato fruitworm; Bt or Spinosad.             Both Bt and Spinosad can be used by organic gardeners safely. Spinosad is a little rougher on bees than Bt so it is always best to spray any pesticide at dusk or early dawn when bees have not started to forage. Always follow label directions for use.

Large Worms Found Munching on Grape Vines Read More »

Beautiful Moth Now, Deadly Assignment in Your Garden

3 Comments / garden pest control, hawk moth, hornworm, hummingbird moth, large green worm, sphinx moth /

I was working in the garage the other night, cleaning out some things and holding a small box. The overhead light was on so I could see the small box in front of me. Startling me, this flew in and landed on the box, attracted to the light. Of course this is not my picture but can be found at http://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/images/hawkmoths/eumorpha_typhon_lg.jpg This is the sphinx moth, hawk moth or sometimes we call them the hummingbird moth because they can pause in mid-air in front of a flower and sip up its nectar. However, my moth was gone as soon as I tried to get my camera. But the feds site will let me use their picture. You will see them flying now, usually around dusk although they feed on the nectar of flowers and serve as very good pollinators, particularly of flowers with very long “throats”. This is because their “tongue” is so long. But….there is a problem for gardeners. This is the hornworm and it is the larva or immature (baby) of the sphinx/hawk/hummingbird moth. You will see them devouring grape leaves (one of their favorites), tomato leaves and other garden crops. They can be devastating this time of year and you might see them again in the fall.   It is your call but if  you want to control these “caterpillars” or larvae then use Bt (Dipel or Thuricide) or Spinosad for organic control. It will not harm the adult moth but will help in controlling the eating by the larvae. This will of course prevent the larvae that you kill from becoming more moths.

Beautiful Moth Now, Deadly Assignment in Your Garden Read More »