At least for roses, the plants themselves drive the aphids away' "Author: MILES P W Author Address: WAITE AGRIC. RES. INST., UNIV. ADELAIDE, ADELAIDE, S. AUST. Title: DYNAMIC ASPECTS OF THE CHEMICAL RELATION BETWEEN THE ROSE APHID MACROSIPHUM-ROSAE AND ROSE BUDS Published in: Entomologia Experimentalis et Applicata, volumn 37, pages 129-136, (1985). Abstract: "Dynamic aspects of the chemical relation between the rose aphid [Macrosiphum rosae] and rose buds.In warm weather, M. rosae (L.) walks off buds of hybrid tea roses during a critical period coinciding with the opening of the sepals. This behavior could not be related to histologically detectable barriers to feeding, nor to changes in the water content of the tissues or in their composition with respect to total soluble carbohydrate, amino nitrogen or phenolic compounds; major changes in tissue chemistry, effected by spraying the bushes with urea, did not affect the time at which the aphids left the buds. Tissue sap expressed from stems and sepals showed a significant increase in catechin content after, rather than during, the critical period. Once expressed, however, sap from buds at the critical stage showed a sharp in vitro rise in catechin content over a few hours, up to levels approximating those against which the insects discriminated in choice tests. The insects could well be sensitive to a developing capacity of tissue to accumulated catechin, possibly in response to their feeding activity." ------------------------------------------------ Other papers of interest: http://link.springer.com/article/10.1631/jzus.B1100087 Ph.D. Thesis http://digital.library.adelaide.edu.au/dspace/handle/2440/19578 ------------------------------------- Research concerning how much control Lady Bug release had on aphids on roses. http://www.sciencedirect.com/science/article/pii/S1049964405000721 -------------------------------------------- Here is a link that might be useful: link for Miles' abstract above

Debra, I have a lady bug house and the lady bugs won't use it. They do try to overwinter in our barn-style garage, our screened-in back porch (we cover the screening with greenhouse plastic in winter to turn it into more of a sunporch) and our laundry room (I vaccuum them up and relocate them back outside). I have found that lady bugs follow the food. They'll be in my garden as long as there are bugs to be found, but once they eat everything they like to eat, they move on. You can't keep them around in a mostly bug-free garden because that is un-natural. They have to follow their food supply. Some years we have enough pest-type bugs around in the pastures to keep some of the lady bugs around, but that has not proven to be true this year. So, when late-season pests, like spider mites, showed up, I didn't have lady bugs around to eat them. I guarantee you, though, that before the first frost they'll return to overwinter in their usual places. I'll have to have a little chat with them about why they abandoned our garden this summer and didn't come back in time to help with the mites. I could have bought and released more, but those usually are the Asian lady beetles and they do like to come inside the house and are a colossal nuisance because of that. I love the lady bugs and often have them all over the place, but this was apparently a bad lady bug year here. Dawn

Here in central Texas we have the same problem. Such a shame as our pastures are full of hackberry trees. Another import that we have no natural controls of. We have some old hackberries that are so large that it would take two people to reach around them. I suppose we will end up loosing them. Can't park any equiptment or cars anywhere near them. They also had the larve of the "hackberry butterfly" on them most of the summer. If the honeydew didn't get you the droppings of the larve did. Patsy

Sounds like you have everything pegged pretty well, except I wouldn't classify C.occidentalis as "almost entirely xeric". Although it occurs more frequently in upland areas, it is adaptable to a wide range of conditions including occasional flooding. It's unlikely that the possible C.tenuifolia was laevigata. They vary considerable in multiple factors including leaf type, bark, and habitat. You could have either tenuifolia or occidentalis. Two differentiating factors between laevigata and occidentalis are leaf margins and fruit. C.tenuifolia's leaf margin is nearly entire on the basal third of the leaf and it's fruit is orange-red when fresh and smooth when dry. C.occidentalis' leaf margins are toothed all the way to the leaf's base and it's fruit is dark purple when fresh and wrinkled when dry. I will attach a link below to the eFloras key to the Celtis genus. I just LOVE eFloras! Maybe one day it will be complete.