What causes sticky plant leaves?
The answer to this question depends upon which type of leaf it is. There are two types of leaf with sticky substance; those that have been damaged and those that do not.
Sticky Leaf Damage:
If your plant has lost its leaves, then there will be some kind of damage on them. If they are dead or dying, then it means that something has eaten away at their tissue causing death. If they are greenish, then it means that something has chewed away at them. Some examples of these kinds of damage include:
Leaves that have died due to drought or other environmental factors. They may be yellowing or turning brown. This is called necrosis (death). When leaves die, they become vulnerable to insects and diseases because their tissues cannot support themselves anymore.
These are leaves that have fallen off the tree. They may be brown, withered or even completely dead. These leaves are called phytophthora infestans (deadly fungus) and can cause disease if left unchecked. Phytophthora infestans can spread from one plant to another through wind, water or insects.
Once they get into a plant’s roots, they can cause death of the whole plant in just days!
These types of leaves have holes, tooth-like marks or just look like they’ve been chewed on. These leaves have been attacked by insects or animals (like slugs). Certain types of insects eat away at plant leaves to lay their eggs or to find shelter. It’s important to identify the insects so that you can find the best way to get rid of them.
Sources & references used in this article:
The geographical distribution, inheritance and pest-resisting properties of sticky-tipped foliar hairs on potato species by RW Gibson – Potato research, 1979 – Springer
Host and microhabitat preferences of forest parasitic Hymenoptera: inferences from captures on colored sticky panels by RM Weseloh – Environmental entomology, 1986 – academic.oup.com
Evaluation of potato psyllid cold tolerance, overwintering survival, sticky trap sampling, and effects of liberibacter on potato psyllid alternate host plants by DC Henne, L Paetzold, F Workneh… – Proc. 10th Annual Zebra …, 2010 – Citeseer
Mirid (Hemiptera: Heteroptera) specialists of sticky plants: adaptations, interactions, and ecological implications by AG Wheeler Jr, BA Krimmel – Annual Review of Entomology, 2015 – annualreviews.org
Do plant trichomes cause more harm than good to predatory insects? by EW Riddick, AM Simmons – Pest management science, 2014 – Wiley Online Library
The siren song of a sticky plant: columbines provision mutualist arthropods by attracting and killing passerby insects by EF LoPresti, IS Pearse, GK Charles – Ecology, 2015 – Wiley Online Library
Transcriptome analysis provides insights into the delayed sticky disease symptoms in Carica papaya by J Madroñero, SP Rodrigues, TFS Antunes, PMV Abreu… – Plant cell reports, 2018 – Springer
Sticky weeds as an understorey vegetation in intensively managed teak plantation for defoliator management by J Loganathan, PMM David – Crop Protection, 1999 – Elsevier
Psyllid Responses to Colored Sticky Traps and the Colors of Juvenile and Adult Leaves of the Heteroblastic Host Plant Eucalyptus globulus by EB Brennan, SA Weinbaum – Environmental entomology, 2001 – academic.oup.com