CSLB C-27 Landscaping ContractorPlanting and LandscapingMedium
A landscape technician observes numerous small, soft-bodied insects clustered on the stems and undersides of new leaves on a client's rose bushes. They also notice a sticky, shiny substance on the leaves below the infestation, and black sooty mold developing. Which pest is most likely responsible for these symptoms?
- AWhiteflies
- BAphids
- CThrips
- DSpider mites
Show answer & explanationAnswer & explanation
Correct answer: B. Aphids
The description perfectly matches an aphid infestation: small, soft-bodied insects, clustering on new growth, producing honeydew (the sticky, shiny substance), which then leads to the growth of sooty mold. Spider mites cause stippling and webbing, whiteflies are winged and fly when disturbed, and thrips cause distorted growth and silvery streaks.
Why the other options are wrong
- A. Whiteflies are small, white, winged insects that fly up in a cloud when disturbed, and while they produce honeydew, their appearance is distinct.
- C. Thrips cause distorted growth, silvery streaks on leaves, and tiny black fecal spots, but not large amounts of sticky honeydew and subsequent sooty mold as described.
- D. Spider mites cause stippling on leaves and fine webbing, not sticky honeydew and sooty mold.
Aphid Infestation
A common plant pest characterized by small, soft-bodied insects that feed on plant sap, often causing distorted growth, honeydew excretion, and sooty mold.
- Cluster on new growth.
- Excrete sticky honeydew.
- Can lead to sooty mold.
Memory trick: Sticky leaves and clusters? It's 'A'phids, for sure!