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# GTBOP Moodle Quiz

## Understanding Tree Pests: Disease Interactions, Invasive Threats, and Management Strategies

### Dr. Ignazio Graziosi — January 15, 2026

Source: Corrected SRT transcript (Stage 1) + Archive Package (Stage 2) Questions: 15 Difficulty Distribution: 6 Recall (40%) | 6 Application (40%) | 3 Analysis (20%) Coverage: Disease triangle/decline spiral (Q1–Q3), EAB (Q4–Q8), CMBS (Q9–Q12), Orange-striped oakworm (Q13–Q15)

### Question 1

Timestamp Reference: 1:28 – 2:32 Difficulty: Recall

According to Dr. Graziosi, the disease triangle describes the interaction of which three components that together cause tree damage?

a) Pest, pathogen, and predator b) Pest, host tree, and environment c) Climate, soil, and genetics d) Insects, fungi, and nematodes

Correct Answer: b Explanation: Dr. Graziosi introduced the disease triangle as the interaction of the pest, the tree (host), and the environment, emphasizing that the pest alone is not sufficient to cause damage. Source in transcript: ~2:04–2:32, blocks 33–35

### Question 2

Timestamp Reference: 3:02 – 5:58 Difficulty: Recall

In the spiral of tree decline diagram, which of the following is classified as a predisposing factor?

a) Defoliating insects b) Wood-boring insects c) Soil compaction d) Fungal pathogens

Correct Answer: c Explanation: Dr. Graziosi identified soil compaction as a predisposing factor in the outermost spiral, calling it "often the number one issue for many trees." Defoliating insects are inciting factors, and wood-boring insects and fungi are contributing factors. Source in transcript: ~4:08–4:31, blocks 49–52

### Question 3

Timestamp Reference: 5:04 – 6:06 Difficulty: Analysis

Dr. Graziosi explained that in the spiral of tree decline, each spiral level contains factors that can "cut through" directly to tree death. What is the practical significance of this for a tree care professional?

a) Only contributing factors can kill a tree b) A single stressor from any level can be severe enough to kill a tree on its own, without the other factors c) Trees can only die when all three levels of stressors are present simultaneously d) Predisposing factors must always precede inciting factors before decline begins

Correct Answer: b Explanation: Dr. Graziosi specifically demonstrated that individual factors from any spiral level — for example, urban environment alone or soil compaction alone — can cut through the different layers and bring the tree directly to death, without requiring all other stressor levels to be present. Source in transcript: ~5:32–5:54, blocks 64–66

### Question 4

Timestamp Reference: 8:23 – 9:10 Difficulty: Recall

Which of the following is a key diagnostic sign that a tree is being attacked by the emerald ash borer?

a) Sooty mold on branches b) Skeletonized leaves c) Water sprouts on the trunk d) Pink egg masses on bark

Correct Answer: c Explanation: Dr. Graziosi described water sprouts as "a very important diagnostic feature in order to understand if a tree is attacked by the emerald ash borer," noting they are the tree's desperate attempt to produce new growth in response to larval damage under the bark. Source in transcript: ~8:56–9:10, blocks 98–100

### Question 5

Timestamp Reference: 10:04 – 10:47 Difficulty: Recall

What is the characteristic shape of the exit hole left by an adult emerald ash borer emerging from a tree?

a) Circular b) Oval c) D-shaped d) T-shaped

Correct Answer: c Explanation: Dr. Graziosi described the "very characteristic, the famous D-shaped exit hole" left when the adult beetle emerges from the tree. Source in transcript: ~10:11–10:15, block 110

### Question 6

Timestamp Reference: 10:48 – 11:42 Difficulty: Application

A landscape manager in southern Georgia discovers EAB in local ash trees and plans a treatment schedule based on a single annual emergence. Based on Dr. Graziosi's presentation, what important consideration might this manager be overlooking?

a) EAB only emerges every two years in all locations b) A portion of the local EAB population may require two years to develop, meaning adults could emerge in both years c) EAB does not complete its life cycle in southern climates d) EAB only feeds on ash trees in northern states

Correct Answer: b Explanation: Dr. Graziosi explained that while EAB is mostly a one-generation-per-year insect, there is always a portion of the population that requires two years to develop. This is more pronounced at northern latitudes but occurs in any location, and it is important to know when planning control. Source in transcript: ~10:48–11:42, blocks 116–124

### Question 7

Timestamp Reference: 13:02 – 13:46 Difficulty: Recall

According to the presentation, what was the single most important factor responsible for the rapid spread of the emerald ash borer across North America?

a) Natural flight dispersal b) Nursery stock trade c) Movement of infested firewood d) Wind currents carrying adult beetles

Correct Answer: c Explanation: Dr. Graziosi identified firewood as the primary culprit, explaining that campers and travelers moved infested firewood, and researchers were able to connect the pattern of EAB spread closely with the highway and freeway system. Source in transcript: ~13:00–13:46, blocks 136–141

### Question 8

Timestamp Reference: 15:26 – 16:44 Difficulty: Application

An arborist inventorying trees in a Georgia neighborhood finds that all the ash trees have been killed by EAB but notices white fringetrees appear healthy. Based on Dr. Graziosi's presentation, should the arborist be concerned about EAB affecting the white fringetrees?

a) No, because white fringetrees are not in the same plant family as ash b) No, because EAB only attacks ash species c) Yes, because white fringetree was discovered to be an alternate host for EAB and could serve as a population reservoir d) Yes, but only if the white fringetrees are under drought stress

Correct Answer: c Explanation: Dr. Graziosi explained that in 2014 it was discovered that EAB could expand its host range to attack white fringetree (same family, Oleaceae). More importantly, white fringetree can function as a reservoir for EAB populations even after all ash trees in an area are gone. Source in transcript: ~15:26–16:44, blocks 162–172

### Question 9

Timestamp Reference: 31:47 – 33:28 Difficulty: Application

A pest control operator inspects a crapemyrtle in December and finds both mature adult females and small mobile nymphs on the bark. Based on the presentation, is this finding unusual?

a) Yes, all CMBS should be in a dormant stage during winter b) Yes, nymphs should only be present during summer months c) No, CMBS has overlapping generations, so multiple life stages can be present at any time of year d) No, but only adults should be present — the nymphs are likely a different insect

Correct Answer: c Explanation: Dr. Graziosi explained that CMBS can have up to five overlapping generations, meaning different stages of the insect can be found at any point. He showed a photo taken in Athens one month prior (winter) that contained both nymphs (crawlers) and adults. Source in transcript: ~33:10–33:47, blocks 327–329

### Question 10

Timestamp Reference: 36:42 – 37:17 Difficulty: Analysis

Dr. Graziosi discussed urban heat island effects in relation to crapemyrtle bark scale. Which of the following best explains why urban heat islands create a "double advantage" for scale insects?

a) Heat kills natural enemies while attracting more scales to the area b) Heat increases tree growth rate, providing more food for scales c) Heat stresses the host tree, increasing its susceptibility, while simultaneously accelerating the insect's development d) Heat causes scales to produce more sooty mold, which protects them from predators

Correct Answer: c Explanation: Dr. Graziosi described two specific effects of urban heat islands: first, it stresses trees, making them more susceptible to pests; second, it accelerates the development of the insect itself. He noted that scales are particularly good at taking advantage of urban heat. Source in transcript: ~36:57–37:21, blocks 363–368

### Question 11

Timestamp Reference: 38:06 – 38:29 Difficulty: Application

A landscape company wants to use trunk injection of systemic insecticides to control a crapemyrtle bark scale infestation. Based on the presentation, what should they know?

a) Trunk injection is the most effective method for CMBS control b) Trunk injection works but must be applied in fall c) Trunk injection is not a viable option because crapemyrtle absorbs systemic insecticides through the trunk very slowly d) Trunk injection is effective only on trees over 6 inches in diameter

Correct Answer: c Explanation: Dr. Graziosi specifically stated that chemical control of CMBS is complicated by the fact that crapemyrtle is not good at absorbing systemic insecticide through trunk injection, and that the chemical moves very slowly, making it not a viable option. Source in transcript: ~38:14–38:30, blocks 378–380

### Question 12

Timestamp Reference: 38:31 – 41:44 Difficulty: Recall

Which of the following is NOT one of the native predators Dr. Graziosi identified as feeding on crapemyrtle bark scale?

a) Twice-stabbed lady beetle b) Green lacewing c) Bigeminal lady beetle d) Parasitoid wasp specialist from Asia

Correct Answer: d Explanation: Dr. Graziosi identified three lady beetle species (twice-stabbed, bigeminal, and Harlequin) and green lacewings (particularly the red-lipped green lacewing) as predators of CMBS in North America. He specifically noted that no effective parasitoid had yet been found for CMBS in the US, unlike the situation in Asia. Source in transcript: ~38:48–41:00, blocks 385–409

### Question 13

Timestamp Reference: 42:25 – 43:35 Difficulty: Recall

According to the presentation, the orange-striped oakworm moth primarily feeds on which group of trees?

a) Ash species b) Crapemyrtles c) Red oaks, but also hickory, birch, and maple d) Pines and other conifers

Correct Answer: c Explanation: Dr. Graziosi described the orange-striped oakworm as a well-known pest of oaks, especially red oaks, but noted it can also feed on hickory, birch, and maple. Source in transcript: ~42:43–42:59, blocks 422–423

### Question 14

Timestamp Reference: 44:51 – 46:10 Difficulty: Analysis

Dr. Graziosi discussed Nuttall oaks on the UGA Athens campus as an example of vulnerability to the orange-striped oakworm. What underlying principle does this example illustrate about urban tree pest management?

a) Nuttall oaks are a non-native species poorly adapted to Georgia b) Monoculture plantings of clonal nursery stock create genetically uniform populations where susceptibility in one tree means susceptibility in all c) Nuttall oaks are particularly attractive to oakworm moths due to their leaf chemistry d) Older trees are always more resistant to defoliating insects than younger ones

Correct Answer: b Explanation: Dr. Graziosi explained that urban trees often come from nurseries as clonal trees with very low genetic variability — "they are basically the same tree." Therefore the susceptibility of one tree reflects the susceptibility of all trees of that clone on campus, making them uniformly vulnerable. Source in transcript: ~45:00–46:05, blocks 452–460

### Question 15

Timestamp Reference: 47:56 – 49:05 Difficulty: Application

A homeowner calls about an oak tree losing leaves in late September to orange-striped oakworm caterpillars. About 30% of the canopy has been defoliated. Based on Dr. Graziosi's decision framework, what is the most appropriate recommendation?

a) Immediately apply a broad-spectrum systemic insecticide via soil drench b) Apply Btk foliar spray urgently before the tree dies c) Consider that late-season defoliation is less harmful because the tree has already stored nutrients, and monitor rather than treat aggressively d) Remove and replace the tree, as 30% defoliation is always fatal

Correct Answer: c Explanation: Dr. Graziosi outlined two key considerations: the 25% defoliation threshold distinguishes aesthetic from actual damage, and late-season defoliation (even if substantial) is less harmful because the tree has already stored its nutrients. A mature oak at 30% defoliation in late September, while above the threshold, benefits from the seasonal timing, suggesting monitoring may be more appropriate than aggressive chemical intervention. Source in transcript: ~48:05–48:44, blocks 482–486

## Verification Checklist

- [x] All 15 questions derived exclusively from presentation content
- [x] Timestamp references verified against corrected transcript
- [x] No external knowledge required to answer correctly
- [x] Difficulty distribution: 6 Recall / 6 Application / 3 Analysis
- [x] Coverage spans early (disease triangle), middle (EAB, CMBS), and late (oakworm) content
- [x] Answer keys unambiguous based on speaker's statements
- [x] Distractors plausible but clearly incorrect per presentation
- [x] No "all of the above" or "none of the above" options used