IPM Specifics/Sugarcane

Question 1

1st principle of IPM: Management, not eradication​

Answer 1

– Proactive prevention / reduction in pest impact = management, not control​

– Human decision-making process aimed at keeping populations at tolerable levels ​

– Recognizes: eradication not possible without serious environmental consequences (some exceptions)​

• • Recognizes: natural controls on herbivore populations. ​
• • Recognizes: plants have a natural ability to tolerate certain levels of injury​

Question 2

2nd principle of IPM: Know your enemy

Answer 2

–IPM is applied biology – based on a thorough understanding of the pest, the crop (host), and the pest-crop (pest-host) interaction​

–IPM is an information-intensive approach

Question 3

3rd principle of IPM: Use pesticides only when their use is justified by cost-benefit analyses

Answer 3

• Economic injury levels and economic thresholds ​
  The basic idea is that insecticides should only be applied when needed, taking into account the ability of the plant to withstand a certain level of injury without yield loss and the economic and other costs associated with applying insecticides​

The “economic threshold” is a tool to ensure that insecticides are applied only when benefits exceed costs​

Question 4

4th principle of IPM: Harmonize/integrate the use of all appropriate pest management tactics or tools​

Answer 4

–a combination of tools or tactics may be more effective (because you are killing pests in multiple ways) and/or cheaper (pesticides can be expensive) ​

– understand interactions among tactics​

–use of multiple tools is more sustainable ​

–often has the effect of reducing pesticide use

Question 5

4th principle of IPM: Contextualization of pest management​

Answer 5

–pest management strategies for one pest must be integrated with strategies for other pests ​

–pest management strategies must be compatible with regional agronomic practices​

–pest management strategies must be consistent with socioeconomic goals and priorities​

–pest management strategies should strive to minimize impacts on environment

Question 6

What is the advantage of making tunnels in plants? What are the main borers of sugarcane?

Answer 6

Protection! reduces exposures against adverse environmental conditions, predators, and parasitoids. The main borers of sugarcane are: Mexican Rice Borer (MRB), Sucarcane Borer (SCB).

Question 7

Describe the stem borer life cycle.

Answer 7

Eggs laid in masses on new leaves (SCB) or dry leaves
(MRB). Larvae feed within leaf sheaths before stalk entry. Larvae then bore into the stalk where they remain sheltered until adult emergence.

Question 8

History of SCB IPM.

Answer 8

1931 - Biological control efforts
1941 – Cultural controls
1944 – Cultivar resistance
1950s – Chemical controls
1950-60s – 12 insecticide applications
• Inorganic materials, organo-chlorines
1970s-1980s – 3 applications/year1
• Economic thresholds • Organophosphates
1990s-2000s – 1.5 insecticide applications/year2
•Widespread scouting
•Selective chemistries (Confirm, tebufenozide)
•Conservation biological control (Fire ants, parasitoids, etc)
2010s-Present – 0.6 insecticide applications/year3
•Diamides (Prevathon, chlorantraniliprole)
•Resistant cultivar, L 01-299, >40% of acreage

Question 9

Advantages of Pheromone Trap Assisted Scouting for MRB

Answer 9

• Can effectively detect spring emergence
• Identify “Hot Spots”
• Guide scouting frequency

Question 10

Borer Insecticides

Answer 10

Tebufenozide [IGR, 17]: Ecdysone receptor agonist
Chlorantraniliprole [28]: disrupts smooth muscle
function
Novaluron [IGR, 15]: chitin synthesis inhibitor

Question 11

SCB Natural Enemies in Louisiana

Answer 11

Fire ants
Southern cornstalk borer
Alabagrus stigma
Leptotrachelus spp.

Question 12

SCB Biological Control Success: Cotesia flavipes

Answer 12

•New association biological control
•D. saccharalis from S. America
•C. flavipes from India
•Released in TX, FL, and South  America
Reduced insecticide applications over the years..

Question 13

Stem Borer IPM methods:

Answer 13

Chemical Control
•Foliar pyrethroid applications
•Chlorantraniliprole seed treatments
Cultural control
•Early planting
•Stubble management
•Weedy host destruction
•Silicon soil amendment
Host plant resistance
•resistant germplasm
Biological control
•Preserve natural enemies

Question 14

Stem Borer Management

Answer 14

• Begin scouting in late tillering
• Pyrethroids can be applied with
fungicides for sheath blight
• Once white-heads are present, losses
have already occurred

Question 15

What is cultural control? Give examples.

Answer 15

Cultural practices are alterations in crop production practices that change the environment of the agroecosystem in ways that affect the pest insect directly or that affect the crop plant in ways that ameliorate the impact of the pest. Examples for borer management include crop sanitation (removal of stubble that might harbor overwintering borers) and planting date (planting the crop early to avoid heavy infestations of stem borers during vulnerable crop stages).

Question 16

How does IPM of borers in sugarcane exemplify the principles of IPM?

Answer 16

Use of thresholds (to some extent) that are based on scouting and monitoring of pests, integration of multiple tactics such as plant resistance and biological control, the adoption of insecticides that are less damaging to non-targets and the environment and that are more compatible with biological control, etc.

Question 17

What physiological process do chitin synthesis inhibitors and ecdysone agonists interfer with?

Answer 17

Newer insecticides are much more specific to Lepidopterans than older insecticides and target molting in insects (ecdysone agonist, chitin synthesis inhibitor)

Question 18

What types of plant resistance (antibiosis, antixenosis, or tolerance) are found in resistant sugarcane varieties?

Answer 18

Antixenoisis due to
•Reduced oviposition preference
•Reduced larval establishment
– Delays or prevents stalk entry
– Leaf pubescence (hair), rind hardness,
leaf sheath (tightness)
•Reduced larval development
–Stalk prevents extensive feeding
–Fiber, pith, Reduced nutrients (amino
acids)