BOLLWORM

Top	Check Your Diagnosis	Data Sheet	Natural Enemies	Management
		DAMAGE SYMPTOMS		MONITOR
		LIFE CYCLE		ECONOMIC THRESHOLD
		SEASONAL CYCLE		CONTROL OPTIONS
				CHECK POINTS

Identification

Photo

Adults have large wings covered in scales.
The pest life stage is the caterpillars.
Caterpillars have chewing mouthparts and feed on plants.

Check Your Diagnosis

Photo

Top	Check Your Diagnosis	Data Sheet	Natural Enemies	Management
		DAMAGE SYMPTOMS		MONITOR
		LIFE CYCLE		ECONOMIC THRESHOLD
		SEASONAL CYCLE		CONTROL OPTIONS
				CHECK POINTS

Data Sheet

Damage Symptoms

on fruit

PHOTO

on leaves

on blossom

Photo

on twigs

1. On Fruit

Feeding damage	Want to know more?
Feeds on fruitlets and blossoms. Seldom seen on larger fruit	Injury sustained on fruitlets, grows with the fruit. Severe injury to fruit must be culled.

2. On Leaves

Never observed in Vaalharts

3. On Blossoms

Feeding damage	Want to know more?
Feeds on blossoms and small fruitlets	Now is the time to take action against bollworm infestations

4. On Twigs

None

Life Cycle

r- strategist

high reproduction (infestation levels rise quickly)
low survival (can easily be killed)
rebound quickly ( after spraying, pest levels can rise fast if all predators are killed)

Diagram of life cycle

Photos of life cycle

Complete metamorphosis: moth – egg – larvae – pupa = 150 days

Larvae is the caterpillars that attack the citrus blossoms

	Must know	Extra info
EGGS	Eggs are laid singly on blossoms or on young leaves. Freshly laid eggs are whitish-yellow but turn darker as the larva grows.
LARVA	Six instars Drops to the soil to pupate.	Larvae are cannibalistic Extremely active Fourth and fifth instars look like the adult with three longitudinal bands
PUPA	overwinter in soil	Cold spells beneath freezing can kill the pupae of the bollworm Temperature plays a major role in emergence of the moths
MOTHS	Males are pale olive gray with reddish brown antennae. Body length = 16-18 mm Females are darker in color than the males Moths feed on nectar Moths are attracted to light traps Males live 8 days and females 11 days	Moths fly at night. The females are attracted to the scent and color of blossoms First flying moths are mostly from the overwintering pupae First flights are in August Egg laying in September and emergence of larvae in mid-September to coincide with blossoms

Seasonal Cycle in Vaalharts

Graph

Bollworm is only a pest in spring in the Vaalharts region

The reason for the short infestation time is that the whole region has a uniform and short blossoming period for all varieties of citrus

The first emergence of bollworm is mid September

The infestation length can be from a week to a month, depending on the level of the pest population

Multivoltine: several generations per year

Top	Check Your Diagnosis	Data Sheet	Natural Enemies	Management
		DAMAGE SYMPTOMS		MONITOR
		LIFE CYCLE		ECONOMIC THRESHOLD
		SEASONAL CYCLE		CONTROL OPTIONS
				CHECK POINTS

Natural Enemies

Photo

Top	Check Your Diagnosis	Data Sheet	Natural Enemies	Management
		DAMAGE SYMPTOMS		MONITOR
		LIFE CYCLE		ECONOMIC THRESHOLD
		SEASONAL CYCLE		CONTROL OPTIONS
				CHECK POINTS

Integrated Pest Management

BOLLWORM
LEPIDOPTERA: NOCTUIDAE: Helicoverpa armigera

Identification

Check Your Diagnosis

Data Sheet

Damage Symptoms

1. On Fruit

2. On Leaves

3. On Blossoms

4. On Twigs

Life Cycle

Seasonal Cycle in Vaalharts

Natural Enemies

Management

Integrated Pest Management

BOLLWORM LEPIDOPTERA: NOCTUIDAE: Helicoverpa armigera

Identification

Check Your Diagnosis

Data Sheet

Damage Symptoms

1. On Fruit

2. On Leaves

3. On Blossoms

4. On Twigs

Life Cycle

Seasonal Cycle in Vaalharts

Natural Enemies

Management

BOLLWORM
LEPIDOPTERA: NOCTUIDAE: Helicoverpa armigera