Brown Marmorated Stink Bug Life Cycle: A Quick and Comprehensive Guide

The brown marmorated stink bug (Halyomorpha halys) is an invasive species originally from Asia.

It has become a significant agricultural pest in the United States since its first discovery in Pennsylvania in the late ’90s.

These bugs are known for their distinctive shield shape and brown mottling, as well as the unpleasant odor they release when disturbed.

The life cycle of the brown marmorated stink bug is an important aspect to understand in order to manage their impact on agriculture.

The bugs go through five nymphal stages before reaching adulthood. Their development is heavily influenced by temperature and food availability.

BMSB Nymph

Adult female stink bugs lay clusters of 20-30 light green or yellow, elliptical-shaped eggs on plant leaves and stems.

The eggs typically hatch within a week, and the emerging nymphs begin to feed on nearby plant tissues.

As they grow and molt through their various life stages, the nymphs cause significant damage to crops by piercing plant tissues and sucking out nutrients.

Brown Marmorated Stink Bug Overview

Origin and Distribution

The brown marmorated stink bug (Halyomorpha halys) is an insect species native to China, Japan, Korea, and Taiwan.

It was first introduced in the Eastern United States in the 1990s, and later spread to North America, Europe, and South America.

Appearance and Identification

This stink bug belongs to the family Pentatomidae and the genus Halyomorpha.

Adult brown marmorated stink bugs are shield-shaped with brown mottling, measuring between 14 and 17 mm long, roughly the size of a U.S. dime.

They have alternating broad light and dark bands on their abdominal edges and last two antennal segments¹.

Invasive Species Status

Since its introduction, the brown marmorated stink bug has become an invasive species, causing damage to fruit, vegetable, and grain crops.

They have piercing-sucking mouthparts with a straw-like stylet that sucks plant juices².

They prefer to feed on reproductive structures like fruits, pods, and seeds².

Brown Marmorated Stink Bug Life Cycle and Development

Mating and Reproduction

The brown marmorated stink bug reproduces through mating.

• Mating: Triggered by pheromones released by the female
• Temperature: Higher mating activities during warmer months (May through August)

Eggs

Brown marmorated stink bug (BMSB) females lay clusters of 20-30 light green or yellow, elliptical-shaped eggs on the underside of leaves and stems, from May to August.

The eggs are typically laid on the host plant, where nymphs will later feed.

Brown Marmorated Stink Bug Eggs and Hatchlings

Nymphs

After hatching, BMSB undergoes five nymphal stages, known as instars, before becoming adults.

Each instar lasts about one week, with the nymphs growing and molting at each stage. Nymphs have distinct characteristics:

• First instar: dark, with orange-red highlights
• Second to fifth instar: black and white striped antennae, and black and red abdominal markings

Nymphal feeding mainly focuses on the leaves, stems, and fruits of host plants.

BMSB Nymphs

BMSB Metamorphosis

Adults

Adult BMSBs reach a size of 14-17 mm long and have a shield-shaped body with brown mottling.

Their abdominal edges and last two antennal segments display alternating broad light and dark bands.

Adult BMSB

Adult BMSBs can live for several months, and their primary role is reproduction.

Throughout the spring and summer, adults feed on various plant species, contributing to their status as agricultural pests.

As temperatures drop in the fall, they seek shelter in buildings and other structures to overwinter.

Once in their overwintering locations, BMSBs enter diapause, a state of dormancy that helps them survive cold temperatures.

They become active again in the spring, continuing their lifecycle.

Feeding and Host Plants

Types of Host Plants

Brown marmorated stink bugs have a wide range of host plants, usually feeding on foliage and fruiting structures. Their preferred host plants include:

• Vegetables
• Orchards
• Soybean
• Tree fruits

The bugs’ hemimetabolous life cycle consists of eggs, nymphs, and adults.

Several generations may occur each year, depending on the availability of host plants.

Crop Damage and Agricultural Impact

The presence of brown marmorated stink bugs causes significant damage to agricultural crops.

They use their piercing-sucking mouthparts to consume plant juices, leading to visible changes in the plants:

• Leaves: chlorotic spots, necrosis, or leaf curling may occur
• Stems: deformation and necrosis can occur, impacting overall plant growth
• Fruit: damage ranging from dimpling to fruit collapse

Additionally, their feeding may lead to the transmission of plant pathogenic microorganisms.

BMSB Nymph

The most significant crop damage typically affects field crops, vegetable crops, and tree fruits.

For example, hazelnut production faces challenges due to stink bug infestations.

Agricultural practices must actively monitor and manage these pests to reduce their impact on crop yield and quality.

Human Interaction

Stink bugs are observed as a nuisance, especially when they invade buildings during overwintering. These pests can cause severe crop damage.

• Habitat: Fruit, vegetable, and grain crops
• Infestations: Damage plants by sucking plant juices
• Natural enemies: Predators, parasitoids, and diseases help limit population growth

Management and Control

Natural Enemies and Predators

One of the natural enemies of the brown marmorated stink bug (BMSB) is the Trissolcus japonicus, also known as the samurai wasp.

It is native to the same region as the BMSB and has been found in the Mid-Atlantic region of the United States.

This tiny wasp is an egg parasitoid that lays its eggs inside the BMSB’s eggs.

Some other predators of the brown marmorated stink bug include:

• Generalist predators (such as spiders and ladybeetles)
• Birds
• Small mammals

Adult BMSB

Effective Pesticides and Solutions

When it comes to managing stink bugs, some effective pesticide options are available.

An example of a pesticide is Surround 95WP, which is an OMRI-listed organic option.

Other chemical options include Warrior II and Baythroid XL. Here is a comparison table showing the properties of each pesticide:

Apart from chemical control, some non-chemical methods are also effective in controlling BMSB populations:

• Mechanical removal (using a vacuum cleaner or hand-picking)
• Exclusion techniques (sealing gaps and cracks in buildings to prevent entry)
• Monitoring and trapping (using pheromone traps)

The brown marmorated stink bug is a significant global issue as an invasive agricultural pest, impacting specialty crops, and as a nuisance when infesting buildings.

Proper management and control of this pest are crucial to minimize its impact on both crops and urban environments.

Other Relevant Information

Comparison to Native Stink Bugs

The brown marmorated stink bug (BMSB) differs from native stink bugs in the following ways:

• Size: BMSB is between 14-17 mm long, while native stink bugs vary in size
• Coloration: BMSB has brown mottling and alternating light and dark bands on antennae and abdominal edges, native stink bugs often have uniform colors

Impact on Specialty Crops

BMSB poses a threat to specialty crops, particularly:

• Tree fruit (apples, peaches, and plums)
• Citrus fruits
• Pecans
• Vegetables (tomatoes, bell peppers, and beans)

These insects feed on leaves, stems, fruits, pods, and seeds, causing damage and reducing crop yields.

BMSB Hatchlings

Orchard Management

Managing BMSB in orchards requires a combination of methods to avoid crop loss:

• Monitoring: Regularly observe for BMSB presence and damage, using traps can be helpful
• Physical controls: Install barriers or nets to prevent BMSB from reaching the crops
• Biological controls: Encourage natural predators, such as parasitic wasps, to control BMSB populations
• Chemical controls: Apply insecticides when BMSB populations reach damaging levels; follow guidelines to avoid harming beneficial organisms and the environment

Orchard management should be tailored to suit the specific crop, climate, and BMSB infestation levels.

Conclusion

The Brown Marmorated Stink Bug, an invasive species from Asia, has become a significant concern for agriculture in the U.S. since its introduction.

With its distinctive shield shape and unpleasant odor, understanding its life cycle is crucial for effective management.

From the laying of 20-30 elliptical-shaped eggs by females to the five nymphal stages leading to adulthood, these bugs have shown adaptability and resilience.

Their feeding habits, which involve piercing plant tissues and extracting nutrients, cause extensive damage to crops.

Effective management strategies, including the use of natural predators and specific pesticides, are essential to mitigate their impact on both agricultural and urban environments.