Three-lined Cockroach | Luridiblatta trivittata

California Pest Rating for
Three-lined cockroach |  Luridiblatta trivittata
Blattodea: Blatellidae
Pest Rating: C



Initiating Event:

Luridiblatta trivittata has a current rating of Z. It was recently reported in Vallejo, California and it is known to occur throughout the San Francisco Bay area. A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background: Luridiblatta trivittata, the three-lined cockroach, is a tiny cockroach in the family Ectobiidae. It looks similar to larvae of the German cockroach (Blatella germanica), but that species has two dark pronotal lines instead of the three in L. trivittata1. It is primarily an outdoor species, but it will enter homes, especially in the late summer. This species is synanthropic (occurring only where humans do), occurring in leaf litter, plant debris, mulch, and compost piles. It is native to Mediterranean Europe and was introduced to the west coast of the United States, first being reported there in 2004. This species has spread throughout the San Francisco Bay area and other parts of northern California2, 3.

Luridiblatta trivittata was formerly known in the literature as Phyllodromica trivittata1.

Worldwide Distribution: Luridiblatta trivittata is native to dry habitats in the Mediterranean. It has been recorded from Morocco, Algeria, Spain, Italy, Libya, and Israel1.

Official Control: Luridiblatta trivittata is not listed as a harmful organism by any states or nations and it is not known to be under official control anywhere6.

California Distribution: Luridiblatta trivittata was known to be present in the San Francisco Bay area as early as 2004 and it is very common in northern California.

California Interceptions: There was only one specimen (PDR1374767) reported in the Pest and Damage Record Database by CDFA5. This was found in mulch in Pinole, Contra Costa County.

The risk Luridiblatta trivittata (three-lined Cockroach) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Luridiblatta trivittata can feed on a variety of leftover food and plant debris in the home. They just need hiding places and access to water. It may establish in larger, but limited, warm metropolitan areas of California. It receives a Medium (2) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Luridiblatta trivittata is an omnivorous scavenger. It prefers sugary, starchy, or protein-rich foods, but can also consume decaying organic matter4. It receives a High (3) in this category.

Evaluate the host range of the pest.

Low (1) has a very limited host range.

Medium (2) has a moderate host range.

High (3) has a wide host range.

3) Pest Dispersal Potential: The adult female produces an egg capsule (ootheca) at the tip of the abdomen that carries eggs during the incubation period. Each egg capsule usually contains between 30 and 40 young. Two generations are produced in one year (spring and fall) 3. It receives a Medium (2) in this category.

Evaluate the natural and artificial dispersal potential of the pest.

Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Luridiblatta trivittata is not expected to lower crop yields or crop value because it is not an agricultural pest. It receives a Low (1) in this category.

Evaluate the economic impact of the pest to California using the criteria below.

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: Luridiblatta trivittata is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It might trigger new chemical treatments by residents who find infestations inside the home or in gardens. It is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. It receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact:  D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score: 2

Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Luridiblatta trivittata  (Three-lined Cockroach):  Medium (10)

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: Luridiblatta trivittata has a localized distribution in California (San Francisco Bay area) and receive Low Score (-1) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (9)


Luridiblatta trivittata has been present in California since at least 2004.  So far its spread has been limited to the San Francisco Bay area.  Much of California is probably suitable for this species and there is a strong possibility that it will continue to spread.

Conclusion and Rating Justification:

Luridiblatta trivittata has established a widespread distribution in the San Francisco Bay area. It does not appear to be having a significant economic or environmental impact. Therefore, a “C” rating is justified.

  1. California Plant Pest & Disease Report Vol. 25. 2009. Accessed September 26, 2017.
  2. Cockroaches Management Guidelines UC-IMP. Accessed September 26, 2017.
  3. Insect of San Francisco Bay Area. Accessed September 26, 2017.
  4. Orkin pest control. Accessed September 26, 2017.
  5. Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services.
  6. phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed September 7, 2017.


Javaid Iqbal,  California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695;[@]

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211,[@]

Comment Period: * CLOSED

1/5/18 – 2/19/18


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Pest Rating: C  

Posted by ls