Samurai Wasp Trissolcus japonicus (Ashmead)Adventive  -  Non-native  


"Trissolcus japonicus is native to China, Japan, and South Korea, where the brown marmorated stink bug is native. Adventive, wild populations of Trissolcus japonicus were discovered in Beltsville, Maryland in 2014 (Talamas et al., 2015), at several additional nearby sites in Maryland, Washington, D.C. and in Winchester, Virginia during 2015 (Jentsch, 2015: unpublished survey data) and in Vancouver, Washington in August 2015 (Milnes et al., 2016). It is speculated that these wild populations of Trissolcus japonicus may have arrived within stink bug egg masses on plant cargo shipped from Asia. ... Females chemically mark the egg in which they oviposit and will defend the egg clutch against other rival parasitoids. Males will commonly emerge first, wait atop the egg mass for the female to emerge, and then mate with females as they emerge" (Neal, 2016).

"Since 2014, the samurai wasp has turned up in 10 states and Washington, D.C. Researchers have identified at least three genetically distinct strains, suggesting multiple introductions" (Servick, 2018).

"Detection of T. japonicus in wooded habitat in the United States is concerning for two reasons and warrants further investigation. First, although T. japonicus could decrease the population of H. halys overall, this parasitoid was not found in the soybean field habitat in which H. halys can be abundant and damaging during the late summer. Second, it has been shown in the laboratory that T. japonicus readily and successfully parasitizes eggs of native beneficial stink bugs including the Spined Soldier Bug, Podisus maculiventris, which is an important predator of both native and invasive pests such as Mexican Bean Beetle (Epilachna varivestis), Colorado Potato Beetle (Leptinotarsa decemlineata), Cabbage Looper (Trichoplusia ni), and Gypsy Moth (Lymantria dispar). Given that woody habitats are preferred for overwintering and in the early season by P. maculiventris, and that our wooded site is the only one where T. japonicus was detected, this poses non-target concerns and will be explored in more detail in future field studies" (Herlihy et al., 2016).


About the size of a sesame seed.


The Samurai Wasp is an egg parasitoid of the Brown Marmorated Stink Bug.

There are 4 records in the project database.

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A female Samurai Wasp in Prince George's Co., Maryland (2014). Scale bars in millimeters. Photo by Elijah J. Talamus. (MBP list)

A female Samurai Wasp emerging from an egg in Prince George's Co., Maryland (2014). Scale bar in millimeters. Photo by Elijah J. Talamus. (MBP list)

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