Geographic Range
Western boxelder bugs (
Boisea rubrolineata
) are found in the Nearctic region. Their range extends along the west coast, as far
north as central British Columbia and as far south as southern California. The eastern
border of their range includes much of Idaho, Utah, and New Mexico, as well as southwestern
Colorado. Western boxelder bugshave not been reported outside of their native range.
Habitat
Western boxelder bugs prefer to live in areas where there are trees and other vegetation
as food sources. This includes natural areas, but also urban, suburban, and agricultural
areas. They are mostly limited to temperate climates, but can inhabit less vernal
biomes such as deserts and mountains. Western boxelder bugs are uncommon in mountainous
areas, but have been reported in places like Del Norte and Humboldt, California. These
insects tend to stay at lower to moderate elevations, with the lowest recorded at
6 m above sea level in Napa, California.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- desert or dune
- savanna or grassland
- forest
- rainforest
- mountains
- Other Habitat Features
- urban
- suburban
- agricultural
Physical Description
Western boxelder bugs are closely related to boxelder bugs ( Boisea trivittata ), and are similar in appearance. Both species have small, black, ovoid bodies with red-orange lines around the edges of their forewings and thoracic sclerites. The main physical difference between the two species is that western boxelder bugs have additional red-orange markings that follow the internal venation of their forewings in addition to the forewing borders.
Western boxelder bugs have small, spade-shaped heads with large, red, lateral compound
eyes. They also have two ocelli, or simple eyes, which detect changes in light and
likely aid in the perception of their environment. Western boxelder bugs have a conspicuous
notch on the anterior portion of their first thoracic segment. This feature is common
in other insects of the subfamily
Rhopalinae
. Western boxelder bugs have black legs with orange coxae and long mouthparts adapted
for piercing plant tissue and sucking out nutrients. It is thought that the bright
orange and black coloration of western boxelder bugs is aposematic, warning predators
of their toxicity. Western boxelder bugs are approximately 13 mm long. Male and female
western boxelder bugs are very similar, although the females are slightly larger.
- Other Physical Features
- ectothermic
- bilateral symmetry
- poisonous
- Sexual Dimorphism
- sexes alike
- female larger
Development
Western boxelder bugs develop from eggs, laying dormant through the winter after they
are laid, emerging in the spring as first instar nymphs. Alternatively, they may emerge
later in summer as a second yearly generation. After hatching, first instar nymphs
go through incomplete metamorphosis consisting of five instars before becoming adults,
which look very physically similar to the nymphal stages. Nymphs slowly increase in
size and physiological development as they progress through each instar stage, until
they reach maturity. Nymphs that emerge from eggs in the late summer or fall reach
adulthood before winter, during which they enter diapause, suspending development
and reproduction until spring when the weather is warmer.
- Development - Life Cycle
- metamorphosis
- diapause
Reproduction
There is very little information available on specific mating systems of western boxelder
bugs. However, they are closely related to boxelder bugs (
Boisea trivittata
), which are promiscuous. It is likely that western boxelder bugs have a similar mating
system.
- Mating System
- polygynandrous (promiscuous)
Western boxelder bugs typically have two mating seasons, depending on the timing of
emergence. For individuals that emerge as nymphs early in the year, mating occurs
in the middle of summer. For individuals that matured in the prior year and entered
diapause in winter, mating occurs in spring after emergence from diapause. Females
typically lay about 10 eggs in a clutch, which then hatch as first instar nymphs after
approximately two weeks. First instar nymphs take about 60 days to reach sexual maturity
as adults.
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- oviparous
There is no research regarding parental investment in western boxelder bugs.
Lifespan/Longevity
There is little data on the lifespan of western boxelder bugs. However, individuals
that emerge in the spring typically live until the end of the breeding season in the
fall, and individuals that emerge later in summer typically overwinter and die after
reproducing in the spring. Thus, the lifespan of western boxelder bugs is estimated
to be between 6 and 12 months.
Behavior
Western boxelder bugs are specialized to live and feed on trees. They are capable
of flying to tall branches or climbing on surfaces such as bark or leaves. However,
they are not entirely restricted to living on trees. Western boxelder bugs crawl on
the ground and are a common nuisance species in human-made structures. Western boxelder
bugs are diurnal insects and can fly up to two miles to look for suitable feeding
sites. While they are often found alone, they aggregate in groups to mate or feed.
One notable behavior of western boxelder bugs is sunbathing as a means of sanitation.
They tend to aggregate in sunny places, at which point they release a monoterpene
that they smear on their exoskeletons. This chemical does not have a use as a pheromone,
but keeps the fungal pathogen
Beauveria bassiana
from reproducing. The fungus dies off naturally, but without creating or spreading
spores, so western boxelder bugs that apply this chemical can keep their cuticles
clear of fungal infection.
- Key Behaviors
- arboreal
- scansorial
- terricolous
- flies
- diurnal
- motile
- nomadic
- sedentary
- hibernation
- solitary
- social
Home Range
There is no record of home range size specified for western boxelder bugs.
Communication and Perception
Western boxelder bugs, like many other insects, perceive their environment visually and through touch. Additionally, western boxelder bugs are sensitive to sound and vibrations due to setae, or sensitive hairs, on their bodies.
Western boxelder bugs communicate with each other primarily with visual and chemical
cues. They also communicate through touch when aggregating in large numbers.
Most importantly, these insects communicate chemically through pheromones and allelochemicals.
Their antennae have receptors to such chemicals that allow them to interact with their
surroundings and other organisms. One of their most notable pheromones is 2-Phenylethanol,
which is an aggregation and mate-attractant pheromone. During mating seasons in the
summer and spring, western boxelder bugs release this pheromone, signaling others
in the area to gather on one tree and seek mates. Western boxelder bugs also receive
chemical cues from their host plants. Volatiles from these plants cue the bugs to
their presence and the readiness of their fruits and seeds for feeding (Schwarz, 2008).
- Other Communication Modes
- pheromones
- Perception Channels
- visual
- tactile
- acoustic
- vibrations
- chemical
Food Habits
Western boxelder bugs are primarily frugivores and granivores. They eat fruits and
seeds from trees like boxelder (
Acer negundo
), maple (
Acer
), ash (
Fraxinus
), bigleaf maple (
Acer grandifolium
), goldenrain tree (
Koelreuteria paniculata
), Western soapberry (
Sapindus saponaria
), apple (
Malus
), peach (
Prunus persica
), kiwi (
Actinidia deliciosa
), almond (
Prunus amygdalus
), cherry (
Prunus avium
), grape (
Vitis vinifera
), plum (
Prunus domestica
), and pear (
Pyrus
spp.). They do not typically do enough damage to be economically impactful, but can
damage fruits and seeds of these trees.
- Plant Foods
- seeds, grains, and nuts
- fruit
Predation
Western boxelder bugs are black and orange. These colors are aposematic, indicating
to predators that they may be poisonous. Western boxelder bugs are not truly poisonous,
but exude a distasteful odor when injured or killed.
Predators of western boxelder bugs mostly include rodents and birds. Species in the
order
Rodentia
, such as rats, chipmunks, and mice have been reported to prey on western boxelder
bugs, as have birds like geese and ducks (family
Anseridae
) as well as guinea hens and chickens (family
Galiiformes
). Western boxelder bugs are often eaten by other arthropods, such as spiders (order
Araneae
), wheel bugs (
Arilus
spp.), and praying mantises (order
Mantodea
).
- Anti-predator Adaptations
- aposematic
Ecosystem Roles
Western boxelder bugs typically live and feed on trees in the
Acer
genus. Their main host species is boxelder maple (
Acer negundo
), but they also use silver maple (
Acer saccharinum
) and red maple (
Acer rubrum
). Additionally, western boxelder bugs may feed on ash trees (genus
Fraxinus
) , as well as orchard fruits like pear, plum, and cherry. Western boxelder bugs will
primarily live on and feed from pistillate (female) trees, as these are the ones bearing
seeds and fruit.
Western boxelder bugs are also well known hosts of the parasitic trypanosome
Leptomonas podlipaevi
, and the fungal pathogen
Beauveria bassiana
.
- Ecosystem Impact
- parasite
- Boxelder trees ( Acer negundo )
- Red maple trees ( Acer rubrum )
- Ash trees ( Fraxinus )
- Silver maple ( Acer saccharinum )
- Pear ( Pyrus )
- Kiwi ( Actinidia deliciosa )
- Almond ( Prunus amygdalus )
- Apple ( Malus )
- Cherry ( Prunus avium )
- Peach ( Prunus persica )
- Plum ( Prunus domestica )
- Grape ( Vitis vinifera )
- plum trees, and on grapes
- Leptomonas podlipaevi
- Beauveria bassiana
Economic Importance for Humans: Positive
There is no known notable economic importance of western boxelder bugs for humans except for as food for species that hunt pest insects, like birds, or as a research subject for hemipteran behavior.
- Positive Impacts
- research and education
Economic Importance for Humans: Negative
These insects are typically categorized as nuisance pests due to their presence in homes and businesses. They frequently enter buildings, and can cause mess with their feces. Also, when western boxelder bugs are killed or threatened, they produce a smelly odor. Fortunately, though these insects gather inside, they do not mate there and therefore cannot grow in numbers in human furnishings.
Western boxelder bugs can also cause marginal damage to ornamental trees, though the
level of damage is rarely significant. Their feeding mainly causes puckering and disfigurement
on fruit.
- Negative Impacts
- crop pest
- household pest
Conservation Status
There is no special conservation status for western boxelder bugs as they are common throughout their range.
Additional Links
Contributors
Amy Bagby (author), Colorado State University, Amy Bagby (editor), Colorado State University, Genevieve Barnett (editor), Colorado State University, Galen Burrell (editor), Special Projects.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- desert or dunes
-
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- urban
-
living in cities and large towns, landscapes dominated by human structures and activity.
- suburban
-
living in residential areas on the outskirts of large cities or towns.
- agricultural
-
living in landscapes dominated by human agriculture.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- poisonous
-
an animal which has a substance capable of killing, injuring, or impairing other animals through its chemical action (for example, the skin of poison dart frogs).
- metamorphosis
-
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
- diapause
-
a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- internal fertilization
-
fertilization takes place within the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- nomadic
-
generally wanders from place to place, usually within a well-defined range.
- sedentary
-
remains in the same area
- hibernation
-
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
- solitary
-
lives alone
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- pheromones
-
chemicals released into air or water that are detected by and responded to by other animals of the same species
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- vibrations
-
movements of a hard surface that are produced by animals as signals to others
- chemical
-
uses smells or other chemicals to communicate
- aposematic
-
having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.
- parasite
-
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- granivore
-
an animal that mainly eats seeds
References
Carroll, S. 2014. "Boisea rubrolineata" (On-line). Soapberry Bugs of the World. Accessed November 29, 2021 at http://soapberrybug.org/01_cms/details.asp?ID=56 .
Davidson, E. 2018. "What Eats Boxelder Bugs" (On-line). Sciencing. Accessed December 30, 2021 at https://sciencing.com/eats-boxelder-bugs-8528486.html .
Elliott, L., H. Nendick-Mason, B. Moisset, R. McLeod, D. Ferguson, B. Velov. 2018. "Species Boisea rubrolineata - Western Boxelder Bug" (On-line). BugGuide. Accessed December 03, 2021 at https://bugguide.net/node/view/15578 .
NC State, 2015. "Insect Communication" (On-line). Agriculture and Life Sciences. Accessed December 29, 2021 at https://genent.cals.ncsu.edu/bug-bytes/communication/ .
NPIC, 2021. "Boxelder Bugs" (On-line). National Pesticide Information Center. Accessed December 03, 2021 at http://npic.orst.edu/pest/boxelder.html .
Schwarz, J., Z. Punja, M. Goettel, G. Gries. 2012. Do western boxelder bugs sunbathe for sanitation? Inferences from in vitro experiments. Entomologia Experimentalis et Applicata , 145: 38-49. Accessed December 30, 2021 at https://www.researchgate.net/publication/235968608_Do_Western_boxelder_bugs_sunbathe_for_sanitation_Inferences_from_in_vitro_experiments .
Schwarz, J. 2008. The chemical ecology of host foraging, aggregation, and prophylactic microbial defense in the western boxelder bug, Boisea rubrolineata (Barber) (Heteroptera: Rhopalidae). Department of Biological Sciences Master's Defense at Simon Fraser University, 0:0: 1-188. Accessed December 03, 2021 at https://www.researchgate.net/publication/279510732_The_chemical_ecology_of_host_foraging_aggregation_and_prophylactic_microbial_defense_in_the_western_boxelder_bug_Boisea_rubrolineata_Barber_Heteroptera_Rhopalidae .
Terry, A. 2021. "Boisea trivittata boxelder bug" (On-line). Animal Diversity Web. Accessed December 23, 2021 at https://animaldiversity.org/accounts/Boisea_trivittata/ .
UC IPM, 2017. "Pests in Gardens and Landscapes: Boxelder Bug" (On-line). University of California Agriculture and Natural Resources: Statewide Integrated Pest Management Program. Accessed December 23, 2021 at http://ipm.ucanr.edu/PMG/PESTNOTES/pn74114.html .
Yurchenko, V., J. Lukeš, X. Xu, D. Maslov. 2006. An Integrated Morphological and Molecular Approach to a New Species Description in the Trypanosomatidae: the Case of Leptomonas podlipaevi n. sp., a Parasite of Boisea rubrolineata (Hemiptera: Rhopalidae). Journal of Eukaryotic Microbology , 53(2): 103-111.