Geographic Range
The geographic range of the parasitoid
Dicopomorpha echmepterygis
spans across eastern North America (Mockford, 1997). Its range coincides with that
of its host,
Echmepteryx hageni
(bark louse).
Habitat
As a parasitic wasp,
Dicopomorpha echmepterygis
spends the majority of its life cycle in the egg of its host, the
bark louse
. The bark louse lays its eggs in the bark of trees.
- Habitat Regions
- temperate
- terrestrial
Physical Description
A great deal of sexual dimorphism exists in Dicopomorpha echmepterygis . The males are blind and wingless, with a body length of only 0.139 to 0.240 mm (Mockford, 1997). Dicopomorpha echmepterygis males are the smallest known adult insects (Gahlhoff, 1998). Male bodies, along with their relatively long legs, are a dull grayish brown. They have small heads that lack compound eyes, with unsegmented antennae (Mockford, 1997). The body volume of males is 1/8 that of the females (Grebennikov, 2008).
Dicopomorpha echmepterygis
females have entirely black bodies with dusky brown legs and antennae. The antennae
are twice as long as they are wide (Mockford, 1997). Unlike the diminutive males,
females have slender wings that are slightly narrowed through the middle. The average
forewing length is 0.447 mm, while the average hindwing length is 0.424 mm. Females
have compound eyes that aid in dispersal from tree to tree (Gahlhoff, 1998). They
also possess mandibles that project mesally and overlap at the tips, each with a pair
of teeth (Mockford, 1997). The females are 40% larger than the males, measuring 0.386
to 0.550 mm long (Grebennikov, 2008). This significant sexual dimorphism is thought
to result from the limited resources provided by host eggs (Gahlhoff, 1998).
- Other Physical Features
- ectothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
- sexes colored or patterned differently
- sexes shaped differently
Development
Nutrients within host eggs are limited; most nutrients contribute to the development
of
Dicopomorpha echmepterygis
females (Mockford, 1997). The diminutive males require less nutrients to develop
into adults (Gahlhoff, 1998).
Reproduction
Dicopomorpha echmepterygis
primarily reproduces through brother-sister matings. Non-sibling matings may occur
when males attach themselves to females, which subsequently disperse in search of
new host eggs (Mockford, 1997).
Dicopomorpha echmepterygis females produce a single egg at a time, and eggs are about 0.106 to 0.110 mm long (Grebennikov, 2008). They lay their fluke-shaped eggs directly into the eggs of the host species, Echmepteryx hageni (Grebennikov, 2008). When parasitized, one host egg typically yields one female and one to three male parasitoids. The limited nutrients within the host egg are consumed primarily by the female wasp (Mockford, 1997). When mature, a female uses her mandibles to chew a hole through the egg (Mockford, 1997). Females breed once before they lay an egg and die. Males may never breed.
Sometimes a male uses his long legs to attach himself to the body of a female, thereby emerging from the host egg (Gahlhoff, 1998). The male then struggles toward the tip of the female’s abdomen and begins copulation. If the female already has copulated, she brushes away the male (Mockford, 1997). Sometimes a male clings to the female as she travels to new host eggs, where he may have non-sibling matings (Mockford, 1997).
Most males never leave the host egg, and they die there; however, females use their
compound eyes and wings to disperse to other trees. By dispersing, females can find
host eggs in which to deposit their own eggs (Gahlhoff, 1998).
- Key Reproductive Features
- semelparous
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- oviparous
There is no observed parental care in this species.
- Parental Investment
- no parental involvement
Lifespan/Longevity
The lifespan is very short, lasting from several hours to a few days (Boivin, 2010).
Behavior
The primary function of
Dicopomorpha echmepterygis
males is to mate with females. Females are vigorous and possess wings that aid in
dispersal among trees in search of hosts (Gahlhoff, 1998).
Home Range
The male home range is limited to the host egg, unless he clings to a female that
subsequently disperses (Mockford, 1997). Further research needs to be conducted to
determine the range that a female will fly in search of a host.
Communication and Perception
Males are blind and wingless, with relatively large antennae. Their large antennae
are believed to help them search for a mate (Mockford, 1997). Females have compound
eyes and antennae.
Food Habits
For
Dicopomorpha echmepterygis
, the majority of the life cycle is spent within the host egg, where females consume
the majority of the nutrients. The males require less nutrients and usually die before
leaving the egg, while the female only lives long enough to chew her way out of the
egg (using mandibles that project mesally and overlap at the tips, each with a pair
of teeth), disperse, and lay her own eggs in other hosts (Mockford, 1997).
- Primary Diet
-
carnivore
- eats eggs
- Animal Foods
- eggs
Predation
Because
Dicopomorpha echmepterygis
spends most of its life within the host egg, it is largely protected from potential
predators. It is unknown whether females have any predators when they disperse to
lay eggs (Resh and Ring, 2003).
Ecosystem Roles
Dicopomorpha echmepterygis
is a species in the family
Mymaridae
, which contains other common parasitoid species that control crop pests (Mockford,
1997).
- Ecosystem Impact
- parasite
Economic Importance for Humans: Positive
Although other parasitoid species in the family
Mymaridae
may help control crop pests (Mockford, 1997),
Dicopomorpha echmepterygis
does not parasitize a pest insect. There is no known positive economic importance
of
D. echmepterygis
.
Economic Importance for Humans: Negative
There is no known negative economic importance of Dicopomorpha echmepterygis .
Conservation Status
The conservation status of Dicopomorpha echmepterygis is not listed or has not yet been evaluated.
Other Comments
Dicopomorpha echmepterygis
males are the smallest known adult insects. They are smaller than a single-celled
paramecium (Gahlhoff, 1998).
Additional Links
Contributors
Amber Fitzgerald (author), Radford University, Elizabeth Wason (author, editor), Animal Diversity Web Staff.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- semelparous
-
offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.
- 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.
- parasite
-
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
- motile
-
having the capacity to move from one place to another.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- parasite
-
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
- carnivore
-
an animal that mainly eats meat
- 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.
References
Boivin, G. 2010. Phenotypic Plasticity and Fitness in Egg Parasitoids. Journal of Neotropical Entomology , 39/4: 457-463. Accessed November 08, 2011 at http://docs.google.com/viewer?a=v&q=cache:bRr9SJjNVn0J:www.scielo.br/pdf/ne/v39n4/01.pdf+Dicopomorpha+echmepterygis+Mockford,+1997&hl=en&gl=us&pid=bl&srcid=ADGEESgXjc10lShwA7AB7jw6Ii97QRsju-YlTer9Hdr-JlI_4oNvljxfrZS1i_f-UYiPR9h85wGYkS46Hej1WyH61WH8llhl3fcYpz0vdwTA2kr5PMLB-wXM7b_vtmoxyQ2H5QZEf2v0&sig=AHIEtbTjtp31dvAm-rzFDWe4sEclBWq2lg .
Gahlhoff, J. 1998. Smallest Adult. Pp. Chapter 38 in University of Florida Book of Insect Records . University of Florida: Department of Entomology & Nematology. Accessed November 12, 2011 at http://entnemdept.ufl.edu/walker/ufbir/files/pdf/UFBIR_Chapter38.pdf .
Grebennikov, V. 2008. How Small You Can Go: Factors Limiting Body Miniaturization in Winged Insects. European Journal of Entomology , 105: 313-328. Accessed November 12, 2011 at http://www.eje.cz/pdfarticles/1333/eje_105 .
Mockford, E. 1997. A New Species of Dicopomorpha ( Hymenoptera : Mymaridae ) with Diminutive, Apterous Males. Annals of the Entomological Society of America , 90: 115-120.
Noyes, J. 2011. "Universal Chalcidoidea Database" (On-line). Species 2000 & ITIS Catalogue of Life: 2011 Annual Checklist. Accessed November 14, 2011 at http://data.gbif.org/datasets/resource/1576 .
Resh, V., C. Ring. 2003. Encyclopedia of Insects . Amsterdam: Amsterdam Academic.