- Sexual Dimorphism
- male larger
- sexes colored or patterned differently
- Range length
- 1.1 to 1.4 mm
- 0.04 to 0.06 in
The life cycle of Melittobia species are often observed to lay eggs on only one host and in fact many females will share a host as an oviposition site. Because of this, a prepupal host becomes virtually covered by larva (which hatch a few days after being laid) in differing stages of development. During this period, the larva feed on the tissue of the host and females begin the process of differentiating into the various polymorphs that are observed in nature. Which polymorph a larva will develop into is ultimately decided by the density of larva present on the host during the critical stages of its development (which in turn is determined by when the egg was laid). Low density values result in ‘crawlers’ that search the immediate vicinity for other hosts. Medium density values result in ‘jumpers’ that are capable of short flight and search the nest site for other nests. Finally, high density values result in ‘fliers’ that are capable of long rang flight and venture out in search of new, distant, nest cells. (Freeman and Ittyeipe, 1993; Matthews and Gonzalez, 2002; Matthews, et al., 2009; Silva-Torres and Matthews, 2003)begins when a fertilized adult female locates a juvenile solitary wasp or bee host in its prepupal stage. Once on the host, the female feeds from it and deposits eggs inside its pupal coverine at a rate of 10 to 50 eggs per day for two weeks, with fertilized eggs becoming female and unfertilized eggs male. One interesting pattern to note is that unlike many other related species that lay eggs on many hosts,
- Development - Life Cycle
- Mating System
- Key Reproductive Features
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- breeds only once in their lives.
- Breeding season
- may breed year round.
- Average eggs per season
- Average age at sexual or reproductive maturity (female)
- 25.5 days
- Average age at sexual or reproductive maturity (male)
- 25.5 days
The only parental involvement in (Matthews, et al., 2009)is shown by the females, who seek out an appropriate host in which to lay their eggs. In doing so, they provide the food and developmental environment that the larvae will need to survive to adulthood.
- Parental Investment
- no parental involvement
There has been very little published on the exact lifespans of (Silva-Torres and Matthews, 2003). One experiment showed that without finding a host, the average adult female will live from 6 to 9 days following adult development. The same study found that developmental time was anywhere from 25 to 28 days depending on the amount of other females that also parasitize on the same host. This results in a range of anywhere from 31 to 37 days for the longevity of this species.
- Typical lifespan
- 31 to 37 days
- Typical lifespan
The exact home range size foris unknown, however many individuals will complete their entire life cycle within or around a single larval host.
Communication and Perception
Courtship and mating is the only major area of communication between members of. The males perform a complex mating dance in which they raise and lower their legs and rub the females with their antennae and legs. Within this ritual, chemical, tactile, and auditory forms of communication are being utilized. The males elicit a strong pheromone from their abdominal region that is a very strong attractant to females. Also, the existence of a large gland in the male antennae suggests that pheremones are also emitted from the antennae as they are rubbed against the female. Tactile communication obviously occurs through the rubbing of the female with leg and antennal segments. Finally, during the mating dance, the males beat their wings in distinct patterns. Since the wings rarely touch the females, it is thought that these patterns of wing beating are a form of auditory communication.
The only other form of "communication" comes in the form of a pheremone that is released by a newly mature female when she has inserted her ovipositor into the pupal covering. This pheremone acts as an attractant to other females, and they will form a chewing circle around the pheremone site and attempt to chew their way out of their birth place. (Freeman and Ittyeipe, 1993; Matthews, et al., 2009)
, being a parasitoid wasp, gets all of its food from the tissues of its host. As a larva, it feeds entirely on its natal host, killing it in the process. Then as adults, the females will feed on the host that it has chosen to oviposit on.
- Animal Foods
Melittobia are parasitoids of other wasps. In many cases, these small wasps will be the biggest mortality-causing agent in the ecosystem for non social hymenopterans. Mortality is caused primarily through the devouring of the juvenile stages of the host as the larvae develop. Because of the high mortality caused by , many common host species have developed defenses such as physical barriers, chemical defenses, behavioral modification, and nest location strategies as a direct result of their association with . To date, there have been no recorded accounts of natural predators of any of the Melittobia species. Only one parasite (Anagrus putnamii, an egg parasite) has been recorded and is, as of yet, unconfirmed. Because of their importance in the mortality of solitary wasps, many of which are pollinators, also can inhibit the reproduction and dispersal of many plant species. Bumblebees have also been shown to be parasitized by . (Matthews, et al., 2009), like all other members of the genus
- Ecosystem Impact
Economic Importance for Humans: Positive
The only positive economic impact of (Matthews, et al., 2009)seems to be the fact that their small generation time, low amount of effort required to culture, and ability to thrive on many different hosts make them a useful organism for research or educational uses. Under ideal conditions, several generations can be cultured and studied in a given year.
- Positive Impacts
- research and education
Economic Importance for Humans: Negative
The primary economic impact of Melittobia species, including , is that they parisitize pollinators that are cultured for use in agricultural pollination. Many important pollinators including bumblebees can be parasitized by . This can severely damage pollination, thereby inhibiting fruit and seed production of agricultural plants. One of the major reasons that Melittobia species are so dangerous in this regard is that they have the ability to chew right through the normally effective protective nests made by many pollinating species. (Matthews, et al., 2009)
is not listed as threatened or endangered on any of the major worldwide conservation classification systems.
Andrew Wood (author), University of Michigan-Ann Arbor, Heidi Liere (editor), University of Michigan-Ann Arbor, John Marino (editor), University of Michigan-Ann Arbor, Barry OConnor (editor), University of Michigan-Ann Arbor, Rachelle Sterling (editor), Special Projects.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
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.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
- 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.
an animal that mainly eats meat
uses smells or other chemicals to communicate
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
An animal that eats mainly insects or spiders.
- internal fertilization
fertilization takes place within the female's body
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
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.
having the capacity to move from one place to another.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
having more than one female as a mate at one time
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
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.
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.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
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).
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
- year-round breeding
breeding takes place throughout the year
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