''Howardula'' is a genus of

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

that infests the larvae of mushroom-feeding flies, beetles, and other insects. Various ''Howardula'' species and strains infest

mushroom-feeding Drosophila Mushroom-feeding ''Drosophila'' (mycophagous ''Drosophila'') are a subset of ''Drosophila'' flies that have highly specific mushroom-breeding ecologies. Often these flies can tolerate toxic compounds from ''Amanita'' mushrooms. Species groups ...

, including ''

Howardula aoronymphium ''Howardula aoronymphium'' is a species of nematode that infects specialist mushroom-feeding fruit flies such as ''Drosophila falleni'' and ''Drosophila neotestacea''. Mated female nematodes pierce the fly larva cuticle and take up residence in th ...

'' and '' Howardula neocosmis''. '' Howardula husseyi'' can infest the mushroom phorid ''

Megaselia halterata The mushroom phorid fly ''(Megaselia halterata)'' is a species of scuttle fly or hump-backed flies in the family Phoridae. "The mushroom phorid" is also used to refer to ''M. halterata''. ''Megaselia halterata'' is a common pest of mushroom culti ...

''.

Life cycle

The life cycle of ''Howardula'' nematodes begins inside the host fly, where infective juvenile nematodes are released by either the fly anus or ovipositor onto mushrooms. There, the juvenile nematodes mature and mate. Mated females will then pierce the cuticle of a fly larva using a specialized stylet, and enter the fly

hemolymph Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which ...

(insect blood) where the nematode resides. Over the course of the fly host's metamorphosis, the female nematode matures into an adult stage called the motherworm. After the adult fly emerges from its

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

, the motherworm begins releasing juvenile nematodes directly into the

hemocoel The blood circulatory system is a organ system, system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascula ...

, renewing the cycle. Other insect-infecting nematodes such as ''

Steinernema Steinernema is a genus of nematodes in the family of Steinernematidae. The genus ''Steinernema'' is named after the nematologist Gotthold Steiner. Life cycle Species form symbiotic relationships with ''Xenorhabdus'' and '' Photorhabdus'' ba ...

'' and '' Heterorhabiditis'' are used as biological control agents, as they efficiently kill their insect prey. However ''Howardula'' species require their hosts to survive into adulthood. As such, while ''Howardula'' infects insects like other nematode parasites, the "goals" of these nematodes differs drastically, leading to distinct host-parasite interactions.

References

{{Taxonbar, from=Q5265307

Life cycle

See also

References