Coelopa frigida

Coelopa frigida
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Diptera
Family:	Coelopidae
Genus:	Coelopa
Species:	C. frigida
Binomial name
Coelopa frigida (Fabricius, 1805)

Coelopa frigida is a species of seaweed fly or kelp fly. It is the most widely distributed species of seaweed fly.^[1] It can be found on most shorelines in the temperate Northern Hemisphere.^[1] Other species of seaweed flies include Coelopa pilipes.^[2]

The fly has a grayish black body and yellow-brown legs.^[1]

The fly oviposits in dead kelp that washes up on beaches.^[3] This is the only place it lays eggs, and it can do so on many species of kelp and seaweed,^[4] including species of Laminaria and Fucus.^[5] A female fly lays up to five clutches of 80 eggs each.^[6] The larvae feed upon the bacteria coating the dead kelp.^[4] The life cycle is about 11^[1] or 12^[6] days long.

"Blooms" of the flies occur at times, possibly when temperatures and amounts of kelp increase.^[3]

This fly is sometimes cultured in the laboratory.^[6] Its behavior is studied in an effort to understand sexual selection, especially the topic of female choice.^[7] Studies suggest that female flies of this species prefer larger males to smaller.^[8][9] The species engages in sexual conflict.^[10] Females perform rejection behaviors when mounted by males, and may mate with larger males because larger males are better able to force the mating.^[10] As females are more likely to successfully reject smaller males, sexual selection favors larger ones.^[10] Mating behaviors are genetically influenced, as evidenced by a preference for smaller males among females of a certain genotype.^[11]

This fly is host to the mite Thinoseius fucicola.^[2] It provides food for seabirds such as the Purple Sandpiper (Calidris maritima).^[12] It competes with another seaweed fly, C. pilipes, for resources.^[5]

References

1. ^ ^{a b c d} Kelp Fly. Oceana.org
2. ^ ^{a b} Gilburn, A. S., et al. (2009). Sex-biased phoretic mite load on two seaweed flies: Coelopa frigida and Coelopa pilipes. Environ Entomol 38:6 1608.
3. ^ ^{a b} Mather, K. South Bay beaches hit by swarms of kelp flies. Los Angeles Times June 18, 2011. Accessed June 18, 2011.
4. ^ ^{a b} Cullen, S. J., et al. (1987). (Dietary requirements of seaweed flies (Coelopa frigida). Estuarine, Coastal and Shelf Science 24:5 701.
5. ^ ^{a b} Edward, D. A., et al. (2008). Investigating dietary preferences in two competing dipterans, Coelopa frigida and Coelopa pillipes, using stable isotope ratios of carbon and nitrogen. Entomologia Experimentalis et Applicata, 127 (3) 169-175.
6. ^ ^{a b c} Burnet, B. and U. Thompson. (1960). Laboratory culture of Coelopa frigida (Fabricius) (Diptera: Coelopidae). Proceedings of the Royal Entomological Society of London. Series A, General Entomology. 35:4-6 85-89.
7. ^ MacDonald, C. and J. F. Y. Brookfield. (2009). Intraspecific molecular variation in the seaweed fly Coelopa frigida consistent with behavioural distinctness of British and Swedish populations. Molecular Ecology 11:9 1637.
8. ^ Gilburn, A. S., et al. (1992). Female mating preference for large size in Coelopa frigida (seaweed fly). Heredity 69 209.
9. ^ Gilburn, A. S. and T. H. Day. (1994). Sexual Dimorphism, Sexual Selection and the $\alpha \beta $ Chromosomal Inversion Polymorphism in the Seaweed Fly, Coelopa frigida. Proc. R. Soc. Lond. B 257: 1350 303-309.
10. ^ ^{a b c} Shuker, D. M. and T. H. Day. Mate sampling and the sexual conflict over mating in seaweed flies. Behavioral Ecology 13:1 83.
11. ^ Blyth, J. E. and A. S. Gilburn. (2011). The function of female behaviours adopted during premating struggles in the seaweed fly, Coelopa frigida. Animal Behaviour 81:1 77.
12. ^ Summers, R. W., et al. (1990). Tidal and sexual differences in the diet of Purple Sandpipers Calidris maritima in Scotland. Bird Study 37:3 187.

Further reading

• Edward, D. A. (2008). Habitat Composition, Sexual Conflict, and Life History Evolution in Coelopa frigida. PhD Thesis, University of Stirling.