Mirinae

 Fine-streaked bugkin Miris striatus, copyright Aleksandrs Balodis.

Belongs within: Miridae.
Contains: Lygus.

The Mirinae are a group of relatively large mirid bugs usually characterised by clearly visible, lamellate, apically divergent parempodia, and pulvilli present and attached to the ventral surface of claws. Members of the tribe Mirini have a distinct, raised pronotal collar and an opaque corium and clavus (Carver et al. 1991).

The mirines
Published 27 October 2019

Every profession has its quirks, tricks of the trade that are difficult to learn and appreciate except through direct experience. One quirk of entomology is that specimens of each distinct type of insect will have their own nuances for the best method to preserve and present them. And there are some particular types of insect that can be particularly challenging in that regard. Which is a roundabout way of saying: I am not a great fan of mirids.

Green mirid Creontiades dilutus, copyright CSIRO.

Mirids are the largest recognised family of the true bugs in the Heteroptera, with over 11,000 species known worldwide and presumably many more remaining undescribed. They can be distinguished from most (though not, it should be stressed, all) other bug families by the presence of the cuneus, a distinct cross-fold near the outer tip of the hemelytron (the toughened basal part of the fore wing). Most mirids can be further recognised by the absence of ocelli. They are mostly smaller bugs, generally somewhat soft-bodied, and mostly plant feeders though there are some notable exceptions. They also (and this is the reason why they have sometimes been the object of my animus in the past) have a tendency to be what I can only describe as weirdly flimsy. Most insect specimens, at least while stil fresh and relaxed, hold together reasonably well when subject to basic handling. Mirids, on the other hand, will throw off legs if you so much as look at them too hard.

An ant-mimicking mirid, Dacerla inflata, copyright Judy Gallagher.

Mirids are divided between several subfamilies, with the type subfamily Mirinae including well over 4000 species (Kim & Jung 2019). Mirines tend to be relatively large compared to other mirids (up to a bit over half a centimetre in length) and are characterised by features of the genitalia, together with a pair of lamellate, divergent parempodia (fleshy structures that may help in gripping onto things) at the end of the legs between the claws. Other notable features (shared with the closely related Deraeocorinae) include a deeply punctate pronotum, and a relatively long beak that extends beyond the mid coxae at rest. Several species of Mirinae are notable pests. The green mirid Creontiades dilutus is one of the more significant bug pests of crops in Australia, attacking a wide range of hosts including cotton, stone fruit, potatoes, legumes and many more (Malipatil & Cassis 1997). It generally feeds from growing points, killing new buds and inhibiting the production of flowers and new growth. Other polyphagous pests causing similar damage include the tarnished plant bugs of the genus Lygus, whose vernacular name is somewhat self-explanatory, and the alfalfa bug Adelphocoris lineolatus.

Tarnished plant bug Lygus pratensis, copyright Hectonichus.

Six tribes have been recognised within the Mirinae, distinguished by their overall habitus. The Mirini, the largest tribe, have a more or less ovoid body shape with a distinct, raised pronotal collar and opaque hemelytra. The Hyalopeplini have a similar body shape to Mirini but transparent hemelytra. The Restheniini have a reduced evaporative area on the abdomen. The Stenodemini and Mecistoscelini are long and slender with long appendages, with the head directed forward in the Stenodemini. The Herdoniini are ant mimics, presumably for defence from predators. The appearance of an ant waist is achieved by a narrowing of the mirid’s own body and wings, and/or an appropriately placed white triangular marking across the hemelytron. Despite the superficial distinctiveness of the tribes, however, a phylogenetic study of the Mirinae by Kim & Jung (2019) found at least two of them to be paraphyletic, with Mecistoscelini being nested within Stenodemini, and Hyalopeplini and Restheniini within Mirini. The affinities of the Herdoniini, unsampled by Kim & Jung, remain to be established.

Systematics of Mirinae
<==Mirinae
    |  i. s.: LygusWEE70
    |--HyalopeplusZS10 [HyalopepliniCGW91]
    |--StenodeminiCGW91
    |    |--MegaloceroeaWEE70
    |    `--TrigonotylusWEE70
    |         |--T. doddiCGW91
    |         `--T. ruficornisH01
    `--MiriniCGW91
         |--AustrocapsusCGW91
         |--Pseudopantilius australisCGW91, G75
         |--NiastamaCGW91
         |--Sidnia kinbergiCGW91
         |--Creontiades dilutus [incl. Megacoelum modestum]CGW91
         |--CalocorisCGW91
         |    |--C. norvegicusCGW91
         |    `--C. striatellusA99
         `--MirisH01
              |--M. calcaratusH01
              |--M. campestrisL02
              |--M. pratensisR26
              |--M. spissicornisL02
              |--M. striatusG20
              |--M. vagansG20 [=Nabis vagansL02]
              `--M. virens [incl. M. virens var. testaceus]H01

*Type species of generic name indicated

References

[A99] Ax, P. 1999. Das System der Metazoa II. Ein Lehrbuch der phylogenetischen Systematik. Gustav Fisher Verlag: Stuttgart (translated: 2000. Multicellular Animals: The phylogenetic system of the Metazoa vol. 2. Springer).

[CGW91] Carver, M., G. F. Gross & T. E. Woodward. 1991. Hemiptera (bugs, leafhoppers, cicadas, aphids, scale insects etc.) In: CSIRO. The Insects of Australia: A textbook for students and research workers 2nd ed. vol. 1 pp. 429–509. Melbourne University Press: Carlton (Victoria).

[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.

[G75] Gross, G. F. 1975. Plant-feeding and Other Bugs (Hemiptera) of South Australia. Heteroptera—Part I. Handbook of the Flora and Fauna of South Australia.

[H01] Horváth, G. 1901. Hemipterák [Hemiptera]. In: Horváth, G. (ed.) Zichy Jenő Gróf Harmadik Ázsiai Utazása [Dritte Asiatische Forschungsreise des Grafen Eugen Zichy] vol. 2. Zichy Jenő Gróf Harmadik Ázsiai Utazásának Állattani Eredményei [Zoologische Ergebnisse der Dritten Asiatischen Forschungsreise des Grafen Eugen Zichy] pp. 245–274. Victor Hornyánszky: Budapest, and Karl W. Hierseman: Leipzig.

Kim, J., & S. Jung. 2019. Phylogeny of the plant bug subfamily Mirinae (Hemiptera: Heteroptera: Cimicomorpha: Miridae) based on total evidence analysis. Systematic Entomology 44: 686–698.

[L02] Latreille, P. A. 1802. Histoire Naturelle, générale et particulière des crustacés et des insectes vol. 3. Familles naturelles des genres. F. Dufart: Paris.

Malipatil, M. B., & G. Cassis. 1997. Taxonomic review of Creontiades Distant in Australia (Hemiptera: Miridae: Mirinae). Australian Journal of Entomology 36: 1–13.

[R26] Risso, A. 1826. Histoire naturelle des principales productions de l’Europe méridionale et particulièrement de celles des environs de Nice et des Alpes maritimes vol. 5. F.-G. Levrault: Paris.

[WEE70] Woodward, T. E., J. W. Evans & V. F. Eastop. 1970. Hemiptera (bugs, leafhoppers, etc.) In: CSIRO. The Insects of Australia: A textbook for students and research workers pp. 387–457. Melbourne University Press.

[ZS10] Zborowski, P., & R. Storey. 2010. A Field Guide to Insects in Australia 3rd ed. Reed New Holland: Sydney.

Leave a comment

Your email address will not be published. Required fields are marked *