Parastrachia

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Parastrachia
Systematics
Order : Schnabelkerfe (Hemiptera)
Subordination : Bed bugs (heteroptera)
Partial order : Pentatomomorpha
Family : Corimelaenidae
Subfamily : Parastrachiinae
Genre : Parastrachia
Scientific name of the  subfamily
Parastrachiinae
Schaefer , Dolling & Tachikawa , 1988
Scientific name of the  genus
Parastrachia
Distant , 1883

Parastrachia is a genus of bedbugs with two known species that both live in East Asia. The genus is notable for thefemale's brood care for her offspring.

features

These are relatively large bugs with a body length of 15 to 18 millimeters and a width of 8 to 10 millimeters with a conspicuous red and black warning color . The body outline is oval, the head slightly drawn into the pronotum, which is outlined in front. The body is predominantly bright red, the five-limbed antennae, the proboscis and the legs are black. The black drawing elements are: a central spot on the pronotum, the long, tapering scutellum with the exception of the tip and part of the adjoining clavus, a round black point on the corium of the hemielytres . The legs are rod-shaped with tibiae round in cross-section and with weak bristles, not transformed into grave-legs as in the case of the earth bugs. The hips (coxes) of the legs have a row of simple bristles on the inside, these are probably homologous to the bristle combs of the other earth bugs in the broader sense. The membrane of the fore wing has a number of large cells at the base. In the rear wing there are intervannal veins (veins not connected to the base of the wing in a field delimited by folding lines); these are not connected to one another. One hamus (a vein that is derived from the media and ends freely in the shape of a hook) is missing. The dorsum of the abdomen, which is covered by the wings, reveals seven terga, these are largely soft-skinned and deslerotized.

distribution

Parastrachia nagaensis lives in the west from China to northeast India and was also found in Laos in 2007 , this is the southern limit of its distribution. It occurs almost only in mountains, at sea levels between 500 and 3500 meters. Parastrachia japonensis is distributed to the east of it, it lives in southern China, from Guizhou north to the Qin Ling , and in the south of Japan . The species do not occur sympatric , significant differences in ecological requirements could not be determined on the basis of the distribution pattern.

Ecology and way of life

Both types are plant-sucking ( phytophag ). The biology of P. nagaensis is also almost unknown. P. japonensis only sucks on the fallen fruits of Schoepfia species, in Japan and probably also in China on Schoepfia jasminodora (Japanese Boroboro-no-ki), the only Japanese representative of the species-rich genus Schoepfia and the Oleaceae family . It avoids the sun and lives in forests, preferably younger secondary forests in the colline altitude range , while the food plant actually prefers sunny locations. It therefore occurs almost only on trees under what are actually marginal, unfavorable site conditions. At high temperatures it becomes inactive ( summer rest or estivation). It is gregarious both during estivation and during wintering and sometimes forms clusters of hundreds of individuals, which are very conspicuous due to the red warning look (comparable to the aggregations of the fire bug , which the animals look extremely similar in color). They either sit on the ground or in low vegetation, never on the host tree itself. For wintering, the aggregations sometimes retreat into the ground or under litter . For reasons unknown, some animals do not become active at all in the first year. They remain in the resting phase until next spring, so they only become active in the second year; they get by for almost two years without any food intake. Mating takes place in April, after which the males die. Only these show flight activity beforehand. The eggs are laid in the ground under the food plant.

Social way of life

Based on observations by Shuji Tachikawa and Carl W. Schaefer that female bedbugs carry around the food crops, it was discovered that females of Paratrachia japonensis provide food for their offspring. This is a behavior that has remained unique within the bugs so far. A female lays around 100 eggs in a small, self-dug cave in the ground. When threatened, the female can pick up the egg mass with her proboscis and carry it away. The larvae live together in this nest, which the female aggressively defends against possible predators. The larvae do not initially feed on fruits, but on other eggs. A nymph does not hatch from a large proportion of the eggs (after about 18 days) , but these remain unchanged and are gradually sucked out. Such food-only eggs are called "trophic" eggs (from the Greek verb trophein "to feed"). During this and later, Schoepfia fruits are carried into the nest from a distance of up to 15 meters from the mother; the fruits are about 1 to 2 centimeters in size and weigh roughly three times that of the bug. Particularly suitable fruits of the right degree of ripeness are carefully selected, which they can recognize by their smell and color; The nymphs cannot develop on inferior fruits. No matter how tortuous the way there was, the female can return to the nest in a straight line. When it comes to finding a home, it is based on the pattern of brightness created by gaps in the canopy. It is active day and night, regardless of the weather. The mother has a special tone produced by stridulation that attracts the nymphs to feed. The nymphs leave the nest in the third instar at the earliest, but they sometimes stay in it until the fifth (last) instar if the mother was unusually successful in collecting. The nymphs also remain aggregated later. The imaginal bugs have to survive after molting into the imago for about nine months, largely without food supply, until fruits of Schoepfia are formed again next spring .

The provision of the nest is interpreted as a possible adjustment to the irregular, unpredictable fruit fall of Schoepfia . The few suitable fruits, which are widely scattered on the ground, are very difficult to reach for the small nymph stages; they would have to expend considerable energy for the search.

Endosymbionts

Like most plant-sucking bed bugs, Parastrachia japonensis also has endosymbiotic bacteria in the gut. These sit in bulges (crypts) of the midgut. The main task of the symbiont is the recycling of uric acid during the rest periods without eating. Bugs sterilized by the administration of antibiotics showed a very high mortality during this period. The intestinal bacterium belonging to the Gammaproteobacteria belongs to its own line of development and is more closely related to symbionts of a cicada species and the tsetse fly . The researchers propose a new species for this, Candidatus Benitsuchiphilus tojoi . The generic name is inspired by the Japanese name of the bug species, Benitsuchi-Kamemushi, the specific epithet honors the microbiologist Sumio Tojo.

Phoretic nematodes

Permanent larvae of the bacteria-eating nematode Caenorhabditis japonica can regularly be found on the body surface of Parastrachia japonensis ; the nematode obviously uses the bug as a means of spreading ( phoresia ). It is host-specific and tied to the female of the bug species. The host is recognized chemically ( Kairomone ).

Taxonomy and Phylogeny

The genus includes only two species:

For a long time, the genus Parastrachia posed particular challenges for scientists with regard to their relationships, because it combines features of the Pentatomidae and the Cydnidae in a mosaic-like manner ; it was incorporated and re-separated into families with unusual frequency. Although a little more is now known about the relationship, this uncertainty persists in principle to this day. P.japonensis were initially placed in the (predatory or zoophage) genus Asopus (Pentatomidae, Asopinae) by the first descriptor John Scott . A number of morphological arguments speak against belonging to the Pentatomidae or the Cydnidae, into which they had also been sorted by many editors. Schaefer et al. Finally proposed a separate subfamily Parastrachiinae within the Cydnidae, which Sweet and Schaefer later elevated to the family rank, in which many editors followed them. A comprehensive processing of the Pentatomoidea according to features of the morphology and the molecular phylogeny (after comparison of homologous DNA sequences) resulted in the genus Dismegistus as sister group . This has a similarly turbulent taxonomic history, its family affiliation is unclear and controversial. While Grazia include them in a redefined subfamily Parastrachiinae within the Corimelaenidae family, other editors have so far refrained from this step. Jerzy Lis, one of the best connoisseurs of earth bugs in the broader sense, does not consider the togetherness based on an important morphological feature (bristle combs on the coxae) to be certain. while another morphological feature (spermatheca) supports grouping. A close relationship between Parastrachia and Dismegistus is likely afterwards, but further investigation is required for final clarification of the status.

Individual evidence

  1. ^ Carl W. Schaefer, Yusaku Kikuhara: Parastrachia nagaensis (Distant) (Hemiptera: Parastrachiidae) from Laos. In: Oriental Insects. Volume 41 (2007), Issue 1, pp. 459-462. doi : 10.1080 / 00305316.2007.10417529
  2. ↑ Gengping Zhu, Guoqing Liu, Wenjun Bu, Jerzy A. Lis: Geographic distribution and niche divergence of two stinkbugs, Parastrachia japonensis and Parastrachia nagaensis. In: Journal of Insect Science. 13 (2013), p. 102. (online)
  3. ^ A b James T. Costa: The Other Insect Societies. Harvard University Press, 2006, ISBN 0-674-02163-0 , pp. 297-301.
  4. ↑ Mantaro Hironaka, Shintaro Nomakuchi, Shiho Iwakuma, Lisa Filippi: Trophic egg production in a subsocial shield bug, Parastrachia japonensis Scott (Heteroptera Parastrachiidae), and its functional value. In: Ethology. 111 (12), 2005, pp. 1089-1102. doi : 10.1111 / j.1439-0310.2005.01112.x
  5. ↑ Mantaro Hironaka, Sumio Tojo, Shintaro Nomakuchi, Lisa Filippi, Takahiko Hariyama: Round-the-clock Homing Behavior of a Subsocial Shield Bug, Parastrachia japonensis (Heteroptera: Parastrachiidae), Using Path Integration. In: Zoological Science. Vol. 24 (2007), Issue 6, pp. 535-541. doi : 10.2108 / zsj.24.535
  6. ↑ Mantaro Hironaka, Koichi Inadomi, Shintaro Nomakuchi, Lisa Filippi, Takahiko Hariyama: Canopy compass in nocturnal homing of the subsocial shield bug, Parastrachia japonensis (Heteroptera: Parastrachiidae). In: Natural Sciences. 95 (4) (2008), pp. 343-346.
  7. ↑ S. Nomakuchi, T. Yanagi, N. Baba, A. Takahira, M. Hironaka, L. Filippi: Provisioning call by mothers of a subsocial shield bug. In: Journal of Zoology. Volume 288 (2012), Issue 1, pp. 50-56, doi : 10.1111 / j.1469-7998.2012.00923.x
  8. ↑ Takahiro Hosokawa, Yoshitomo Kikuchi, Naruo Nikoh, Xian-Ying Meng, Mantaro Hironaka, Takema Fukatsu: Phylogenetic position and peculiar genetic traits of the midgut bacterial symbiont in the stinkbug Parastrachia japonensis. In: Applied and Environmental Microbiology. Vol. 76 (2010), No. 13, pp. 4130-4135. (on-line)
  9. ↑ Etsuko Okumura, Ryusei Tanaka, Toyoshi Yoshiga: Species-specific recognition of the carrier insect by duration larvae of the nematode Caenorhabditis japonica. In: Journal of Experimental Biology. 216, pp. 568-572, doi : 10.1242 / jeb.073593
  10. ^ A b Merrill H. Sweet, Carl W. Schaefer: Parastrachiinae (Hemiptera: Cydnidae) Raised to Family Level. In: Annals of the Entomological Society of America. 95 (4) 1990, pp. 441-448, doi : 10.1603 / 0013-8746 (2002) 095 [0441: PHCRTF] 2.0.CO; 2
  11. ↑ Randall T. Schuh, James Alexander Slater: True Bugs of the World (Hemiptera Heteroptera): Classification and Natural History. Cornell University Press, 1995, ISBN 0-8014-2066-0 , p. 222.
  12. ^ CW Schaefer, WR Dolling, S. Tachikawa: The shieldbug genus Parastrachia and its position within the Pentatomoidea (Insecta: Hemiptera). In: Zoological Journal of the Linnean Society. Volume 93 (1988), Issue 4, pp. 283-311. doi : 10.1111 / j.1096-3642.1988.tb01365.x
  13. ^ Thomas J. Henry: Biodiversity of Heteroptera. In: Robert G. Foottit, Peter H. Adler: Insect Biodiversity: Science and Society. Wiley-Blackwell, 2009, ISBN 978-1-4051-5142-9 .
  14. ↑ Jocelia Grazia, Randall T. Schuh, Ward C. Wheeler: Phylogenetic relationships of family groups in Pentatomoidea based on morphology and DNA sequences (Insecta: Heteroptera). In: Cladistics. 24 (2008), pp. 932-976. doi : 10.1111 / j.1096-0031.2008.00224.x
  15. ^ IAD Robertson: The Pentatomoidea (Hemiptera: Heteroptera) of Sub-Saharan Africa: a database. Malindi 2009 (online)
  16. ↑ Jerzy A. Lis: Coxal combs in the Cydnidae sensu lato and three other related “cydnoid” families - Parastrachiidae, Thaumastellidae, Thyreocoridae (Hemiptera: Heteroptera): functional, taxonomic, and phylogenetic significance. In: Zootaxa. 2476 (2010), pp. 53-64.
  17. ↑ Dominique Pluot-Sigwalt & Jerzy A. Lis: Morphology of the spermatheca in the Cydnidae (Hemiptera: Heteroptera): Bearing of its diversity on classification and phylogeny. In: European Journal of Entomology. Vol. 105 (2008), Issue 2, pp. 279-312.

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