Blattisocius

Harmfulness rating

HARMFUL | NOT HARMFUL | UNCERTAIN

generalist predators that are expected to be neutral to beneficial, but may be harmful if they can enter brood cells; preys on microarthropods in bee nests

Name

Blattisocius Keegan, 1944

Taxonomy

Superorder Parasitiformes » Order Mesostigmata » Suborder Monogynaspida » Hyporder Dermanyssiae » Family Blattisociidae » Genus Blattisocius

Type species

Blattisocius triodons Keegan, 1944 (=Lasioseius tarsalis Berlese, 1918)

Common synonyms

Paragarmania Nesbitt, 1951 (this synonymy has not been accepted by all authors; in these references (Bregetova, 1977cBregetova, 1977c:
Bregetova, N. G. 1977c. [Family Aceosejidae]. In [Opredelitel' obytayshchikh v pochve kleshchey Mesostigmata = Identification key to soil-inhabiting mites Mesostigmata], eds. M. S. Gilarov amp; N. G. Bregetova, 169-226. Leningrad: Nauka.
; Karg, 1971Karg, 1971:
Karg, W. 1971. Acari (Acarina), Milben. Unterordnung Anactinochaeta (Parasitiformes). Die freilebenden Gamasina (Gamasides), Raubmilben. Die Tierwelt Deutschlands. 59. 475 pp.
), Paragarmania is treated as a separate genus).

Diagnosis

Female: Dorsal shield undivided and without midlateral incisions (Figs. 1, 3). Sternal shieldsternal shield:
A shield in the anterior intercoxal region of parasitiform mites that bears one or more pairs of sternal setae.
with 3 pairs of setae (Fig. 20) or st3 on partially separate platelets (Figs. 4, 5, 6, 7); st4 situated on soft cuticle (Fig. 20) or on corners of sternal shieldsternal shield:
A shield in the anterior intercoxal region of parasitiform mites that bears one or more pairs of sternal setae.
platelets (Figs. 4, 6, 7). Metsternal shields absent (Figs. 4, 6, 7, 20). Ventrianal shieldventrianal shield:
In Mesostigmata, a ventral shield bearing the anal opening, circumanal (postanal and adanal) setae, and one or more pairs of ventral setae or pores (lyrifissures) (see anal shield); may be narrow or very broad and covering most of the gaster.
elongated, subtriangular to bullet-shaped, bearing 3-4 pairs of ventral (preanal) setae (JV, ZV), in addition to the three circumanal setae (Figs. 8, 9). Adanal setae inserted anterior to hind margin of anus (Figs. 8, 9). Peritrematic shield slender, barely wider than stigma at level of stigma (Fig. 10). CorniculiCorniculus:
Paired, horn-like process (sometimes toothed, bifurcate, trifurcate, spine-like, spatulate, or membranous) on the subcapitulum of parasitiform mites. These processes usually support the salivary styli. If toothed could be confused with a rutellum, a possibly homologous structure in Acariformes and Opilioacarida.
narrowly separated, slender (Fig. 11). Fixed digit with filiform pilus dentilispilus dentilis:
A seta-like or membranous sensory organ inserted ventrolaterally on the fixed digit of the chelicera of many Mesostigmata.
(Figs. 12, 17). Tectumtectum:
The leading dorsal, shelf-like projection of the basis capitulum in Mesostigmata. Also known as gnathotectum or epistome.
convex (Fig 16).

Species identification

A dichotomous key is available in Britto et al., 2012Britto et al., 2012:
Britto, E. P. J., P. C. Lopes amp; G. J. De Moraes. 2012. Blattisocius (Acari, Blattisociidae) species from Brazil, with description of a new species, redescription of Blattisocius keegani and a key for the separation of the world species of the genus. Zootaxa.3479: 33-51.
.

Similar genera

Lasioseius. Blattisocius can be separated from Lasioseius by narrow ventrianal shieldventrianal shield:
In Mesostigmata, a ventral shield bearing the anal opening, circumanal (postanal and adanal) setae, and one or more pairs of ventral setae or pores (lyrifissures) (see anal shield); may be narrow or very broad and covering most of the gaster.
(broader in Lasioseius), metasternal shieldsmetasternal shield:
Small, usually teardrop to subtriangular paired shields bearing metasternal setae st4; sometimes fused to the sternal shield or the endopodal shields. Present in Mesostigmata.
absent (present in Lasioseius); corniculicorniculus:
Paired, horn-like process (sometimes toothed, bifurcate, trifurcate, spine-like, spatulate, or membranous) on the subcapitulum of parasitiform mites. These processes usually support the salivary styli. If toothed could be confused with a rutellum, a possibly homologous structure in Acariformes and Opilioacarida.
narrowly separated (widely separated in Lasioseius), and peritrematic shield barely wider than diameter of stigma at level of stigma (clearly wider in Lasioseius).

Distribution

Worldwide. Species associated with bees have been found in the Nearctic (Canada), Palaearctic (Czech Republic, Poland, Russia, and Ukraine), Neotropical (Argentina), Oriental (India), and Australasian (New Zealand and Australia) regions.

Bee hosts

Members of this genus have been found in honey bee (Apis) hives (e.g., B. tarsalis) and on adult honey bees (e.g., B. apisassociae and B. apis). Blattisocius tarsalis has also been found in nests of leafcutter bees Megachile gomphrenae and M. pallefacta.

Host association level

facultativefacultative:
can complete entire life cycle without bees or their close relative, wasps

Host associations, feeding, and dispersal

  • All stages are probably predatory on microarthropods in habitats where they are found, including honey bee hives. Some species may feed on eggs of larger insects or attack their larvae.
  • Females of a few species (B. apisassociae and B. apis) have been found on honey bee workers, indicating a possibility of phoresyphoresy:
    Attaching to or boarding another organism (i.e., a host) for dispersal to new habitats. Can be distinguished from parasitism because feeding typically does not occur.
    . Mites probably also invade nearby bee nests by walking.

Biology

Six species (Blattisocius apis, B. apisassociae, B. dentriticus, B. keegani, B. mali, and B. tarsalis) have been recorded from hives of honey bees or on adult bees.

Species of Blattisocius are also predators in soil, stored food, the nests of small mammals and birds, ripe, dried, and rotting vegetables, on plants (e. g., roses, apple trees, and Citrus trees), and in insect cultures. Prey may include acarid mites. One species, Blattisocius patagiorum (Figs. 18-20), is parasitic on adult noctuid moths.

 Fig. 1.  Blattisocius dentriticus  female, dorsal view.

Fig. 1. Blattisocius dentriticus female, dorsal view.

 Fig. 2.  Blattisocius dentriticus  female, ventral view.

Fig. 2. Blattisocius dentriticus female, ventral view.

 Fig. 3.  Blattisocius dentriticus  female idiosoma, dorsal view.

Fig. 3. Blattisocius dentriticus female idiosoma, dorsal view.

 Fig. 4.  Blattisocius dentriticus  female idiosoma, ventral view.

Fig. 4. Blattisocius dentriticus female idiosoma, ventral view.

 Fig. 5.  Blattisocius dentriticus  female sternal shield.

Fig. 5. Blattisocius dentriticus female sternal shield.

 Fig. 6.  Blattisocius dentriticus  female sternal shield region.

Fig. 6. Blattisocius dentriticus female sternal shield region.

 Fig. 7.  Blattisocius dentriticus  female epigynal shield.

Fig. 7. Blattisocius dentriticus female epigynal shield.

 Fig. 8.  Blattisocius dentriticus  female ventrianal shield region.

Fig. 8. Blattisocius dentriticus female ventrianal shield region.

 Fig. 9.  Blattisocius dentriticus  female ventrianal shield.

Fig. 9. Blattisocius dentriticus female ventrianal shield.

 Fig. 10.  Blattisocius dentriticus  female peritreme.

Fig. 10. Blattisocius dentriticus female peritreme.

 Fig. 11.  Blattisocius dentriticus  female gnathosoma, ventral view.

Fig. 11. Blattisocius dentriticus female gnathosoma, ventral view.

 Fig. 12.  Blattisocius dentriticus  female chelicera, lateral view.

Fig. 12. Blattisocius dentriticus female chelicera, lateral view.

 Fig. 13.  Blattisocius dentriticus  male, dorsal view.

Fig. 13. Blattisocius dentriticus male, dorsal view.

 Fig. 14.  Blattisocius dentriticus  male, ventral view.

Fig. 14. Blattisocius dentriticus male, ventral view.

 Fig. 15.  Blattisocius dentriticus  male gnathosoma, ventral view.

Fig. 15. Blattisocius dentriticus male gnathosoma, ventral view.

 Fig. 16.  Blattisocius dentriticus  male gnathosoma, dorsal view.

Fig. 16. Blattisocius dentriticus male gnathosoma, dorsal view.

 Fig. 17.  Blattisocius dentriticus  male chelicera, lateral view.

Fig. 17. Blattisocius dentriticus male chelicera, lateral view.

 Fig. 18.  Blattisocius   patagiorum  female, dorsal view.

Fig. 18. Blattisocius patagiorum female, dorsal view.

 Fig. 19.  Blattisocius   patagiorum  female, ventral view.

Fig. 19. Blattisocius patagiorum female, ventral view.

 Fig. 20.  Blattisocius   patagiorum  female sternal shield region.

Fig. 20. Blattisocius patagiorum female sternal shield region.