Pneumolaelaps longanalis Hunter and Husband, 1973, family Laelapidae

Bee Mites : Acari : Parasitiformes : Mesostigmata : Laelapidae : Pneumolaelaps

Pneumolaelaps longanalis Hunter and Husband, 1973

Pneumolaelaps longanalis Hunter and Husband, 1973: 81, Fig. 1F-N; Royce and Krantz, 1989: 161; Crozier, 1989: 167.

Material (show database records). Holotype female - USA: Michigan, Kalamazoo Co., Gull Lake Biological Station, ex petiole of female of Bombus griseocollis, 10 Aug 1964, R. W. Husband (kept in University of Georgia, Athens). 2 females - USA: Ohio Franklin Co., Columbus, Bombus fervidus nest, 6 Jul 2002, J. Wenzel, UMMZ BMOC 02-0706-001; 1 female - USA: New York, Tompkins Co., Ithaca, ex Bombus impatiens worker, 21 May 1974, B.M. OConnor, UMMZ BMOC 74-0521-001.

Hosts.

Apis mellifera Linnaeus, 1758
Bombus (Bombias) nevadensis Cresson, 1874
Bombus (Bombus) affinis Cresson, 1863
Bombus (Bombus) terricola Kirby, 1837 (including occidentalis)
Bombus (Fervidobombus) fervidus (Fabricius, 1798) (including californicus)
Bombus (Fervidobombus) pensylvanicus (DeGeer, 1773) (as americanorum)
Bombus (Fraternobombus) fraternus (Smith, 1854)
Bombus (Psithyrus) suckleyi Green, 1860
Bombus (Pyrobombus) bifarius Cresson, 1878
Bombus (Pyrobombus) bimaculatus Cresson, 1863
Bombus (Pyrobombus) frigidus Smith, 1854
Bombus (Pyrobombus) impatiens Cresson, 1863 (first record)
Bombus (Pyrobombus) mixtus Cresson, 1878
Bombus (Pyrobombus) ternarius Say, 1837
Bombus (Pyrobombus) vagans Smith, 1854
Bombus (Separatobombus) griseocollis (DeGeer, 1773) (type host)

Distribution (show map). USA: Kansas, Michigan (type locality), Ohio (first record), Pacific Northwest of the United States; Canada: Alberta (Hunter et Husband, 1973; Royce and Krantz, 1989; our data)

Biology. The following account on the feeding behavior of Pneumolaelaps longanalis is modified from Royce and Krantz (1989). Wandering P. longanalis congregates in considerable numbers on the brood cells, and larvae feeding on pollen grains provided by the adult bumblebees. When an individual pollen grain was chosen, the gnathosoma was depressed ventrally relative to the opisthosoma, and the grain removed from its sticky substrate by the palps and chelicerae. The nectar-coated grain was held in the region of the hypostome under the encircling palpi and rapidly rotated with the help of the chelicerae. During the manipulation, the nectar coating applied earlier by the foraging bee was stripped from the pollen grain surface. The mite probably also removed much of the surface pollenkitt, a lipoidal substance that covers the pollen grain surface and is incorporated to some extent in the outer wall (exine). Pollenkitt, however, does not trigger feeding in the absence of nectar. It appears that the removed nectar and pollenkitt are dissolved by salivary secretions that are directed over the rotating pollen-grain surface, and then recaptured and redirected to the preoral cavity via the fluid transport system formed by the capitular groove and overlying tritosternum. Following feeding, the stripped pollen grain was discarded and another quickly chosen for manipulation. Females were found to process pollen grains twice as rapidly as either males or deutonymphs. The mites may rupture thin-walled pollen grains during the feeding process, and it is possible that nutrients are acquired from the pollen core in this way.

References

Crozier, L. 1989. Melittiphis alvearius (Berlese) and other mites found in honeybee colonies in Nova Scotia. Journal of Apicultural Research.28: 166-168.

Hunter, P. E. & R. W. Husband. 1973. Pneumolaelaps (Acarina: Laelapidae) mites from North America and Greenland. The Florida Entomologist.56: 77-91.

Royce, L. A. & G. W. Krantz. 1989. Observations on pollen processing by Pneumolaelaps longanalis (Acari, Laelapidae), a mite associate of bumblebees. Experimental & Applied Acarology.7: 161-165.