Dynamic associations between Ips sexdentatus (Coleoptera: Scolytinae) and its phoretic mites in a Pinus pinaster forest in northwest Spain

Abstract

The relationship between the pine bark beetle Ips sexdentatus and its phoretic mites in a Pinus pinaster forest in northwest Spain was studied during 2014. Four species of mites were collected, three of them from the body of the beetle-Histiostoma ovalis, Dendrolaelaps quadrisetus and Trichouropoda polytricha-the fourth, Cercoleipus coelonotus, was collected from the sediments. The main aims of this study were to explore (1) mite diversity and related parameters, (2) the location on the body of the (male and female) beetle, as well as mite assemblages, and (3) the seasonal dynamic association between mite species and the beetle. Results indicated that the diversity oscillated around 0.71 through the study period and the most dominant, frequent and abundant mite was H. ovalis. Histiostoma ovalis was found attached to almost all parts of the body (mainly on the elytral declivity and ventral thorax), whereas D. quadrisetus was exclusively found under the elytra, and T. polytricha displayed affinity towards the elytral declivity as well as the ventral thorax. None of the mite species displayed any preference for the sex of the beetle and the most frequent mite assemblage was H. ovalis, T. polytricha and D. quadrisetus all together. Maximum abundance of each phoretic mite species was related with each of the flight peaks of the beetle that would indicate that these mite species use phoresy as a primary method of transport for colonizing new food sources.

Disparity of Phoresy in Mesostigmatid Mites upon Their Specific Carrier Ips typographus (Coleoptera: Scolytinae)

“…Our findings related to the presence of deutonymphs of D. quadrisetus attached to the internal part of the elytra confirms other studies that noticed a particular preference for this body part [46,49] even on a different beetle host species [42]. The attachment location for H. piceae supports previous findings [46] that indicated the same position on the same host, I. typographus, for all mite specimens belonging to this genus.…”

“…T. polytricha feeding behavior is unknown and has also been found on I. typographus in other studies [49,50,55] and other beetles: I. sexdentatus [42], I. duplicatus [57], Hylastes cunicularius [15], Dendroctonus, and Polygraphus species [32].…”

“…They utilize external beetle parts like antennae, legs, and wings but some mite species have preferences for specific locations or beetle parts [41]. For a safe dispersal, mites must synchronize their life cycle to one of the carriers, but little is known about how and when mites locate their hosts [42].…”

Associations of Phoretic Mites on Bark Beetles of the Genus Ips in the Black Sea Mountains of Turkey

“…In recent studies of phoretic mites on I. typographus in Romania, D. quadrisetus was the most abundant and frequent mite species, while less abundant was H. piceae [34]. Similar results were demonstrated in Spain on I. sexdentatus [35].…”

The phoretic mite (Arachnida: Acari) assemblage of the Douglas-fir beetle,Dendroctonus pseudotsugaeHopkins (Coleoptera: Curculionidae)

“…Other OTUs were most abundant on the early flying beetles before mostly declining throughout the rest of the sampling period (Figure 3). Previous studies have noted that mite abundances tended to peak at similar times as the flight peaks of their bark beetle hosts and during the highest abundances of their coleopteran host (Knee et al 2012b;Paraschiv et al 2018). This is mostly supported by OTUs A, B2 and C being negligibly and moderately positively correlated with the number of beetles.…”