Xylosandrus declivigranulatus

Taxonomic history

Xyleborus declivigranulatus Schedl, 1936d: 30.
Xylosandrus declivigranulatus (Schedl, 1936): Wood 1977Wood 1977:
Wood SL. 1977. Introduced and exported American Scolytidae (Coleoptera). The Great Basin Naturalist 37: 67-74. (as a synonym of X. crassiusculus)

Diagnosis

2.1 mm long (n = 3); 2.0 times as long as wide; elytralelytral:
'pertaining to the elytra
discdisc:
the flat central upper surface of any body part (e.g. pronotum and elytra)
gradually curving toward declivitydeclivity:
downward slope of either the pronotum or elytra
, elytraelytron:
' the two sclerotized forewings of beetles that protect and cover the flight wings
rounded; posterolateralposterolateral:
'relating to end of the side part/portion
margins of elytraelytron:
' the two sclerotized forewings of beetles that protect and cover the flight wings
carinate to interstriaeinterstria:
'longitudinal spaces along the elytra between the striae, which is not as<br /> impressed and bear smaller punctures.
7; declivitaldeclivital:
pertaining to the elytral declivity
face with six striae; interstriaeinterstria:
'longitudinal spaces along the elytra between the striae, which is not as<br /> impressed and bear smaller punctures.
and striaestria:
punctures in rows, which may or may not be impressed to make grooves
granulategranulate:
'pertaining to a coarse, grainy surface texture'
, interstrial granulesgranule:
'a small rounded protuberance, like grains of sand
strongly confusedconfused:
of markings, having indefinite outlines or running together as lines or spots without definite pattern; usually referring to punctures
, strial granulesgranule:
'a small rounded protuberance, like grains of sand
subseriate, declivitydeclivity:
downward slope of either the pronotum or elytra
appearing dull, with erecterect:
'pertaining to setae that have their apices directed away from the body and appear straight
hair-like setaeseta:
small hair-like or scale-like structure
longer than the width of two interstriae; pro­notum as long as wide pronotumpronotum:
'the dorsal surface of the thorax
from dorsaldorsal:
'of or relating to the upper surface; opposite of ventral
view rounded (type 1) and laterallateral:
'pertaining to the side
view basic (type 0), summitsummit:
highest point, used for pronotum and elytra, denotes the peak between pronotal frontal slope and disc, and between elytral disc and declivity
at midpoint, erecterect:
'pertaining to setae that have their apices directed away from the body and appear straight
/2 smooth, shiny, sparsely minutely punc­tate; and dense mycangial tuftmycangial tuft:
'tuft of setae that denotes the mycangia exterior opening
on the pronotalpronotal:
'pertaining to the pronotum
basebase:
point or edge closest to the body; opposite of apex
.

The species can be distinguished from X. crassiusculus by the following combination of characters (X. declivigranulatus given first): 2.1 mm long vs. 2.3–2.9 mm long; 2.0 times as long as wide vs. 2.17–2.42 times as long as wide (Smith et al. 2020bSmith et al. 2020b:
Smith SM, Beaver RA, and Cognato AI. 2020b. A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China. ZooKeys 983: 1-442. https://doi.org/10.3897/zookeys.983.52630); pronotumpronotum:
'the dorsal surface of the thorax
as long as wide vs. 0.73–0.93 times as long as wide; declivitydeclivity:
downward slope of either the pronotum or elytra
densely granulategranulate:
'pertaining to a coarse, grainy surface texture'
, granulesgranule:
'a small rounded protuberance, like grains of sand
spaced by less than one diameter of a granulegranule:
'a small rounded protuberance, like grains of sand
, surface of declivitaldeclivital:
pertaining to the elytral declivity
face difficult to discern between granulesgranule:
'a small rounded protuberance, like grains of sand
, granulesgranule:
'a small rounded protuberance, like grains of sand
comparatively larger vs. declivitydeclivity:
downward slope of either the pronotum or elytra
sparsely to moderately granulategranulate:
'pertaining to a coarse, grainy surface texture'
, granulesgranule:
'a small rounded protuberance, like grains of sand
spaced 2–5 diameters of a granulegranule:
'a small rounded protuberance, like grains of sand
, surface of declivitaldeclivital:
pertaining to the elytral declivity
face apparent, granulesgranule:
'a small rounded protuberance, like grains of sand
comparative smaller, often minute.

May be confused with

Xylosandrus crassiusculus

Distribution

East & West Malaysia, Thailand

Remarks

This species was recently recognized as distinct from X. crassiusculus by Smith et al. (2022a)

DNA data

Sequences available for COI and CAD.

COI: OM523180

CAD: OM562603