Xyleborus cognatus

Taxonomic history

Xyleborus cognatus Blandford, 1896a: 19.

Diagnosis

2.8−3.1 mm long (mean = 2.96 mm; n = 5); 2.8−3.1 times as long as wide. This species is distinguished by the protibiaprotibia:
tibia of the first pair of legs
obliquely triangular, broadest at distaldistal:
situated away from the body
third; elytralelytral:
pertaining to the elytra
declivitydeclivity:
downward slope of either the pronotum or elytra
smooth, shiningshining:
appearing glossy or bright in luster; referring to a surface that is polished and reflects light well
(specimen must be dry); large size; declivitaldeclivital:
pertaining to the elytral declivity
interstriae 1, 3 armed with 2−3 pairs of large tubercles; interstriaeinterstria:
longitudinal spaces along the elytra between the striae, which is not as<br /> impressed and bear smaller punctures.
2 sparsely granulategranulate:
pertaining to a coarse, grainy surface texture
at declivitaldeclivital:
pertaining to the elytral declivity
summit; elytraelytron:
the two sclerotized forewings of beetles that protect and cover the flight wings
darker on declivitydeclivity:
downward slope of either the pronotum or elytra
than discdisc:
the flat central upper surface of any body part (e.g. pronotum and elytra)
.

This species is very similar to X. perforans with which it has often been treated as a synonym. It can be distinguished by the larger size, generally more slender form (vs 2.67–2.89 times as long as wide), larger interstrial tuberclestubercle:
a small knob-like or rounded protuberance of the exoskeleton
and typically a bicolored elytraelytron:
the two sclerotized forewings of beetles that protect and cover the flight wings
.

May be confused with

Xyleborus affinis, X. ferrugineus, X. festivus, X. perforans, X. pfeilii, and X. volvulus

Distribution

Australia, India (Andaman Is, Bihar, Uttarakhand, West Bengal), Indonesia (Java, Kalimantan, Sulawesi, Maluku, Sumatra, Sumbawa), East & West Malaysia, Myanmar, New Caledonia, New Guinea, Philippines, Singapore, Solomon Is., Sri Lanka, Thailand, Vietnam

Host plants

polyphagous (Beeson 1930Beeson 1930:
Beeson CFC. 1930. The biology of the genus Xyleborus , with more new species. Indian Forest Records 14: 209-272., Browne 1961bBrowne 1961b:
Browne FG. 1961b. The biology of Malayan Scolytidae and Platypodidae. Malayan Forest Records 22: 1-255., Ohno 1990Ohno 1990:
Ohno S. 1990. The Scolytidae and Platypodidae (Coleoptera) from Borneo found in logs at Nagoya port 1. Research Bulletin of the Plant Protection Service, Japan 26: 83-94.)

Remarks

The species is frequently associated with mangrove forests, but also attacks a very wide variety of other trees (Browne 1961bBrowne 1961b:
Browne FG. 1961b. The biology of Malayan Scolytidae and Platypodidae. Malayan Forest Records 22: 1-255., Maiti and Saha 2004Maiti and Saha 2004:
Maiti PK, Saha N. 2004. Fauna of India and the adjacent countries. Scolytidae: Coleoptera (bark and ambrosia beetles). Vol. 1. Part 1. Zoological Survey of India, Kolkata, 268 pp.).

DNA data

specimens not available for sequencing