Figures
Fig. 1: Antenna (inset: III. and IV. antennal segment)
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Forewing
Fig. 6: Tergites VI and VII
Fig. 7: Tergites IV and V
Fig. 8: Tergites VIII and IX
Taxonomic Information
Species:
Oxythrips ajugae Uzel, 1895
Synonyms:
Oxythrips flavus Morison, 1928
Oxythrips pernicis Bagnall, 1926
Oxythrips bicolor Uzel, 1895
Common name:
Conifer thrips
Present taxonomic position:
Family: Thripidae Stephens, 1829
Subfamily:
Thripinae (Stephens) Karny, 1921
Genus:
Oxythrips Uzel, 1895
Species Recognition
General information about the genus Oxythrips:Common characters in the genus Oxythrips include eight segmented antennae with segments III and IV having forked sense cones, three ocellar setae, two long setae on the pronotum, two segmented tarsi, the forewing first vein contains only a few widely spaced setae whereas the second vein contains several evenly spaced setae, and there is no comb on abdominal tergite VIII. Many of the species in this genus contain a partial suture on antennal segment VI. There are 45 species currently known in the genus Oxythrips, most are associated with pines and the genus is structurally close to the genera Anaphothrips and Chirothrips and only O. ajugae is discussed in this key.
Typical character states of Oxythrips ajugae:
Body color
Mainly brown
Antennae
Number of antennal segments: 8
Segment IV - forked sensorium: scarcely extending beyond base of segment V
Segments II and III shape: more or less symmetric
Segments III & IV sensoria: emergent and forked
Base of sensorium on antennal segment VI: no more than 2 times as wide as base of nearest seta
Terminal antennal segments: rarely elongate
Head:
Distance between bases of ocellar setae III: greater than width of first ocellus
Head shape between compound eyes: not prolonged
Major postocular setae: less than half as long as ocellar setae III
Ocellar setae III on head: arising on anterior margin of, or in front of, ocellar triangle
Postocular setae I: present
Surface of head, pronotum and fore legs: without strong reticulate sculpture
Ocellar setae I in front of anterior ocellus: present
Prothorax
Number of pairs of elongate pronotal setae: 0-3
Number of pairs of elongate posteroangular pronotal setae: 1
Pronotum shape: rectangular
Number of pairs of pronotum posteromarginal minor setae: 5-6
Number of pairs of pronotum anteromarginal minor setae: 4-5
Mesothorax
Mesothoracic endofurca: with median spinula
Metathorax
Metanotal median area sculptured lines: transverse at anterior, but with irregular equiangular reticulation near posterior or with mainly equiangular reticulation
Metanotal median setae length: shorter than lateral metanotal setae
Metanotal median setae position: arising behind anterior margin
Metanotum: without campaniform sensilla
Metanotum major sclerite: with two major sclerites, metascutum and metascutellum
Metanotum median area: with at least some equiangular reticulation
Metanotum sculpture: without dominant sculptured triangle medially
Metathoracic endofurca: transverse, sometimes with simple median spinula
Wings
Wings: present and more than half as long as abdomen
First vein of forewing: distinct from costal vein
Forewing anterior margin: with setae and cilia but cilia longer than setae
Forewing color: uniformly pale or weakly shaded
Forewing costal fringe of cilia: arising at anterior margin of wing
Forewing costal setae at middle of wing: longer than median width of wing
Forewing first vein setal row: incomplete, with setae not closely and uniformly spaced
Forewing posterior margin cilia: undulated near apex
Forewing second vein setal row: complete, with setae closely and uniformly spaced
Forewing surface: not reticulate
Forewings: with veins, setae and microtrichia
Legs
Fore tibial apex: not extending around fore tarsus
Mid and hind tarsi: with two segments
Abdomen:
Abdominal segment X: never tubular, longitudinally incomplete ventrally in both sexes
Abdominal sternite III of female: without glandular areas
Abdominal sternite VII: with marginal setae but no discal setae
Abdominal sternite VII median marginal setae: arising in front of margin
Abdominal sternites IV , V and VI: with discal setae present medially as well as marginal setae
Abdominal tergites: without curved wing-retaining setae
Abdominal tergites IV & V median setal pair: much shorter than distance between their bases
Abdominal tergites V-VII: without paired ctenidia, sometimes with irregular microtrichia
Setae on abdominal tergite X: slender
Surface of lateral thirds of abdominal tergites: without regular rows of fine microtrichia
Tergite VIII posteromarginal comb of microtrichia: absent
Biology
Life history:
As with other thrips species the life cycle from egg to adult is dependent on temperature. The full cycle can take about 15 days (Lewis, 1973) to over a month and adults may live for more than one month producing several generations in one year depending on seasonal weather. With greenhouse temperatures the developmental time from egg to adult can decrease to about one week.
Host plants:
Pinus, univoltine
Vector capacity:
None identified
Current known distribution:
Asia, Europe
Additional notes:
This species has been found breeding in the male cones of pines.
Bibliography
Bailey, SF (1957): The
thrips of California Part I: Suborder Terebrantia. Bulletin of the
California Insect Survey 4, no. 5: 143-220.
Lewis, T (1973): Thrips their biology, ecology and
economic importance. Academic Press Inc., London Ltd. 349 pp.
Merkel, EP, Fatzinger, CW & Dixon, WN (1994): Keys
for distinguishing thrips (Thysanoptera) commonly found on slash pine
in Florida. - Journal of Entomological Science 29 (1): 92-99.
Moritz G, Morris DC, Mound LA (2001): ThripsID -
Pest thrips of the world. ACIAR
and CSIRO Publishing Collingwood, Victoria, Australia, CDROM ISBN
1 86320 296 X.
Moritz G, Mound LA, Morris DC, Goldarazena A (2004): Pest
thrips of the world - an identification and information system using molecular
and microscopial methods. CBIT, University of Queensland,CDROM ISBN 1-86499-781-8.
Mound, LA & Marullo, R (1996): The
thrips of Central and South America: An Introduction (Insecta: Thysanoptera).
Associated Publishers, Gainesville.
Stannard, LJ (1968): The thrips, or Thysanoptera, of Illinois.
Illinois Natural History Survey Bulletin 29: 215-552.
Links:
Mound, LA (2005): Thysanoptera (Thrips) of the World
- A Checklist. http://www.ento.csiro.au/thysanoptera/worldthrips.html