Three genera are recognised in this family, Heratythrips
and Oligothrips from California,
each containing a single species (Mound & Marullo 1999), and Holarthrothrips
from the Old World between India and the Mediterranean. The four species
described in this genus are all associated with the flowers of date
palms (Phoenix dactylifera). The adults of all six species
of Adiheterothripidae have a curious
conical sensorium on antennal segments III and IV, a character state
that is found otherwise only in a few fossil Thysanoptera.
Available names: Original name Holarthrothrips
indicus Bhatti & Ananthakrishnan, 1978.
Biology: Known only from the inflorescences of Phoenix dactylifera,
the date palm, but nothing is known of the biology of the species.
Distribution: India and Bangladesh.
Recognition: Body brown to light brown, legs yellow with femora
tinged with brown; antennae brown with segments III-IV yellow; forewing
uniformly pale. Head without long setae, eyes not prolonged ventrally.
Antennae 9-segmented, segments all clearly distinct from each other
and bearing rings of weak microtrichia, VIII long and slender; segments
III and IV each with one conical sensorium externally at apex. Pronotum
with 2 or 3 pairs of posteroangular setae that are twice length of
discal setae. Tarsi 2-segmented; fore tarsi with stout recurved hamus
that meets a stout seta at its tip. Mesonotum with one pair of setae
medially. Metanotum with concentric rings of sculpture lines bearing
microtrichia; median setae close to posterior margin. Forewing slender
with apex almost acute; only one cross vein well-developed; basal
stem of second longitudinal vein with 3 setae; costal margin with
long cilia as well as setae. Tergites II-VI with marginal comb of
microtrichia laterally, VII-VIII with comb complete across median
area; lateral areas of tergites with many rows of microtrichia; pleurotergal
sutures weakly developed. Median sternites with 4 pairs of marginal
setae. Male with two pairs of stout setae posterolaterally on segment
Related species: Four species are recognised in the genus Holarthrothrips,
distributed between India and the Mediterranean (Bhatti 1986). Curiously,
all four species apparently live only in the inflorescences of Phoenix
dactylifera, the Date Palm. In H. tenuicornis
from the Mediterranean, and also H. jambudvipae
from southern India, the apical half of the forewings is shaded, and
the abdominal sternites lack discal setae. In contrast, in H.
josephi from Iraq and Oman, and also in H.
indicus , the forewings are pale, and the abdominal
sternites bear discal setae laterally. In H. josephi,
abdominal tergites II-VI bear a complete posteromarginal comb of microtrichia,
whereas this comb is absent medially on these tergites in H.
Generic relationships: Holarthrothrips
is placed in the family Adiheterothripidae,
together with two monobasic genera from western North America (Mound
& Marullo 1999).