374 A. D. N. T. Kumara et al.
Coconut Black-Headed Caterpillar
Biosystematics
The black-headed caterpillar (BHC) was first de-
scribed by Walker and was placed under the fami-
ly Cryptophasidae (Lepidoptera). Meyrick (1905)
described the same as Nephantis serinopa under
the family Xyloryctidae. In 1981, Baker com-
pared the holotype of O. arenosella by Walker
and N. serinopa by Meyrick and found that both
are conspecific. Hence, the name Opisina areno-
sella is being used again with N. serinopa as a
synonym.
Distribution and Host Range
The BHC is considered a serious defoliating
pest on coconut. Its natural range extends from
India to Sri Lanka (Perera 1987 ), Burma (Ghosh
1923 ), Bangladesh (Alam 1962 ), and, recently
reported, Thailand (Bao-qian et al. 2013 ). Dam-
age to coconut in India was first recorded from
Andhra Pradesh in 1909 (Rao et al. 1948 ), and
this pest menace is frequently noticed in South
India. The distribution within the region showed
patchy or spot distribution and recorded frequent
outbreaks (Perera 1987 ; Sundararaju 1985 ;
Nadarajan and Channabasavanna 1980 ).
Coconut Palmyra and some ornamental palms
were recorded in Sri Lanka and India as hosts,
i.e., Palmyra ( Borassus), Corypha, Hyphaene,
Phoenix, and Roystonia (Rao et al. 1948 ; Nirula
et al. 1951b). Butani ( 1975 ) recorded it as a
minor pest of date palm. Manjunath (1985) re-
corded that larvae feed on banana leaves during
an outbreak in India. However, from laboratory
studies it was concluded that fan palm ( Livisto-
nia chinensis), wild date palm ( Phoenix sylves-
tris), and date palm ( P. dactylifera) are suitable
host plants, but banana is not.
Bioecology
Females of O. arenosella lay their eggs in small
groups on the undersurface of coconut leaflets.
Eggs are generally deposited in the vicinity of
feeding larvae, and it has been suggested that
this results in the slow spread of outbreaks to
peripheral, uninfested trees (Perera 1987 ). The
larvae usually have five instars and feed on the
undersurface of coconut leaves, at first gregari-
ously, then singly, consuming the lower epi-
dermis and mesophyll but leaving the upper
epidermis intact. The upper surface of the leaf
has a characteristic scorched appearance where
caterpillars have fed. The larvae construct a gal-
lery of silk and frass, into which they retreat if
disturbed. Pupation takes place within the larval
gallery. Adults are frequently found during the
day resting on the undersurface of the leaves of
palms damaged by the larvae. The moth flies at
night, but little is known of its dispersal abili-
ties. The egg stage lasts on average 3 days and
the five larval instars last six, seven, seven,
five, and ten days, respectively (Perera, 1987 ).
Although there are normally five instars, up to
eight have been recorded in the laboratory when
the larvae are stressed (the supernumerary in-
stars would be indistinguishable from the fifth
instar in the field). The pupal stage lasts for an
average of 8 days, and the total length of the pre-
adult life cycle is thus approximately 46 days.
Adult longevity is 7–9 days, during which the
female lays about 152 eggs (Perera 1987 ). In Sri
Lanka, (Perera et al. 1988 ) BHCs have shown to
follow partially discrete generation cycles dur-
ing outbreaks. Ramkumar et al. ( 2006 ) studied
the population cycles of the BHC and found that
there are discrete generation cycles. Further,
they suggested that the possible reason for the
discrete generation may be protandry.
The BHC is an important and the most destruc-
tive pest in many commercial and subsistence
coconut-cultivating areas, because moderate- to
high-density populations of the BHC do indeed
cause considerable yield loss. The pest infestation
is mainly confined to the lower fronds, and in se-
vere infestation, several hundreds to thousands of
larvae can be observed on a palm. The caterpillar
feeds on chlorophyll by scraping lower epidermis
of leaflets and constructs galleries of silk and frass.
The infested fronds give burnt-up appearance and
the affected palms often take several years to