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CRYPTASPASMA SPP. Cryptaspasma spp. Walsingham
-- Lepidoptera, Tortricidae ----- CLICK on Photo to enlarge
& search for Subject Matter with Ctrl/F. GO TO ALL: Bio-Control Cases Cryptaspasma spp Walsingham (Lepidoptera:
Tortricidae) belong to one of the most primative tribes in the sub-family
Olethreutinae, the Microcorsini. This genus is composed of around 33 species
that are found in the neotropics, thesoutheastern USA, Japan, eastern Russia,
Africa, Madagascar, New Zealand, and Australia (Brown and Brown 2004). Very
little is known about the ecology and biology of Cryptaspasma sp.
Known food plants include acorns of Quercus spp.,
seeds of stone fruits, macadamia nuts, and fruit of aceitunillo (Aextoxicon
punctatum [Aextoxicaceae]). In the Lauraceae, hosts include the fruit of Belschmiedia
pendula, Persea borbonia (red
bay), P. palustris (swamp bay), and P.
americana (avocado) (Brown and Brown 2004).
Some
species of Cryptaspasma have been
reared from avocado seeds collected in Puerto Rico, Mexico (Michoacán), and
Guatemala. The pest status of Cryptaspasma spp.
infesting avocado fruit in Mexico (i.e., C. lugubris)
is uncertain as larvae have been found in seeds removed from fruit that had
been collected from the ground. In Guatemala, C. sp.
nr. lugubris (referred to hereafter as Cryptaspasma sp.)
was reared from avocados collected across multiple locations. However, fruit
picked from trees and collected from the ground at study sites in Guatemala
was commingled making it impossible to determine of larvae had infested fruit
hanging in trees or had attacked fruit lying on the ground. However,
this moth was reared from recently picked avocados that were being sold along
the side of the road in Santiago Atitlan in Guatemala (see below). Since Cryptaspasma
has been reared from fruit collected from the ground in Mexico (Brown and Brown
2004) this finding suggests one of two possibilities: (1) avocados lying on
the ground and collected for rearing studies had been prematurely aborted
because of larval feeding damage within fruit that were originally hanging on
trees, or (2) Cryptaspasma females
only oviposit on avocado fruit that have dropped to the ground because of
other reasons (e.g., strong winds caused fruit to fall off tree prematurely)
or ovipositing females utilize bare avocado seeds that have been exposed once
protective flesh has been removed (i.e., eaten by animals or rotted away). Determining the pest status of Cryptaspasma spp.
attacking avocados in countries exporting fruit is important for
understanding the risk this insect poses to countries importing avocado fruit
from areas that have endemic populations of this avocado seed feeding moth.
Exotic Cryptaspasma spp. may pose an invasive threat to
avocado industries in importing countries, such as California in the USA
which receives imported avocados from Michoacán Mexico. Characteristics Eggs and oviposition. The eggs
of Cryptaspasma sp. are laid in masses and
individual eggs are flat somewhat irregular in shape and white in color when
first laid, but turn grey as larvae approach eclosion. Examination of the
placement of 633 eggs in 30 randomly selected egg masses laid by Cryptaspasma sp.
in the laboratory revealed that the average egg mass size was 21.10 ± 3.52
eggs (range 2 to 73 eggs), and that ~80% of eggs were laid on smooth plastic
which included clear plastic cups and lids holding avocado seeds or fruit,
and the floor and walls of the Bug-Dorm used for ovipositional studies. The
remaining ~20% of eggs were distributed evenly across seeds and fruit in the
cage. At 22.14°C ± 0.13 it took 10.78 ± 2.53 days for Cryptaspasma sp.
eggs to hatch. Larvae. Upon
hatching, Cryptaspasma sp.
larvae bore quickly through the skin of avocado fruit and tunnel into seeds
where they complete larval development. Evidence of first instar larval
tunneling into fruit is readily discerned by the detection of very fine
"dust-like" frass on the outsides of fruit. Larvae emerging from
eggs laid on plastic readily bore into clean avocado seeds that are adjacent
to egg masses and a single avocado seed can support as many as 5-8 Cryptaspasma sp.
larvae. In the laboratory at 22.14°C ± 0.13 it took Cryptaspasma sp.
larvae around three weeks to complete development and emerge from seeds in
search of pupation sites. Of 301 larvae reared on avocado seeds in the
laboratory 72% reached adulthood. Pupae. In the
laboratory, mature Cryptaspasma sp.
larvae readily formed pupal cells between layers of paper towel that line the
floors of rearing boxes. Occassionally, larvae would force their way between
layers of paper fibers that comprised a single sheet of paper towel and form
pupal cells between the upper and lower sides of a piece of paper towel. At
this stage of development, larvae are very sensitive to disturbance. Premature
seperation of paper towels before the pupal case has been formed can
result in larvae abandoning pupal chambers and commencing walking again.
Larvae that were very close to pupating and unable to walk could die of
dessication following the disturbance of the pupal chamber. The prepupal
stage is variable in duration and may be affected by the fitness of the
larva. Smaller malnourished larvae appear to take longer to form pupae in
comparison to larger healthier larvae and smaller larvae may be more likely
to die following disturbance. Approximately 95% of mature larvae would
abandon avocado seeds to locate pupation sites, the remaining 5% of larvae
would pupate within feeding tunnels in avocado seeds. Casual observations in
the laboratory at 22.14°C ± 0.13 suggest that the sedentary prepupal stage
lasts around 2-4 days (depending on the status of the larva) and the pupal
stage is around 8 - 12 days in duration. When adult moths emerge, the pupal
case is forcibly discharged from the pupal cell and will protrude from the
margin of the pupal cell within which pupation occurred. Pupae are very
sensitive to contact and vigorously flick the abdomen when disturbed or
touched. Adults. Adult Cryptaspasma sp.
are dark grey moths that are almost black upon emergence. This dark
coloration quickly fades as wing scales are lost during activity and wing
venation becomes apparent. Under laboratory rearing conditions the sex ratio
of Cryptaspasma sp. is 54% female. Adult females
use pheromones to attract males. In the laboratory, female calling is easily
recognized by rapid wing vibrating and the slight upturned end of the abdomen
that has large pheromone glands protuding. Calling begins almost immediately
following sunset and lasts for approximately one hour after which time all
obvious locomotor activity by males and females ceases. At sunrise, adult
moths rapidly seek dark concealed hiding places at ground level to rest. When
provided access to 10% honeywater adult Cryptaspasma sp.
live for around seven days at 22.14°C ± 0.13. Biological Control One species of endoparasitoid, Pseudophanerotoma sp.
(Hymenoptera: Braconidae: Cheloninae), was reared from ~30% of field
collected Cryptaspasma sp.
larvae. This is the first host record for aPseudophanerotoma sp.
Members of the Cheloninae are generally egg-larval parasitoids of tortricoids
and pyraloids. REFERENCES: [Additional references may be found at: MELVYL Library ] Brown, J. W. & R. L. Brown. 2004. A new species of
Cryptaspasma Walsingham (Lepidoptera: Tortricidae: Olethreutinae) from
Central America, the Caribbean, and southeastern United States, with a
catalog of the world fauna of Microcorsini.
Proc. Entomol. Soc. Wash. 106: 288-297. Gilligan, Todd M., Brown, John W.
& Hoddle, Mark S. 2011. A new avocado pest in Central America
(Lepidoptera: Tortricidae) with a key to Lepidoptera larvae threatening avocados
in California. Zootaxa 3137, pp.
31-45: 32-38 Razowski, Jozef & Vitor O.
Becker. 2011. Systematics and distribution of
neotropical microcorsini (Lepidoptera: Tortricidae). Polish J. Entomol.80: 47=52. |
