|Crop Knowledge Master|
Othreis fullonia (Clerk)
|Pacific Fruit-Piercing Moth|
Jayma L. Martin Kessing, Educational Specialist
Ronald F.L. Mau, Extension Entomologist
Department of Entomology
The Pacific fruit-piercing moth attacks many fruit and vegetable crops. Fruit crops attacked include apples, apricots, bananas, breadfruit, coffee, figs, grapefruit, guava, kiwifruit, litchi, longan, mandarins, mangoes, nectarines, oranges (especially navels), papaya, passion fruit, peaches, persimmons, pineapple, plums, and star fruit. Vegetable crops attacked include tomatoes and melons (Waterhouse and Norris, 1987).
Except in the Pacific, larvae develop on plants belonging to the Menispermaceae family, especially the creepers belonging to the Tinospora, Tiliacora, Triclisia, and the Stephania genuses (Banziger, 1982; Comstock, 1963; Hargreaves, 1936; Mosse-Robinson, 1968). In the Pacific, the larvae of this moth almost exclusively develop on plants belonging to the Erythrina genus, or false wiliwilis, a common landscaping plant, the only exception being the creeper, Stephania forsteri (Menispermaceae) (Cochereau, 1977). In Hawaii larvae have been found on Erythrina fusca and Erythrina variegata orientalis (Heu et al., 1985).
This moth is native to the Indo-Malaysian region, and widespread throughout the Pacific basin, Asia, and Africa. It is not recorded in the Americas. Some countries where it is found include Australia, China, India, Japan, Korea, the Philippines, Papua New Guinea and Thailand. Refer to Waterhouse and Norris (1987) for an extensive list of countries where this moth is present. It was first reported in Hawaii on Oahu in 1985, and by 1986, it was present on Kauai, Hawaii, Maui and Molokai.
For most moth and butterfly pests, the caterpillars are the damaging stage. The Pacific fruit-piercing moth differs in this aspect because it is the adult moth that is the damaging stage, and the larvae are essentially not harmful. The mouth parts of the moth are about an inch (2.5 cm) long and strong enough to penetrate through tough-skinned fruit. Once the moth has punctured the skin of the fruit, a process that usually takes a few seconds, it feeds upon the juices of the fruit. Feeding occurs at night and the fruit does not have to be ripe to be fed upon by this moth (Waterhouse and Norris, 1987). Fruit flesh damaged by this moth becomes soft and mushy differing from fruit damaged by fruit flies which is more liquid (Heu et al., 1985).
Damage caused by this pest is not only a result of the direct feeding of this moth but also by the fungal and bacterial infections that develop at the wound site. This moth is a known vector of Oospora citri, a fungus that rots the fruit and has a penetrating odor that attracts this moth. Other microorganisms that gain entrance into the fruit and cause rotting include Fusarium sp., Colletotrichum sp. (Banziger, 1982), and several types of bacteria (Hargreaves, 1936). When moths are abundant green fruit is attacked, causing premature ripening and dropping of fruits (Kumar and Lal, 1983). On oranges, a green fruit turns yellow at the site of the piercing and fungi soon develop within the wound (Waterhouse and Norris, 1987). On tomatoes, the puncture of the tomato skin causes the fruit to turn white and quickly rot (Comstock, 1963).
Incidence of damage by this moth is normally low, however when outbreaks occur, most of the crop is affected.
The duration of the life cycle from egg to egg-laying adult female was 35 to 49 days in a study conducted in Fiji at temperatures between 82.4û to 91.4û F (28û to 33û C) (Kumar and Lal, 1983) and 30 to 33 days in the warmer conditions of new Caledonia (Waterhouse and Norris, 1987). Generations are continuous throughout the year.
The small hemispherical eggs are about 1/25 inch (1 mm) in diameter and are colored yellowish green. When moth populations are low, a single female moth lays her eggs in batches of up to 100. When moth populations are high, eggs are laid in batches of several hundred eggs by individual females. Eggs are generally laid on the underside of leaves but may be found on the bark or on other plants nearby. Eggs hatch in 3 to 4 days at temperatures between 82.4û to 91.4û F (28û to 33û C) (Kumar and Lal, 1983).
This moth has 5 larval stages, or instars, separated by 4 molts. After each molt, the discarded skins are eaten by the newly emerged caterpillars. Caterpillars are cylindrical in shape and are 1/5 to 1/3 inch long during the first larval stage (Hargreaves, 1936). They reach up to two inches in length when fully grown (Tryon, 1898). Like other caterpillars belonging to the Noctuidae family, they have eight pairs of legs - three pairs under the thorax, four pairs in the middle portion of the abdomen (the first of which is rudimentary), and the last pair at the end of the abdomen. The last segment (the 11th) is considerably humped (Tryon, 1898), a feature that develops during the second instar (Hargreaves, 1936). They are either dark green to black or pale green to yellow (Comstock, 1936, Hargreaves, 1963). The dark coloration occurs when larval densities are high, and the light colored larvae are found with isolated larvae (Waterhouse and Norris, 1987). On the second and third abdominal segments, there are paired, lateral markings resembling eyes (Waterhouse and Norris, 1987). On the upper surface of the body, they have numerous small creamy-white spots and bars edged with black that tend to coalesce in some places (Tryon, 1898). Duration of the five larval stages at temperatures between 82.4û to 91.4û F (28û to 33û C) are 3 to 5 days, 3 to 5 days, 2 to 3 days, 2 to 5 days, and 4 to 10 days, respectively (Kumar and Lal, 1983).
Mature larvae pupate within a cocoon spun between leaves and woven together with silk. The leaves containing the cocoon may remain on the host plant or dry and fall to the ground (Waterhouse and Norris, 1987). Pupae are very dark brown with a purplish cast (Tryon, 1898) and about 1-1/8 inch (28 mm) long (Comstock, 1963). Pupation lasts for 14 to 21 days. If pupation occurs under very dry conditions the adult may not be able to emerge successfully (Hargreaves, 1936).
The adult moth is large and robust. It has a wingspan of almost 4 inches (10 cm) and a stout body, about 2 inches (5 cm) long (Waterhouse and Norris, 1987) that does not extend, or slightly extends, beyond the hindwings (Tryon, 1898). The eyes are large. The area behind the head of the moth, the thorax, is pale to purple-brown and the abdomen is pale brown at the base brightening to yellow-orange at the tip. The forewings resemble a leaf by being olive to purple-brown and may have white and green colored flecks (the colored flecks are more common on females). This leaf-like appearance of the forewings makes this moth difficult to see when it is at rest, especially, because the bright hindwings are not visible. The outer edges of the female's forewings are scalloped or toothed where those of the male's are evenly curved. The hindwings are bright orange, have a black comma-shaped mark and are fringed by a black border with white dots.
After emerging from the pupa, females have a preoviposition period of 4 to 8 days before she begins to lay her eggs. Each female may lay up to 750 eggs during her lifetime. Females live for 27 to 30 days and males 26 to 28 days (Kumar and Lal, 1983).
Caterpillars mostly feed between 5:00 PM and 10:00 AM, but may feed at any time. They are usually located beneath or on the edges of leaves (Hargreaves, 1936). Young larvae drop to the ground at any sign of danger, while the older larvae take an aggressive attitude by hanging on to the food plant with their hind legs and swaying the rest of their body from side to side (Mosse-Robinson, 1968).
Although their flight is slow and heavy (Baptist, 1944), the adult moths are very strong fliers and can travel great distances from their breeding grounds in search of food (Waterhouse and Norris, 1987). Adults fly mainly between the hours of dusk and 11:00 PM (Tryon, 1898). They are not usually attracted to light (Kumar and Lal, 1983). When disturbed, the moth flares its forewings, exposing its conspicuous hindwings (Waterhouse and Norris, 1987).
The low incidence of damage by this pest is attributed to the effectiveness of its natural enemies throughout most of the world. Two of the seven recorded parasites of the Pacific fruit-piercing moth, Trichogramma chilonis (Trichogrammatidae) and Euplectrus plathypenae (Eulophidae), are present in Hawaii. Five predators and a fungus are also reported in the literature, but presently, they have not been found in Hawaii. The parasites in Hawaii usually control this pest efficiently (Heu et al., 1985).
Other Non-Chemical Control Measures
Several means of controlling fruit-piercing moths were evaluated in India (Baptist, 1944) and are outlined below.
Capture and Destruction of Moths -- Since this moth is not easily disturbed from fruit once it has begun to feed, netting and killing of moths is possible. This is best accomplished an hour after sunset when there is sufficient darkness with the aid of torches or a strong flashlight. This method is most feasible when fruit are easily accessible and populations of this moth are small. This method is not very effective once a large population of this moth exists and is usually recommended only if no other control means is possible.
Lanterns and Lights -- This moth prefers darkness and avoids light, therefore the illumination of orchards was tested as a possible means of deterring Pacific fruit-piercing moth attack. Although damage was less severe under illuminated conditions, this method was determined to be an impractical means of reducing damage based on a small scale trial (Baptist, 1944). However, Nomura (1965) reported a substantial reduction of moths by 60% in Japan and other investigators have also found this method effective (Whitehead and Rust, 1967, 1972; Bosch, 1971a; Bnziger, 1982; Kumar and Lal, 1983). These moths are attracted by ultraviolet light and repelled by white light (Bosch, 1971a). If exposed to green-yellow light of mercury lamps, they adapt to the light and assume their resting daylight behavior (Bosch, 1971a).
Bagging or Screening Fruits -- Mechanical protection of fruit against moth attack was achieved by covering the fruit with brown paper or transparent oil paper bags. Brown paper bags last for about a month in the field and the transparent oil paper bags may be used for up to two seasons if the weather is not very wet. This method is most practical when each individual fruit is of significant value or when fruits are easily accessible and are of large size or relatively compact bunches. Although this method is labor intensive, it is especially good if regular attention cannot be given to the crop or it is desired to have the fruits fully ripen on the trees. This method is not practical when fruits are small, scattered, and not within easy reach.
Smoking of the Orchard -- This method involves the obscuring of the odor of mature and ripening fruit that attracts the moth with the odor of the smoke. Containers full of inflammable material, oil, tar and some green plant trimmings to enhance the smoke were placed within the orchard at a rate of 2 to 4 per acre. The smoking process was started a half an hour before dusk and continued for 2 to 3 hours after nightfall. This period represents the time in which the moths are seeking their nighttime feeding grounds. If the smell of the orchard is masked, the moths choose various wild hosts and remain on them throughout the night to feed. This method reduced some damage caused by the Pacific fruit-piercing moth in India (Baptist, 1944), but for the most part, it was ineffective in Thailand (Bnziger, 1982).
Orchard Sanitation -- This method involves the regular collection and proper disposal of all attacked and spoiled fruit. Both fallen fruit and attacked fruit on the tree should be collected, buried deeply or boiled in water for 10 minutes then broken up for compost. These procedures dissipate the odor emanating from the spoiled fruit so they cannot serve as an attractant for the moths (Baptist, 1944). This method was somewhat effective in India (Baptist, 1944) but ineffective in Thailand (Bnziger, 1982). The ineffectiveness of this method in Thailand was attributed to the preference for fruit still on the tree by the moths (Bnziger, 1982).
Forced Harvesting -- When severe infestations are anticipated, damage may be avoided by harvesting the entire crop as soon as signs of fruit ripening is observed. The grower must determine if the revenue loss from premature harvesting is less than that from possible damage (Baptist, 1944).
The effectiveness of chemical baits is variable. In Thailand, Bnziger (1982) reported chemical baits were ineffective, while Kumar and Lal (1983) reported satisfactory control in India. The ineffectiveness of baits is primarily based on the lack of the appropriate bait, but this method may become useful in the future as new baits are discovered (Bnziger, 1982).
Repellents can be either taste repellents or odor repellents. Since odor is the initial attractant for getting the moths to the host sight, control methods using repellent sprays focus on odor repellents (Bosch, 1971b). Although Bosch (1971b) reported some success using citronella oil as a repellent, repellent sprays are generally considered ineffective (Baptist, 1944; Bnziger, 1982).
Bnziger, H. 1982. Fruit-Piercing Moths (Lep., Noctuidae) in Thailand: A General Survey and Some New Perspectives. Mitteilungen der Schweizerischen Entomologischen Gesellschaft. 55: 213-240.
Baptist, B.A. 1944. The Fruit-Piercing Moth (Othreis fullonica L.) with Special Reference to its Economic Importance. Indian J. Entomology. 6: 1-13.
Bosch, J.E. 1971a. Fruit Piercing Moth Research. Rhodesia Agric. J. 68: 19-21.
Bosch, J.E. 1971b. The Possibility of Controlling Fruit Piercing Moths by Means of an Odor Repellent. Rhodesia Agric. J. 68: 113.
Comstock, J.A. 1963. A Fruit-Piercing Moth of Samoa and the South Pacific Islands. Canadian Entomologist. 95(2): 218-222.
Hargreaves, E. 1936. Fruit-Piercing Lepidoptera in Sierra Leone. Bull. Entomol. Res. 27: 589-605.
Heu, R., K. Teramoto, E. Shiroma, B. Kumashiro, and R. Dinker. 1985. Hawaii Pest Report. 5(1-4): 4-5.
Kumar, K. and S.N. Lal. 1983. Studies on the Biology, Seasonal Abundance and Host-Parasite Relationship of Fruit Sucking Moth Othreis fullonia (Clerk) in Fiji. Fiji Agric. J. 45(2): 71-77.
Mosse-Robinson, I. 1968. Fruit-Sucking Moths (Lepidoptera: Noctuidae). Australian Zoologist. 14(3): 290-293.
Nomura, K. 1965. Studies on Orchard Illumination Against Fruit-Piercing Moths. II. Some Considerations on the Effect of Orchard Illumination Against Fruit-Piercing Moths. Technical Bulletin of the Faculty of Horticulture of Chiba University. 14: 21-28.
Tryon, H. 1898. Orange-Piercing Moths - Fam. Ophiderinae. Queensland Agric. J. 2: 308-315.
Waterhouse, D.F. and K.R. Norris. 1987. Chapter 29 Othreis fullonia (Clerk). pp. 240-249. In: Biological Control Pacific Prospects. Inkata Press; Melbourne. 454 pages.
Whitehead, V.B. and Rust, D.J. 1967. Orchard Illumination as a Counter to the Fruit Piercing Moths. Decid. Fruit Grow. 17: 357-358.
Whitehead, V.B. and Rust, D.J. 1972. Fruit-Piercing Moths: Ecology and Reduction of Damage. Dried Fruit 4: 4 pp.