4 Berry-feeding Insects Introduction Many of the insects that feed on green berries are also found on leaves or green shoots, and these are dealt with in Chapter 5. These include scale insects (Coccoidea) of various kinds, leaf-eating caterpillars (Lepidoptera) in several families, mites (Acari) and some Orthoptera, including grasshoppers and tree crickets. The insects dealt with in this chapter include the more important species that feed primarily on berries, although Antestia bugs can damage green shoots also. Coffee Berry Borer Hypothenemus hampei (Ferrari) [Coleoptera: Scolytidae] Morphology The female adult beetle is 1.5–2.0 mm long × 1 mm wide; the adult male is smaller, but this can vary somewhat from place to place, American specimens being somewhat smaller than Old World specimens. When first emerging, the beetle is brown, but as it matures over the next few days it becomes black, with a reddish tinge to the thorax. The pupae are a similar length to the adult and the larvae are a little smaller, having a white body and brown head (see Fig. 4.1). © J.M. Waller, M. Bigger and R.J. Hillocks 2007. Coffee Pests, Diseases and their 68 Management (J.M. Waller, M. Bigger and R.J. Hillocks) Berry-feeding Insects 69 Fig. 4.1. Adult and larva of Hypothenemus hampei. Pest status and distribution A serious pest in many countries of low-altitude arabica and robusta coffee (CABI, 1981). Damage by the coffee berry borer is rarely severe at altitudes > 1370 m, and this species has not been found > 1680 m. The centre of origin of the species is in some doubt, but must have been somewhere in West or Central Africa. Morstatt (1941) considered it to have originated in the area around Lake Victoria, but Schedl (1961) disputes this. Bredo (1939) points out that at the time he was writing, the beetle had never been found in truly wild coffee in the Democratic Republic of Congo. The beetle was described by Ferrari (as Cryphalus) in 1867 from beetles found in stored produce, but the country of origin is not recorded. The first field record of berry borer was from material collected by O.F. Cook in Liberia in 1897, and described as Stephanoderes cooki Hopkins (Hopkins, 1915), now considered to be a synonym of H. hampei. It was reported from Gabon in 1901, the Congo Republic and Chad in 1902–1904, Uganda in 1908, Angola in 1909 and the Democratic Republic of Congo in 1911 (Schedl, 1961). In 1914 in Tanzania, damage to coffee was restricted to robusta to the west of Lake Victoria (Morstatt, 1914), although he found it to occur in the Usambara Mountains but not on coffee. By 1929 it was affecting areas to the east of Lake Victoria, but did not reach the arabica-growing areas of Kilimanjaro until 1968. The first report of the insect in Kenya was in 1928 (Wilkinson, 1928). It appeared at an early date in Indonesia, presumably as an import from 70 Chapter 4 West Africa. Kalshoven (1950–1951) gives 1909 as the date of the first record from Java, but Schedl (1961) cites a report from there by Zimmermann in 1904. The first records from Sumatra are around 1919, from Malaysia 1928 (Corbett, 1933), from Sri Lanka 1935 (Hutson, 1936) and from the Philippines 1965 (Anon, 1965). After the Second World War it spread across the Pacific, being recorded from New Caledonia in 1948 (Cohic, 1958) and Tahiti in 1963 (Johnston, 1963). It was found in Irian Jaya in 1961 (Thomas, 1961), but so far has not reached Papua New Guinea. Hypothenemus hampei was not reported in India until 1990 but, 10 years later, some 36% of the coffee in the ‘traditional’ coffee areas was affected (Reddy and Rao, 1999). The first report from the New World was in 1922, when a new Scolytid found boring into coffee twigs in the São Paulo region of Brazil was named Xyleborus coffeicola by De Campos Novaes (1922). This was shown by Da Costa Lima (1924) to be synonymous with H. hampei. It gradually spread to the other coffee-growing states of Brazil, and later to other South and Central American countries. It reached Peru in 1961 and had moved from there to Ecuador by 1981. It gradually spread north through Ecuador and reached Colombia in 1988 (Cárdenas and Posada, 2001) and Venezuela in 1995. In Central America and the Caribbean, it was discovered first in Guatemala in 1971 (Hernandez Paz and Penagos Dardon, 1974), and from thence spread to Honduras in 1977, Mexico (Baker, 1984) and Jamaica (Reid, 1983) in 1978, El Salvador in 1981, Nicaragua in 1988, Cuba in 1994 (Vega et al., 2002), the Dominican Republic in 1995 (Vega et al., 2002) and Costa Rica in 2000. Extensive surveys reported by Vega et al. (2002) failed to find the pest in Puerto Rico, and the authors conclude that Le Pelley’s inclusion of the island in the original distribution list was incorrect. Damage Hypothenemus hampei invades mostly older berries and cuts through the berry to penetrate the bean through a small hole at or near the apex of large green or ripe berries (see Fig 4.2). In Colombia, a high rate of survival and speedy development of the larvae required berries that were at least 120 days old (Baker, 1999). The larvae then consume one or both seeds (see Plate 4). Damaged berries either fall or are rotted by secondary bacterial and fungal growth. Wet rot in the mesocarp of berries superficially damaged by H. hampei has been associated with the bacteria Erwinia steartii and E. salicis (Sponagel, 1994, cited in Damon, 2000). Attacks are more severe where coffee is grown under heavy shade and where pruning has been neglected. Host range Breeding takes place almost entirely in Coffea species, with C. arabica being the most attractive, followed by C. canephora, C. dewevrei, C. dybowskii, C. Berry-feeding Insects 71 Fig. 4.2. Cross-section of coffee berry to show how the nest tunnel of Hypothenemus hampei is initiated from the apex of the fruit. excelsa and finally C. liberica (Le Pelley, 1968). It should be noted that in a recent review of the genus Coffea by Davis et al. (see Chapter 1), the status of some of these species has changed, and C. dewevrei, C. dybowskii and C. excelsa are shown to be synonyms of C. liberica var. dewevrei. The fruits of wild coffee growing in dense forest are often heavily infested. There is quite a long list of plants, other than coffee, from which H. hampei has been recorded (see Table 4.1), and it has been assumed by many authors (e.g. Le Pelley, 1968; Hill, 1975) that these are either exploratory attacks by the beetle on plants in which it cannot breed or that the beetle has been confused with other, similar, species of Scolytid. However, it seems likely that the beetle is able to breed in certain leguminous hosts. Ghesquiere (1933) found all stages of the beetle in pods of Dialium engleranum in Democratic Republic of Congo, and Morallo-Rejesus and Baldos (1980) found eggs, larvae and pupae in Leucaena leucocephala and Gliricidia sepium in the Philippines, as well as in other non-leguminous hosts, whilst CABI (2003) reports that the beetle has been experimentally reared to adulthood on Melicocca bijuga in Colombia and on Cajanus cajan in Guatemala. It seems, therefore, that Leguminosae should not be overlooked as possible alternative hosts for the beetle. 72 Chapter 4 Table 4.1. Host plants of H. hampei other than Coffea (from Schedl, 1961 except where indicated). Family Species Reported locations Apocynaceae Pleiocarpa tubicina Democratic Republic of Congo Bignoniaceae Spathodea campanulata Democratic Republic of Congo Dioscoriaceae Dioscorea sp. Philippinesa Guttiferae Allanblackia floribunda Democratic Republic of Congo Mammea africana Democratic Republic of Congo Leguminosae (sensu lato) Caesalpinia pulcherrima Democratic Republic of Congo Cajanus cajan Guatemala Centrosema plumeri Java Crotalaria sp. Java Dialium engleranum Democratic Republic of Congo Gliricidia sepium Philippinesa Leucaena leucocephala Java, Philippinesa Melicocca bijuga Colombiac Oxystigma oxyphyllum Democratic Republic of Congo Phaseolus lunatus Uganda, Nigeriab Tephrosia candida Sumatra Tephrosia sp. Java Malvaceae Hibiscus sp. Democratic Republic of Congo Meliaceae Trichilia gilgiana Democratic Republic of Congo Myristicaceae Pycnanthus angolensis Democratic Republic of Congo Rosaceae Eriobothrya japonica New Caledonia Rubus sp. Tanzania Rubiaceae Nauclea diderrichii Democratic Republic of Congo Oxyanthus sp. Uganda Psychotria (two spp.) Philippinesa Sterculiaceae Cola sp. near lateritia Democratic Republic of Congo Theobroma cacao Democratic Republic of Congo Verbeneaceae Vitex lanceolaria Java a Morallo-Rejesus and Baldos (1980). b Ghesquiere (1933). c CABI (2003). Berry-feeding Insects 73 Life cycle The life cycle of H. hampei takes 28–35 d from egg-laying to the mature beetle, but the beetle often remains in the berry for 1–2 weeks before emerging. Having a preference for older berries, the life cycle may not be completed before harvest and there is therefore a danger of spreading the beetle within green beans (see Chapter 14). The female beetle bores through the berry into the bean and lays eggs in the tunnel. Over a period of 3–7 weeks, up to 60 eggs may be laid, which hatch in 5–9 d (Ticheler, 1961; Waterhouse and Norris, 1989). The larvae feed on the bean for 10–16 d. The females moult twice before pupation and the pupal stage lasts for 4–9 d. The female becomes sexually mature soon after emergence, is fertilized by the male within the berry and is capable of laying eggs 3–4 d later. Males cannot fly and are capable of fertilizing up to 30 females during their lifespan (Bergamin cit.