Abstract: From 2005 to 2007, field studies undertaken in West-Cameroon permitted to enrich the biodiversity of Psyllids of Psyllidae family. This family include 7 sub-families which are: Aphalaroidinae with Yangus genus (4 species); Ciriacreminae with 3 genus and species (Heteropsylla cubana, Ciriacremum sp., Kleiniella sp.); Diaphorininae with 2 genus, Diaphorina (4 species) and Epipsylla (1 species); Paurocephalinae with 2 genus, Paurocephala (5 species) and Diclidophlebia (1 species); Rhinocolinae with 2 genus, Cerationotum (2 species) and a new genus with 1 species; Spondyliaspidinae with 2 genus, Ctenarytaina (1 species) and Blastopsylla (1 species); Psyllinae sub-family is the most diverse with 14 genus among which only 4 genus are knew; Cacopsylla (1 species), Acizzia (1 species), Psylla (3 species), Palaeolinbergiella (4 species); 5 genus are new to Science. Among the 37 species captured during this survey, 35 are unknown and Blastopsylla occidentalis, eucalyptus psyllid is captured for the first time in West- Cameroon. Host plants belong to more than 16 families. The damages caused by psyllids are mainly leaves folded, wrapped, deformed, discolourated with necrosis and these leaves become dry.
INTRODUCTION
Psyllids or jumping plant-lice are generally very host specific plant-sap sucking insects (Burckhardt et al., 2006a). They can be harmful to their angiosperm hosts in removing large quantities of plant-sap, in producing honey dew and this soiling leaves and fruits or attracting slime moulds, or by transmitting diseases (Burckhardt et al., 2004). Data on biodiversity and taxonomy of psyllids are well known in the temperate and sub-tropical regions. Few records are knew from Africa, South Sahara and in Cameroon in particular. The Convention on the Biological Diversity adopted during the summit of Rio de Janeiro recommends the conservation and the sustained use of the biodiversity and the genetics resources. In several groups, in particular those rich in number of species as it is the case of insects, only a little proportion of existing species is described. This situation has been considered as the obstacle to the taxonomy by the Global Taxonomy Initiative.
In Cameroon, within the Triozidae family, Tamesse et al. (2007) recorded two genus and 35 species; the genus Trioza has 24 species and the genus Pauropsylla has only 11 species. Within the Psyllidae family, no biodiversity and taxonomy studies have been undertaken in various regions of this country. Some psyllids of Psyllidae family are considered as the major pest of some cultivated plants or of pharmaceutical and commercial timber of greater importance as Ricinodendron heudelotii (Messi et al., 1998). The taxonomy studies of some psyllids of Psyllidae family have been recently published from Cameroon; it is the case of five species of Diclidophlebia genus (Burckhardt et al., 2006b) and it is also the case of three species of Ciriacremum genus (Tamesse, 2005).
Cameroon is a country situated in the Central Africa at the extreme North-East of the Gulf of Guinea with a surface area of 475,000 km2. The climate is equatorial in the South with a vegetation of dense forest and tropical in the northern part with the grass field, the sahel and the desert. Local factors such as continentally, proximity to the sea and altitude have introduced some regional nuance.
The Western Province is one of the ten administrative provinces of Cameroon; its surface area is about 13,892 km2. It is composed of Bamoun plateau and the grass-high lands. The climate is pseudo-tropical of altitude (Cameroonian climate of altitude), hot and wet with two seasons; one wet for about 8 months and the other dry for about 4 months. The altitude is between 697 m at Magba and 1840 m at Bangou. The longitude is between 9°58` at Santchou and 11°14` at Magba. The latitude is between 5°03` at Bassamba and 5°58` at Magba or Tonga. The majority of soils are volcanic and rich enough. The original vegetation has ceded to crops (maize, bean and bananas), fruit trees (Dacryodes edulis, Pearsea americana, Mangifera indica, Cola sp., Theobroma cacao, Citrus sp.) and also vegetables (Vernonia sp., Crassocephalum sp., etc.).
In South Africa psyllids biodiversity is well known in Africa (Tamesse et al., 2007). Twenty eight species of Diaphorina, 3 species of Paurocephala, 2 species of Acizzia, one species of Psylla and one of Ctenarytaina within the Psyllidae family were recorded in Africa. In Cameroon, the only known psyllid family biodiversity is the Triozidae studied by Tamesse et al. (2007). It is therefore very important to better know the diversity of different psyllids family and especially from the Western part of the country. The species involved usually caused damages to their host plants. In order to undertake an integrated pest management against psyllid in Cameroon. The aim of this study was to study the biodiversity of psyllids of Psyllidae family and to list all the species and the material recorded in Western Cameroon and their host plants.
MATERIALS AND METHODS
Psyllidae were collected in 6 Divisions in West-Province and in Bambui in the North-West Province of Cameroon from 2005 to 2007 (Table 1).
Psyllids were captured with the help of an entomological net of 0.5 mm mesh size and with the help of a mouth aspirator. Host plants and only accessible branches (2 m high) were visually searched at random. Psyllids seen on the lower four feet of canopy were captured with the help of the mouth aspirator. These insects were preserved in the 70% alcohol. The collection (Table 2) is kept in the Laboratory of Zoology, University of Yaoundé I (LZUY) and in the Naturhistorisches Museum Basle, Switzerland (NHMB). Psyllids were identified under stereomicroscope using keys of Hollis (1976), White and Hodkinson (1985), Burckhardt (1986, 1987b, 1991, 1996), Burckhardt and Misfud (2003), Burckhardt and Lauterer (1989), Heslop-Harrison (1951, 1959, 1960) and Ossiannilson (1992). Host plants were identified in National Herbarium at Yaounde (Cameroon) and kept in the Laboratory of Zoology.
| Table 1: | Divisions, subdivisions and localities where, Psyllidae were collected with their geographic co-ordinates in Western and in North West Cameroon |
| Table 2: | List of known species of Psyllidae (Hemiptera: Psylloidea) from West-Cameroon with their host plants, the region where, species were collected for the first time and references of described species |
RESULTS
The findings revealed that 5704 Psyllidae of 7 sub-families of different developmental stages were captured of which 828 belong to sub-family Aphalaroidinae, 918 to Ciriacreminae, 703 to Diaphorininae, 606 to Paurocephalinae, 136 to Rhinocolinae, 528 to Spondyliaspidinae and 1985 to Psyllinae. Eleven hundred and fifty males, 1284 females and 3270 larvae were recorded. There is no information about the larvae of 10 species. Thirty seven species were collected during this survey (Table 2). Among these 37 species, Blastopsylla occidentalis and Heteropsylla cubana are knew and 35 other species unknown.
Psyllidae feed on different host plants of 16 families: Loranthaceae (2 species), Fabaceae (4 species), Ceasalpinaceae (2 species), Sterculiaceae (3 species), Euphorbiaceae (1 species), Hypericaceae (4 species), Connaraceae (1 species), Asteraceae (3 species), Celastraceae (1 species), Mimosaceae (5 species), Pittosporaceae (1 species), Rosaceae (1 species), Myrtaceae (2 species), Melianthaceae (1 species), Anacardiaceae (1 species), Urticaceae (1 species) and 6 unknown host plants.
Subfamily Aphalaroidinae Loginova
Yangus Genus
| • | Yangus sp.n.1, psyllid of Albizia adianthifolia ( Mimosaceae), (CAM064): 25 males, 20 females and 66 larvae, Lingang, 13 (I) 2006; 1 male and 4 females, Fossong, 14 (ii) 2006; 1 male, 7 females and 100 larvae, Lingang, 8 (iii) 2006 (JL Tamesse and VJ Dzokou); 1 male, 1 female and 17 larvae, Ndang, 4 (ii) 2006; 8 males, 6 females and 31 larvae, Fossong, 21 (iii) 2006; 1 male, 1 female and 9 larvae, Fossong, 11 (iv) 2006; 3 males, 11 females and 6 larvae, Kentsop, 12 (v) 2006; 2 males, 7 females and 47 larvae, Tsinfeum, 17 (ix) 2006; 7 males, 2 females and 22 larvae, Nkop, 21 (x) 2006; 18 males, 12 females and 21 larvae, Tsinkop, 15 (xi) 2006; 4 males, 6 females and 13 larvae, Nkop, 29 (xii) 2006; 1 male and 1 female, Nzem, 10 (i) 2007 |
| • | Yangus sp.n.2, psyllid of Albizia cf. attissima ( Mimosaceae), (CAM027): 2 males and 4 females, Dedah, 1 (ii) 2006; 3 males, 11 females and 4 larvae, Fossong, 13 (ii) 2006; 100 males, 100 females and 150 larvae, Fossong, 14 (ii) 2006; 1 male, 17 females and 8 larvae, Fossong, 21 (iii) 2006; 1 male, 1 female and 5 larvae, Dedah, 11 (iv) 2006; 9 males, 7 females and 6 larvae, Denkop, 14 (vi) 2006; 3 males, 7 females and 6 larvae, Bafounda, 20 (vii) 2006; 1 male and 1 larvae, Dedah, 13 (ix) 2006; 2 males and 3 females, Dedah, 27 (ix) 2006; 1 male and 4 females, Leppe, 10 (iii) 2007; 1 male, 17 females and 8 larvae, Fossong, 21 (iii) 2006 |
| • | Yangus sp.n.3, psyllid of Albizia zygia (Mimosaceae), (CAM042): 21 males, 24 females and 16 larvae, Foumbot, 7 (iv) 2006; 9 males, 6 females and 2 larvae, Mango`o, 10 (vii) 2006; 7 males, 12 females and 5 larvae, 15 (xi) 2006; 1 male, 3 females and 4 larvae, Bangam, 3 (ii) 2007 |
| • | Yangus sp.n.4, psyllid of Albizia glaberrima (Mimosaceae), (CAM131): 3 males, 2 females and 1 larvae, Mbokou, 12 (x) 2006 |
Subfamily Ciriacreminae Enderlein
Heteropsylla Genus
| • | Heteropsylla cubana, Psyllid of Leucena glauca ( Mimosaceae) (CAM075): 9 males, 14 females and 27 larvae, Dschang-Ville, 13 (i) 2006; 10 males, 10 females and 102 larvae, Foreke, 12 (iii) 2006; 50 males, 58 females and 43 larvae, Foumbot, 7 (iv) 2006; 20 males, 21 females and 4 larvae, Foto, 14 (ix) 2006; 8 males, 8 females and 32 larvae, Tsinfeum, 21 (x) 2006; 500 larvae, Tsinfeum, 13 (xi) 2006 |
Ciriacremum Genus
| • | Ciriacremum sp.n., host plant unknown (D73): 1 female, Foto-Chefferie, 15 (xi) 2006 |
Kleiniella Genus
| • | Kleiniella sp.n. host plant unknown (D60): 1 female, Foto-Chefferie, 15 (xi) 2006 |
Subfamily Diaphorininae Vondracek
Diaphorina Genus
| • | Diaphorina sp.n.1, psyllid of Maytenus senegalensis (Celastraceae) (CAM056): 7 males, 11 females and 1 larvae, Foumbot, 7 (iv) 2006 (JL Tamesse and VJ Dzokou); 1 male and 4 females, Foumbot, 26 (v) 2006 |
| • | Diaphorina sp.n.2, psyllid of Vernonia amygdalina and Crassocephalum mannii (Asteraceae) (CAM055a): 40 males, 38 females and 39 larvae, Tsinfeum, 11 (iv) 2006; 100 males, 100 females and 70 larvae, Tsinfeum, 14 (iv) 2006; 1 male, 3 females and 7 larvae, Mboum, 8 (vi) 2006; 30 males, 21 females and 69 larvae, Tsinfeum, 14 (vi) 2006; 22 males, 23 females and 2 larvae, Nzem, 28 (ix) 2006; 4 males, 6 females and 33 larvae, Tsinfeum, 12 (x) 2006; 7 males, 12 females and 27 larvae, Tsinkop, 15 (xi) 2006; 3 males and 1 female, Fomopea, 13 I 2007 |
| • | Diaphorina sp.n.3, Globimetula braunii (Loranthaceae) (CAM117): 1 female, Nkop, 27 (iii) 2006; 2 females, Fossong, 31 (v) 2007 |
| • | Diaphorina sp.n.4, psyllid of Microglossa angolensis (Asteraceae) (CAM055b): 11 males, 7 females and 10 larvae, IRAD Bambui, 06 (xii) 2007 |
Epipsylla Genus
| • | Epipsylla sp.n., host plant unknown (D44): 1 female, Fossong, 18 (vi) 2006 |
Sub-family Paurocephalinae Bekker-Migdisova
Paurocephala Genus
| • | Paurocephala sp.n.1, psyllid of Dombeya ledermannii (Sterculiaceae) (CAM020): 25 males, 35 females and 6 larvae, Lingang, 30 (xi) 2005; 16 males and 23 females, Lingang, 27 (i) 2006; 1 male and 1 female, Dschang-Ville, 11 (ii) 2006; 19 males, 18 females and 2 larvae, Makong, 11 (v) 2006; 34 males, 28 females and 3 larvae, Foumbot, 26 (v) 2006; 9 males and 10 females, Bafounda, 20 (vii) 2006; 10 males and 13 females, Lingang, 27 (ix) 2006 |
| • | Paurocephala sp.n.2, psyllid of Psorospermum cf. aurantiacum (Hypericaceae) (CAM024): 2 males, 7 females and 5 larvae, Fonakeukeu, 1 (v) 2006; 1 male and 1 female, Mboum, 8 (vi) 2006; 2 males, 2 females and 6 larvae, Lingang, 16 (vi) 2006; 1 male, 3 females and 3 larvae, 6 (vii) 2006; 5 males, 8 females and 25 larvae, Fossong, 18 (viii) 2006; 7 males, 8 females and 17 larvae, Fossong, 13 (ix) 2006; 1 female, Mboum, 24 (vi) 2007 |
| • | Paurocephala sp.n.3, psyllid of Cnestis ferruginae (Connaraceae) (CAM146): 29 males, 37 females and 60 larvae, Massagam, 21 (vii) 2006 |
| • | Paurocephala sp.n.4, psyllid of Psorospermum sp. (Hypericaceae) (CAM013): 1 male, 1 female and 1 larvae, Fonakeukeu, 1 (v) 2006; 1 male and 1 female, Banékané, 10 (vii) 2006; 2 females and 2 larvae, Fossong, 18 (viii) 2006; 1 female, Nzem, 10 (i) 2007 |
| • | Paurocephala sp.n.5, psyllid of Psorospermum aurantiacum (Hypericaceae) (CAM143): 7 males, 10 females and 14 larvae, Nzem, 10 (i) 2007 |
Diclidolphlebia Genus
| • | Diclidolphlebia sp.n.1, psyllid of Boehmeria platyphylla (Urticaceae) (D55): 1 male and 14 larvae, Mbokou, 12 (x) 2006 |
Sub-Family Psyllinae Löw
Psylla Genus
| • | Psylla s.I. sp.n.1, host plant unknown (CAM025a): 2 females, Fossong, 5 (vi) 2006; 3 males and 1 female, Fossong, 13 (vi) 2006; 1 female, Fossong, 18 (iii) 2006; 7 males and 10 females, Fossong, 24 (i) 2007 |
| • | Psylla s.I. sp.n.2, host plant unknown (CAM025b): 33 males and 27 females, Nzem, 10 (i) 2007; 4 males and 4 females, Meteu, 10 (i) 2007 |
| • | Psylla s.I. sp. n.3, psyllid of Tapinauthus ogowensis (Loranthaceae) (CAM025c): 2 males and 2 females, Dschang-Ville, 12 (viii) 2007 |
Cacopsylla Genus
| • | Cacopsylla sp.n., psyllid of Pittosporum viridiflorum (Pittosporaceae) (CAM119): 1 male, 1 female and 5 larvae, Dschang-Ville, 11 (ii) 2006; 5 males, 3 female and 8 larvae, Lingang, 15 (ii) 2006; 8 females and 7 larvae, Nkop, 22 (iii) 2006; 16 males and 12 females, Lingang, 27 (iii) 2006; 1 female, Mboum, 8 (x) 2006; 2 females and 9 larvae, Nkop, 21 (x) 2006; 8 males, 12 females and 18 larvae, Nkop,29 (xii) 2006; 7 males, 1 female and 9 larvae, Meteu, 10 (i) 2007 |
Acizzia Genus
| • | Acizzia sp.n., psyllid of Albizia cf adianthifolia ( Mimosaceae), (CAM023): 8 males, 10 females and 4 larvae, Lingang, 8 (ii) 2006; 2 males and 1 larvae, Kentsop, 12 (iii) 2006; 19 males, 12 females and 14 larvae, Lingang, 21 (iii) 2006; 12 males, 10 females and 71 larvae, Nkop, 21 (iii) 2006; 1 female and 2 larvae, Lingang, 14 (iv) 2006; 7males, 12 females and 6 larvae, Nkop, 27 (iii) 2006; 5 males, 6 females and 4 larvae, Fongo-Tongo, 14 (iv) 2006; 1 male and 1 female, Fongo-Tongo, 18 (iv) 2006; 2 males, 5 females and 1 larvae, Makong, 11 (v) 2006;7 males, 8 females and 2 larvae, Tsinkop, 15 (xi) 2006 |
Palaeolinbergiella Genus
| • | Palaeolinbergiella sp.n.1, psyllid of Dalbergia saxitilis (Fabaceae) (CAM123): 7 larvae, Foreke, 11 (ii) 2006; 3 males, 1 female and 1 larvae, Nkop, 12 (ii) 2006 |
| • | Palaeolinbergiella sp.n.2, psyllid of Dalbergia grandibracteata (Fabaceae) (CAM125): 1male and 1 female, Nkop, 23 (iii) 2006; 17 males and 14 females, Nkop, 11 (v) 2006; 1 male, 1 female and 25 larvae, Nkop, 18 (viii) 2006; 3 males, 2 females and 22 larvae, Nkop,21 (x) 2006 |
| • | Palaeolinbergiella sp.n.3, psyllid of Dalbergia grandibracteata (Fabaceae) (CAM124): 4 males, 1 female and 4 larvae, Nkop, 27 (iii) 2006 |
| • | Palaeolinbergiella sp.n.4, psyllid of Dalbergia albiflora (Fabaceae) (D68): 1 male, 2 females and 26 larvae, Bangam, 3 (ii) 2007 |
| • | gen. sp.n.1, psyllid of Pygeum sp.(Rosaceae) (CAM029): 4 males, 8 females and 2 larvae, Dschang-Ville, 13 (i) 2006; 16 males, 25 females and 18 larvae, Dschang-Ville, 23 (iii) 2006; 2 females and 6 larvae, Dschang-Ville, 16 (ix) 2006; 23 males, 16 females and 58 larvae, Dschang-Ville, 8 (xii) 2006 |
| • | gen. sp.n.2, psyllid of Piliostigma thonningii (Ceasalpinaceae) (CAM057a): 200 males, 200 females and 700 larvae, Foumbot, 7 (iv) 2006; 2 males, 1 female and 96 larvae, Banékané, 10 (vii) 2006; 8 males, 4 females and 1 larvae, Basse-Bamougoum, 20 (vii) 2006 |
| • | gen. sp.n.3, host plant unknown (CAM057b): 2 males, Bansoa-Chefferie, 3 (v) 2006. |
| • | gen. sp.n.4, psyllid of Psorospermum febrifugum (Hypericaceae) (CAM004): 3 males and 1 larvae, Mboum, 8 (vi) 2006; 13 males and 13 females, Mboum, 24 (vi) 2007; 2 males and 1 female, Mboum, 24 (vi) 2007 |
| • | gen. sp.n.5, host plant unknown (D65): 1 female, Meteu, 10 (i) 2007 |
Sub-Family Rhinocolinae Vondr� cek
Cerationotum Genus
| • | Cerationotum sp.n.1. cf. bicorne, psyllid of Lannea sp. (Anacardiaceae) (CAM059): 5 males, 13 females and 6 larvae, Foumbot, 7 (iv) 2006; 3 males, 1 female and 20 larvae, Foumbot, 26 (v) 2006; 2 males, 7 females and 3 larvae, Foumbot, 27 (vii) 2006 |
| • | Cerationotum sp.n.2. cf. cuneipennis, psyllid of Lannea sp. (Anacardiaceae) (CAM060): 3 males, 4 females and 11 larvae, Foumbot, 26 (v) 2006; 16 males, 17 females and 23 larvae, Foumbot, 27 (vii) 2006 |
| • | gen n. sp., Bersama abyssinica (Melianthaceae) (CAM001): 2 females, Massangam, 21 (vii) 2006 |
Sub-Family Spondyliaspidinae Heslop-Harrison
Ctenarytaina Genus
| • | Ctenarytaina sp.n., psyllid of Syzygium guineense (Myrtaceae) (CAM058): 4 males, 5 females and 6 larvae, Mboum, 15 (iii) 2006;26 males, 28 females and 80 larvae, Mboum, 19 (iii) 2006; 1 male, 3 females and 30 larvae, Mboum, 8 (vi) 2006 |
Blastopsylla Genus
| • | Blastopsylla occidentalis, psyllid of Eucalytus globulus (Myrtaceae) (CAM061): 2 males, 3 females and 11 larvae, Nkop, 26 (iv) 2006; 14 males, 13 females and 123 larvae, Dschang-Ville, 1 (v) 2006; 1 male, 1 female and 2 larvae, Foto, 11 (v) 2006; 14 males, 5 females and 23 larvae, Bafounda, 20 (vii) 2006; 5 males, 13 females and 11 larvae, Nkop, 26 (iv) 2006; 14 males, 13 females and 22 larvae, Dschang-Ville, 17 (ix) 2006; 4 males, 4 females and 8 larvae, Nkop, 21 (x) 2006; 5 males, 8 females and 12 larvae, Dschang-Ville, 8 (xii) 2006; 7 males and 7 females, Nzem, 10 (i) 2007 |
DISCUSSION
Burckhard`s (1987a) recognise among Psyllidae family, 16 sub-families all over the world. But in Cameroon, Tamesse (2005) recognise in Cameroon, 8 sub families, 14 genus and 25 differents species. During this survey in the western part of Cameroon, 7 sub-families of 37 species exist. Among 37 species, 35 are undescribed species.
The sub-family Aphalaroidinae is mentioned in Western province of Cameroon for the first time. It has one genus, Yangus (Fang, 1990). The single species described all over the world was collected on Albizia procera (Mimosaceae) in Taiwan (Fang, 1990). Tamesse (2005) announce the presence of 2 species of Yangus associated with Albizia glaberrima and A. ferruginea (Mimosaceae) in Soa (Yaounde) for the first time. This study confirm the presence in West- Cameroon of Yangus species associated with A. glaberrima. We also collected 3 other new species of Yangus feeding on Mimosaceae. This genus is very host specific on Mimosaceae.
According to Hollis (1976), the sub-family Ciriacreminae has 3 species of Ciriacremum (C. nigeriense, C. nigripes, C. capillicorne) and one species of Kleiniella (K. jassina) in Cameroon, without any information about their host plants. Three genus, Heteropsylla cubana, Ciriacremum sp. and Kleiniella sp. were collected during this study. Only one specimen of Ciriacremum and one specimen of Kleiniella were recorded in Western Cameroun. The 3 genus are colleted in West-Cameroon for the first time. H. cubana feeds on Leucena glauca (Mimosaceae) introduced in Cameroon by International Centre for Research in Agro forestry in 1980, in order to fertilize the soil. Before 1980, this psyllid did not exist in Cameroon.
The sub-family Diaphorininae has 2 genus, Diaphorina (4 new species) and Epipsylla sp.n. Diaphorina host plants are Celastraceae, Asteraceae and Loranthaceae in West- Cameroon. In South Africa, among the 28 Diaphorina species recorded, only D. valens was collected on Maytenus oliodes (Celastraceae) (Capener, 1970). Host plants of Psyllidae are very diverse.
Earlier field study in Cameroon permitted the description of Psyllids belonging to the sub-family Paurocephalinae: Diclidophlebia xuani Messi (Messi et al., 1998), associated with Ricinodendron heudelotii (Euphorbiaceae), Diclidophlebia harrisoni Osisanya (Osisanya, 1969), Diclidophlebia eastopi Vondracek (Vondracek, 1963) associated with Triplochiton scleroxylon (Sterculiaceae), Diclidophlebia irvingiae (Burckhardt et al., 2006b) associated with Irvingia gabonensis (Irvingiaceae) and Diclidophlebia leptonychiae (Burckhardt et al., 2006b) associated with Leptonychiae cf. macrantha (Sterculiaceae). In Western Cameroon, the subfamily Paurocephalinae has 2 genus, Paurocephala and Diclidophlebia. Paurocephala genus has 5 new species and Diclidophlebia genus has only one new species. The host plants of Paurocephalinae belong to 4 different families. According to Burckhardt et al. (2006b), Diclidophlebia species host plants are 7 families in 4 orders; the information on unpublished psyllids collections of different natural history museum, indicates that host plants of Diclidophlebia is even more diverse. Burckhardt and Misfud (2003), based on a cladistic analysis of 22 morphological characters (16 adult and 6 larval), raised the confusion which existed with the definition of the psyllid subfamily Paurocephalinae and the subfamily was redefined to comprise five genera.
The subfamily Psyllinae Löw is very rich of number of species. 4 genus, Cacopsylla sp.n., Psylla sp.n., Palaeolinbergiella sp.n. and Acizzia sp.n. are knew in the region. Five genus are to define. Acizzia sp.n (Psyllinae) and Yangus sp.n.1 (Aphalaroidinae) feed on the same host, Albizia cf. adianthifolia (Mimosaceae) in Western Cameroon, without any segregation for the nutrition and nymphal stages sites.
The subfamily Rhinocolinae has 2 new species of Cerationotum feed on Lannea sp. (Anacardiaceae) and a new genus associated with Bersama abyssinica (Melianthaceae). Cerationotum genus is collected for the first time in Western Cameroon.
The subfamily Spondyliaspidinae has 2 genus, Ctenarytaina sp.n, psyllid of Syzygium guineense (Myrtaceae) and Blastopsylla occidentalis. B. occidentalis, very well known in the old world (Brennan et al., 2001), is collected on Eucaluptus globulus in West Cameroon for the first time. In South Africa, Ctenarytaina eucalypti Maskell, feeds also on E. globulus (Myrtaceae) (Capener, 1970). This remark shows that, in some conditions, the two species, Ctenarytaina and Blastopsylla can feed on the same host plant. Now, in West Cameroon, Ctenarytaina sp.n. is more dangerous than Blastopsylla occidentalis, according to damages.
Ciriacremum nigeriense, C. nigripes, C. capillicorne, Kleiniella jassina, Diclidophlebia harrisoni, D. eastopi D. irvingiae, D. leptonychiae and D. xuani knew before from Cameroon were not captured during this survey in the Western Province.
Psyllidae host plants belong to 17 different families: Anacardiaceae, Asteraceae, Ceasalpinaceae, Celastraceae, Connaraceae, Fabaceae, Hypericaceae, Loranthaceae, Melianthaceae, Mimosaceae, Myrtaceae, Pittosporaceae, Rosaceae, Sterculiaceae, Euphorbiaceae and Urticaceae. Nine host plants are still unknown. Some host are rich with species, Mimosaceae (5 species), Fabaceae (4 species) and Hypericaceae (4 species). Loranthaceae family is known as host of psyllid in afrotropical region for the first time. Globimetula braunii (Loranthaceae) growth on Ficus platyphylla (Moraceae) and Tapinauthus ogowensis (Loranthaceae) on Coniferale. Considering the list of family host of 36 Psyllidae species from South Africa, cited by Capener (1970), only 4 families are Psyllidae host plants in West-Cameroon (Celastraceae, Anacardiaceae, Myrtaceae and Euphorbiaceae). Twelve other families host plants from West Cameroon are different of those from South Africa. Psyllidae host are very diverse in West Cameroon and some have various economical and pharmaceutical importance. Eucalyptus sp. is used as wood for industries and as post for transporting electric cord in Cameroon. Bersama abyssinica (Melianthaceae) produces a hard, heavy wood that is used for the construction of houses in West Africa (Heywood, 1993). Vernonia amygdalina (Asteraceae) is used in Nigerian for folk medicine as a tonic and remedy against constipation, fever, high blood pressure and many infectious diseases (Iwalokun et al., 2006). It`s elicited hepatoprotectivity through antioxidant activity on acetaminophen- induced hepatic damage in mice (Iwalokun et al., 2006). Leaves of V. amygdalina are used as vegetable in Central Africa. Extracts of Cnestis ferruginae (Connaraceae) showed a great activity against Aspergillus niger, pathogen agent of human aspergillums (Le Grand et al., 1988). Psyllidae caused severe damages on their host plants. The sap feeding activity on host plant caused a stress to the plant; the injection of toxins to the plant tissues provokes the degeneration of leaves, buds or the whole plant; the distortion of leaves, the apparition of necrosis on leaves and stems occurred during larval development.
| Fig. 1: | Leucena glauca (Mimosaceae) with adults and larvae showing mould and necrosis |
| Fig. 2: | Vernonia amygdalina with larvae and adults of Diaphorina sp.n.2, associated with ants |
Heteropsylla cubana feed and laid their eggs preferentially on the youngest buds (Fig. 1). In the period of higher proliferation, adults and larvae lay all the surface of buds and youngest leaves. Adults and larvae of Diaphorina sp.n.2 feed and laid their eggs at the lower side of the leaves of Vernonia amygdalina (Asteraceae) (Fig. 2). This psyllid is associated with ants probably in search for secretes by larvae. Leaves are very deformed (Fig. 3) as it is the case of the leaves of Pittosporum viridiflorum (Pittosporaceae) (Fig. 4), host plant of Cacopsylla sp.n. In the nursery, the uncovered young plants of Pygeum sp. (Rosaceae) has their leaves puffed, deformed and sometimes wrapped (Fig. 5). These youngest Pygeum plants were weak and unfit for commercialisation. Leaves of Syzygium guineense (Myrtaceae), host of Ctenarytaina sp.n. are deformed and sometimes, young leaves and buds remain dwarfs after the period of higher proliferation (Fig. 6). On young plants of Eucalyptus globulus (Myrtaceae), the attack lessened considerably, but the old leaves present strong discolourations (Fig. 7). The larvae of Diclidophlebia sp.n.2. form often dense colonies and feed on young leaves of Psorospermum aurantiacum (Hypericaceae) (Fig. 8); on Boehmeria platyphylla (Urticaceae), larvae of Diclidophlebia sp.n. feed also on flowers or fruits as well as terminal buds (Fig. 9). It is the case of Diaphorina sp.n.4 on Microglossa angolensis (Asteraceae) (Fig. 10). This type of damages is similar to those caused by Diclidophlebia smithi in Brazil (Burckhardt et al., 2006a) on Miconia calvescens (Melastomataceae). The populations of Psyllinae gen.sp.n.2 feed on the upper side of the young leaves of Piliostigma thoningii (Ceasalpinaceae). These leaves are twisted, deformed, covered by mould and necrosis (Fig. 11). Adults and larvae are also associated with ants. Other Psyllidae did not provoke visual damages on their host plants; it is the case of Palaeolinbergiella sp.n.2 and Palaeolinbergiella sp.n.3 on Dalbergia grandibracteata (Fabaceae) (Fig. 12), Psylla sp.n.3 on Tapinauthus ogowensis (Loranthaceae) (Fig. 13) and Diaphorina sp.n.1 on Maytenus senegalensis (Celastraceae) (Fig. 14).
| Fig. 3: | Vernonia amygdalina with leaves deformation by Diaphorina sp.n.2 |
| Fig. 4: | Pittosporum viridiflorum (Pittosporaceae) with leaves deformation, rolled up and sheltering the larvae of Psyllinae gen.sp.n.2 |
| Fig. 5: | Young plants of Pygeum sp. already attacked by Psyllinae gen.sp.n.1 |
| Fig. 6: | Syzygium guineense (Myrtaceae), with wax filaments in terminal buds produce by the larvae of Ctenarytaina sp.n. |
| Fig. 7: | Leaves of Eucalytus globulus (Myrtaceae) discoloured by Blastopsylla occidentalis |
| Fig. 8: | Psorospermum aurantiacum Engl. (Hypericaceae) with leaves deformation by Pauropsylla sp.n.5 |
| Fig. 9: | Boehmeria platyphylla (Urticaceae), host of Diclidolphlebia sp.n. |
| Fig. 10: | Adults and larvae of Diaphorina sp.n.4 feed on young leaves and infrutescence of Microglossa angolensis (Asteraceae) |
| Fig. 11: | Piliostigma thonningii (Ceasalpinaceae) with twisted leaves, covered by mould and necrosis |
| Fig. 12: | Dalbergia grandibracteata (Fabaceae), host of Palaeolinbergiella sp.n.with no visual damage |
| Fig. 13: | Tapinauthus ogowensis (Loranthaceae), host of Psylla sp.n.3 with no visual damages |
| Fig. 14: | Maytenus senegalensis (Celastraceae), host of Diaphorina sp.n.2 |
CONCLUSION
In West Cameroon, 37 species of psyllids of Psyllidae family were recorded in 7 subfamilies: Aphalaroidinae (one genus), Ciriacreminae (3 genus), Diaphorininae (2 genus), Paurocephalinae (2 genus), Rhinocolinae (3 genus), Spondyliaspidinae (2 genus) and Psyllinae (9 genus). Among these 37 species, 35 are undescribed species and the 2 other species earlier described elsewhere but unknown from Western Cameroon. Nine species previously described from Cameroon were not captured during this study. Psyllidae host plants are diverse with various economical and pharmaceutical importances. Damages caused by these insects on their host plants are mainly deformation and distortion of leaves, mould and necrosis. In order to undertake an integrated pest management against species with an economic and pharmaceutical interests, it will be important to pursue these works notably by completing the taxonomy and biology studies of psyllids of Psyllidae family in Western Cameroon.
ACKNOWLEDGMENTS
This research is partly funded by the Swiss National Sciences Foundation (Research Partnerships with Developing Countries, project No. 3170 AO-109221/1 (2005-2008) to Daniel Burckhardt and Joseph Lebel Tamesse.