 |
|||
|
|
|
|
|
|
|
|||
|
|
|
|
|
NOTES ON TAXONOMY AND BIOLOGY: The morphological characteristics of the vermiform stages of this reniform nematode are similar to those of R. reniformis. R. macrodoratus vermiform females, however they have a longer stylet than those of R. reniformis (22-26 vs. 16-21µm). R. macrodoratus swollen females lack the characteristic spike-like mucro, which is present at the body posterior end of R. reniformis females. This reniform nematode has semi-endoparasitic sedentary habits. Second stage juveniles (J2) and following juvenile stages (J3 and J4) develop and attain the adult stage in the soil without feeding. The vermiform females penetrate host roots and become sedentary. The anterior portion of their body remains embedded in the roots and the posterior portion protrudes from the root surface and swells. They establish a specialized feeding site (a mononucleate giant cell) in the stele. After gonad maturation they deposit eggs in a gelatinous matrix, which suurounds the female posterior body (Robinson et al., 1997).
GEOGRAPHICAL DISTRIBUTION: Rotylenchulus macrodoratus is a Mediterranean species, which occurs in France, Greece, Israel, Italy and Malta (Robinson et al., 1997). . It has been reported recently in South Africa (Van den Berg, 1998).
HOSTS: This reniform nematode parasitizes many fruit and ornamental trees such as almond (Prunus amygdalus), apricot (Prunus armeniaca), carob (Ceratonia siliqua), fig (Ficus carica), grape (Vitis vifera), laurel (Laurus nobilis), loquat (Eurybotria japonica), oleander (Nerium oleander), olive (Olea europaea), oak (Quercus calliprinos and Q. farnetto), pistacio (Pistacia vera) and plum (Prunus domestica). Herbaceous hosts include carnation (Dianthus caryophyllus), ivy (Hedera ilex), large-flowered sweet William (Dianthus barbatus), pellitory (Parietaria officinalis), phlomis (Phlomis fruticosa) and soybean (Glycine max).
CROP LOSSES: The damage caused by this nematode to fruit trees has not been quantified.
MEANS OF MOVEMENT AND DISPERSAL: Nematode is dispersed with soil debris and poorly sanitized propagative plant material.
RATING: (M) Although the crop losses caused by this nematode have not been quantified under field conditions, there is evidence that this nematode has the potential to become a pest of many fruit trees because of its wide host range. On the basis of these considerations this nematode is given a moderate priority rating.
REFERENCES:
Robinson, A. E., R. N. Inserra, E. P. Caswell-Chen,
N. Vovlas, and A. Troccoli.1997. Rotylenchulus species: identification,
distribution, host ranges, and crop plant resistance. Nematropica 27:127-180.
Van Den Berg, E. 1998. New records and notes on
known specie of Hoplolaimidae (Nemata) in South Africa. Journal of Nematode
Morphology and Systematics 1:29-46.