New Zealand Journal of Crop and Horticultural Science abstracts
Thrips (Thysanoptera: Terebrantia) on flowers and fruit of citrus
in New Zealand
R. H. BLANK
G. S. C. GILL
The Horticulture & Food Research
Institute of New Zealand
Whangarei Research Centre
Private Bag 9003
Whangarei, New Zealand
Abstract Thrips were collected from flowers, immature and
mature fruit from commercial citrus orchards mainly in the Northland region of
New Zealand and c. 23 000 were identified to species. Thrips
obscuratus (Crawford) comprised 84-100% of all thrips recovered from
flowers of all citrus varieties. Infestation levels of adults and larvae were
commonly c. 20 thrips/flower but they were not associated with damage to the
rind of fruit. Megalurothrips kellyanus (Bagnall) was also commonly
found in flowers, usually in association with T. obscuratus. The highest
infestations of M. kellyanus of 50 thrips/flower on lemons and 22
thrips/flower on tangelos occurred at times when T. obscuratus was
present at a level of less than 1 thrips/flower. Approximately a third of M.
kellyanus in flowers were larvae and the remainder were adults indicating
that breeding occurred in the flowers. M. kellyanus larvae were commonly
found on immature fruit of lemon, navel orange and tangelo, where their feeding
caused scarring of the fruit. The low incidence of M. kellyanus on
mandarin and Valencia orange flowers was reflected in low numbers of larvae on
immature fruit and little evidence of damage. Heliothrips
haemorrhoidalis (Bouché) was commonly found on mature fruit of all
citrus varieties where their feeding activity caused a whitening of the rind.
Fruit of Valencia orange were particularly susceptible to damage by this
species of thrips, with mandarin, navel orange, and tangelo also damaged. The
tubuliferan Nesothrips propinquus (Bagnall) was found on fruit of all
citrus varieties, but there was no evidence of it producing any damage.
Keywords Thrips obscuratus; Megalurothrips
kellyanus; Heliothrips haemorrhoidalis; Nesothrips
propinquus; citrus; damage
New Zealand Journal of Crop and Horticultural Science, 1997, Vol. 25:
319-332
0114-0671/97/2504-0319 $7.00/0 (c) The Royal Society of New Zealand
1997
PDF file of entire paper: medium quality (2202K); (scanned from paper original: notes about this process)
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