Biological Control of Insect Pests: Southeast Asian Prospects - EcoPort

4.4 Aphis gossypii 63
that the lycosid spider Pardosa astrigata is an important predator in cotton
fields and Dong (1988) that the coccinellid Harmonia axyridis was an
effective natural enemy when present in adequate numbers. Other predators
include the anthocorid bug Orius minutus (Miao & Sun 1987), the
coccinellids Scymnus hoffmanni (Zhao and Holling 1986), Propylea
japonica and Harmonia axyridis (Zou et al. 1986; Lei et al. 1987 ).
The aphidiid Aphidius picipes (= A. avenae) parasitised more than 80%
of A. gossypii individuals on Chinese cabbage growing near cotton fields (Li
& Wen 1988). Laboratory studies showed that Trioxys communis was more
effective than Aphelinus mali in suppressing A. gossypii populations (Shi
1985). Of the 5 species of parasitoid recorded by Xi and Zhu (1984) on
A. gossypii on cotton in Jiangsu Province, Lysiphlebia japonica and Trioxys
indicus were dominant and each accounts for about 45% of all parasitoids. In
the laboratory, female L. japonica laid an average of 120 eggs and produced
a parasitisation rate of up to 14%. In the field it overwinters as larvae inside
A. gossypii, A. craccivora or Myzus persicae. In an earlier study Tian et al.
(1981) recorded the same two parasitoids on both A. craccivora and
A. gossypii with a combined parasitisation rate of 13%. This did not provide
effective control and it was pointed out there was heavy attack by
hyperparasitoids, such as Aphidencyrtus sp. (Encyrtidae).
Larvae of the mite Allothrombium pulvinum have been observed
attacking A. gossypii in cotton fields (Zhang and Chen 1993; Zhang et al.
1993).
COLOMBIA
Aphelinus sp. caused 2.2% and Lysiphlebus sp. 0.3% parasitisation of
A. gossypii on cotton in the field (Ramirez and Zuluaga 1995).
CUBA
Aphis craccivora is a common pest of vegetables and many other crops and
also occurs on wayside trees, such as Gliricidia. In beans and other annual
crops it occurs for a short period only, whereas on wayside trees it is present
more or less continuously. The native parasitoid Lysiphlebus testaceipes
parasitises the aphid heavily on Gliricidia, but poorly or not at all on young
beans. This appears to be primarily a matter of the relative rates of dispersal
of the aphid and its parasitoid (Starù 1970).
EAST ASIA
A list of parasitoids recorded from A. gossypii in East Asia is shown in table
4.4.1 in which most entries from this region are based on Takada (1992). The
most comprehensive information within this region is available from
Taiwan (Starù and Schlinger 1967; Tao and Chiu 1971; Chou 1984), Japan
(Takada 1968; Takada and Yamauchi 1979; Takada unpublished) and India
(Raychaudhuri 1990). For Southeast Asia, there are two records from