Biological Control of Insect Pests: Southeast Asian Prospects - EcoPort

4.4 Aphis gossypii 67
Lysiphlebus testaceipes (26%), Ephedrus cerasicola (23%) and Aphidius
matricariae (less than 5%). The general principles of selection and
establishment of species are relevant elsewhere, although only the first of the
three species selected (Lysiphlebus testaceipes, Aphidius matricariae,
Ephedrus cerasicola) would appear to be particularly relevant to Southeast
Asia or the Pacific.
PAKISTAN
In investigations from 1967 to 1970, 6 parasitoid species and 22 predator
species were recorded attacking Aphis craccivora on a range of leguminous
crops and weeds in 5 climatologically different zones of Pakistan (Hamid et
al. 1977). Alate A. craccivora were found on soybean (Glycine max), but
colonies of apterous aphids never developed, possibly due to the presence of
abundant plant hairs.
Aphelinus abdominalis (= A. basalis), which was widespread and active
throughout the year, parasitised from 0.6% to 17.6% of A. craccivora, the
level depending upon host plant, location (hills, foothills or plains) and
season. Perhaps due to its small size, A. abdominalis was the only parasite
that attacked A. craccivora under the covering of hairs on Phaseolus aureus.
The period from oviposition in the aphid to mummy formation was 3 to 4
days and adult wasps then emerged in 5 days. Trioxys ?sinensis parasitised
up to 21.3% of aphids. Development from oviposition in the aphid to
mummy formation took 14 to 16 days and adults emerged 4 to 7 days later.
Lysiphlebus fabarum parasitised between 1.3% and 72.9% of available
hosts, Ephedrus nr cerasicola 1.3% to 1.4% and Aphidius absinthii 11%. A
low level of attack on most of the parasitoids was recorded by the
hyperparasitoids Alloxysta sp. and Pachyneuron sp.
Ants (Monomorium indicum and Pheidole sp.) were associated with over
90% of the aphid colonies. The size of A. craccivora on Vicia faba nursed by
ants was far greater than those not attended and aphid mortality was higher
when ants were absent. The most abundant of 22 predator species (Table
4.4.2) were Cheilomenes sexmaculata, Coccinella septempunctata and
Syrphus spp.
In the same environment Trioxys sinensis and Lysiphlebus fabarum
parasitised Aphis gossypii on cucumbers and on Hibiscus esculentus (Hamid
et al. 1977).
PHILIPPINES
A. craccivora is commonly attacked by Lipolexis scutellaris; and A. gossypii
by this species and also Trioxys communis. Both parasitoids also attack other
species of aphids, but not the banana aphid Pentalonia nigronervosa (V.J.
Calilung pers. comm. 1995).