Parthenium is attacked by 44 insects and mites. Insects like aphids, leaf and plant hoppers, mealy bugs, scale insects, moths and beetles are important ones. Among these Zygogramma bicolorata is most promising and hence it was introduced to India during 1983 from Mexico.

The adult Z. bicolorata measures about 6 mm in length, lays eggs singly or in small groups on the under surface of leaves of parthenium. The eggs hatch in four to six days and the larve feed voraciously on parthenium, first attacking terminal and axillary buds and later the leaf blades. The young larvae check plant growth and flower production due to severe defoliation. Full grown larvae desert the plant, drop off and pupate in the soil. The inseect complets its development period in 25-30 days. The adult beetles lay an average of 2000 eggs during their life span of three or four months. Z. bicolorata remains active in thee field during rainy season from June to October.

The beetle can tolerate dry spells in between, although their multiplication rates may be affected. The weed killer is capable of over coming winter and summer months by getting into the soil and diapausing monsoon rains in June.

Operational tips for IPWM

1. Mark the boundary of the area to be treated.
2. Don't disturb the naturally existing vegetation except parthenium.
3. Uproot parthenium plants, if any.
4. In open soils, (where there is no vegetation) open shallow furrows of about 2.5 cm deep and sprinkle seeds of C. sericea  or any other proven botanical agent at fixed seed rate. Furrows opened at 22.5 cm apart are optimum for the purpose.
5. When the seeds germinate after rains, encourage the growth of plants by uprooting only parthenium. Pay special attention to protect and promote the regrowth of the following plant species which exist in the waste lands in natural course:C. sericea SW., (Syn: Cassia uniflora), Cassia tora L., Cassia auriculata L., Croton bonplandiamum Baill (Syn: C sparsiflorus Morung), Amaranthus  spinosus L. Tephrosia purpurea Pers. Hyptis Suaveolens Poit, Sida spinosa L. sand Mirabillis jalapal L.
6. Uproot parthenium plants at intervals so as to enable botanical agents to put up full growth.
7. Once these are accomplished, they perpetuate on their own and there will be no need to plant them again unless the soil is scraped to take out self sown seeds of biological agents.
8. The sowing of seeds can be taken up just before the onset of rains or after the first rains.
9. Release of adults of Z. bicolorata in areas where their activity is not noticed. As an inoculative release it is recommened to release 100 pairs of beetle per acre during June month.