Biology
This grasshopper is a native of southern Brazil. Thomas (1980)
reports extensive studies on the biology of this insect. The
life cycle took 38-85 days at 25-36 C. Nymphal mortality was
about 50%. There were 5 or 6 nymphal instars. Estimated growth
rate was 8000 per year with 3 generations (Thomas 1980).
History
Releases of P. acuminata were made in
Kenya, Botswana Sri Lanka, Rhodesia (Lake Kariba), India,
Fiji, and Queensland (Bennett 1976). It appeared to establish
in Botswana but later died out (Thomas & Room 1986). Cage
tests in Rhodesia and Botswana suggest that the plant growth
rate could be reduced by the populations that had built up
in the cages (Bennett 1976).
Status
P. acuminata has not been very successful as a biological
control agent.
Management
This insect is of questionable value as a biological
control agent for giant salvinia. The wide host range makes
it unacceptable for some locations as a biological control
agent.
Weeds Affected
Adults and nymphs feed on giant salvinia, water lettuce,
and azolla. Adults also heavily damaged strawberries.
Literature
Bennett, F. D. 1977. Insects as Agents for Biological
Control of Aquatic Weeds. Aquatic Botany 3:165-174.
Oliver, J. D. 1993. A Review of the Biology of Giant Salvinia
(Salvinia molesta Mitchell). J. Aquat. Plant Manage. 31: 227-231.
Sands, D. P. A., and R. C. Kassulke. 1986. Assessment of
Paulinia acuminata (Orthoptera: Acrididae) for biological
control of Salvinia molesta in Australia. Entomophaga 31:
11-17.
Thomas, P. A. 1980. Life-cycle studies on Paulinia acuminata
(DeGeer) (Orthoptera: Pauliniidae) with particular reference
to the effects of constant temperature. Bull. Ent. Res. 70:
381-389.
Thomas, P. A., and P. M. Room. 1986. Taxonomy and control
of Salvinia molesta. Nature 320: 581-584.
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