Biology
Female weevils chew into the side of a young puncturevine
bur, deposit eggs into the seed and seal it with fecal material.
Females may deposit up to 324 eggs. Weevils grubs develop
inside the seed and pupate therein. Each seed may produce
1-3 weevils. The life cycle from egg to adult requires about
25 days. Adult weevils may feed on the plant but do not cause
appreciable damage to the plant. The number of generations
per year depends on the climate. Adults overwinter.
History
The first release of Microlarinus lareynii for the
biological control of puncturevine in the United States occurred
in 1961. In the early summer months of 1961, Microlarinus
lareynii seed weevils were released in Clark County, Nevada
and Stanislaus County, California. Subsequent releases were
made in Arizona, California, Colorado, Utah and Washington.
The weevil became established in Arizona, California and Nevada
but failed in Colorado, Washington and Utah. Today, puncturevine
weevils are widely established throughout the United States.
In 1991, 28,000 weevils were released in the High Plains
of Texas to augment the population in that region. In 1992,
22,000 weevils were also released in that area. Rummel and
Arnold (1992) document the releases and infestation rates
in the area.
Successes
In 1961, 250 weevils were released at sites near Amarillo
and Big Spring, Texas. By 1963 the weevil was established
in Big Spring but had failed in Amarillo. The weevil was again
released at sites near Amarillo and Wellington, Texas. The
weevil was once again unsuccessful in Amarillo but was established
in Wellington. The lack of the weevils success in Amarillo
was attributed to the extreme winter conditions and the inability
of the weevil to adapt. By 1966, the puncturevine weevil
had spread throughout West Texas and by the mid-1970's puncturevine
was no longer a weed pest in West Texas.
Implementation
Both the seed weevil and the stem weevil for biological
control of puncturevine are native insects of Europe, however
the first releases of these species in the United States were
imported from Italy. Weevil establishment is favored by warm
temperature areas associated with mild winters. Sufficient
puncturevine density is another factor necessary to support
substantial weevil populations. The number of weevils released
in an area for control of puncturevine is dependent on both
these factors; the time of year and puncturevine densities.
The number of weevils released is ordinarily between 250 and
1000 weevils
Host Range
Microlarinus lareynii feeds on puncturevine, Tribulus
terrestris, Jamaica feverplant, Tribulus cistoides
and Kallstroemia spp.
Research
The winter of 1983-84 was one of the harshest winters to
date and most likely had a devastating effect on the weevil
population. By 1987 puncturevine had returned as an economic
pest in Texas. In 1991, 28,000 weevils were released in the
High Plains of Texas to augment the population in that region.
In 1992, 22,000 weevils were also released in that area. Rummel
and Arnold (1992) document the releases and infestation rates
in the area.
Literature
Daniels, N. E., and A. F. Wiese. 1967. Survival and Spread
of the Puncturevine Seed Weevil in Texas. MP-827. Texas Agricultural
Experiment Station. Texas A&M Univ. College Station, TX.
2 pp.
Goeden, R. D., and R. L. Kirkland. 1978. An Insecticidal-Check
Study of the Biological Controlof Puncturevine (Tribulus
terrestris L.) by Imported Weevils, Microlarinus lareynii
and M. lypriformis (Col.: Curculionidae). Environ.
Entomol. 7(3):349-354.
Kirkland, R. L., and R. D. Goeden. 1978. Biology of Microlarinus
lareynii (Col.: Curculionidae) on Puncturevine in Southern
California. Annals of the Entomol. Soc. Amer. 71:13-18.
Maddox, D. M. 1976. History of Weevils on Puncturevine in
and Near the United States. Weed Science 24(4):414-419.
Rummel, D. R., and M. D. Arnold. 1992. Status of the Puncturevine
Seed Weevil in the Texas Southern High Plains. Southwestern
Entomologist. 17: 347-349.
Turner, C. E. 1995. Microlarinus lareynii. In Biological
Control of Weeds in the West. Western Society of Weed Science.
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