Biochemistry and Physiology of Overwintering in the Mature Larva of the Sunflower Stem Weevil, Cylindrocopturus adspersus (Coleoptera: Curculionidae) in the Northern Great Plains

نویسندگان

  • ROBERT R. ROJAS
  • LAURENCE D. CHARLET
  • ROGER A. LEOPOLD
چکیده

The sunflower stem weevil, Cylindrocopturus adspersus (LeConte), overwinters as a mature larva at the base of the stalk and in the root crown of cultivated sunflower plants. Sunflower stalks from fields known to be infested with C. adspersus larvae were collected in southeastern North Dakota in October 1991. Larvae from stalks kept outdoors accumulated a high whole-body concentration of trehalose (up to 69 pg/mg wet wt) at the expense of glycogen with the onset of winter followed by a partial reconversion of trehalose to glycogen with the onset of spring. Larvae from stalks acclimated to O’C also accumulated a high level of trehalose (N 69 pg/mg wet wt) with a concomitant decrease in glycogen. Those larvae from stalks kept at 20°C showed an initial sharp increase in whole-body trehalose that then stabilized but at a concentration well below that of larvae acclimated to OOC. This indicates that there exists in the larva an underlying developmental component to trehalose accumulation which is further enhanced by low temperature (OOC) exposure. The mean temperature of crystallization (T,) of larvae exposed to outdoor conditions showed an abrupt drop from October (-25.0 + 1.3OC) to November (-28.2 f 0.6OC) with a minimum in February (-29.1 + 0.3’C). The level of trehalose accumulated by the sunflower stem weevil larva is to our knowledge the highest reported in an overwintering insect.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Impact of combining planting date and chemical control to reduce larval densities of stem-infesting pests of sunflower in the central plains.

The guild of stem-infesting insect pests of sunflower, Helianthus annuus L., within the central Plains is a concern to producers chiefly due to losses caused by plant lodging from the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae), and Dectes texanus texanus LeConte (Coleoptera: Cerambycidae). The incidence of a root boring moth, Pelochrista womonana (Ke...

متن کامل

Sunflower stem weevil and its larval parasitoids in native sunflowers: is parasitoid abundance and diversity greater in the U.S. Southwest?

Classical biological control programs often target a pest's region of origin as a likely source for new biological control agents. Here, we use this approach to search for biological control agents of the sunflower stem weevil (Cylindrocopturus adspersus LeConte), an economically important pest of commercial sunflower. We conducted surveys of weevil natural enemy diversity and abundance across ...

متن کامل

Nonlinear degree-day models for postdiapause development of the sunflower stem weevil (Coleoptera: Curculionidae).

The sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae), has caused yield losses across much of the western Great Plains. Little is known about the field biology of this pest. Simple prediction models, such as degree-day models, are an integral tool for development of C. adspersus management strategies. Using data collected in Colorado, Kansas, and Nebraska, ...

متن کامل

Impact of the Stem Borer, Dectes texanus, on Yield of the Cultivated Sunflower, Helianthus annuus.

Foliar and soil-drench insecticide treatments were used in attempts to manipulate infestation of cultivated sunflower plants, Helianthus annuus LeConte (Asterales: Asteraceae) by Dectes texanus LeConte, (Coleoptera: Cerambycidae) a serious pest of sunflowers in the High Plains of the USA. Seed yields were assessed on a per-plant basis for both oilseed and confection type sunflower hybrids in tw...

متن کامل

POPULATION ECOLOGY Parasitization of the Red Sunflower Seed Weevil (Coleoptera: Curculionidae) by its Larval Parasitoid Triaspis aequoris (Hymenoptera: Braconidae) in Cultivated Sunflower

The red sunßower seed weevil, Smicronyx fulvus LeConte, is a pest of sunßower in the northern and central Plains sunßower production regions. Weevil larvae feed and develop in the sunßower achene dropping to the soil to overwinter. A total of 630 parasitoids emerging from seed weevil larvae recovered fromNorth and SouthDakota andMinnesota from1991 to 1995was identiÞed as Triaspis aequoris Marti...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2003