Western corn rootworm (Diabrotica virgifera virgifera LeConte) (Coleoptera: Chrysomelidae) oviposition can be released by decapitation

Joseph L. Spencer, Luis R. Orellana

Research output: Contribution to journalArticle

Abstract

Nervous system control of western corn rootworm (Diabrotica virgifera virgifera LeConte, WCR) (Coleoptera: Chrysomelidae) oviposition was studied using decapitation. Gravid females (n = 364) were decapitated with scissors and floated in water-filled Petri dishes. Oviposition by individuals was observed at 30 min intervals for 4 hr after decapitation; cumulative oviposition was tallied at 48 hr post-treatment. Overall, 82.7% of females laid eggs within 48 hr. Oviposition commenced quickly; 78.4% of females laid eggs during the observation period, 81.8% of these began egg laying within 30 min of decapitation. Egg-laying females deposited a total of 66.8 ± 2.1 eggs (mean ± SEM); this was 85.1% of the total mature egg load. Dissection revealed that 31.9% of n = 301 laying females and 14.3% of 63 non-laying females had a rupture of the common oviduct, manifest as an egg-filled hernia containing a mean of 8.17 ± 1.3 eggs (range: 1–83). Among n = 237 females that laid eggs during observations, females with hernias laid significantly fewer eggs (35.8 ± 4.2) than intact females (48.0 ± 2.7) during the 4-hr interval. There was no difference in the mean proportion of hatch for eggs collected from the same n = 10 females before (0.88 ± 0.03) or after decapitation (0.84 ± 0.04). Rapid oviposition following decapitation suggests that WCR egg laying is under constant descending neural inhibition; the motor programme controlling egg laying must reside posterior to the head. Decapitation can be used to quickly collect mature, fertilized WCR eggs.

Original languageEnglish (US)
Pages (from-to)534-541
Number of pages8
JournalJournal of Applied Entomology
Volume144
Issue number6
DOIs
StatePublished - Jul 1 2020

Keywords

  • descending neural inhibition
  • egg
  • egg laying
  • hernia
  • oviduct
  • rupture

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Insect Science

Fingerprint Dive into the research topics of 'Western corn rootworm (Diabrotica virgifera virgifera LeConte) (Coleoptera: Chrysomelidae) oviposition can be released by decapitation'. Together they form a unique fingerprint.

  • Cite this