Journal of Medical Entomology (1998) 35, 239-244

Alec C. Gerry and Bradley A. Mullens (1998)
Response of male Culicoides variipennis sonorensis (Diptera: Ceratopogonidae) to carbon dioxide and observations of mating behavior on and near cattle
Journal of Medical Entomology 35 (3), 239-244
Abstract: The response of male Culicoides variipennis sonorensis Wirth and Jones to carbon dioxide (CO₂) was examined at a dairy in the Chino Basin of southern California. Males were collected using CDC-type suction traps (no light) during 6 evenings in September and October 1995 when C. v. sonorensis were abundant. Traps were baited with 1.8 kg of dry ice, 200-350 nulliparous females, or nothing. Greater than 8 times as many males were captured in CO₂-baited suction traps than in either female-baited or unbaited traps. Female-baited and unbaited traps did not differ in the number of males captured. Observations of mating behavior near and on a host calf were made at a nearby dairy. Males swarmed 1-2 m downwind (east) of a restrained calf and 0.3-1.0 m above ground level. Males were also observed coupled with blood-feeding females on the calf venter (especially umbilicus and teats). Virgin female C. v. sonorensis were captured in CO₂-baited suction traps and by aspiration while they were engorging on the venter of a tethered calf. There appear to be at least two mating strategies in this species: mating presumably may occur near hosts in male swarms as well as stenogamously on the venter of the host. These mating strategies may serve as prezygotic reproductive isolating mechanisms between closely related and sometimes sympatric members of the C. variipennis complex.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Bradley A. Mullens, Alec C. Gerry

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Culicoides sonorensis		U.S.A. (SW)